https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33414 Wed 31 Oct 2018 14:51:44 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29511 Cucumis sativa L. (cucumber). The parameter log K_f was predicted with soil pH_ca, logCEC and log OC. Transfer of soil pore-water Cd²⁺ to shoots was described with a power function (R² = 0.73). The dataset was validated with 13 long-term contaminated soils (plus 2 control soils) ranging in Cd concentration from 0.2 to 300 mg kg⁻¹. The series of equations predicting Cd_shoot from pore-water Cd²⁺ were able to predict the measured data in the independent dataset (root mean square error = 2.2). The good relationship indicated that Cd uptake to cucumber shoots could be predicted with Cd_pore and Cd²⁺ without other pore-water parameters such as pH or Ca²⁺. The approach may be adapted to a range of plant species.]]> Wed 23 Feb 2022 16:06:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28347 Wed 11 Apr 2018 12:38:19 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29405 Wed 11 Apr 2018 12:16:54 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25133 -1 of diesel range hydrocarbons (C9-C36) with a concomitant removal of 47.4 ± 2.7% hydrocarbons in MERS. Here, we also report the first study that shows an initial evidence for the existence of a hydrocarbonoclastic behavior in the strain RP2 when grown in different electron accepting and illuminated conditions (anaerobic and MERS degradation). Such observations reveal the importance of photoorganotrophic growth in the utilization of hydrocarbons from contaminated environments. Identification of such novel petrochemical hydrocarbon degrading electricigens, not only expands the knowledge on the range of bacteria known for the hydrocarbon bioremediation but also shows a biotechnological potential that goes well beyond its applications to MERS.]]> Wed 11 Apr 2018 09:28:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24098 in vitro data for barite contaminated soils using the physiologically based extraction test (PBET) methodology. The existence of barite in plant tissue and the possibility of 'biomineralised' zones was also investigated using Scanning Electron Microscopy. Soils with low barium (Ba) concentrations showed a higher proportion of Ba extractability than barite rich samples. Barium uptake to spinach from soil was different between short term spiking studies and field weathered soils. Furthermore, Ba crystals were not evident in spinach tissue or acid digest solutions grown in barium nitrate spiked soils despite high accumulation. Barite was found in the plant digest solutions from barite contaminated soils only. Results indicate that under the conservative assumptions made, a child would need to consume extreme quantities of soil over an extended period to cause chronic health problems.]]> Wed 10 Nov 2021 15:05:34 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42940 Wed 07 Sep 2022 15:23:30 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34067 Wed 06 Feb 2019 09:51:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30266 Stenotrophomonas (MTS-2) followed by Citrobacter (MTS-3) and Pseudomonas (MTS-1) were furthermost effective in the degradation of HMW PAHs either as individual or in the presence of co-substrate (LMW PAHs). MTS-1, 2 and 3 (co)degraded model LMW PAHs, Phe (100% of 150 mg L^-1) and HMW PAHs Pyr (100% of 150 mg L^-1) or BaP (90-100% of 50 mg L^-1) in 3, 12-15 and 30 days, respectively and recorded the least half-life time (t^1/2) and highest biodegradation rate constants (k). One of the significant findings is the diazotrophic P-solubilization ability, acid and alkali tolerance (optimum pH=5.0-8.0) of the HMW PAHs degrading Pseudomonas strain MTS-1. Stenotrophomonas (MTS-2) was also found to be superior as it could solubilize P and tolerate acidic condition (optimum pH=5.0-7.5) during HMW PAHs degradation. Further, our study is the first evidence of diazotrophic P solubilization potential of Agrobacterium (MTS-4) and P-solubilizing capacity of Citrobacter (MTS-3) during bioremediation. Thus, the results of this study demonstrate the promising use of the newly identified PAH degraders, notably MTS-1, 2 and 3 either as individuals or as consortia as an excellent candidate in the bioremediation or phytoremediation of PAHs contaminated soils.]]> Wed 04 Sep 2019 10:24:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30369 -1 dyes at wide ranging pH (2–10). Adsorption equilibriums were attained within 3 h. Sorbent (5 g L^-1) adsorption capacity was 109.43, 115.92 and 111.85 mg g^-1 for MB, AO and MG, respectively. Adsorption kinetics was described using pseudo-second-order model. Equilibrium adsorption data were interpreted by Langmuir and Freundlich isotherms. Dye removal was by coagulation-coupled adsorption. Coagulation was due to the formation of complexes between the dye molecules and OP polyphenols that led to the deposition of precipitated flocs.]]> Wed 04 Sep 2019 09:54:36 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30371 Wed 04 Sep 2019 09:54:34 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30777 Wed 02 Mar 2022 14:25:53 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26146 Tue 31 Jul 2018 16:35:15 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29583  L28 > C1. Strains AB3, C31, and L28 accumulated higher levels of intracellular vitamin B12 than strain C1. However, only strain C1 produced SAM and showed As biovolatilization activity. When strain C1 was incubated under microaerobic light conditions, it produced arsenobetaine [(AsB(V)] in medium with As(III) and monomethylarsonic acid [MMA(V)] in medium with As(V), which were found in the culture supernatants. Volatile methylated As compounds, such as dimethylarsenic acid [DMA(V)] and MMA(V)], were also detected in strain C1 during 30 days of incubation with As(III) and As(V). Strains AB3, C1, and L28 were identified as Rhodopseudomonas palustris and strain C31 as Rubrivivax benzoatilyticus. The resistance of these strains to As [As(III) and As(V)] based on minimum inhibition concentration values under aerobic dark and microaerobic light conditions, respectively, was in the order of C1 > AB3 > C31 > L28. The overall results demonstrate that all four selected strains of PNSB have a great potential for future application in the remediation of As-contaminated areas although R. palustris C1 was the most effective candidate.]]> Tue 31 Jul 2018 16:28:15 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32559 Tue 19 Jun 2018 11:56:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32558 Tue 19 Jun 2018 11:56:15 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26409 Tue 16 Oct 2018 12:10:24 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24008 -1 and which now showed complete removal of this concentration of diesel within 30days was compared to that of a freshly inoculated new anode MFC (showing 83.4% removal of diesel) with a simultaneous power generation of 90.81mW/m² and 15.04mW/m² respectively. The behaviour of pre-cultured anodes at a higher concentration of PH (8000mgl^-1) was also investigated. Scanning electron microscopy observation revealed a thick biofilm covering the pre-cultured anodic electrode but not the anode from the freshly inoculated MFC. High resolution imaging showed the presence of thin 60nm diametre pilus-like projections emanating from the cells. Anodic microbial community profiling confirmed that the selection for diesel degrading exoelectrogenic bacteria had occurred. Identification of a biodegradative gene (alkB) provided strong evidence of the catabolic pathway used for diesel degradation in the DMFCs.]]> Tue 14 Nov 2023 13:55:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33185 Eisenia fetida in spiked soils by exposing the worms for 28 days following standard procedures. The toxicity studies revealed that Hg exerted less lethal effect on earthworms in acidic soil with higher organic carbon (S-3 soil) where water soluble Hg recovery was very low compared to the water soluble Hg fractions in soils with less organic carbon and higher pH (S-1 and S-2 soils). The concentrations of total Hg that caused 50 % lethality to E. fetida (LC50) after 28 days of exposure in S-1, S-2 and S-3 soils were 152, 294 and 367 mg kg⁻¹, respectively. The average weight loss of E. fetida in three soils ranged from 5 to 65 %. The worms showed less weight loss in the organic carbon-rich soil (S-3) compared to less organic carbon containing soils (S-1 and S-2). The bioconcentration of Hg in E. fetida increased with increased Hg concentrations. The highest bioaccumulation took place in the acidic soil with higher organic carbon contents with estimated bioaccumulation factors ranging from 2 to 7.7. The findings of this study will be highly useful for deriving a more robust soil ecological guideline value for Hg.]]> Tue 11 Sep 2018 12:15:44 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29407 2+ and Pd²⁺, had no obvious effect on removing Orange II since less than 2.0% was removed. Kinetics study revealed that the removal rate fitted well to the pseudo-first-order reduction and pseudo-second-order adsorption model, meaning that removing Orange II via Fe/Pd NPs involved both adsorption and catalytic reduction. The remarkable stability of Fe/Pd NPs showed the potential application for removing azo dyes. Furthermore, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) confirmed the changes in Fe/Pd NPs before and after reaction with Orange II. High Performance Liquid Chromatography-Mass Spectrum (HPLC-MS) identified the degraded products in the removal of Orange II, and finally a removal mechanism was proposed. This one-step strategy using grape leaf aqueous extract to synthesize Fe/Pd NPs is simple, cost-effective and environmentally benign, making possible the large-scale production of Fe/Pd NPs for field remediation.]]> Thu 27 Jan 2022 15:59:16 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24104 Thu 21 Oct 2021 12:52:12 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48966 Thu 20 Apr 2023 10:29:33 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32271 -1 soil). Both the bacterial strains exhibited a great potential in remediating weathered hydrocarbons of engine oil. Addition of inorganic fertilizers (NPK), at recommended levels for bioremediation, resulted in significant inhibition in biostimulation/enhanced natural attenuation as well as bioaugmentation. The data on dehydrogenase activity clearly confirmed those of bioremediation strategies used, indicating that this enzyme assay could serve as an indicator of bioremediation potential of oil-contaminated soil. Extraction of TPHs from engine oil-contaminated soil with hydroxypropyl-ß-cyclodextrin (HPCD), but not 1-butanol, was found reliable in predicting the bioavailability of weathered hydrocarbons. Also, 454 pyrosequencing data were in accordance with those of bioremediation strategies used in the present microcosm study, suggesting the possible use of pyrosequencing in designing approaches for bioremediation.]]> Thu 17 May 2018 13:51:27 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30370 Bacillus and Pseudomonas, respectively. These strains completely degraded the model 3-(phenanthrene), 4-(pyrene) and 5-(benzo-a-pyrene) ring PAHs at 6, 7 and 40–50 days, correspondingly. They were shown to be able to produce a rhamnolipid type of biosurfactant during PAH degradation. The biosurfactants produced from both the strains showed good pH (2–12) as well as thermal (up to 80 °C) stability and were able to tolerate up to 20 g L−1 salinity. The strains also had resistance towards heavy metals, attributed to the amount of biosurfactant produced. The Bacillus strain in particular showed excellent metal resistance; the minimum inhibitory concentrations were 5 (Cd2+, Cu2+) and 7 (Pb2+, Zn2+) mg L−1 of relatively bioavailable metal ions, but >15 mg L−1 metal concentrations were lethal to the microbe. Additionally, both strains possessed activity of more than one extracellular enzyme (cellulase, lipase and protease). The limiting factors in PAH biodegradation are low PAH bioavailability and microbial intolerance towards HMW PAHs and co-contaminants (heavy metals). The novel strains identified thus had (a) potential to biodegrade both LMW and HMW PAHs, (b) pH, thermal and saline-tolerant biosurfactant production that aids PAH solubility enhancement, and importantly, (c) heavy metal resistance. Both Bacillus and Pseudomonas strains are appropriate candidates in field-scale PAH bioremediation at mixed contamination sites and for several industrial applications due to their enzymatic activities.]]> Thu 17 Feb 2022 09:25:16 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31931 Thu 14 Apr 2022 10:58:46 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34677 In vivo studies were conducted using juvenile swine as a surrogate model for young children. Two compartment pharmacokinetic models were used to analyze the biological response produced by Pb oral solution and spiked soils. Absolute and relative bioavailability of Pb in soils (oral dose of 100 µ g Pb/kg body weight/day) were estimated by comparing them with intravenously administered soluble Pb salt (25 µ g Pb/kg/day) and orally administered the same Pb salt [Pb acetate = (CH₃COO)₂Pb·3H₂O] administered to 3 juvenile pigs per treatment. Lead bioaccessibility was calculated using the in vitro RBALP (i.e. relative bioaccessibility leaching procedure) method. The in vitro results of RBALP were compared to in vivo relative Pb bioavailability to ascertain whether the changes in bioaccessibility correlated with the in vivo data. Although the in vivo Pb relative bioavailability (RB) in all soils except in MLA (Mount Lofty Acidic) revealed an increase (18%-159%) in the presence of Zn, the in vitro RBALP bioaccessibility results indicated otherwise (1%-38% decrease). In vivo RB of Pb in MLA declined by 37% in the presence of Zn. However, the RBALP in vitro bioaccessible Pb did not correlate with the relative bioavailabilities of Pb in the juvenile swine dosing experiment. Caution is therefore needed when predicting Pb bioavailability/bioaccessibility in the presence of metal mixtures. The literature contains much information on the correlation of metal and metalloid bioaccessibility with their bioavailability. There is, however, a paucity of studies investigating the effects of other metals on Pb and their IVIVC (in vitro and in vivo correlations). The current study addresses this knowledge gap by assessing in vivo and in vitro bioavailability of Pb in the presence of Zn.]]> Thu 11 Apr 2019 15:08:08 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30372 Thu 03 Feb 2022 12:19:08 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31459 Sphingobium SA2. The sensing element contained green fluorescence protein gene gfp fused to short segment of merA gene of Sphingobium SA2. The sensing element was introduced into electro-competent cells of Sphingobium SA2, where it integrated into the bacterial DNA due to homologous recombination. The transformed cells were able to produce green fluorescence in 5 h in the presence of nano-molar concentrations of mercury. A linear positive correlation was observed between 0–40 nm Hg and fluorescence intensity.]]> Sat 24 Mar 2018 08:43:50 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31400 Cucumis sativa L) conducting 4 weeks pot study in 5 different soils spiked with As (0, 2, 4, 8 to 1024 mg kg_{-1 ) individually and with Zn at two phytotoxic doses. The As pore-water concentration was significantly reduced (df = 289, Adjusted R² = 0.84, p < 0.01) in the presence of Zn in the whole dataset, whereas Zn and Zn²⁺ activity in pore-water was reduced significantly only in the two alkaline soils. This outcome may be due to adsorption/surface precipitation or tertiary bridging complexation. No homogenous precipitation of zinc arsenate could be established using electron microscopy, XRD or even equilibrium calculations. For bioaccumulation phase, no significant effect of Zn on As uptake was observed except acidic MG soil whereas, Zn uptake was significantly reduced (p < 0.05) by As in whole dataset. However, an additive response was observed mostly except acidic MG soil. The synergistic response (more than additive) was predominant in this soil for a wide range of inhibition concentration (0¿80%) at both Zn EC10 and EC50 levels. Since additive response is mostly considered in risk assessment for mixtures, precautions should be implemented for assessment of toxicity for As-Zn mixture in acidic soil due to their synergistic response in some soils.]]>} Sat 24 Mar 2018 08:43:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30237 Sat 24 Mar 2018 07:41:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30187 50 and MIC values. Estimated EC₅₀ and MIC values in nutrient-rich media and low nutrient media had the following respective recordings - 22.6 mg L^-1; 23.1 mg L^-1 and 1.4 mg L^-1 and 1.7 mg L^-1. The isolate was able to volatilize inorganic mercury demonstrated by a modified photographic film experiment and subsequently revealed its ability to remove mercury from the solution. The ICP-QQQ-MS analysis of SE1 inoculated solution showed almost 60% of 1.5 mg L^-1 mercury was volatilized in 6 h and almost 40% were accumulated in cell pellets. The mercuric reductase gene merA was identified in the genome of isolate SE1 and sequenced. The deduced amino acid sequence of merA gene indicated a sequence homology with different organisms from the alpha proteobacteria group and eukaryotic fungi. merA encoded enzyme mercuric reductase activity was evident in the crude protein of the isolate. The isolate's ability to resist Hg, it's Hg volatilization potential and the presence of merA gene and mercuric reductase enzyme demonstrates the potential application of this strain in mercury bioremediation.]]> Sat 24 Mar 2018 07:41:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26275 Sat 24 Mar 2018 07:40:16 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29699 −1. The pH and EC varied widely in the 3.9–8.4 and 152–7311 µS ranges, respectively. Nine plant species growing over the copper mine site were selected to screen for metal uptake to determine their suitability for phytoremediation. The Australian native tree species Eucalyptus camaldulensis indicated enrichment factor (EF) of 2.17, 1.89, and 1.30 for Cu, Zn, and Pb, respectively, suggesting that this species of tree can accumulate these metals to some degree. The stress-resistant exotic olive, Olea europaea exhibited EF of ≤ 0.01 for Cu, Cd, and Pb, and 0.29 for Zn, which is characteristic of an excluder plant. Acacia pycnantha, the Australian pioneer legume species with EF 0.03, 0.80, 0.32, and 0.01 for Cu, Zn, Cd, and Pb, respectively, emerged as another strong metal excluder and consequently as an ideal metal stabilizer.]]> Sat 24 Mar 2018 07:38:48 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29734 50—48 h of 2, 4-dinitroanisole was determined as 14.87 ± 1.70 (mg L⁻¹) and its metabolites exhibited the similar toxic range although the toxicity of 2, 4, 6-trinitro toluene was seven-fold more toxic (2.32 ± 0.29 mg L⁻¹) than 2, 4-dinitroanisole and its metabolites. Exposure to sub-acute toxicity concentration ranges of 2, 4-dinitroanisole and its metabolites and 2, 4, 6-trinitro toluene showed significant (P < 0.01) DNA damage. The higher concentration of each test chemical exhibited higher tail DNA per cent and increased olive tail moment. The results from this study can be used to identify genotoxic biomarkers for the risk assessment of insensitive munitions exposure in aquatic invertebrates.]]> Sat 24 Mar 2018 07:37:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26341 Sat 24 Mar 2018 07:35:56 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26483 Sat 24 Mar 2018 07:35:30 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29332 Sat 24 Mar 2018 07:34:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26611 Bacillus fusiformis and Fenton oxidation of their degraded metabolites using nanoscale zero-valent iron (nZVI). A 99.0% naphthalene was biodegraded by B. fusiformis in 96 h, while only 59.4% chemical oxygen demand (COD) was removed, indicating that the degraded metabolites existed in solution. To further degrade the metabolites, nanoscale zero-valent iron (nZVI) was used as heterogeneous catalyst for Fenton-like oxidation of the metabolites after biodegradation lasting 40 h. Results showed that the total the removal COD increased from 36.4% to 91.6% at pH 3.0, 1.0 g L⁻¹ nZVI, 10.0 mM L⁻¹ H₂O₂ and temperature of 35 °C. Scanning electron microscopy (SEM) showed the aggregation and corrosion of nZVI. X-ray diffraction (XRD) confirmed the existence of Fe⁰ and the presence of iron oxide (Fe(II)) and iron oxohydroxide (Fe(III)). A possible degradation pathway was proposed since two naphthalene metabolites (1-Naphthalenol and 1,4-Naphthalenedione) were detected by GC–MS.]]> Sat 24 Mar 2018 07:33:58 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30283 Sat 24 Mar 2018 07:33:33 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27553 Sat 24 Mar 2018 07:33:15 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29515 A. pycnantha was grown under greenhouse condition in six different soils collected from abandoned copper mine at Kapunda in South Australia. Among the six soil samples, soil-1 with the highest copper concentration produced 2.05 mmol g⁻¹ tissue of proline. Proline expression was prominent in more saline soils (1, 5 and 6) having electrical conductivity (EC) 1184, 1364 and 1256 μS, respectively. Chlorophyll a, b and carotenoid levels in plants showed a gradually decreasing trend in all the soils as experiment progressed. The plants grown on soil sample-1, containing 4083 ± 103 mg kg⁻¹ of copper resulted in 18 ± 2 mg kg⁻¹ accumulation in its leaf. The calcium accumulation was significant up to 11648 ± 1209 mg kg⁻¹ in leaf. Although pore water samples showed higher Cu concentration in soils, an increased mobility of arsenic and lead was observed in all the soil samples. Our experiment points out the need for proper monitoring of revegetation processes to avoid revegetation and reclamation failure.]]> Sat 24 Mar 2018 07:32:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29623 Zn (37.3%) > Cu (15.4%) > Pb (1.7%) and is consistent to earlier findings. There was no significant correlation between litter samples and concentration of metals in worm tissue. However, the bioavailability percent for copper in all samples are dominant except for Acacia pycnantha leaf litter being the lowest 90.9%. Earthworm reproduction test revealed that even with a high copper concentration in all samples, Eucalyptus camaldulensis litter produced the highest juvenile count (160%). Evidently, earthworms are seen to reproduce well even in contaminated litter irrespective of level of metal content. Our findings suggest that there are various risks associated with metal transfer and pollution through plant and animal litter in ecosystem and should be appropriately managed.]]> Sat 24 Mar 2018 07:32:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29932 Cucumis sativa L) using 10 contrasting soils. Arsenate phytotoxicity was shown to be related to soluble carbonate and phosphate. The data indicated that dissolved phosphate and carbonate had an antagonistic impact on arsenate toxicity to cucumber. To predict arsenate phytotoxicity in soils with a diverse range of soil solution properties, both carbonate and phosphate were required. The relationship between arsenic and pore-water toxicity parameters was established initially using multiple regression. In addition, based on the relationship with carbonate and phosphate we successively applied a terrestrial biotic ligand-like model (BLM) including carbonate and phosphate. Estimated effective concentrations from the BLM-like parametrization were strongly correlated to measured arsenate values in pore-water (R² = 0.76, P < 0.001). The data indicates that an ion interaction model similar to the BLM for arsenate is possible, potentially improving current risk assessments at arsenic and co-contaminated soils.]]> Sat 24 Mar 2018 07:30:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29927 Cucumis sativa L. (cucumber) focusing primarily on pore-water Pb data from 10 different soils after 12 weeks ageing. Phytotoxicity expressed in terms of Pb²⁺ was observed to occur in the nanomolar range in neutral to alkaline soils (EC50 values 90 to 853 nM) and micromolar levels for acidic soils (EC50 values 7.35 to 9.66 μM). Internal Pb concentrations relating to toxicity (PT50) in roots and shoots also decreased with increasing pore-water pH (R² = 0.52 to 0.53). From a series of dose-response studies, we developed transfer functions predicting Pb uptake in C. sativa and we validated these functions with long-term Pb contaminated soils. The significant independent parameters were pore-water Pb²⁺ and dissolved Pb plus dissolved organic carbon (DOC). The observed RMSE for the Pb-DOC model and Pb²⁺ were 2.6 and 8.8, respectively. The Pb-DOC model tended to under-predict Pb, whilst Pb²⁺ tended to over-predict accumulation despite reasonable RMSE values. Further validation is needed in soils with higher pore-water Pb solubility.]]> Sat 24 Mar 2018 07:30:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29802 Atriplex nummularia, Atriplex semibaccata, Salsola kali, Phragmites australis and Medicago sativa, representing the taxonomic orders Caryophyllales, Poales and Fabales are evaluated in terms of phytoremediation in this review. Phytoremediation processes, microbial and algal bioremediation, the use and implication of tissue culture and biotechnology are critically examined. Overall, an integration of available remediation plant-based technologies, referred to here as ‘integrated remediation technology,’ is proposed to be one of the possible ways ahead to effectively address problems of toxic heavy metal pollution.]]> Sat 24 Mar 2018 07:30:34 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30613 −, toxic contaminants CN⁻ and AsO₃³⁻/AsO₄³⁻, and anionic fluorosurfactants. The anionic fluorosurfactants mainly include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), both of which have recently been listed as emerging contaminants and categorised as persistent organic pollutants. This review addresses recent advancements in the development of gold nanoparticle-based nano-sensors for such anions and outlines their performance limitations towards on-site applications.]]> Sat 24 Mar 2018 07:28:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26437 Cucumis sativus L.) in spiked soils. Pore-water effective concentration (ECx, x=10%, 20% and 50% reduction) values were negatively related to pH, indicating lower Zn pore water concentration were needed to cause phytotoxicity at high pH soils. Total dissolved zinc (Zn_pw) and free zinc (Zn²⁺) in soil-pore water successfully described 78% and 80.3% of the variation in relative growth (%) in the full dataset. When the complete data set was used (10 soils), the estimated EC50_pw was 450 and 79.2µM for Zn_pw and Zn²⁺, respectively. Total added Zn, soil pore water pH (pH_pw) and dissolve organic carbon (DOC) were the best predictors of Znpw and Zn²⁺ in pore-water. The EC10 (total loading) values ranged from 179 to 5214mg/kg, depending on soil type. Only pH measurements in soil were related to ECx total Zn data. The strongest relationship to ECx overall was pH_ca, although pH_w and pH_pw were in general related to Zn ECx. Similarly, when a solution-only model was used to predict Zn in shoot, DOC was negatively related to Zn in shoot, indicating a reduction in uptake/ translocation of Zn from solution with increasing DOC.]]> Sat 24 Mar 2018 07:27:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26475 -1), to simultaneously determinate multiple petroleum hydrocarbons (PHs) in real mixture samples. This system includes: an object oriented baseline correction; Band decomposition (curve fitting) method with mathematical optimization; and Artificial Neural Network (ANN) for determination, which is suitable for the characteristics of this IR regions, where the spectra are normally with low signal to noise ratio and high density of peaks. BTEX components are potentially lethal carcinogens and contained in many petroleum products. As a case study, six BTEX components were determinate automatically and simultaneously in mixture vapor samples. The robustness of the BTEX determination was validated using real petroleum samples, and the prediction results were compared with gas chromatography-mass spectrometry (GC-MS).]]> Sat 24 Mar 2018 07:27:14 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28313 Sat 24 Mar 2018 07:27:06 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26959 Diplosphaera sp. MM1 for its ability to generate energy through biomass production from wastewater remediation. 33% dairy wastewater and 50% winery wastewater demonstrated as promising alternative media for cultivating Diplosphaera sp. MM1 biomass. Interestingly, the alga cultivated in 50% winery wastewater with limited nitrogen produced the highest lipid content (43.07% total solid) and the lowest carbohydrate content (9.35%TS). On the contrary, the lowest lipid content (16.98%TS) and the highest carbohydrate content (29.39%TS) were exhibited by the alga cultivated in 33% dairy wastewater. The results from anaerobic digestion processes in terms of biochemical methane potential of the alga cultivated in BG-11 medium, 33% dairy wastewater and 50% winery wastewater were 197.39, 129.75 and 218.51 NmL g^-1VS, respectively. Further, this study demonstrates the potential of winery wastewater as a candidate to increase the lipid content of algae and enhance biofuel production of algal biomass.]]> Sat 24 Mar 2018 07:27:01 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26960 Diplosphaera sp. and was designated strain MM1. The growth of this strain was evaluated in different diluted dairy and winery wastewaters. The highest algal biomass production (up to 2.3 g L^-1) was obtained in dairy wastewater (D3; dairy wastewater 1:2 deionised water) after 14 days of culture. However, for winery wastewater, the highest algal biomass production (up to 1.46 g L^-1) was obtained in wastewater combination W2 (winery wastewater 1:1 deionised water) after 14 days of culture. Turbid dairy wastewater with high concentration of nitrogen and phosphorous slowed down the initial growth of the alga. However, at the end of day 14, biomass production was nearly twofold higher than that of winery wastewater. The findings from both types of wastewater suggest that Diplosphaera sp. MM1 has potential for its application in generating biomass with simultaneous remediation of nutrient-rich wastewater.]]> Sat 24 Mar 2018 07:27:01 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25551 -1. The study concluded that the residual TPHs in soils had little impact on a range of environmental receptors. Assessment of the residual TPH ecotoxicity was complicated by the elevated salinity of stockpile soils which impacted on the earthworm and phytotoxicity assessments. Therefore results of this study suggest that it is paramount to focus beyond target contaminants while implementing risk-based management approach. Indicators for risk based assessment are considered critical for regulatory decision making. The results of this study provide a valuable input in to the risk based management of contaminated sites.]]> Sat 24 Mar 2018 07:26:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25891 Sat 24 Mar 2018 07:25:51 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25358 Alliumcepa through chromosomal aberration and comet assay using root meristem cells. A. cepa root tips were exposed to Tridol-S 3% and Tridol-S 6% with six different concentrations (0%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04% and 0.05%) for 24 h. Cytogenetic effect endpoints such as mitotic index, and chromosomal aberrations were observed. Chromosomal aberrations in the control (untreated onion root tips) was negligible with the mitotic index (MI) value of 79.6%, while the MI significantly decreased in all the test concentrations of firefighting compounds. Genotoxicity assessment through comet assay also revealed that both the products were genotoxic with a significant increase in per cent tail DNA and olive tail moment. Among the test compounds, Tridol-S 3% was more toxic than Tridol-S 6%. To our knowledge, this is the first study on the cyto- and genotoxic effects of class B firefighting foams to A. cepa root meristem cells. This study also suggests that the toxicological studies using A. cepa root meristem cells can be employed for evaluating the toxicological impacts of firefighting foams in the environment.]]> Sat 24 Mar 2018 07:24:42 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30028 Sat 24 Mar 2018 07:24:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30473 Iseilema membranaceum (Barcoo), Dichanthium sericeum (Queensland Blue) and Sporobolus africanus (Tussock) were grown in three different soils spiked with different concentrations of inorganic mercury and the root elongation was monitored up to 28 days following the germination. Results showed that mercury at certain concentrations significantly inhibited the root growth of all three tested native grasses grown in three soils, however, the toxicity was less in the soil with high organic carbon content and acidic pH. The calculated EC₅₀ values ranged from 10 to 224 mg/kg total Hg in soil. However, the EC₁₀ values indicated that existing guideline values for mercury may be of protective to the native Australian vegetation. Considering their tolerance to soil mercury, these grass species have the potential for their use in rehabilitation of mercury contaminated sites.]]> Sat 24 Mar 2018 07:24:16 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30591 Sat 24 Mar 2018 07:24:00 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30592 6—FC) upon exposure to perfluorooctanoic acid (PFOA), the most common fluorosurfactant. FC is employed as a redox probe to monitor the switch on-off response of the SAM formed on gold electrode surface. In an effort to understand the hydrophilic terminate group's influence from the surfactant, we dope the pristine C₆—FC SAM with 6-amino-1-hexanethiol (C₆—NH₂), 1-hexanethiol (C₅—CH₃), or 6-mercaptohexanoic acid (C₅—COOH) via a thiol-gold bond. We also dope it with 1-dodecanethiol (C₁₁—CH₃) or 12-mercaptododecanoic acid (C₁₁–COOH) to investigate the length effect of the carbon chain. We observe there is a similar switch on-off response either from the presence of PFOA or from the doping C₅—COOH/C₁₁–COOH, suggesting the insertion of PFOA into the C₆—FC SAM, which is also evidenced by electrochemical quartz crystal microbalance (EQCM) and Raman spectrum. This research paves the way towards the development of an electrochemical sensor and an approach for remediation of the fluorosurfactants.]]> Sat 24 Mar 2018 07:24:00 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30582 Sat 24 Mar 2018 07:23:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25119 Cupriavidus (strain MTS-7) was identified from a long-term PAHs and heavy metals mixed contaminated soil with the potential to biodegrade both LMW and HMW PAHs with added unique traits of acid and alkali tolerance, heavy metal tolerance, self-nutrient assimilation by N fixation and P solubilization. This strain completely degraded the model 3 (150 mg L^-1 Phe), 4 (150 mg L^-1 Pyr) and 5 (50 mg L^-1 BaP) ring PAHs in 4, 20 and 30 days, respectively. It could mineralize 90-100% of PAHs (200 mg L^-1 of Phe and Pyr) within 15 days across pH ranging from 5 to 8 and even in the presence of toxic metal contaminations. During biodegradation, the minimum inhibitory concentrations were 5 (Cu²⁺) and 3 (Cd²⁺, Pb²⁺, Zn²⁺) mg L^-1 of the potentially bioavailable metal ions and over 17 mg L^-1 metal levels was lethal for the microbe. Further, it could fix 217-274 µg mL^-1 of N and solubilize 79-135 µg mL^-1 of P while PAHs degradation. MTS-7 as a superior candidate could be thus used in the enhanced bioaugmentation and/or phytoremediation of long-term mixed contaminated sites.]]> Sat 24 Mar 2018 07:17:06 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24015 Sphingobium and Sphingomonas of α-proteobacteria group. However, the isolate formed a distinct phyletic line with the genus Sphingobium suggesting the strain belongs to Sphingobium sp. Toxicity studies indicated resistance to high levels of mercury with estimated EC₅₀ values 4.5 mg L^-1 and 44.15 mg L^-1 and MIC values 5.1 mg L^-1 and 48.48 mg L^-1 in minimal and rich media, respectively. The strain SA2 was able to volatilize mercury by producing mercuric reductase enzyme which makes it potential candidate for remediating mercury. ICP-QQQ-MS analysis of Hg supplemented culture solutions confirmed that almost 79% mercury in the culture suspension was volatilized in 6 h. A very small amount of mercury was observed to accumulate in cell pellets which was also evident according to ESEM-EDX analysis. The mercuric reductase gene merA was amplified and sequenced. The deduced amino acid sequence demonstrated sequence homology with α-proteobacteria and Ascomycota group.]]> Sat 24 Mar 2018 07:16:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24022 Sat 24 Mar 2018 07:16:44 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24388 -1) and lowest half-life time (t_1/2 = 1-26 days) values reported to date in liquid cultures and highlighted the use of consortium-A for the remediation of acidic soils due to its tolerance up to pH 5. Furthermore, bioaugmentation of these consortia has proven to be effective in degradation of LMW (>95%) and HMW (90%) PAHs from spiked soil slurries. Amendment of consortia-A and N exhibited 10.7 and 44.3% more total PAHs degradation, respectively than natural attenuation in 60 days even from the real long-term mixed contaminated soils. Thus the results of this study demonstrate the great potential of these novel bacterial consortia, particularly consortium-N for use in field-scale bioremediation of PAHs in long-term mixed contaminated neutral soils.]]> Sat 24 Mar 2018 07:16:17 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24802 -1 was 119.05, 126.8, 116.28 and 94.34 mg g^-1 for MB, AO, MG and EB, respectively. The water extract obtained from the plant material induced fast decolourization of both categories of dyes followed by gradual flocculation, indicating its potential as a natural coagulant. Gas chromatographic analysis also indicated that the main electrostatic attraction between 1,8-cineole, 1-p-methene-8-thiol and furfural compounds of the biomaterial, and dye molecules resulted in the formation of initial supramolecular complexes which further progressed into strong aggregates, leading to precipitation of dye-biomaterial complexes. Subsequently, the overall complex mechanism of dye removal was confirmed to be a combined process of adsorption and coagulation. Consistent with the batch studies, using selected plant material in real environmental water samples also resulted in effective dye removal, highlighting its potential for use in wastewater treatment.]]> Sat 24 Mar 2018 07:15:14 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24876 Chlorella sp. MM3, to unused or used engine oil, or their water accommodated fractions (WAFs) to determine growth inhibition and response of antioxidant enzymes. Oil type and oil concentration greatly affected the microalgal growth. Used oil at 0.04% (0.4g L^-1) resulted in 50% inhibition in algal growth, measured in terms of chlorophyll-a, while the corresponding concentration of unused oil was nontoxic. Similarly, used oil WAF showed significant toxicity to the algal growth at 10% level, whereas WAF from unused oil was nontoxic even at 100% concentration. Peroxidase enzyme in the microalga significantly increased with used oil at concentrations above 0.04g L^-1 whereas the induction of superoxide dismutase and catalase was apparent only at 0.06g L^-1. Activities of the antioxidant enzymes increased significantly when the microalga was exposed to 75 and 100% WAF obtained from used oil. The used oil toxicity on microalga could be due to the presence of toxic soluble mono- and polyaromatic compounds, heavy metals, and other compounds attained by the oil during its use in the motor engines.]]> Sat 24 Mar 2018 07:14:56 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24409 Trabulsiella sp. tolerant to pH 5. MTS-6 completely degraded the model 3 [150 mg L⁻¹ phenanthrene (Phe)], 4 [150 mg L⁻¹ pyrene (Pyr)] and 5 [50 mg L⁻¹ benzo[a]pyrene (BaP)] ring PAHs in 6, 25 and 90 days, respectively. Presence of co-substrate (100 mg L⁻¹ Phe) increased the biodegradation rate constant (k) and decreased the half-life time (t_1/2) of HMW PAHs (100 mg L⁻¹ Pyr or 50 mg L⁻¹ BaP). The strain fixed 47 μg mL⁻¹ N and solubilized 58 μg mL⁻¹ P during PAH metabolism and exhibited an EC₅₀ value of 3–4 mg L⁻¹ for Cu, Cd, Pb and Zn. Over 6 mg L⁻¹ metal levels was lethal for the microbe. The identified bacterium (MTS-6) with exceptional multi-functional traits opens the way for its exploitation in the bioremediation of manufactured gas plant sites in a sustainable way by employing bioaugmentation strategy.]]> Sat 24 Mar 2018 07:14:23 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24925 Alphaproteobacteria persist relatively more in the real contaminated sites compared to Gram +ves, (2) Gram +ves are not always resistant to heavy metal toxicity, (3) Stenotrophomonas followed by Burkholderia and Pseudomonas are the dominant genera of PAH degraders with high metabolic activity in long-term contaminated soils, (4) Actinobacteria is the predominant group among the Gram +ves in soils contaminated with high molecular weight PAHs that co-exist with toxic heavy metals like Pb, Cu and Zn, (5) Microbial communities are nutrient-driven in natural environments and (6) Catabolically potential Gram +/-ves with diverse applicability to remediate the real contaminated sites evolve eventually in the historically-polluted soils. Thus, the most promising indigenous Gram +/-ve strains from the long-term contaminated sites with increased catabolic potential, enzymatic activity and metal tolerance need to be harnessed for mixed contaminant cleanups.]]> Sat 24 Mar 2018 07:14:19 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24773 Chlorella sp. MM3 biomass produced from the remediation of brewery wastewater. The algal growth characteristics, biomass production, nutrient removal, and nanoparticle synthesis including its characterisation were studied to prove the above approach. The growth curve of Chlorella depicted lag and exponential phase characteristics during the first 4 days in a brewery wastewater collected from a single batch of brewing process (single water sample) indicating the growth of algae in brewery wastewater. The pollutants such as total nitrogen, total phosphorus and total organic carbon in single water sample were completely utilised by Chlorella for its growth. The X-ray photoelectron spectroscopy spectra showed peaks at 706.56 eV, 727.02 eV, 289.84 eV and 535.73 eV which corresponded to the zero-valent iron, iron oxides, carbon and oxygen respectively, confirming the formation of iron nanoparticle capped with algal biomolecules. Scanning electron microscopy and particle size analysis confirmed the presence of spherical shaped iron nanoparticles of size ranging from 5 to 50 nm. To our knowledge, this is the first report on nanoparticle synthesis using the biomass generated from phycoremediation of brewery wastewater.]]> Sat 24 Mar 2018 07:14:08 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24516 Quercus robur) acorn peel (OP), to remove toxic Cr(VI) from aqueous solutions was studied in a batch system as a function of contact time, adsorbate concentration, adsorbent dosage, and pH. In an equilibrium time of 420 min, the maximum Cr removal by OP at pH 2 and 10 was 100 and 97 %, respectively. The sorption data fitted well with Langmuir adsorption model. Evaluation using Langmuir expression presented a monolayer sorption capacity of 47.39 mg g^-1 with an equilibrium sorbent dose of 5 g L^-1 and pH 7. Uptake of Cr by OP was described by pseudo-second-order chemisorption model. ICP-OES, LC-ICPMS analysis of the aqueous and solid phases revealed that the mechanism of Cr(VI) removal is by 'integrated adsorption and reduction' mechanism. ESEM-EDX and XRD analysis of OP before and after adsorption also confirmed that both adsorption and reduction of Cr(VI) to less toxic Cr³⁺ forms followed by complexation onto the adsorbent surface contributed to the removal of Cr(VI). Consistent with batch studies, OP effectively removed (>95 %) Cr from the real water samples collected from lake and sea. The results of this study illustrate that OP could be an economical, green, and effective biomaterial for Cr(VI) removal from natural aquatic ecosystems and industrial effluents.]]> Sat 24 Mar 2018 07:13:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24101 Cucumis sativus L. (cucumber) and Triticum aestivum L. (wheat) and shoot end-points with a 4 week a pot study using cucumber only. Root elongation of cucumber was a substantially less sensitive indicator to As than data from the 4 weeks pot study. Effective concentrations (50%)(EC₅₀) from cucumber root elongation studies were overall 1.6 times higher than the 4 week shoot data. Cucumber was however considerably more sensitive to wheat. Given the large discrepancy in phytotoxicity end points for 7 soils, root elongation data for ecotoxicological assessment should be treated with some caution. Arsenic phytotoxicity was strongly related to the sorption constants of each of the seven soils in our study. Both root elongation and shoot data were related strongly to Freundlich partitioning constants (K_f) (L/kg). Wheat and cucumber root elongation had R² values 0.90 and 0.91 respectively, while cucumber shoot data was 0.79. The K_f values were related to soil pH and also EC₅₀ data and, thus, shows that As phytotoxicity in our study was primarily controlled by sorption reactions. The rate of As bioaccumulation to cucumber shoots depended heavily on the soil under consideration. Chlorophyll and carotenoid content of cucumber shoots increased with As content in 3 soils and decreased in other soils.]]> Sat 24 Mar 2018 07:11:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24555 Eisenia fetida, and the soil health was investigated. C-nZVI at concentration level of 3 g kg^-1 soil showed no effect on the survival of E. fetida in the three soil types. However, varying effects such as concentration-dependent increase in tissue iron concentration, lipid peroxidation, and damage to DNA molecules by C-nZVI were observed. C-nZVI at an exposure concentration of 60 mg kg^-1 soil induced oxidative stress in E. fetida. Tissue Fe concentration appeared correlated to the DNA damage. Oxidative stress and DNA damage may explain the toxicity mechanisms of nZVI to E. fetida.]]> Sat 24 Mar 2018 07:11:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24550 Sat 24 Mar 2018 07:11:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24839 Coelosphaerium sp., Synechococcus sp., Oscillatoria sp. and Chroococcus sp. to environmentally relevant concentrations of Cr⁶⁺, Cd²⁺ and Zn²⁺was assessed based on fluorescence change as a proxy for growth reduction. At 24 h exposure, the growth reduction inthe cyanobacteria followed the order: Zn²⁺ < Cr⁶⁺ ≤ Cd²⁺. Of the four cyanobacteria, Synechococcus was the most sensitive for Cr⁶⁺, where as Chroococcus was the most sensitive for Cd²⁺ and Zn²⁺. Sensitivity was gradually decreased by 96 h implying the acquisition of tolerance by cyanobacteria to heavy metal ions with prolonged exposure.]]> Sat 24 Mar 2018 07:11:19 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24707 Melaleuca diosmifolia, fallen off from the plant, to detoxify and remove hexavalent chromium or Cr(VI) from aqueous systems. Initial characterization by gas chromatography revealed that the selected biomaterial is one of the natural sources of eucalyptol. It constituted high concentrations of reducing compounds (iron, phenols and flavonoids). Batch studies revealed that the biosorbent (5 g L^-1) was able to remove 97-99.9% of 250 mg L-1 Cr(VI) at wide-ranging pH (2-10) and temperature (24-48 °C). Adsorption kinetics was well described using the pseudo-second-order kinetic model, while the equilibrium adsorption data were interpreted in terms of the Langmuir isotherm model. The monolayer adsorption capacity was 62.5 mg g^-1. Both inductively coupled plasma optical emission spectrometry and liquid chromatography analyses of the aqueous and solid phases revealed that the mechanism of Cr(VI) removal was 'adsorption-coupled reduction'. Scanning electron microscope, infrared spectroscopy and X-ray diffraction analyses of the biosorbent before and after adsorption also confirmed that both adsorption and reduction of Cr(VI) to Cr(III) followed by complexation onto functional groups of the active surface contributed to the removal of Cr(VI) from aqueous solution. The selected biomaterial effectively (99.9%) removed Cr(VI) in lake and sea water samples, highlighting its potential for remediating Cr(VI) in real environmental conditions.]]> Sat 24 Mar 2018 07:11:05 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24705 Escherichia coli DH5α cells. Based on the results, all three genes were actively expressed and their products could act on their corresponding substrates.]]> Sat 24 Mar 2018 07:10:56 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24675 Eisenia fetida is a terrestrial organism, which can be used to diagnose sub-lethal concentrations of PFOA by using molecular biomarkers. In order to identify potential molecular biomarkers, we have exposed E. fetida to 10 mg/kg of PFOA in soil for 8 months. The mRNA isolation, sequencing, transcriptome assembly followed by differential gene expression studies have revealed that genes that are involved in apoptotic process, reproduction, calcium signalling, neuronal development and lipid metabolism are predominantly affected. Highly specific genes that are altered by PFOA can be further validated and used as biomarker to detect sub-lethal concentrations of PFOA in the soil.]]> Sat 24 Mar 2018 07:10:52 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24350 -1 of total PAHs using novel acid-, metal-tolerant, N-fixing, P-solubilizing, and biosurfactant-producing LMW and HMW PAH-degrading bacterial combinations as inoculums was compared in slurry- and solid-phase microcosms over natural attenuation. Bioaugmentation of 5 % of bacterial consortia A and N in slurry- and solid-phase systems enhanced 4.6-5.7 and 9.3-10.7 % of total PAH degradation, respectively, over natural attenuation. Occurrence of 62.7-88 % of PAH biodegradation during natural attenuation in soil and slurry illustrated the accelerated rate of intrinsic metabolic activity of the autochthonous microbial community in the selected MGP soil. Monitoring of the total microbial activity and population of PAH degraders revealed that the observed biodegradation trend in MGP soil resulted from microbial mineralization. In the slurry, higher biodegradation rate constant (k) and lower half-life values (t_1/2) was observed during bioaugmentation with consortium N, highlighting the use of bioaugmentation in bioslurries/bioreactor to achieve rapid and efficient bioremediation compared to that of a static solid system. In general, natural attenuation was on par with bioaugmentation. Hence, depending on the type of soil, natural attenuation might outweigh bioaugmentation and a careful investigation using laboratory treatability studies are highly recommended before the upscale of a developed bioremediation strategy to field level.]]> Sat 24 Mar 2018 07:10:17 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24355 2+ was used to describe phytotoxicity of cucumber (Cucumis sativa L) in 10 contrasting soils at different soil Cu loadings. Both soil solution Cu (Cu_pw) and Cu²⁺ successfully described the response variable for all ten soils with R² values of 0.73 and 0.66, respectively. Separation of soils as acid and alkaline and fitting separately showed that there was a strongly significant fit for both log Cu²⁺ and log Cu_pw in acidic soils (R² = 0.92 and 0.86, respectively) but weakly significant fit for alkaline soils. The pCu EC₅₀ and EC₁₀ values in all acidic soils for cucumber were 5.83 (6.03–5.63) and 7.53 (8.27–7.00), respectively. In our dataset alkaline soils need to be treated individually. In addition, pCu could be predicted based on pH and total concentration alone. Despite only 12 weeks ‘ageing’ there was quantitative agreement between pCu model from this study and predicted pCu from Sauvé et al. This agreement from studies performed independently indicates that, at least in the case of Cu²⁺, the difference in an ageing period of ≥10 years appears minimal.]]> Sat 24 Mar 2018 07:10:17 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24996 Sat 24 Mar 2018 07:09:54 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24068 Azospirillum sp. based on phylogenetic analysis of 16S rRNA. The strain oxidized 100 µM As(III) to As(V) in both culture media (minimal salts) and real groundwater within 8 and 10 h, respectively. The oxidation of As(III) by this strain was observed within the pH range 5-10 with the best performance at pH 7-8. As(III) oxidation was found to be independent of cell growth which implies the oxidation enzymes are constitutively expressed. The whole cell kinetic study highlighted a lower value of kinetic constant, K_s as 32.9 µM As(III), which indicates that the strain MM-17 has greater affinity for As(III). The gene sequence of the large subunit of arsenite oxidase of MM-17 showed 99 and 72% similarity to the large subunit of arsenite oxidase of Stenotrophomonas sp. MM-7 and Sinorhizobium sp. M14, respectively. Sphaeroplasts experiments suggest that arsenite oxidase is a membrane associated protein in MM-17.]]> Sat 24 Mar 2018 07:09:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24051 Chlorella sp., were investigated using different phosphate levels. The results indicated that arsenate was highly toxic than arsenite to the alga, and the phosphate limitation in growth media greatly enhanced arsenate toxicity. The uptake of arsenate in algal cells was more than that of arsenite, and the predominant species in the growth media was arsenate after 8 days of exposure to arsenite or arsenate, indicating arsenite oxidation by this microalga. Arsenate reduction was also observed when the alga was incubated in a phosphate-limiting growth medium. Similar to the process of biotransformation, the alga accumulated more arsenic when it was exposed to arsenate and preferably more in a phosphate-limiting condition. Although phosphate significantly influences the biotransformation and bioaccumulation of arsenic, the oxidizing ability and higher accumulation capacity of this alga have great potential for its application in arsenic bioremediation.]]> Sat 24 Mar 2018 07:09:36 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30778 Mon 29 Jan 2024 18:03:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36515 Mon 25 May 2020 14:00:47 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27309 Mon 23 Sep 2019 14:19:56 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30026 neutral > alkaline soil. The EC50 values resulting in 50% decrease in worm weight over control for Pb in acidic, neutral and alkaline soils were 460, 3606 and 5753 mg/kg soil, respectively. Thus, the acidic soil recorded an EC50 well below the soil guideline value for Pb. Whereas, the LC50 values resulting in 50% mortality in worms over control were 1161, 4648 and 7851 mg/kg, respectively, for acidic, neutral and alkaline soils. The Pb concentrations in earthworms ranged from 0.2 to 740 mg/kg wet weight. Soils with low clay content and acidic to neutral pH values demonstrated an increased Pb toxicity in earthworms compared to the soils with alkaline pH. Conclusions: The worm weight loss is a more sensitive parameter than the mortality. This study emphasizes that the soil regulatory levels for Pb are not protective of worms in acidic soils. Therefore, care should be taken when using the current regulatory limits to assess and predict the safety of a contaminated site with acidic soils towards the ecological health.]]> Mon 23 Sep 2019 12:50:26 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33872 Pseudokirchneriella subcapitata and Chlorella sp. MM3. The toxicity criteria included were: chlorophyll a content as a growth parameter and induction of enzyme activities linked to oxidative stress. Increase in concentrations of diesel or its WAF significantly increased toxicity towards growth, measured in terms of chlorophyll a content in both the algae. Activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) in response to addition of diesel or diesel WAF to the microalgal cultures were dose-dependent. Diesel WAF was more toxic than diesel itself, suggesting that use of WAF may be more relevant for environmental risk assessment of diesel. The overall response of the antioxidant enzymes to toxicants’ stress followed the order: POX≥SOD>CAT. The present study clearly demonstrated the use of SOD, POX and CAT as suitable biomarkers for assessing diesel pollution in aquatic ecosystem.]]> Mon 21 Jan 2019 10:42:50 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42616 Fri 26 Aug 2022 15:54:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24387 Melaleuca diosmifolia leaf, Melia azedarach pod, Alnus cordata leaf and Pinus radiata cones because they all contain the essential elements (N, P, K, S and Fe) for dietary intake, applications as soil amendments, contaminant biosorbents and substrates for composting or biofertilizer preparation. Fruit peel of Quercus robur, M. diosmifolia leaf and bark, Eucalyptus leucoxylon pod and leaf, Pyrus ussuriensis and Prunus cerasifera leaf aqueous extracts indicated high phenolic content (35–66 mg GAE/g) and antioxidant activity (70–90%). A. cordata and Morus alba pendula leaf emerged as a unique source of flavonoids (>95%). There are greater prospects for the green synthesis of metallic nanoparticles using these polyphenol-rich residues.]]> Fri 22 Apr 2022 10:27:02 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24877 Fri 22 Apr 2022 10:25:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26632 Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8–C36) of petroleum hydrocarbons (PH) including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells (MFCs), maximum current density of 273 ± 8 mA/m² (1000 Ω) was produced (power density 113 ± 7 mW/m²) by strain MK2 with a coulombic efficiency of 34.8%. Further, the presence of possible alkane hydroxylase genes (alkB and rubA) in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS.]]> Fri 22 Apr 2022 10:23:10 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24007 Fri 20 Apr 2018 11:13:32 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32983 max) and Michaelis constant (K_m) in unpolluted soils were 0.012-0.267 mM h^-1 and 1.34-3.79 mM respectively. The competitive inhibition constant (K_ic) was 0.17-0.70 mM, which was lower than K_m, suggesting higher enzyme affinity for As than for substrate. The ecological doses, ED₁₀ and ED₅₀ (concentration of As that results in 10% and 50% inhibition on enzyme parameter) for inhibition of catalytic efficiency (V_max/K_m) were lower than those for inhibition of enzyme activity at different substrate concentrations. This suggests that the integrated kinetic parameter, catalytic efficiency is substrate concentration independent and more sensitive to As than ALP activity. Thus, catalytic efficiency was proposed as a more reliable indicator than ALP activity for risk assessment of As pollution.]]> Fri 17 Aug 2018 15:44:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43401 Fri 16 Sep 2022 09:58:33 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43390 Fri 16 Sep 2022 09:37:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29737 Fri 08 Sep 2017 17:28:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44107 Fri 07 Oct 2022 13:58:33 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33332 Fri 03 Dec 2021 10:34:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25426 Eisenia andrei to estimate the pollutant-induced stress. In this study, comet assay was used as an additional endpoint to evaluate the genotoxicity of weathered hydrocarbon contaminated soils containing 520 to 1450 mg hydrocarbons kg^-1 soil. Results showed that significantly higher DNA damage levels (two to sixfold higher) in earthworms exposed to hydrocarbon impacted soils. Interestingly, hydrocarbons levels in the tested soils were well below site-specific screening guideline values. In order to explore the reasons for observed toxicity, the contaminated soils were leached with rainwater and subjected to earthworm tests, including the comet assay, which showed no DNA damage. Soluble hydrocarbon fractions were not found originally in the soils and hence no hydrocarbons leached out during soil leaching. The soil leachate's Electrical Conductivity (EC) decreased from an average of 1665 ± 147 to 204 ± 20 µS cm^-1. Decreased EC is due to the loss of sodium, magnesium, calcium, and sulphate. The leachate experiment demonstrated that elevated salinity might cause the toxicity and not the weathered hydrocarbons. Soil leaching removed the toxicity, which is substantiated by the comet assay and soil leachate analysis data. The implication is that earthworm comet assay can be included in future eco (geno) toxicology studies to assess accurately the risk of contaminated soils.]]> Fri 03 Dec 2021 10:33:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34310 Eisenia fetida is a sentinel organism in soil which can be used to diagnose the health of the soil. In order to identify potential molecular markers from Eisenia fetida to diagnose the presence of benzo(a) pyrene in soil, we exposed the organism to sub-lethal (10 mgKg^-1) concentrations for a period of eight months and carried out transcriptome analysis. From the transcriptome, we have identified differentially expressed genes. Results showed that benzo(a)pyrene has altered the expression of calcium binding and calcium homeostasis, apoptotic process, cytoskeletal proteins, protein transport, nucleotide binding, lipid metabolism, peripheral neuronal development, cell division, wound healing and processing genes at transcription level. Several of the genes we reported here were not reported earlier. The highly up regulated and down regulated genes could be used as a molecular marker to diagnose the presence of benzo(a)pyrene in the soil.]]> Fri 01 Apr 2022 09:28:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24989 Fri 01 Apr 2022 09:25:44 AEDT ]]>