https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53481 Wed 28 Feb 2024 14:56:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50864 Wed 28 Aug 2024 09:33:57 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38581 Wed 23 Feb 2022 15:53:14 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27108 Wed 11 Apr 2018 12:13:49 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:15822 Wed 11 Apr 2018 09:51:36 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27498 Wed 11 Apr 2018 09:37:47 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39312 Proteobacteria and Actinobacteria were identified as the two dominant phyla in the remediation of diesel contaminated soil. Metagenomics analysis revealed that the preferred metabolic pathway of nitrogen was from ammonium to glutamate via glutamine, and the enzymes governing this transformation were glutamine synthetase and glutamate synthetase; while in nitrate based amendment, the conversion from nitrite to ammonium was restrained by the low abundance of nitrite reductase enzyme and therefore retarded the TPH degradation rate. It is concluded that during the process of nitrogen enhanced bioremediation, the most efficient nitrogen cycling direction was from ammonium to glutamine, then to glutamate, and finally joined with carbon metabolism after transforming to 2-oxoglutarate.]]> Wed 10 Aug 2022 11:08:14 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51885 Wed 07 Feb 2024 14:25:54 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44791 Wed 07 Feb 2024 14:24:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44026 Wed 05 Oct 2022 15:18:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43940 Wed 05 Oct 2022 12:51:29 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:32556 Tue 19 Jun 2018 11:56:29 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:32679 Tue 10 Jul 2018 15:38:12 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37718 Thu 25 Mar 2021 09:31:53 AEDT ]]> 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:43360 Thu 15 Sep 2022 15:47:17 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49337 Thu 11 May 2023 15:21:07 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31523 Sphingobium SA2 and nutrient amendment. In a field with ~ 280 mg/kg Hg, 60% of Hg was removed by bio-augmentation in 7 days, and the removal was improved when nutrients were added. Whereas in artificially spiked soils, with ~ 100 mg/kg Hg, removal due to bio-augmentation was 33 to 48% in 14 days. In the field contaminated soil, nutrient amendment alone without bio-augmentation removed 50% of Hg in 28 days. Nutrient amendment also had an impact on Hg remediation in the spiked soils, but the best results were obtained when the strain and nutrients both were applied. The development of longer root lengths from lettuce and cucumber seeds grown in the remediated soils confirmed that the soil quality improved after bioremediation. This study clearly demonstrates the potential of Hg-reducing bacteria in remediation of Hg-contaminated soils. However, it is desirable to trap the volatilized Hg for enhanced bioremediation.]]> Sat 24 Mar 2018 08:43:51 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1961 Sat 24 Mar 2018 08:33:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:2480 Sat 24 Mar 2018 08:27:44 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:263 Sat 24 Mar 2018 07:42:56 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:29856 Mycobacterium gilvum VF1 in the presence of a palmitic acid (PA)-grafted Arquad® 2HT-75-based organobentonite in cadmium (Cd)-phenanthrene co-contaminated water. The PA-grafted organobentonite (ABP) adsorbed a slightly greater quantity of Cd than bentonite at up to 30 mg L^{− 1} metal concentration, but its highly negative surface charge imparted by carboxylic groups indicated the potential of being a significantly superior adsorbent of Cd at higher metal concentrations. In systems co-contained with Cd (5 and 10 mg L^{− 1}), the Arquad® 2HT-75-modified bentonite (AB) and PA-grafted organobentonite (ABP) resulted in a significantly higher (72–78%) degradation of phenanthrene than bentonite (62%) by the bacterium. The growth and proliferation of bacteria were supported by ABP which not only eliminated Cd toxicity through adsorption but also created a congenial microenvironment for bacterial survival. The macromolecules produced during ABP–bacteria interaction could form a stable clay-bacterial cluster by overcoming the electrostatic repulsion among individual components. Findings of this study provide new insights for designing clay modulated PAH bioremediation technologies in mixed-contaminated water and soil.]]> Sat 24 Mar 2018 07:40:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30131 Sat 24 Mar 2018 07:39:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30893 14C-labelled phenanthrene and a model bacterium Burkholderia sartisoli, we studied the mineralization of phenanthrene on the surface of a moderately heat-treated (up to 400 °C) palygorskite. The heat treatment at 400 °C induced a reduction of binding sites (e.g., by the elimination of organic matter and/or channel shrinkage) in the palygorskite and thus imparted a weaker sequestration of phenanthrene on its surface and within the pores. As a result, a supplement with the thermally modified palygorskite (400 °C) significantly increased (20–30%; p < 0.05) the biomineralization of total phenanthrene in a simulated soil slurry system. These results are highly promising to develop a clay mineral based technology for the bioremediation of PAH contaminants in water and soil environments.]]> Sat 24 Mar 2018 07:30:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30891 14C-tracing study showed that the mild acid/alkali-treated clay products increased the PAH biodegradation (5–8%) in the order of 0.5 M HCl ≥ unmodified > 3 M NaOH ≥ 0.5 M NaOH for smectite, and 0.5 M HCl > 0.5 M NaOH ≥ unmodified ≥ 3 M NaOH for palygorskite. The biodegradation was correlated (r = 0.81) with the bioavailable fraction of PAHs and microbial growth as affected particularly by the 0.5 M HCl and 0.5 M NaOH-treated clay minerals. These results could be pivotal in developing a clay-modulated bioremediation technology for cleaning up PAH-contaminated soils and sediments in the field.]]> Sat 24 Mar 2018 07:30:38 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30892 Sat 24 Mar 2018 07:30:38 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: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:30778 Mon 29 Jan 2024 18:03:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48487 Acinetobacter calcoaceticus strain, GSN3, with biofilm-forming and phenol-degrading abilities. Three biofilm reactors were spiked with activated sludge (R1), green fluorescent plasmid (GFP) tagged GSN3 (R2), and their combination (R3). More than 99% phenol removal was achieved during four weeks in R3 while this efficiency was reached after two and four further operational weeks in R2 and R1, respectively. Confocal scanning electron microscopy revealed that GSN3-gfp strains appeared mostly in the deeper layers of the biofilm in R3. After four weeks, almost 7.07 x 10⁷ more attached sludge cells were counted per carrier in R3 in comparison to R1. Additionally, the higher numbers of GSN3-gfp in R2 were unable to increase the efficiency as much as measured in R3. The presence of GSN3-gfp in R3 conveyed advantages, including enhancement of cell immobilization, population diversity, metabolic cooperation and ultimately treatment efficiency.]]> Mon 29 Jan 2024 18:01:37 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37161 Mon 24 Aug 2020 16:04:57 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37158 Desmodesmus sp. MAS1 and Heterochlorella sp. MAS3, isolated from neutral environments, for simultaneous removal of heavy metals such as copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn), and production of biodiesel when grown at pH 3.5. Excepting Cu, the selected metals at concentrations of 10–20 mg L⁻¹ supported good growth of both the strains. Cellular analysis for metal removal revealed the predominance of intracellular mechanism in both the strains resulting in 40–80 and 40–60% removal of Fe and Mn, respectively. In-situ transesterification of biomass indicated enhanced biodiesel yield with increasing concentrations of metals suggesting that both these acid-tolerant microalgae may be the suitable candidates for simultaneous remediation, and sustainable biomass and biodiesel production in environments like metal-rich acid mine drainages.]]> Mon 24 Aug 2020 15:43:43 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52333 Mon 09 Oct 2023 14:50:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46864 Mon 05 Dec 2022 08:29:59 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32736 Fri 20 Sep 2019 02:34:30 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:50216 Fri 07 Jul 2023 12:23:35 AEST ]]>