https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47672 Wed 28 Feb 2024 15:21:16 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:24104 Thu 21 Oct 2021 12:52:12 AEDT ]]> 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:31331 Sat 24 Mar 2018 08:44:39 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: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: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: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: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: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: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:51982 Mon 25 Sep 2023 13:54:41 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49573 Mon 22 May 2023 09:55:08 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41866 Mon 15 Aug 2022 09:49:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54933 SAs (manure: 0.90‒73; soil: 0.20‒48.40) > QNs (manure: nd‒3.60; soil: nd‒1.80) > MLs (manure: nd‒1.50; soil: nd‒0.90). Poultry manure-applied farmlands exhibited the highest antibiotic contamination levels, with total antibiotic concentrations surpassing the ecotoxicological effect trigger value of 100 μg kg−1 set by the Steering Committee of the Veterinary International Committee on Harmonization, highlighting the potential hazard of VAs to the soil ecosystem. The translocation of VAs in vegetables was in the order: leaf > root > fruit, and bioaccumulation of 0.10‒3.90 μg kg−1 was recorded. Notably, the calculated risk quotients of antibiotics in vegetables were ˂1, indicating the negligible risk to human health. Overall, our study unveils a concerning state of VAs pollution in organic farmlands in India that warrants special attention, as it may contribute to the proliferation of antibiotic resistance.]]> Fri 22 Mar 2024 14:33:11 AEDT ]]> 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:29737 Fri 08 Sep 2017 17:28:22 AEST ]]>