https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34995 −1 biosolids for ≤50, 50–100, 100–250, 250–1000 μm size fractions, respectively. The Scanning Electron Microscope (SEM) images illustrated wrinkled and fractured surfaces due to degradation. The adsorption of dissolved organic matter onto microbeads was confirmed through FT-IR microscopy, while using Inductively Coupled Plasma Mass Spectrometer (ICP-MS) the presence of trace metals including Cd (2.34 ng g⁻¹), Cu (180.64 ng g⁻¹), Ni (12.69 ng g⁻¹), Pb (1.17 ng g⁻¹), Sb (14.43 ng g⁻¹), and Zn (178.03 ng g⁻¹) was revealed. Surface modified microbeads were capable of adsorbing Cu compared to the pure microbeads, which may be attributed to the complexation of Cu with dissolved organic matter associated with the microbeads in the matrix. It was further revealed that the biosolids derived microbead-metal complexes decreased soil respiration (up to ∼ 26%) and dehydrogenase activity (up to ∼ 39%). Hence, microbeads reaching biosolids during wastewater treatment are likely to serve as a vector for trace element contamination, transportation, and toxicity when biosolids are applied to soil.]]> Wed 29 May 2019 11:33:56 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37384 Bacillus licheniformis strain KX657843 based on 16S rRNA sequencing and phylogenetic analysis, was isolated from earthworms (Metaphire posthuma). The bacteria was found to be uniquely influenced by the amino acid L-asparagine monohydrate. The organism produced the maximum yield of 2.7 g L⁻¹ EPS in the presence of sucrose supplemented with L-asparagine monohydrate while no EPS was produced in absence of the amino acid. The order of growth and EPS production in presence of different carbon substrates supplemented with L-asparagine monohydrate was observed as sucrose > glucose > glycerol > mannitol > citrate > cellulose > starch. L-asparagine monohydrate could serve as the sole nitrogen source for the organism but it alone cannot satisfy the requisite carbon demand for growth and EPS production. EPS production showed a positive correlation with sucrose concentration but a negative correlation with citrate levels. Analysis of extracted EPS using Fourier transform infrared spectroscopy and measurement of its zeta potential revealed the chemical composition and anionic nature of the EPS. The bacterium produced 119.235 IU mL⁻¹ extracellular L-asparaginase. This is the first report of an L-asparagine monohydrate dependent EPS producing Bacillus licheniformis from the gut of the earthworm, Metaphire posthuma.]]> Wed 28 Oct 2020 18:05:03 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49315 Wed 28 Feb 2024 14:48:43 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45147 −1) and high (50 and 5000 mg kg⁻¹) concentrations of Cd and Pb, respectively, in an artificially contaminated soil. In a laboratory incubation experiment, bio-available and potentially bio-available metal concentrations, selected soil properties (pH, electrical conductivity, total organic carbon and total nitrogen), and microbial parameters (microbial activity as basal respiration, microbial biomass carbon (MBC) and microbial functional groups) were determined at two sampling occasions (7 and 49 days). Metal contamination had no effect on the selected soil properties, while it significantly inhibited both microbial activity and MBC formation. Contaminated soils had higher microbial quotient (qCO₂), suggesting there was higher energy demand with less microbially immobilized carbon as MBC. Notably, the efficiency of microbial carbon use was repressed as the metal concentration increased, yet no difference was observed between metal types (p > 0.05). Based on the microbial phospholipid fatty acids (PLFA) analysis, total PLFAs decreased significantly under metal stress at the end of incubation. Heavy metals had a greater negative influence on the fungal population than bacteria with respective 5–35 and 8–32% fall in abundances. The contaminant-driven (metal concentrations and types) variation of soil PLFA biomarkers demonstrated that the heavy metals led to the alteration of soil microbial community compositions and their activities, which consequently had an adverse impact on soil microbial carbon immobilization.]]> Wed 26 Oct 2022 13:44:24 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43514 Wed 21 Sep 2022 11:18:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33205 Wed 12 Sep 2018 16:43:02 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30603 Wed 09 Mar 2022 15:58:43 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32890 m) values were 90.90 and 75.75 mg/g at pH 5.5 and 8.5, respectively while the Freundlich equilibrium constant (K_f) values were 4.67 and 4.36 mg/g at pH 5.5 and 8.5, respectively. The rate of adsorption confirmed to follow pseudo-second order kinetics with a better correlation. The thermodynamic parameters predicted that the adsorption process is an endothermic and spontaneous process.]]> Wed 08 Aug 2018 09:51:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43096 Wed 07 Feb 2024 17:17:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37659 Tue 09 Mar 2021 17:58:52 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39474 Acacia inaequilatera, Acacia pyrifolia, Acacia stellaticeps, Banksia seminuda, Chloris truncata, Hakea prostrata, Hardenbergia violacea, and Triodia wiseana were transplanted in a soil contaminated with diesel and engine oil as TPH at pollution levels of 4,370 (TPH1) and 7,500 (TPH2) mg kg^-1, and an uncontaminated control (TPH0). After 150 days, the presence of TPH negatively affected the plant growth, but the growth inhibition effect varied between the plant species. Plant growth and associated root biomass influenced the activity of rhizo-microbiome. The presence of B. seminuda, C. truncata, and H. prostrata significantly increased the TPH removal rate (up to 30% compared to the unplanted treatment) due to the stimulation of rhizosphere microorganisms. No significant difference was observed between TPH1 and TPH2 regarding the plant tolerance and rhizoremediation potentials of the three plant species. The presence of TPH stimulated cluster root formation in B. seminuda and H. prostrata which was associated with enhanced TPH remediation of these two members of Proteaceae family. These results indicated that B. seminuda, C. truncata, and H. prostrata wild plant species could be suitable candidates for the rhizoremediation of TPH-contaminated soil.]]> Tue 09 Aug 2022 14:32:31 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35243 Tue 02 Jul 2019 16:10:45 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35990 Thu 23 Jan 2020 11:40:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33595 Thu 22 Nov 2018 13:41:25 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29605 week 4 > week 3 > week 2. On the other hand, under the 50 % FC loading rate treatments, the highest N₂O emission was recorded in the first few weeks and in the following order: week 1 > week 2 > week 3 > week > 4. Since N₂O is a greenhouse gas with high global warming potential, its emission from wastewater irrigation is likely to impact global climate change. Therefore, it is important to examine the effects of abattoir wastewater irrigation on soil for N₂O emission potential.]]> Thu 21 Oct 2021 12:53:23 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31956 −1 biosolids. Soil samples were analyzed for SOC fractions, including total organic carbon (TOC), labile, and non-labile carbon contents. The natural abundances of soil δ¹³C and δ¹⁵N were measured as isotopic tracers to fingerprint carbon derived from biosolids. An automated soil respirometer was used to measure in-situ diurnal CO₂ fluxes, soil moisture, and temperature. Application of biosolids increased the surface (0–15 cm) soil TOC by > 45% at both sites, which was attributed to the direct contribution from residual carbon in the biosolids and also from the increased biomass production. At both sites application of biosolids increased the non-labile carbon fraction that is stable against microbial decomposition, which indicated the soil carbon sequestration potential of biosolids. Soils amended with biosolids showed depleted δ¹³C, and enriched δ¹⁵N indicating the accumulation of biosolids residual carbon in soils. The in-situ respirometer data demonstrated enhanced CO₂ fluxes at the sites treated with biosolids, indicating limited carbon sequestration potential. However, addition of biosolids on both the clay loam and sandy loam soils found to be effective in building SOC than reducing it. Soil temperature and CO₂ fluxes, indicating that temperature was more important for microbial degradation of carbon in biosolids than soil moisture.]]> Thu 21 Oct 2021 12:52:20 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33207 o), Fe(III) oxide and cow manure increased Cr(VI) retention. The effect of S^o on Cr(VI) sorption is mediated through a decrease in soil pH, which facilitated an increased retention of Cr(VI) as measured by Freundlich sorption coefficient from 0.079 (in pristine soil, pH7.15) to 21.06L/kg (in S^o amended soil, pH4.08). Also, Fe(III) oxide addition at 5% has favoured for an increase in the retention of Cr(VI) (K_f =91.15L/kg). Cow manure promoted Cr(VI) reduction, possibly due to the presence of functional groups that are present along with dissolved organic carbon and also by increased microbial activity. It is concluded that the mitigation of Cr toxicity is brought about by the addition of amendments which manipulate the properties of soil to increase retention of Cr(III) and Cr(VI).]]> Thu 21 Oct 2021 12:51:17 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47848 Thu 02 Feb 2023 16:32:49 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29304 Sat 24 Mar 2018 07:34:23 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29543 Sat 24 Mar 2018 07:33:09 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24017 Sat 24 Mar 2018 07:16:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44838 Zea mays L. as test crop. In the alkaline MGB soil, the availability of Cd was reduced, while that of As increased. An opposite behaviour was observed in the acid KPD soil. All amendments, when added to KPD soil, increased pH and consequently reduced the mobility of Cd and increased the mobility of As. In MGB, the amendment addition had an effect only on As mobility and bioavailability, which increased likely as a result of the increased competition for adsorption with DOC released by organic compounds. These trends were confirmed by the amounts of Cd and As uptaken by maize plants.]]> Mon 24 Oct 2022 10:48:36 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44805 0.9, p < 0.001), which was affected by plant identity and P levels. The results indicated that an integrated approach involving wild plant species and optimum P amendment, which was determined through experimentation using different plant species, was an efficient way to remediate soil contaminated with TPH.]]> Mon 24 Oct 2022 09:24:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52720 Mon 23 Oct 2023 16:25:51 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43435 P_app), with differences in ML retention and complexation amongst the chelants and the gut microbes. The decrease in ML permeability varied amongst the MLs. Chelating agents reduce intestinal absorption of MLs by forming complexes thereby making them less permeable. In the case of gut bacteria, the decrease in the intestinal permeability of MLs may be associated to a direct protection of the intestinal barrier against the MLs or indirect intestinal ML sequestration by the gut bacteria through adsorption on bacterial surface. Thus, both gut microbes and chelating agents can be used to decrease the intestinal permeability of MLs, thereby mitigating their toxicity.]]> Mon 19 Sep 2022 11:35:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51765 Cd > Pb > As(III)>As(V) for E. coli; and Hg > Cd > As(III)>Pb > As(V) for the two Lactobacillus sp. Arsenite (AsIII) showed higher toxicity than arsenate (AsV) to gut bacteria. While As is an anion, Cd, Pb and Hg are cations and hence their binding capacity to the bacterial cell wall varied based on the charge dependent functional groups. However, the toxic effects of PTEs for a bacteria are controlled by their speciation and bioavailability.]]> Mon 18 Sep 2023 14:23:29 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43027 3), fly ash (FA), unreacted lime (CaO) and portlandite (Ca[OH]₂) or calcite (CaCO₃). Chemical and mineralogical composition, leachate chemistry and textural properties of basic slags are helpful for understanding their nature and assessing their impacts on the environment. The characterization of various slags can be analyzed by different instrumental methods. Inductively coupled plasma mass spectrometry and optical emission spectrometry (ICP-MS/OES) are the most commonly analytical techniques for chemical composition, and X-ray diffractometry (XRD) is used to provide further information on types of minerals and their phases. Additionally, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) could be auxiliary to analyze some specific samples, which are not easily identified or quantified by XRD. Some slags have been commercialized to be the source of nutrients and soil amendments, with the major nutrients including P, S, Ca, Mg and silicon (Si). Slags from steel industry are rich in Ca and Mg, which are beneficial to deficient soils. Slags from coal combustion are a good source of sulfur, while the presence of calcium in the form of lime and gypsum helps to mitigate the soil acidity and improves soil structure. However, they also possibly contain toxic metal contaminants, such as chromium (Cr) and vanadium (V). There have been some concerns about the toxic effects of slag materials on farm animals. Slag poisoning of animals can be avoided or minimized by increasing the dissolution of slag through soil incorporation and by avoiding overgrazing of slag treated paddocks.]]> Mon 12 Sep 2022 11:14:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38496 Mon 11 Oct 2021 15:51:00 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:39212 Lactobacillus acidophilus, Lactobacillus rhamnosus and Escherichia coli. Lead toxicity to these three microbes was also examined at various pH values. Bioaccessibility of Pb was measured using gastric and intestinal extractions. Both Pb spiked and Pb-contaminated shooting range field soils were used to measure Pb bioaccessibility in the presence and absence of gut microbes. The results indicated that Pb toxicity to gut microbes, as measured by LD₅₀ value, decreased with increasing pH, and was higher for Lactobacillus species. Gut microbes decreased the bioaccessible Pb; the effect was more pronounced at low pH, mimicking gastric conditions than in conditions closer to the intestine. Lead adsorption by these microbes increased at the higher pH tested, and E. coli adsorbed higher amounts of Pb than did the Lactobacillus species. The effect of gut microbes on reducing Pb bioaccessibility may be attributed to microbially-induced immobilization of Pb through adsorption, precipitation, and complexation reactions. The study demonstrates that bioaccessibility and subsequently bioavailability of metal(loid)s can be modulated by gut microbes, and it is important to undertake bioaccessibility measurements in the presence of gut microbes.]]> Fri 27 May 2022 11:09:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24499 Fri 22 Apr 2022 10:22:46 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39995 Fri 01 Jul 2022 13:49:31 AEST ]]>