ORCID Profile
0000-0002-3143-5109
Current Organisation
University of Newcastle Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.CHEMOSPHERE.2017.11.081
Abstract: The phytoremediation potential of 14 different plant species belonging to C3 and C4 carbon fixation pathway for soils spiked with polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (B[a]P) and pyrene (PYR) was investigated. A glasshouse experiment was conducted to measure the changes in morphological, physiological, biochemical parameters and the bioaccumulation and biodegradation ability of the plants in soils spiked with 48 and 194 mg kg
Publisher: Elsevier BV
Date: 2023
DOI: 10.1016/J.JENVMAN.2022.116425
Abstract: A methylotrophic enrichment culture, MM34X, has been assessed for its exceptional ability in biodegradation of dimethylformamide (DMF) and bioremediation of laboratory wastewater (LWW) co-contaminated with polycyclic aromatic hydrocarbons (PAHs). The culture MM34X tolerated high concentrations of DMF and efficiently degraded 98% of 20,000 mg L
Publisher: Informa UK Limited
Date: 24-08-2022
DOI: 10.1080/10934529.2022.2119741
Abstract: Pyroligneous acid (PA) is a highly oxygenated organic condensate obtained by cooling the gases generated from the pyrolysis process. PA has been used in agriculture for several years with multiple beneficial effects, including plant health and yields, pest resilience, and seed germination. It is generally applied to agricultural soils in the dilution of 1:1000 to 1:100, corresponding to 0.1-1% PA concentration. In this study, the cyto-genotoxic potential of PA to
Publisher: Elsevier BV
Date: 08-2020
Publisher: Wiley
Date: 10-02-2023
DOI: 10.1111/AJR.12969
Abstract: To investigate student supervisor experiences of supervising students on clinical placements since the onset of the COVID‐19 pandemic. Studies on the impact of COVID‐19 on student clinical placements have focused largely on student reports and have been specific to in idual professions or topic areas. There is a need to investigate student supervisor experiences. This study was conducted in Queensland (Australia) in four regional and rural public health services and four corresponding primary health networks. The anonymous, mixed methods online survey, consisting of 35 questions, was administered to student supervisors from allied health, medicine, nursing and midwifery between May and August 2021. Numerical data were analysed descriptively using chi‐square tests. Free‐text comments were analysed using content analysis. Complete datasets were available for 167 respondents. Overall trends indicated perceived significant disruptions to student learning and support, plus mental health and well‐being concerns for both students and supervisors. Extensive mask wearing was noted to be a barrier to building rapport, learning and teaching. Some positive impacts of the pandemic on student learning were also noted. This study has highlighted the perceived impact of the pandemic on supervisors' mental health, and on the mental health, learning and work readiness of students. This study provides evidence of the pandemic impacts on student clinical placements from a supervisor point of view. Findings can assist in future‐proofing clinical education and ensuring that students continue to receive learning experiences of benefit to them, meeting curriculum requirements, in the event of another pandemic.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.CHEMOSPHERE.2018.09.170
Abstract: Polycyclic aromatic hydrocarbons are an important group of persistent organic pollutants. Using plants to remediate PAHs has been recognized as a cost-effective and environmentally friendly technique. However, the overall impact of PAHs on the regulation of plant metabolism has not yet been explored. In this study, we analyzed the alteration in the maize (Zea mays L.) metabolome on exposure to high molecular weight PAHs such as benzo[a]pyrene (BaP) and pyrene (PYR) in a hydroponic medium, in idually and as a mixture (BaP + PYR) using GC-MS. The differences in the metabolites were analyzed using XCMS (an acronym for various forms (X) of chromatography-mass spectrometry), an online-based data analysis tool. A significant variation in metabolites was observed between treatment groups and the unspiked control group. The univariate, multivariate and pathway impact analysis showed there were more significant alterations in metabolic profiles between in idual PAHs and the mixture of BaP and PYR. The marked changes in the metabolites of galactose metabolism and aminoacyl tRNA biosynthesis in PAHs treated maize leaves exhibit the adaptive defensive mechanisms for in idual and PAHs mixture. Therefore, the metabolomics approach is essential for an understanding of the complex biochemical responses of plants to PAHs contaminants. This knowledge will shed new light in the field of phytoremediation, bio-monitoring, and environmental risk assessment.
Publisher: Wiley
Date: 10-12-2020
DOI: 10.1002/ETC.4905
Abstract: Per‐ and polyfluoroalkyl substances (PFAS) have emerged as contaminants of global concern. Among several PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are persistent and bioaccumulative compounds. We investigated the cyto‐genotoxic potential of PFOS to Allium cepa root meristem cells. The A. cepa root tips were exposed to 6 different concentrations (1–100 mg L −1 ) of PFOS for 48 h. Reduction in mitotic index and chromosomal aberrations was measured as genotoxic endpoints in meristematic root cells. Exposure to PFOS significantly affected cell ision by reducing the miotic index at higher concentrations ( mg L −1 ). The median effect concentration of PFOS to elicit cytotoxicity based on the mitotic index was 43.2 mg L −1 . Exposure to PFOS significantly increased chromosomal aberrations at concentrations mg L −1 . The common aberrations were micronuclei, vagrant cells, and multipolar anaphase. The alkaline comet assay revealed a genotoxic potential of PFOS with increased tail DNA percentage at concentrations mg L −1 . To our knowledge, this is the first study to report the cyto‐genotoxic potential of PFOS in higher plants. Environ Toxicol Chem 2021 :792–798. © 2020 SETAC
Publisher: Springer Science and Business Media LLC
Date: 02-2018
DOI: 10.1038/S41598-018-20317-0
Abstract: The phytoremediation technique has been demonstrated to be a viable option for the remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated sites. This study evaluated the potential applicability of plants with C3 and C4 carbon fixation pathways for the phytoremediation of recalcitrant high molecular weight (HMW) PAHs contaminated soil. A 60 and 120-day greenhouse study was conducted which showed higher degradation of HMW PAHs in soil grown with C4 plants when compared to C3 plants. Also, no PAHs were detected in the maize cobs, sunflower, wallaby, and Sudan grass seeds at the end of the experiment. The effect of plants in modifying the microbial community and dynamics in the rhizosphere was also examined by measuring soil biochemical properties such as dehydrogenase activity and water-soluble phenols. The results demonstrate a substantial difference in the microbial populations between planted and unplanted soils, which in turn facilitate the degradation of PAHs. To the best of our knowledge, this study for the first time evaluated the phytoremediation efficacy through the A. cepa cyto- and genotoxicity assay which should be considered as an integral part of all remediation experiments.
Publisher: MDPI AG
Date: 14-01-2022
DOI: 10.3390/SOILSYSTEMS6010010
Abstract: Pyroligneous acid (PA) is often used in agriculture as a plant growth and yield enhancer. However, the influence of PA application on soil microorganisms is not often studied. Therefore, in this study, we investigated the effect of PA (0.01–5% w/w in soil) on the microbial ersity in two different soils. At the end of eight weeks of incubation, soil microbial community dynamics were determined by Illumina-MiSeq sequencing of 16S rRNA gene licons. The microbial composition differed between the lower (0.01% and 0.1%) and the higher (1% and 5%) concentration in both PA spiked soils. The lower concentration of PA resulted in higher microbial ersity and dehydrogenase activity (DHA) compared to the un-spiked control and the soil spiked with high PA concentrations. Interestingly, PA-induced plant growth-promoting bacterial (PGPB) genera include Bradyrhizobium, Azospirillum, Pseudomonas, Mesorhizobium, Rhizobium, Herbaspiriluum, Acetobacter, Beijerinckia, and Nitrosomonas at lower concentrations. Additionally, the PICRUSt functional analysis revealed the predominance of metabolism as the functional module’s primary component in both soils spiked with 0.01% and 0.1% PA. Overall, the results elucidated that PA application in soil at lower concentrations promoted soil DHA and microbial enrichment, particularly the PGPB genera, and thus have great implications for improving soil health.
Publisher: Elsevier
Date: 2023
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 08-2022
Publisher: Springer Science and Business Media LLC
Date: 30-09-2020
DOI: 10.1038/S41598-020-72844-4
Abstract: Pyrosequencing of 16S ribosomal RNA (rRNA) was employed to characterize bacterial communities colonizing the rhizosphere of plants with C3 and C4 photosynthetic pathways grown in soil contaminated with polycyclic aromatic hydrocarbons (PAHs) after 60 and 120 days. The results of this study exhibited a clear difference in bacterial ersity between the rhizosphere and non-rhizosphere s les and between the rhizospheres of the C3 and C4 plants after 120 days. In both C3 and C4 rhizospheres, an incremental change in PAHs degrading bacterial genera was observed in the 120th day s les compared to the 60th day ones. Among the PAHs degrading bacterial genera, Pseudomonas showed good resistance to PAHs in the 120th day rhizosphere of both C3 and C4 plants. Conversely, the genus Sphingomonas showed sensitivity to PAHs in the 120th day rhizosphere soils of C3 plants only. Also, a significant increase in the PAHs degrading genera was observed at 120th day in the C4 rhizosphere in comparison to the C3 rhizosphere, which was reflected in a reduced PAHs concentration measured in the soil remediated with C4 plants rather than C3 plants. These results suggest that the rhizoremediation of PAHs was primarily governed by the plant photosystems, which led to differences in root secretions that caused the variation in bacterial ersity seen in the rhizospheres. This study is the first report to demonstrate the greater effectiveness of C4 plants in enhancing the PAHs degrading bacterial community than C3 plants.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.CHEMOSPHERE.2021.132896
Abstract: Perfluorooctane sulfonate (PFOS) is a well-known global persistent organic pollutant of grave concern to ecological and human health. Toxicity of PFOS to animals and humans are well studied. Although few studies have reported the behavioral effect of PFOS on nematode Caenorhabditis elegans, it's transgenerational effects were seldom studied. Therefore, we investigated the toxicity of PFOS on several behavioral responses besides bioaccumulation and transgenerational effects in C. elegans. In contrast to the several published studies, we used lower concentrations (0.5-1000 μg/L or 0.001-2.0 μM) that are environmentally relevant and reported to occur close to the contaminated areas. The 48 h median lethal concentration of PFOS was found to be 3.15 μM (1575 μg/L). PFOS (≥0.01 μM) caused severe toxicity to locomotion, and this effect was even transferred to progeny. However, after a few generations, the defect was rectified in the progeny of single-time exposed parent nematodes. Whereas, continuous exposure at 0.001 μM PFOS, no visible defects were observed in the progeny. PFOS (≥0.01 μM) also significantly decreased the brood size in a concentration-dependent manner. Besides, lifespan was affected by the higher concentration of PFOS (≥1.0 μM). These two behavioral endpoints, lifespan and reproduction defects, became less severe in the progeny. Chemotaxis plasticity was also significantly retarded by ≥ 1.0 μM PFOS compared to the control group. Results indicate that PFOS can exert severe neurobehavioral defects that can be transferred from parents to their offspring. The findings of this study have significant implications for the risk assessment of perfluorinated substances in the environment.
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.01.110
Abstract: The biodegradation potential of three bacterial cultures isolated from the rhizosphere of maize (Zea mays) and Sudan grass (Sorghum sudanense) grown in PAHs contaminated soils to degrade benzo[a]pyrene (BaP) and pyrene (PYR) was assessed. Of the three bacterial cultures isolated, two belonged to Gram-positive bacteria of phylum Actinobacteria namely Arthrobacter sp. MAL3 and Microbacterium sp. MAL2. The Gram-negative bacterial culture was Stenotrophomonas sp. MAL1, from the phylum Proteobacteria. The cultures were grown in the presence of BaP and PYR as sole carbon sources and with the addition of low molecular weight organic acids (LMWOAs) mixture. After 10-14 days of exposure, all the bacterial isolates exhibited a complete degradation of PYR with the addition of LMWOAs mixture, whereas only 38.7% of BaP was degraded by Stenotrophomonas sp. MAL1 with the addition of LMWOAs mixture. In addition, enhanced PAHs biodegradation by bacterial culture was observed when the PAHs present as mixture (BaP + PYR) with the addition of LMWOAs. Dioxygenase genes were detected in Stenotrophomonas sp. MAL1 (phnAC), and Arthrobacter sp. MAL3 (nidA and PAH-RHDα). Therefore, this study provides new insights on the influence of LMWOAs in enhancing the degradation of high molecular weight (HMW) PAHs in soil by rhizosphere bacterial cultures.
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.CHEMOSPHERE.2019.05.005
Abstract: Endpoint assessment using biological systems in combination with the chemical analysis is important for evaluating the residual effect of contaminants following remediation. In this study, the level of residual toxicity of polycyclic aromatic hydrocarbons (PAHs) after 120 days of phytoremediation with five different plant species:- maize (Zea mays), Sudan grass (Sorghum sudanense), vetiver (Vetiveria zizanioides), sunflower (Helianthus annuus) and wallaby grass (Austrodanthonia sp.) has been evaluated by ecotoxicological tests such as root nodulation and leghaemoglobin assay using garden pea (Pisum sativum) and acute, chronic and genotoxicity assays using earthworm (Eisenia fetida). The phytoremediated soil exhibited lesser toxicity supporting improved root nodulation and leghaemoglobin content in P. sativum and reducing DNA damage in E. fetida when compared to contaminated soil before remediation. Also, the results of the ecotoxicological assays with the legume and earthworm performed in this study complemented the results obtained by the chemical analysis of PAHs in phytoremediated soil. Therefore, these findings provide a basis for a framework in which remediation efficacy of PAHs-contaminated sites can be evaluated effectively with simple ecotoxicological bioassays using legumes and earthworms.
Publisher: Elsevier BV
Date: 04-2022
No related grants have been discovered for Anithadevi Kenday Sivaram.