ORCID Profile
0000-0001-9076-1492
Current Organisation
Missouri University of Science and Technology
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Publisher: MDPI AG
Date: 17-01-2023
Abstract: The most common approaches for the in-situ bioremediation of contaminated sites worldwide are bioaugmentation and biostimulation. Biostimulation has often proved more effective for chronically contaminated sites. This study examined the effectiveness of optimized water hyacinth compost in comparison with other organic and inorganic amendments for the remediation of crude oil-polluted soils. Water hyacinth was found to be rich in nutrients necessary to stimulate microbial growth and activity. An organic geochemical analysis revealed that all amendments in this study increased total petroleum hydrocarbon (TPH) biodegradation by ≥75% within 56 days, with the greatest biodegradation (93%) occurring in sterilized soil inoculated with optimized water hyacinth compost. This was followed by polluted soil amended with a combination of spent mushroom and water hyacinth composts (SMC + WH), which recorded a TPH biodegradation of 89%. Soil amendment using the inorganic fertilizer NPK (20:10:10) resulted in 86% TPH biodegradation. On the other hand, control s les (natural attenuation) recorded only 4% degradation. A molecular analysis of residual polycyclic aromatic hydrocarbons (PAHs) showed that the 16 PAHs designated by the US EPA as priority pollutants were either completely or highly degraded in the combined treatment (SMC + WH), indicating the potential of this amendment for the environmental remediation of soils contaminated with recalcitrant organic pollutants.
Publisher: Springer Science and Business Media LLC
Date: 14-06-2021
DOI: 10.1186/S13568-021-01250-4
Abstract: The pollution of terrestrial and aquatic environments by petroleum contaminants, especially diesel fuel, is a persistent environmental threat requiring cost-effective and environmentally sensitive remediation approaches. Bioremediation is one such approach, but is dependent on the availability of microorganisms with the necessary metabolic abilities and environmental adaptability. The aim of this study was to examine the microbial community in a petroleum contaminated site, and isolate organisms potentially able to degrade hydrocarbons. Through successive enrichment of soil microorganisms from s les of an historic petroleum contaminated site in Wietze, Germany, we isolated a bacterial consortium using diesel fuel hydrocarbons as sole carbon and energy source. The 16S rRNA gene analysis revealed the dominance of Alphaproteobacteria . We further reconstructed a total of 18 genomes from both the original soil s le and the isolated consortium. The analysis of both the metagenome of the consortium and the reconstructed metagenome-assembled genomes show that the most abundant bacterial genus in the consortium, Acidocella , possess many of the genes required for the degradation of diesel fuel aromatic hydrocarbons, which are often the most toxic component. This can explain why this genus proliferated in all the enrichment cultures. Therefore, this study reveals that the microbial consortium isolated in this study and its dominant genus, Acidocella , could potentially serve as an effective inoculum for the bioremediation of sites polluted with diesel fuel or other organic contaminants.
Publisher: Cold Spring Harbor Laboratory
Date: 26-03-2021
DOI: 10.1101/2021.03.26.437261
Abstract: The slow rate of natural attenuation of organic pollutants, together with unwanted environmental impacts of traditional remediation strategies, has necessitated the exploration of plant-microbe systems for enhanced bioremediation applications. The identification of microorganisms capable of promoting both plant growth and hydrocarbon degradation is crucial to the success of plant-based remediation techniques. Through successive enrichments of a soil s le from a historic oil-contaminated site in Wietze, Germany, we isolated a plant growth-promoting and hydrocarbon-degrading bacterial consortium. Metagenome analysis of the consortium led to the identification of genes and taxa putatively associated with these processes. The majority of the coding DNA sequences involved in these reactions were affiliated to Acidocella aminolytica and Acidobacterium capsulatum. In microcosm experiments performed in association with Medicago sativa L., the consortium achieved 91% rhizodegradation of diesel fuel hydrocarbons within 60 days, indicating its potential for biotechnological applications in the remediation of sites contaminated by organic pollutants.
Publisher: MDPI AG
Date: 14-01-2021
Abstract: Environmental contamination by petroleum hydrocarbons is of concern due to the carcinogenicity and neurotoxicity of these compounds. Successful bioremediation of organic contaminants requires bacterial populations with degradative capacity for these contaminants. Through successive enrichment of microorganisms from a petroleum-contaminated soil using diesel fuel as the sole carbon and energy source, we successfully isolated a bacterial consortium that can degrade diesel fuel hydrocarbons. Metagenome analysis revealed the specific roles of different microbial populations involved in the degradation of benzene, toluene, ethylbenzene and xylene (BTEX), and the metabolic pathways involved in these reactions. One hundred and five putative coding DNA sequences were identified as responsible for both the activation of BTEX and central metabolism (ring-cleavage) of catechol and alkylcatechols during BTEX degradation. The majority of the Coding DNA sequences (CDSs) were affiliated to Acidocella, which was also the dominant bacterial genus in the consortium. The inoculation of diesel fuel contaminated soils with the consortium resulted in approximately 70% hydrocarbon biodegradation, indicating the potential of the consortium for environmental remediation of petroleum hydrocarbons.
Publisher: Cold Spring Harbor Laboratory
Date: 30-03-2021
DOI: 10.1101/2021.03.30.437699
Abstract: The biotechnological application of microorganisms for rhizoremediation of contaminated sites requires the development of plant-microbe symbionts capable of plant growth promotion and hydrocarbon degradation. Studies focusing on microbial consortia are often difficult to reproduce, thereby necessitating the need for culturable single bacterial species for biotechnological applications. Through genomic analyses and plant growth experiments, we examined the synergistic interactions of Medicago sativa L. and Paraburkholderia tropica for enhanced remediation of diesel fuel-contaminated soils. Comparative genomics revealed strong potential of P. tropica for plant growth-promotion, chemotaxis and motility, root nodulation and colonization, and diesel fuel degradation. Plant growth experiments confirmed that P. tropica thrived in the contaminated soils and effectively enhanced M. sativa growth. Geochemical analysis showed that the M. sativa + P. tropica treatment resulted in an efficient degradation of diesel fuel hydrocarbons within two months, offering great prospects for enhanced biodegradation of organic pollutants.
Publisher: MDPI AG
Date: 25-02-2022
DOI: 10.3390/W14050739
Abstract: The Clean Air Act (42 U.S. Code § 7401) is one of the United States of America’s most influential environmental laws. Under the Clean Air Act Amendments of 1990, oxygen-containing organic compounds must be added to some fossil fuels with the goal of combating CO2 and particulate emissions. However, one major implication is the effect of co-solvency on the leaching potentials of polycyclic aromatic hydrocarbons (PAHs) into groundwater. Our research investigated this effect on three groups of recalcitrant PAHs that are present in diesel fuel. Our results reveal that ethanol addition enhances the leaching potentials of these otherwise hydrophobic contaminants, with 10% ethanol (E10) resulting in elution of all the PAHs studied. While 5% ethanol addition to diesel fuel resulted in the elution of an average of 2.5% of all the trimethylnaphthalenes and 6.0% of the C2 alkylphenanthrenes present in diesel fuel, 10% ethanol addition led to the elution of more than 80% of each of the studied trimethylnaphthalene peaks and more than 70% of each of the studied C2 alkylphenanthrene peaks present in diesel fuel. In view of the known mutagenic and carcinogenic risks associated with exposure to PAHs through groundwater contamination, our study highlights the need for energy scientists to carefully consider the environmental and health implications of ethanol-blended innovations holistically. It is not enough to save the atmosphere but ruin the hydrosphere and most importantly, human health.
Publisher: MDPI AG
Date: 12-08-2023
DOI: 10.3390/APPLMICROBIOL3030062
Abstract: Alternaria leaf spot of cabbage, caused by the Alternaria brassicicola, affects leaves of cabbages and often results in head rots causing severe decline in yield. In this work, the effects of systemic and combination fungicides on A. brassicicola mycelia growth in vitro and disease severity in field trials were investigated. The results of in vitro evaluation revealed that both fungicides significantly inhibited (p 0.05) the growth of A. brassicicola under in vitro conditions. However, metalaxyl-M 6% was less effective with 100 μg/mL having only 30 ± 3.5% inhibition. On the other hand, 100 μg/mL of mancozeb 63% + carbendazim 12% had 94 ± 3.5% growth inhibition of A. brassicicola, respectively, under the same conditions. Dose-response analysis of the efficacy of the two fungicides showed that the LC50 of metalaxyl-M 6% and mancozeb 63% + carbendazim 12% were 125.52 ppm and 57.22 ppm, respectively, indicating the superiority of combination fungicide over systemic fungicide alone. Field studies showed that while manure type significantly impacted on biomass production (p 0.001), it did not significantly affect disease severity. On the other hand, the frequency of fungicide application impacted on disease severity, with biweekly application leading to a significant reduction in disease severity after 10 weeks.
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.CHEMOSPHERE.2021.133143
Abstract: The slow rate of natural attenuation of organic pollutants, together with unwanted environmental impacts of traditional remediation strategies, has necessitated the exploration of plant-microbe systems for enhanced bioremediation applications. The identification of microorganisms capable of promoting rhizoremediation through both plant growth-promoting and hydrocarbon-degrading processes is crucial to the success and adoption of plant-based remediation techniques. In this study, through successive enrichments of soil s les from a historic oil-contaminated site in Wietze, Germany, we isolated a plant growth-promoting and hydrocarbon-degrading bacterial consortium dominated by Alphaproteobacteria. In microcosm experiments involving Medicago sativa L. and the isolated bacterial consortium, we examined the ability of the consortium to enhance rhizoremediation of petroleum hydrocarbons. The inoculation of M. sativa with the consortium resulted in 66% increase in plant biomass, and achieved a 91% reduction in diesel fuel hydrocarbon concentrations in the soil within 60 days. Metagenome analysis led to the identification of genes and taxa putatively involved in these processes. The majority of the coding DNA sequences associated with plant growth promotion and hydrocarbon degradation in this study were affiliated to Acidocella aminolytica and Acidobacterium capsulatum indicating their potential for biotechnological applications in the rhizoremediation of sites contaminated by petroleum-derived organic pollutants.
Publisher: American Society for Microbiology
Date: 21-05-2020
DOI: 10.1128/MRA.00333-20
Abstract: Crude oil-polluted sites are a global threat, raising the demand for remediation worldwide. Here, we investigated a crude oil metagenome from a former borehole in Wietze, Germany, and reconstructed 42 metagenome-assembled genomes, many of which contained genes involved in crude oil degradation with a high potential for bioremediation purposes.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9RA10919F
Abstract: Ethanol addition to diesel fuels significantly affects the leaching potentials of petroleum hydrocarbons, thereby making them inaccessible to rhizoremediation.
Publisher: Sciencedomain International
Date: 10-01-2015
Publisher: MDPI AG
Date: 19-08-2020
Abstract: The remediation of contaminated sites using plant-based techniques has gained increasing attention in recent decades. However, information on the effects of contaminant imbibition on seed viability and germination rates are often lacking in the literature. To this end, our research investigated, by means of an event-time model, the effect of diesel fuel imbibition on the seed viability and germination rate of Medicago sativa, a plant species with great potential for remediation of organic contaminants. The event-time model provided an accurate and biologically relevant method for analysing germination data. Our results reveal that the direct imbibition of diesel fuel by M. sativa seeds for ≤48 h, or their exposure to soil diesel fuel concentrations of 0–10 g/kg diesel fuel, affects their germination rates, as shown by increasing t50 values from 90.6 (±2.78) to 114.2 (±2.67) hours, without significantly affecting seed viability. On the other hand, diesel fuel imbibition of longer duration, or the exposure of M. sativa seeds to ≥20 g/kg diesel fuel-contaminated soils, leads to no further effect on time to seed emergence. Instead, these conditions compromise seed viability, resulting in a decrease in the proportion of germinated seeds from 0.91 (±0.03) in 10 g/kg diesel fuel contaminated soil to 0.84 (±0.04) and 0.70 (±0.05) in 20 and 30 g/kg diesel fuel-contaminated soils, respectively. The fact that low concentrations of diesel fuel and 0–48 h of direct imbibition delayed seed emergence without adversely affecting the percentage of viable seeds suggests that this inhibitory effect on germination at low diesel fuel exposure could be attributed more to physical constraints rather than biological damage on the seeds. The models used in this study provide an accurate and biologically relevant method for the analyses of germination data. This is vital since expensive germination experiments, be it in the field of toxicology or agriculture, deserve to be accurately analysed.
Publisher: Cold Spring Harbor Laboratory
Date: 25-03-2021
DOI: 10.1101/2021.03.25.436929
Abstract: The pollution of terrestrial and aquatic environments by petroleum contaminants, especially diesel fuel, is a persistent environmental threat requiring cost-effective and environmentally sensitive remediation approaches. Bioremediation is one such approach, but is dependent on the availability of microorganisms with the necessary metabolic abilities and environmental adaptability. The aim of this study was to examine the microbial community in a petroleum contaminated site, and isolate organisms potentially able to degrade hydrocarbons. Through successive enrichment of soil microorganisms from s les of an historic petroleum contaminated site in Wietze, Germany, we isolated a bacterial consortium using diesel fuel hydrocarbons as sole carbon and energy source. The 16S rRNA gene analysis revealed the dominance of Alphaproteobacteria . We further reconstructed a total of 18 genomes from both the original soil s le and the isolated consortium. The analysis of both the metagenome of the consortium and the reconstructed metagenome-assembled genomes show that the most abundant bacterial genus in the consortium, Acidocella , possess many of the genes required for the degradation of diesel fuel aromatic hydrocarbons, which are often the most toxic component. This can explain why this genus proliferated in all the enrichment cultures. Therefore, this study reveals that the microbial consortium isolated in this study and its dominant genus, Acidocella , could potentially serve as an effective inoculum for the bioremediation of sites polluted with diesel fuel or other organic contaminants.
Publisher: Springer Science and Business Media LLC
Date: 29-08-2022
DOI: 10.1038/S43247-022-00526-2
Abstract: The biotechnological application of microorganisms for rhizoremediation of contaminated sites requires the development of plant-microbe symbionts capable of plant growth promotion and hydrocarbon degradation. Here, we present a study aimed at isolating single microbial strains that are capable of promoting plant growth as well as rhizoremediation of diesel fuel hydrocarbons. Through genomic analyses and greenhouse-based experiments, we examined the synergistic interactions of Medicago sativa L. and Paraburkholderia tropica WTPI1 for enhanced rhizoremediation of diesel fuel-contaminated soils. Plant growth-based experiments confirmed that the inoculation of M. sativa with P. tropica led to a 99% increase in plant biomass. Furthermore, organic geochemical analysis revealed that 96% of all the distinctive diesel fuel hydrocarbons, including C 10 –C 25 n -alkanes, branched alkanes, cycloalkanes and aromatic hydrocarbons were degraded in the M. sativa + P. tropica treatment. These results will prove beneficial for biotechnological application of P. tropica WTPI1 for plant growth promotion and most importantly for environmental remediation of organic pollutants.
Publisher: Elsevier BV
Date: 2021
Location: United States of America
Start Date: 2020
End Date: End date not available
Funder: American Association of Petroleum Geologists Foundation
View Funded ActivityStart Date: 2019
End Date: End date not available
Funder: Macquarie University
View Funded ActivityStart Date: 2019
End Date: End date not available
Funder: Macquarie University
View Funded ActivityStart Date: 2019
End Date: 2020
Funder: Deutscher Akademischer Austauschdienst
View Funded Activity