The Experts below are selected from a list of 1566 Experts worldwide ranked by ideXlab platform
Ravendra Naidu - One of the best experts on this subject based on the ideXlab platform.
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biodegradation of tnt using Bacillus Mycoides immobilized in pva sodium alginate kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
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Biodegradation of TNT using Bacillus Mycoides immobilized in PVA–sodium alginate–kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
Zuliang Chen - One of the best experts on this subject based on the ideXlab platform.
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biodegradation of tnt using Bacillus Mycoides immobilized in pva sodium alginate kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
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Aerobic and anaerobic biodegradation of TNT by newly isolated Bacillus Mycoides
Ecological Engineering, 2013Co-Authors: Hong-yan Lin, Zuliang ChenAbstract:Abstract A TNT-degrading strain, which was isolated from Fe-reducing bacterial consortia and was identified as Bacillus Mycoides based on its 16S rDNA sequence, was first used to degrade TNT under aerobic or anaerobic conditions. The results shows that 93% of the initial TNT was degraded after 16 h under aerobic environment, while 94% of TNT was reduced after 24 h under anaerobic environment. This is attributed to slower microorganism growth under anaerobic conditions and was confirmed in a biokinetic study, where lower degradation rates were obtained under anaerobic condition. Two TNT degradation metabolites, 4-amino-2,6-dinitrotoluene and 6-amino-2,4-dinitrotoluene, were identified by GC–MS and the degradation pathways of TNT by B. Mycoides were proposed. Finally, B. Mycoides was used to degrade TNT in industrial wastewater, where more than 88% of the TNT was removed, irrespective of the aerobic or anaerobic conditions.
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Biodegradation of TNT using Bacillus Mycoides immobilized in PVA–sodium alginate–kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
Oscar P. Kuipers - One of the best experts on this subject based on the ideXlab platform.
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exploring plant microbe interactions of the rhizobacteria Bacillus subtilis and Bacillus Mycoides by use of the crispr cas9 system
Environmental Microbiology, 2018Co-Authors: Chunxu Song, Oscar P. KuipersAbstract:Bacillus subtilis HS3 and Bacillus Mycoides EC18 are two rhizosphere-associated bacteria with plant growth-promoting activity. The CRISPR-Cas9 system was implemented to study various aspects of plant-microbe interaction mechanisms of these two environmental isolates. The results show that fengycin and surfactin are involved in the antifungal activity of B. subtilis HS3. Moreover, this strain emits several other volatile organic compounds than 2,3-butanediol, contributing to plant growth promotion. Confocal laser scanning microscopy observations of the GFP-labelled strain showed that HS3 selectively colonizes root hairs of grass (Lolium perenne) in a hydroponic system. For B. Mycoides EC18, we found that the wild-type EC18 strain and a ΔasbA (petropectin-deficient) mutant, but not the ΔdhbB (bacillibactin-deficient) and ADKO (asbA and dhbB double knockout) mutants, can increase the plant biomass and total chlorophyll. All the mutant strains have a reduced colonization capability on Chinese cabbage (Brassica rapa) roots, at the root tip and root hair region compared with the wild-type strain. These results indicate that the siderophore, bacillibactin, is involved in the plant growth promoting activity and could affect the root colonization of B. Mycoides. Collectively, the CRISPR-Cas9 system we developed for environmental isolates is broadly applicable and will facilitate deciphering the mechanisms of Bacillus-plant interactions. © 2018 The Authors.
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Exploring plant‐microbe interactions of the rhizobacteria Bacillus subtilis and Bacillus Mycoides by use of the CRISPR‐Cas9 system
Environmental microbiology, 2018Co-Authors: Chunxu Song, Oscar P. KuipersAbstract:Bacillus subtilis HS3 and Bacillus Mycoides EC18 are two rhizosphere-associated bacteria with plant growth-promoting activity. The CRISPR-Cas9 system was implemented to study various aspects of plant-microbe interaction mechanisms of these two environmental isolates. The results show that fengycin and surfactin are involved in the antifungal activity of B. subtilis HS3. Moreover, this strain emits several other volatile organic compounds than 2,3-butanediol, contributing to plant growth promotion. Confocal laser scanning microscopy observations of the GFP-labelled strain showed that HS3 selectively colonizes root hairs of grass (Lolium perenne) in a hydroponic system. For B. Mycoides EC18, we found that the wild-type EC18 strain and a ΔasbA (petropectin-deficient) mutant, but not the ΔdhbB (bacillibactin-deficient) and ADKO (asbA and dhbB double knockout) mutants, can increase the plant biomass and total chlorophyll. All the mutant strains have a reduced colonization capability on Chinese cabbage (Brassica rapa) roots, at the root tip and root hair region compared with the wild-type strain. These results indicate that the siderophore, bacillibactin, is involved in the plant growth promoting activity and could affect the root colonization of B. Mycoides. Collectively, the CRISPR-Cas9 system we developed for environmental isolates is broadly applicable and will facilitate deciphering the mechanisms of Bacillus-plant interactions. © 2018 The Authors.
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Comparative Transcriptomics of Bacillus Mycoides Strains in Response to Potato-Root Exudates Reveals Different Genetic Adaptation of Endophytic and Soil Isolates
Frontiers in microbiology, 2017Co-Authors: Anne De Jong, Elrike Frenzel, Oscar P. KuipersAbstract:Plant root secreted compounds alter the gene expression of associated microorganisms by acting as signal molecules that either stimulate or repel the interaction with beneficial or harmful species, respectively. However, it is still unclear whether two distinct groups of beneficial bacteria, non-plant-associated (soil) strains and plant-associated (endophytic) strains, respond uniformly or variably to the exposure with root exudates. Therefore, Bacillus Mycoides, a potential biocontrol agent and plant growth-promoting bacterium, was isolated from the endosphere of potatoes and from soil of the same geographical region. Confocal fluorescence microscopy of plants inoculated with GFP-tagged B. Mycoides strains showed that the endosphere isolate EC18 had a stronger plant colonization ability and competed more successfully for the colonization sites than the soil isolate SB8. To dissect these phenotypic differences, the genomes of the two strains were sequenced and the transcriptome response to potato root exudates was compared. The global transcriptome profiles evidenced that the endophytic isolate responded more pronounced than the soil-derived isolate and a higher number of significant differentially expressed genes were detected. Both isolates responded with the alteration of expression of an overlapping set of genes, which had previously been reported to be involved in plant-microbe interactions; including organic substance metabolism, oxidative reduction, and transmembrane transport. Notably, several genes were specifically upregulated in the endosphere isolate EC18, while being oppositely downregulated in the soil isolate SB8. These genes mainly encoded membrane proteins, transcriptional regulators or were involved in amino acid metabolism and biosynthesis. By contrast, several genes upregulated in the soil isolate SB8 and downregulated in the endosphere isolate EC18 were related to sugar transport, which might coincide with the different nutrient availability in the two environments. Altogether, the presented transcriptome profiles provide highly improved insights into the life strategies of plant-associated endophytes and soil isolates of B. Mycoides.
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Development of an efficient electroporation method for rhizobacterial Bacillus Mycoides strains
Journal of microbiological methods, 2016Co-Authors: Oscar P. KuipersAbstract:In order to develop a method for electroporation of environmental Bacillus Mycoides strains, we optimized several conditions that affect the electroporation efficiency of this bacterium. By combining the optimized conditions, the electroporation efficiency of strain EC18 was improved to (1.3±0.6)×105cfu/μg DNA, which is about 103-fold increase in comparison with a previously reported value. The method was further validated on various B. Mycoides strains, yielding reasonable transformation efficiencies. Furthermore, we confirmed that restriction/modification is the main barrier for electroporation of this bacterium. To the best of our knowledge, this is the first systematic investigation of various parameters of electroporation of B. Mycoides. The electroporation method reported will allow for efficient genetic manipulation of this bacterium.
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Draft Genome Sequence of Bacillus Mycoides M2E15, a Strain Isolated from the Endosphere of Potato.
Genome announcements, 2016Co-Authors: Anne De Jong, Jan Spoelder, J. Theo M. Elzenga, Jan Dirk Van Elsas, Oscar P. KuipersAbstract:We present the draft genome sequence of Bacillus Mycoides M2E15, a bacterium isolated from potato endosphere. Analysis of the 6.08-Mbp draft genome sequence identified 6,386 protein-encoding sequences, including potential plant growth promoting genes. Specifically, genes for proteins involved in phosphate utilization, iron acquisition, and bacteriocin production were identified.
Hong-yan Lin - One of the best experts on this subject based on the ideXlab platform.
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biodegradation of tnt using Bacillus Mycoides immobilized in pva sodium alginate kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
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Aerobic and anaerobic biodegradation of TNT by newly isolated Bacillus Mycoides
Ecological Engineering, 2013Co-Authors: Hong-yan Lin, Zuliang ChenAbstract:Abstract A TNT-degrading strain, which was isolated from Fe-reducing bacterial consortia and was identified as Bacillus Mycoides based on its 16S rDNA sequence, was first used to degrade TNT under aerobic or anaerobic conditions. The results shows that 93% of the initial TNT was degraded after 16 h under aerobic environment, while 94% of TNT was reduced after 24 h under anaerobic environment. This is attributed to slower microorganism growth under anaerobic conditions and was confirmed in a biokinetic study, where lower degradation rates were obtained under anaerobic condition. Two TNT degradation metabolites, 4-amino-2,6-dinitrotoluene and 6-amino-2,4-dinitrotoluene, were identified by GC–MS and the degradation pathways of TNT by B. Mycoides were proposed. Finally, B. Mycoides was used to degrade TNT in industrial wastewater, where more than 88% of the TNT was removed, irrespective of the aerobic or anaerobic conditions.
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Biodegradation of TNT using Bacillus Mycoides immobilized in PVA–sodium alginate–kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
Mallavarapu Megharaj - One of the best experts on this subject based on the ideXlab platform.
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biodegradation of tnt using Bacillus Mycoides immobilized in pva sodium alginate kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
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Biodegradation of TNT using Bacillus Mycoides immobilized in PVA–sodium alginate–kaolin
Applied Clay Science, 2013Co-Authors: Hong-yan Lin, Zuliang Chen, Mallavarapu Megharaj, Ravendra NaiduAbstract:Abstract In this study, a newly isolated TNT-degrading bacterium, Bacillus Mycoides , was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20 mg/L to 120 mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4 °C for 42 days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT.
