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Zhao X, Li J, Zhang D, Huang Z, Luo C, Jiang L, Huang D, Zhang G. Mechanism of salicylic acid in promoting the rhizosphere benzo[a]pyrene biodegradation as revealed by DNA-stable isotope probing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 810:152202. [PMID: 34890682 DOI: 10.1016/j.scitotenv.2021.152202] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 06/13/2023]
Abstract
Benzo[a]pyrene (BaP) is a typical high-molecular-weight PAH with carcinogenicity. Rhizoremediation is commonly applied to remove soil BaP, but its mechanism remains unclear. The role of inducers in root exudates in BaP rhizoremediation is rarely studied. Here, to address this problem, we firstly investigated the effect of the inducer salicylic acid on BaP rhizoremediation, rhizosphere BaP degraders, and PAH degradation-related genes by combining DNA-stable-isotope-probing, high-throughput sequencing, and gene function prediction. BaP removal in the rhizosphere was significantly increased by stimulation with salicylic acid, and the rhizosphere BaP-degrading microbial community structure was significantly changed. Fourteen microbes were responsible for the BaP metabolism, and most degraders, e.g. Aeromicrobium and Myceligenerans, were firstly linked with BaP biodegradation. The enrichment of the PAH-ring hydroxylating dioxygenase (PAH-RHD) gene in the heavy fractions of all 13C-treatments further indicated their involvement in the BaP biodegradation, which was also confirmed by the enrichment of dominant PAH degradation-related genes (e.g. PAH dioxygenase and protocatechuate 3,4-dioxygenase genes) based on gene function prediction. Overall, our study demonstrates that salicylic acid can enhance the rhizosphere BaP biodegradation by altering the community structure of rhizosphere BaP-degrading bacteria and the abundance of PAH degradation-related genes, which provides new insights into BaP rhizoremediation mechanisms in petroleum-contaminated sites.
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Affiliation(s)
- Xuan Zhao
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Jibing Li
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100039, China.
| | - Dayi Zhang
- College of New Energy and Environment, Jilin University, Changchun 130021, China
| | - Zilin Huang
- Joint Institute of Environmental Research & Education, South China Agricultural University, Guangzhou 510642, China
| | - Chunling Luo
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China; Joint Institute of Environmental Research & Education, South China Agricultural University, Guangzhou 510642, China.
| | - Longfei Jiang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China
| | - Deyin Huang
- Guangdong Institute of Eco-environmental and Soil sciences, Guangdong Academy of Sciences, Guangzhou 510650, Guangdong, China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China
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Liang J, Gao S, Wu Z, Rijnaarts HHM, Grotenhuis T. DNA-SIP identification of phenanthrene-degrading bacteria undergoing bioaugmentation and natural attenuation in petroleum-contaminated soil. CHEMOSPHERE 2021; 266:128984. [PMID: 33234305 DOI: 10.1016/j.chemosphere.2020.128984] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 11/08/2020] [Accepted: 11/13/2020] [Indexed: 06/11/2023]
Abstract
DNA-stable isotope probing (SIP) with 13C labeled phenanthrene (PHE) as substrate was used to identify specific bacterial degraders during natural attenuation (NA) and bioaugmentation (BA) in petroleum contaminated soil. BA, with the addition of a bacterial suspension mixture named GZ, played a significant role in PHE degradation with a higher PHE removal rate (∼90%) than that of NA (∼80%) during the first 3 days, and remarkably altered microbial communities. Of the five strains introduced in BA, only two genera, particularly, Ochrobactrum, Rhodococcus were extensively responsible for PHE-degradation. Six (Bacillus sp., Acinetobacter sp., Xanthomonas sp., Conexibacter sp., Acinetobacter sp. and Staphylococcus sp.) and seven (Ochrobactrum sp., Rhodococcus sp., Alkanindiges sp., Williamsia sp., Sphingobium sp., Gillisia sp. and Massilia sp.) bacteria responsible for PHE degradation were identified in NA and BA treatments, respectively. This study reports for the first time the association of Xanthomonas sp., Williamsia sp., and Gillisia sp. to PHE degradation.
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Affiliation(s)
- Jidong Liang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Sha Gao
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; Department of Environmental Technology, Wageningen University and Research, Wageningen, 6700AA, the Netherlands
| | - Zijun Wu
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Huub H M Rijnaarts
- Department of Environmental Technology, Wageningen University and Research, Wageningen, 6700AA, the Netherlands
| | - Tim Grotenhuis
- Department of Environmental Technology, Wageningen University and Research, Wageningen, 6700AA, the Netherlands
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Li Q, Li J, Jiang L, Sun Y, Luo C, Zhang G. Diversity and structure of phenanthrene degrading bacterial communities associated with fungal bioremediation in petroleum contaminated soil. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123895. [PMID: 33264959 DOI: 10.1016/j.jhazmat.2020.123895] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/14/2020] [Accepted: 08/29/2020] [Indexed: 06/12/2023]
Abstract
Fungal bioremediation is a promising technique for the cleanup of sites contaminated with polycyclic aromatic hydrocarbons (PAHs). However, due to limited understanding of the composition and dynamics of the native PAH-degrading microorganisms in contaminated sites, its application has been difficult. In the present study, DNA stable-isotope probing was performed to identify indigenous phenanthrene (PHE)-degrading bacteria and determine their diversity during the fungal bioremediation process. The results showed a total of 14 operational taxonomic units (OTUs) enriched in the heavy DNA fractions, which were related to seven genera (Sphingomonas, Sphingobacterium, Acidovorax, Massilia, Flavobacterium, Cupriavidus, Aeromicrobium, and unclassified Chitinophagaceae). Along with enhanced efficiency of PHE removal, the number and diversity of indigenous PHE-degrading bacteria in soil bioaugmented with fungi were significantly increased. Furthermore, based on the results of linear model analysis, we found that PHE degraders affiliated with the genus Sphingomonas were significantly enriched during fungal bioremediation. Moreover, fungal bioaugmentation promoted indigenous functional Proteobacteria involved in PAH degradation through co-metabolism, suggesting that PAH biodegradation was attributable to cooperative metabolism by fungi and indigenous bacteria. Our findings provide new insights into the diversity of PHE-degrading communities and support a more comprehensive view of the fungal bioremediation process.
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Affiliation(s)
- Qiqian Li
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; College of Chemical and Biological Engineering, Hechi University, Yizhou, 546300, China; University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Jibing Li
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Longfei Jiang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Yingtao Sun
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Chunling Luo
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
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Tong H, Liu C, Li F, Luo C, Chen M, Hu M. The key microorganisms for anaerobic degradation of pentachlorophenol in paddy soil as revealed by stable isotope probing. JOURNAL OF HAZARDOUS MATERIALS 2015; 298:252-260. [PMID: 26073380 DOI: 10.1016/j.jhazmat.2015.05.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/26/2015] [Accepted: 05/28/2015] [Indexed: 06/04/2023]
Abstract
Pentachlorophenol (PCP) is a common residual persistent pesticide in paddy soil and has resulted in harmful effect on soil ecosystem. The anaerobic microbial transformation of PCP, therefore, has been received much attentions, especially the functional microbial communities for the reductive transformation. However, the key functional microorganisms for PCP mineralization in the paddy soil still remain unknown. In this work, DNA-based stable isotope probing (SIP) was applied to explore the key microorganisms responsible for PCP mineralization in paddy soil. The SIP results indicated that the dominant bacteria responsible for PCP biodegradation belonged to the genus Dechloromonas of the class β-Proteobacteria. In addition, the increased production of (13)CH4 and (13)CO2 indicated that the addition of lactate enhanced the rate of biodegradation and mineralization of PCP. Two archaea classified as the genera of Methanosaeta and Methanocella of class Methanobacteria were enriched in the heavy fraction when with lactate, whereas no archaea was detected in the absence of lactate. These findings provide direct evidence for the species of bacteria and archaea responsible for anaerobic PCP or its breakdown products mineralization and reveal a new insight into the microorganisms linked with PCP degradation in paddy soil.
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Affiliation(s)
- Hui Tong
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, PR China; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chengshuai Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550009, PR China
| | - Fangbai Li
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, PR China.
| | - Chunling Luo
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China
| | - Manjia Chen
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, PR China
| | - Min Hu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, PR China
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Sun W, Li Y, McGuinness LR, Luo S, Huang W, Kerkhof LJ, Mack EE, Häggblom MM, Fennell DE. Identification of Anaerobic Aniline-Degrading Bacteria at a Contaminated Industrial Site. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11079-11088. [PMID: 26280684 DOI: 10.1021/acs.est.5b02166] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Anaerobic aniline biodegradation was investigated under different electron-accepting conditions using contaminated canal and groundwater aquifer sediments from an industrial site. Aniline loss was observed in nitrate- and sulfate-amended microcosms and in microcosms established to promote methanogenic conditions. Lag times of 37 days (sulfate amended) to more than 100 days (methanogenic) were observed prior to activity. Time-series DNA-stable isotope probing (SIP) was used to identify bacteria that incorporated (13)C-labeled aniline in the microcosms established to promote methanogenic conditions. In microcosms from heavily contaminated aquifer sediments, a phylotype with 92.7% sequence similarity to Ignavibacterium album was identified as a dominant aniline degrader as indicated by incorporation of (13)C-aniline into its DNA. In microcosms from contaminated canal sediments, a bacterial phylotype within the family Anaerolineaceae, but without a match to any known genus, demonstrated the assimilation of (13)C-aniline. Acidovorax spp. were also identified as putative aniline degraders in both of these two treatments, indicating that these species were present and active in both the canal and aquifer sediments. There were multiple bacterial phylotypes associated with anaerobic degradation of aniline at this complex industrial site, which suggests that anaerobic transformation of aniline is an important process at the site. Furthermore, the aniline degrading phylotypes identified in the current study are not related to any known aniline-degrading bacteria. The identification of novel putative aniline degraders expands current knowledge regarding the potential fate of aniline under anaerobic conditions.
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Affiliation(s)
- Weimin Sun
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Yun Li
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | | | - Shuai Luo
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | | | - E Erin Mack
- DuPont, Corporate Remediation Group, Wilmington, Delaware 19714, United States
| | | | - Donna E Fennell
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
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Identification of benzo[a]pyrene-metabolizing bacteria in forest soils by using DNA-based stable-isotope probing. Appl Environ Microbiol 2015; 81:7368-76. [PMID: 26253666 DOI: 10.1128/aem.01983-15] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/02/2015] [Indexed: 01/21/2023] Open
Abstract
DNA-based stable-isotope probing (DNA-SIP) was used in this study to investigate the uncultivated bacteria with benzo[a]pyrene (BaP) metabolism capacities in two Chinese forest soils (Mt. Maoer in Heilongjiang Province and Mt. Baicaowa in Hubei Province). We characterized three different phylotypes with responsibility for BaP degradation, none of which were previously reported as BaP-degrading microorganisms by SIP. In Mt. Maoer soil microcosms, the putative BaP degraders were classified as belonging to the genus Terrimonas (family Chitinophagaceae, order Sphingobacteriales), whereas Burkholderia spp. were the key BaP degraders in Mt. Baicaowa soils. The addition of metabolic salicylate significantly increased BaP degradation efficiency in Mt. Maoer soils, and the BaP-metabolizing bacteria shifted to the microorganisms in the family Oxalobacteraceae (genus unclassified). Meanwhile, salicylate addition did not change either BaP degradation or putative BaP degraders in Mt. Baicaowa. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHD) genes were amplified, sequenced, and quantified in the DNA-SIP (13)C heavy fraction to further confirm the BaP metabolism. By illuminating the microbial diversity and salicylate additive effects on BaP degradation across different soils, the results increased our understanding of BaP natural attenuation and provided a possible approach to enhance the bioremediation of BaP-contaminated soils.
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Jiang L, Song M, Luo C, Zhang D, Zhang G. Novel Phenanthrene-Degrading Bacteria Identified by DNA-Stable Isotope Probing. PLoS One 2015; 10:e0130846. [PMID: 26098417 PMCID: PMC4476716 DOI: 10.1371/journal.pone.0130846] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 01/20/2023] Open
Abstract
Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP). The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP) results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ.
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Affiliation(s)
- Longfei Jiang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Mengke Song
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
- Graduate University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Chunling Luo
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
- * E-mail:
| | - Dayi Zhang
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
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Jones MD, Rodgers-Vieira EA, Hu J, Aitken MD. Association of Growth Substrates and Bacterial Genera with Benzo[ a]pyrene Mineralization in Contaminated Soil. ENVIRONMENTAL ENGINEERING SCIENCE 2014; 31:689-697. [PMID: 25469077 PMCID: PMC4245834 DOI: 10.1089/ees.2014.0275] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 07/27/2014] [Indexed: 05/24/2023]
Abstract
Benzo[a]pyrene (BaP) is a carcinogenic polycyclic aromatic hydrocarbon (PAH) that is not known to be a bacterial growth substrate. Organisms capable of cometabolizing BaP in complex field-contaminated systems have not previously been identified. We evaluated BaP mineralization by a bacterial community from a bioreactor treating PAH-contaminated soil during coincubation with or after pre-enrichment on various PAHs as growth substrates. Pyrosequence libraries of 16S rRNA genes were used to identify bacteria that were enriched on the added growth substrate as a means of associating specific organisms with BaP mineralization. Coincubating the bioreactor-treated soil with naphthalene, phenanthrene, or pyrene inhibited BaP mineralization, whereas pre-enriching the soil on the same three PAHs enhanced BaP mineralization. Combined, these results suggest that bacteria in the bioreactor community that are capable of growing on naphthalene, phenanthrene, and/or pyrene can metabolize BaP, with coincubation competitively inhibiting BaP metabolism. Anthracene, fluoranthene, and benz[a]anthracene had little effect on BaP mineralization compared to incubations without an added growth substrate under either coincubation or pre-enrichment conditions. Substantial increases in relative abundance after pre-enrichment with phenanthrene, naphthalene, or pyrene, but not the other PAHs, suggest that members of the genera Cupriavidus and Luteimonas may have been associated with BaP mineralization.
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Affiliation(s)
- Maiysha D. Jones
- Present Address: The Procter & Gamble Company, Mason Business Center, 8700 S. Mason Montgomery Road, Mason, OH 45040. Phone:+1-513-622-5592; E-mail:
| | | | - Jing Hu
- Present Address: The Dow Chemical Company, 1803 Building, Midland, MI 48674. Phone:+1-989-638-4847; E-mail:
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Bučková M, Puškarová A, Chovanová K, Kraková L, Ferianc P, Pangallo D. A simple strategy for investigating the diversity and hydrocarbon degradation abilities of cultivable bacteria from contaminated soil. World J Microbiol Biotechnol 2013; 29:1085-98. [DOI: 10.1007/s11274-013-1277-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 01/30/2013] [Indexed: 10/27/2022]
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Metaproteogenomic insights beyond bacterial response to naphthalene exposure and bio-stimulation. ISME JOURNAL 2012; 7:122-36. [PMID: 22832345 PMCID: PMC3526184 DOI: 10.1038/ismej.2012.82] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Microbial metabolism in aromatic-contaminated environments has important ecological implications, and obtaining a complete understanding of this process remains a relevant goal. To understand the roles of biodiversity and aromatic-mediated genetic and metabolic rearrangements, we conducted ‘OMIC' investigations in an anthropogenically influenced and polyaromatic hydrocarbon (PAH)-contaminated soil with (Nbs) or without (N) bio-stimulation with calcium ammonia nitrate, NH4NO3 and KH2PO4 and the commercial surfactant Iveysol, plus two naphthalene-enriched communities derived from both soils (CN2 and CN1, respectively). Using a metagenomic approach, a total of 52, 53, 14 and 12 distinct species (according to operational phylogenetic units (OPU) in our work equivalent to taxonomic species) were identified in the N, Nbs, CN1 and CN2 communities, respectively. Approximately 10 out of 95 distinct species and 238 out of 3293 clusters of orthologous groups (COGs) protein families identified were clearly stimulated under the assayed conditions, whereas only two species and 1465 COGs conformed to the common set in all of the mesocosms. Results indicated distinct biodegradation capabilities for the utilisation of potential growth-supporting aromatics, which results in bio-stimulated communities being extremely fit to naphthalene utilisation and non-stimulated communities exhibiting a greater metabolic window than previously predicted. On the basis of comparing protein expression profiles and metagenome data sets, inter-alia interactions among members were hypothesised. The utilisation of curated databases is discussed and used for first time to reconstruct ‘presumptive' degradation networks for complex microbial communities.
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Baskar S, Baskar R, Thorseth IH, Ovreås L, Pedersen RB. Microbially induced iron precipitation associated with a neutrophilic spring at Borra Caves, Vishakhapatnam, India. ASTROBIOLOGY 2012; 12:327-346. [PMID: 22519973 DOI: 10.1089/ast.2011.0672] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The present investigation uncovers various pieces of evidence for the possible biologically induced mineralization in iron mats associated with a pH-neutral spring in the Borra caves, Vishakhapatnam, India. Electron microscopy [scanning electron microscopy (SEM) and transmission electron microscopy (TEM)] demonstrated large numbers of (i) hollow tubes (diameter ∼1 μm) resembling sheaths of the iron-oxidizing bacteria Leptothrix, (ii) thin (diameter <<1 μm) solid fibers of uncertain origin, (iii) nanoscale subspherical to irregularly shaped particles encrusting tubes and fibers, and (iv) aggregates of broken and partially disintegrated sheaths, fibers, and particles embedded in extracellular polymeric substances (EPS) occasionally including microbial cells. X-ray microanalyses by energy dispersive spectroscopy (EDS) revealed that the mat accumulated largely Fe but also smaller amounts of Si and traces of P and Ca. Particles rich in Si and Al (possibly kaolinite) and Ca (carbonate) were also observed. High-resolution TEM/EDS of unstained ultrathin sections suggests that microbial sheaths were highly mineralized by amorphous to cryptocrystalline Fe-rich phases and less frequently by other fine-grained and fibrous authigenic claylike minerals. Total number of microorganisms in the iron mats was 5.8×10(5) cells, g sed(-1) (wet weight). Analysis of the 16S rRNA gene diversity revealed microorganisms assigned to eight different phyla [Proteobacteria (62%), Chloroflexi (8%), Bacteroidetes (7%), Planctomycetes (1%), Actinobacteria (5%), Acidobacteria (6%), Nitrospira (1%), Firmicutes (5%)]. Within the Proteobacteria, Betaproteobacteria was the predominant class, which accounted for 28% of the sequences. Within this class some obvious similarities between the obtained sequences and sequences from other cave systems could be seen, especially sequences affiliated with Leptothrix, Siderooxidans, Crenothrix, Comamonadaceae, Dechloromonas, and many uncultured Betaproteobacteria. Four (4%) of the sequences could not be assigned to phylum level but were affiliating with the candidate division TM7 (2%), candidate division OP11 (1%), and candidate division WWE3 (1%). The results allow us to infer a possible relationship of microbial sheaths, EPS, and the iron precipitates to microbial community diversity in the Borra cave springs. Understanding biogenic iron oxides in caves has important astrobiological applications as it provides a potential tool for the detection of extraterrestrial life.
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Owabor CN, Ogbeide SE, Susu AA. Growth kinetics of some subsurface microbial strains using naphthalene as a probe contaminant. ENVIRONMENTAL TECHNOLOGY 2011; 32:1453-1462. [PMID: 22329135 DOI: 10.1080/09593330.2010.538933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The focus of this study is the unravelling of the microbial dynamics of the biodegradation of naphthalene, a polycyclic aromatic hydrocarbon, in an aqueous-sediment matrix. The Pour plate procedure was adopted for the isolation of the microbial colonies, while the sub-culturing of the isolates was based on their cultural (biochemical) and morphological characteristics. Investigations showed that the microbial colonies consisted of the bacterial and fungal strains. The logarithmic growth curve was characterized by an initial lag phase, a rapid and exponential increase in cell biomass, a stationary phase and finally a death phase. Both strains in the presence of naphthalene-impacted basal salt medium demonstrated that the microbial growth results in an almost linear increase in biomass concentration--an indication that mass transfer from the solid phase to the liquid phase (lag phase) is limiting for growth. The kinetics of the utilization of naphthalene expressed as the growth and consumption rates indicated that all the microbial strains isolated from an indigenous soil used in this study exhibited a high metabolic affinity for naphthalene. Optimal performance was demonstrated by the bacterial strains that could use naphthalene as their sole carbon and energy source.
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Affiliation(s)
- C N Owabor
- Department of Chemical Engineering, University of Benin, P.M.B. 1154 Benin City, Nigeria.
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Zhu H, Singleton D, Aitken MD. Effects of nonionic surfactant addition on populations of polycyclic aromatic hydrocarbon-degrading bacteria in a bioreactor treating contaminated soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:7266-71. [PMID: 20707373 PMCID: PMC2947603 DOI: 10.1021/es100114g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We studied the effects of two polyethoxylated nonionic surfactants, Brij 30 and C(12)E(8), on populations of polycyclic aromatic hydrocarbon- (PAH-) degrading bacteria from a bioreactor treating PAH-contaminated soil. Each surfactant was evaluated at doses that corresponded to aqueous-phase concentrations both above and below the critical micelle concentration (CMC) after mixing with reactor slurry. Real-time quantitative PCR was used to quantify 16S rRNA (rRNA) gene sequences representing degraders of salicylate, naphthalene, phenanthrene, or pyrene previously identified in the bioreactor community by stable-isotope probing. Sequences representing two groups of organisms associated with degradation of naphthalene and/or salicylate in the bioreactor increased in abundance by more than an order of magnitude after incubation with either surfactant at each dose tested. In contrast, the abundance of a group of uncultivated pyrene-degrading bacteria, whose relative abundance in the soil without surfactant addition was up to 9% of the total 16S rRNA genes, decreased by an order of magnitude or more in the presence of each surfactant at each dose. These results indicate that surfactant addition can have substantial, differential effects on populations of organisms responsible for contaminant degradation within a microbial community.
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Xie S, Sun W, Luo C, Cupples AM. Novel aerobic benzene degrading microorganisms identified in three soils by stable isotope probing. Biodegradation 2010; 22:71-81. [PMID: 20549308 DOI: 10.1007/s10532-010-9377-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 05/28/2010] [Indexed: 11/26/2022]
Abstract
The remediation of benzene contaminated groundwater often involves biodegradation and although the mechanisms of aerobic benzene biodegradation in laboratory cultures have been well studied, less is known about the microorganisms responsible for benzene degradation in mixed culture samples or at contaminated sites. To address this knowledge gap, DNA based stable isotope probing (SIP) was utilized to identify active benzene degraders in microcosms constructed with soil from three sources (a contaminated site and two agricultural sites). For this, replicate microcosms were amended with either labeled (¹³C) or unlabeled benzene and the extracted DNA samples were ultracentrifuged, fractioned and subject to terminal restriction fragment length polymorphism (TRFLP). The dominant benzene degraders (responsible for ¹³C uptake) were determined by comparing relative abundance of TRFLP phylotypes in heavy fractions of labeled benzene (¹³C) amended samples to the controls (from unlabeled benzene amended samples). Two phylotypes (a Polaromonas sp. and an Acidobacterium) were the major benzene degraders in the microcosms constructed from the contaminated site soil, whereas one phylotype incorporated the majority of the benzene-derived ¹³C in each of the agricultural soils ("candidate" phylum TM7 and an unclassified Sphingomonadaceae).
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The role of salicylate and biosurfactant in inducing phenanthrene degradation in batch soil slurries. Appl Microbiol Biotechnol 2010; 86:1563-71. [DOI: 10.1007/s00253-010-2453-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 01/14/2010] [Accepted: 01/16/2010] [Indexed: 10/19/2022]
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Montgomery MT, Boyd TJ, Osburn CL, Smith DC. PAH mineralization and bacterial organotolerance in surface sediments of the Charleston Harbor estuary. Biodegradation 2009; 21:257-66. [PMID: 19760111 PMCID: PMC2829130 DOI: 10.1007/s10532-009-9298-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 09/01/2009] [Indexed: 11/16/2022]
Abstract
Semi-volatile organic compounds (SVOCs) in estuarine waters can adversely affect biota but watershed sources can be difficult to identify because these compounds are transient. Natural bacterial assemblages may respond to chronic, episodic exposure to SVOCs through selection of more organotolerant bacterial communities. We measured bacterial production, organotolerance and polycyclic aromatic hydrocarbon (PAH) mineralization in Charleston Harbor and compared surface sediment from stations near a known, permitted SVOC outfall (pulp mill effluent) to that from more pristine stations. Naphthalene additions inhibited an average of 77% of bacterial metabolism in sediments from the more pristine site (Wando River). Production in sediments nearest the outfall was only inhibited an average of 9% and in some cases, was actually stimulated. In general, the stations with the highest rates of bacterial production also were among those with the highest rates of PAH mineralization. This suggests that the capacity to mineralize PAH carbon is a common feature amongst the bacterial assemblage in these estuarine sediments and could account for an average of 5.6% of bacterial carbon demand (in terms of production) in the summer, 3.3% in the spring (April) and only 1.2% in winter (December).
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