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Olivera C, Laura Tondo M, Girardi V, Sol Herrero M, Lucía Balaban C, Matías Salvatierra L. High-performance diesel biodegradation using biogas digestate as microbial inoculum in lab-scale solid supported bioreactors. CHEMOSPHERE 2024; 352:141384. [PMID: 38350516 DOI: 10.1016/j.chemosphere.2024.141384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 02/15/2024]
Abstract
Industrial anaerobic digestion (AD) produces biogas and a digestate that is usually applied as a biofertilizer. However, the study and application of this by-product in terms of its rich microbial diversity and high metabolic activity have been barely investigated. In this work, the digestate regarded as an inoculum-without any further manipulation-was faced to a target hydrocarbon (i.e., diesel oil) to explore its biodegradation capability and potential application in bioaugmentation strategies. Lab-scale single batch bioreactors with solid support (i.e., sand or gravel) embedded with the inoculum and diesel were used to improve bioaccessibility and biofilm formation. In addition, different experimental conditions were assayed varying the initial diesel concentration, microbial load, type of solid support, inoculum aging time, and presence or absence of oxygen. Remaining diesel concentration, dehydrogenase activity and microbial community structure were periodically determined. Remarkably, this low-cost consortium was capable of a significant reduction (>90%) in the concentration of diesel, within 14 days and when the initial load was as high as 6950 mg/kg dry solid support. Furthermore, a 10-fold increment in dehydrogenase activity, alongside an increase in the abundance of hydrocarbon-degrading bacterial groups, and the enrichment of genes for alkane monooxygenase and aromatic ring-hydroxylating dioxygenases, encourage further study of this consortium for bioremediation purposes.
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Affiliation(s)
- Camila Olivera
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada - INGEBIO-, Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA), Av. Pellegrini 3314, (S2002QEO), Rosario, (Santa Fe), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - María Laura Tondo
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada - INGEBIO-, Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA), Av. Pellegrini 3314, (S2002QEO), Rosario, (Santa Fe), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Valentina Girardi
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada - INGEBIO-, Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA), Av. Pellegrini 3314, (S2002QEO), Rosario, (Santa Fe), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - María Sol Herrero
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada - INGEBIO-, Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA), Av. Pellegrini 3314, (S2002QEO), Rosario, (Santa Fe), Argentina
| | - Cecilia Lucía Balaban
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada - INGEBIO-, Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA), Av. Pellegrini 3314, (S2002QEO), Rosario, (Santa Fe), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Lucas Matías Salvatierra
- Instituto de Investigaciones en Ingeniería Ambiental, Química y Biotecnología Aplicada - INGEBIO-, Facultad de Química e Ingeniería del Rosario, Pontificia Universidad Católica Argentina (UCA), Av. Pellegrini 3314, (S2002QEO), Rosario, (Santa Fe), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Chi Z, Liu X, Li H, Liang S, Luo YH, Zhou C, Rittmann BE. Co-metabolic biodegradation of chlorinated ethene in an oxygen- and ethane-based membrane biofilm reactor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167323. [PMID: 37742949 DOI: 10.1016/j.scitotenv.2023.167323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/15/2023] [Accepted: 09/22/2023] [Indexed: 09/26/2023]
Abstract
Groundwater contamination by chlorinated ethenes is an urgent concern worldwide. One approach for detoxifying chlorinated ethenes is aerobic co-metabilims using ethane (C2H6) as the primary substrate. This study evaluated long-term continuous biodegradation of three chlorinated alkenes in a membrane biofilm reactor (MBfR) that delivered C2H6 and O2 via gas-transfer membranes. During 133 days of continuous operation, removals of dichloroethane (DCE), trichloroethene (TCE), and tetrachloroethene (PCE) were as high as 94 % and with effluent concentrations below 5 μM. In situ batch tests showed that the co-metabolic kinetics were faster with more chlorination. C2H6-oxidizing Comamonadaceae and "others," such as Methylococcaceae, oxidized C2H6 via monooxyenation reactions. The abundant non-ethane monooxygenases, particularly propane monooxygenase, appears to have been responsible for C2H6 aerobic metabolism and co-metabolism of chlorinated ethenes. This work proves that the C2H6 + O2 MBfR is a platform for ex-situ bioremediation of chlorinated ethenes, and the generalized action of the monooxygenases may make it applicable for other chlorinated organic contaminants.
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Affiliation(s)
- Zifang Chi
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China
| | - Xinyang Liu
- Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China
| | - Huai Li
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China.
| | - Shen Liang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China
| | - Yi-Hao Luo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA; Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun 130117, PR China.
| | - Chen Zhou
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA
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Obayori OS, Adesina OD, Salam LB, Ashade AO, Nwaokorie FO. Depletion of hydrocarbons and concomitant shift in bacterial community structure of a diesel-spiked tropical agricultural soil. ENVIRONMENTAL TECHNOLOGY 2023:1-16. [PMID: 38118139 DOI: 10.1080/09593330.2023.2291421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/26/2023] [Indexed: 12/22/2023]
Abstract
Bacterial community of a diesel-spiked agricultural soil was monitored over a 42-day period using the metagenomic approach in order to gain insight into key phylotypes impacted by diesel contamination and be able to predict end point of bioattenuation. Soil physico-chemical parameters showed significant differences (P < 0.05) between the Polluted Soil (PS) and the Unpolluted control (US)across time points. After 21 days, the diesel content decreased by 27.39%, and at the end of 42 days, by 57.11%. Aromatics such as benzene, anthanthrene, propylbenzene, phenanthrenequinone, anthraquinone, and phenanthridine were degraded to non-detected levels within 42 days, while some medium range alkanes and polyaromatics such as acenaphthylene, naphthalene, and anthracene showed significant levels of degradation. After 21 days (LASTD21), there was a massive enrichment of the phylum Proteobacteria (72.94%), a slight decrease in the abundance of phylum Actinobacteriota (12.74%), and > 500% decrease in the abundance of the phylum Acidobacteriodota (5.26%). Day 42 (LASTD42) saw establishment of the dominance of the Proteobacteria (34.95%), Actinobacteriota, (21.71%), and Firmicutes (32.14%), and decimation of phyla such as Gemmatimonadota, Planctomycetota, and Verrucromicrobiota which play important roles in the cycling of elements and soil health. Principal component analysis showed that in PS moisture contents, phosphorus, nitrogen, organic carbon, had greater impacts on the community structure in LASTD21, while acidity, potassium, sodium, calcium and magnesium impacted the control sample. Recovery time of the soil based on the residual hydrocarbons at Day 42 was estimated to be 229.112 d. Thus, additional biostimulation may be required to achieve cleanup within one growing season.
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Affiliation(s)
| | | | - Lateef Babatunde Salam
- Microbiology Unit, Department of Biological Sciences, Elizade University, Ilara-Mokin, Nigeria
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Abe M, Kanaly RA, Mori JF. Genomic analysis of a marine alphaproteobacterium Sagittula sp. strain MA-2 that carried eight plasmids. Mar Genomics 2023; 72:101070. [PMID: 38008530 DOI: 10.1016/j.margen.2023.101070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/21/2023] [Accepted: 09/21/2023] [Indexed: 11/28/2023]
Abstract
Bacteria that belong to the family Roseobacteraceae in the Alphaproteobacteria class are widely distributed in marine environments with remarkable physiological diversity, which is considered to be attributed to their genomic plasticity. In this study, a novel isolate of the genus Sagittula within Roseobacteraceae, strain MA-2, was obtained from a coastal marine bacterial consortium enriched with aromatic hydrocarbons, and its complete genome was sequenced. The genome with a total size of 5.69 Mbp was revealed to consist of a 4.67-Mbp circular chromosome and eight circular plasmids ranging in size from 19.5 to 361.5 kbp. Further analyses of functional genes in the strain MA-2 genome identified homologous genes responsible for the biotransformation of gentisic acid, which were located on one of its plasmids and were not found in genomes of other Sagittula strains available from databases. This suggested that strain MA-2 had acquired these genes via horizontal gene transfers that enabled them to degrade and utilize gentisic acid as a growth substrate. This study provided the second complete genome sequence of the genus Sagittula and supports the hypothesis that acquisition of ecologically relevant genes in extrachromosomal replicons allows Roseobacteraceae to be highly adaptable to diverse lifestyles.
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Affiliation(s)
- Mayuko Abe
- Graduate School of Nanobiosciences, Yokohama City University, Japan
| | - Robert A Kanaly
- Graduate School of Nanobiosciences, Yokohama City University, Japan
| | - Jiro F Mori
- Graduate School of Nanobiosciences, Yokohama City University, Japan.
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Zhu H, Fu Y, Yu J, Jing W, Zhou M. Metagenomic insight on consortium degradation of soil weathered petroleum and its supplement based on gene abundance change. Enzyme Microb Technol 2023; 169:110285. [PMID: 37413912 DOI: 10.1016/j.enzmictec.2023.110285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/24/2023] [Accepted: 06/29/2023] [Indexed: 07/08/2023]
Abstract
Petroleum biodegradation is of importance for the mitigation of secondary pollutants from soil chemical remediation. Describing the gene abundance change of the petroleum degradation emerged as an important practice for success. In this study, an indigenous consortium with targeting-enzyme was utilized to develop a degradative system that was later subjected to metagenomic analysis on the soil microbial community. Centering on ko00625 pathway, abundance change of dehydrogenase gene was firstly found increasing from groups D, DS to DC in turn, just in an opposite direction with that of oxygenase. In addition, gene abundance of responsive mechanism went rising with degradative process as well. This finding sufficiently promoted that equal attention should be paid to both degradative and responsive processes. Hydrogen donor system was innovatively built on the consortium-used soil to satisfy the demand of dehydrogenase gene tendency and to sustain further petroleum degradation. Anaerobic pine-needle soil was supplemented to this system, bi-functionally serving as dehydrogenase substrate with nutrients and hydrogen donor. In doing so, two successive degradations optimally achieved the total removal rate 75.6-78.7% for petroleum hydrocarbon. The conception on the gene abundance changes and its corresponding supplement helps industries of concern to develop geno-tag guided framework.
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Affiliation(s)
- Hongfei Zhu
- College of Environmental Science and Engineering of Liaoning Technical University, No. 47 Zhonghua Road, Fuxin, Liaoning 123000, China.
| | - Yuting Fu
- College of Environmental Science and Engineering of Liaoning Technical University, No. 47 Zhonghua Road, Fuxin, Liaoning 123000, China
| | - Jiashuai Yu
- College of Environmental Science and Engineering of Liaoning Technical University, No. 47 Zhonghua Road, Fuxin, Liaoning 123000, China
| | - Wenjie Jing
- College of Environmental Science and Engineering of Liaoning Technical University, No. 47 Zhonghua Road, Fuxin, Liaoning 123000, China
| | - Mengting Zhou
- College of Environmental Science and Engineering of Liaoning Technical University, No. 47 Zhonghua Road, Fuxin, Liaoning 123000, China
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Nemoto Y, Ozawa K, Mori JF, Kanaly RA. Nondesulfurizing benzothiophene biotransformation to hetero and homodimeric ortho-substituted diaryl disulfides by the model PAH-degrading Sphingobium barthaii. Biodegradation 2023; 34:215-233. [PMID: 36808269 DOI: 10.1007/s10532-023-10014-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/06/2023] [Indexed: 02/21/2023]
Abstract
Understanding the biotransformation mechanisms of toxic sulfur-containing polycyclic aromatic hydrocarbon (PASH) pollutants such as benzothiophene (BT) is useful for predicting their environmental fates. In the natural environment, nondesulfurizing hydrocarbon-degrading bacteria are major active contributors to PASH biodegradation at petroleum-contaminated sites; however, BT biotransformation pathways by this group of bacteria are less explored when compared to desulfurizing organisms. When a model nondesulfurizing polycyclic aromatic hydrocarbon-degrading soil bacterium, Sphingobium barthaii KK22, was investigated for its ability to cometabolically biotransform BT by quantitative and qualitative methods, BT was depleted from culture media but was biotransformed into mostly high molar mass (HMM) hetero and homodimeric ortho-substituted diaryl disulfides (diaryl disulfanes). HMM diaryl disulfides have not been reported as biotransformation products of BT. Chemical structures were proposed for the diaryl disulfides by comprehensive mass spectrometry analyses of the chromatographically separated products and were supported by the identification of transient upstream BT biotransformation products, which included benzenethiols. Thiophenic acid products were also identified, and pathways that described BT biotransformation and novel HMM diaryl disulfide formation were constructed. This work shows that nondesulfurizing hydrocarbon-degrading organisms produce HMM diaryl disulfides from low molar mass polyaromatic sulfur heterocycles, and this may be taken into consideration when predicting the environmental fates of BT pollutants.
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Affiliation(s)
- Yuki Nemoto
- Department of Life and Environmental System Science, Graduate School of Nanobiosciences, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama, Kanagawa, 236-0027, Japan
| | - Kohei Ozawa
- Department of Life and Environmental System Science, Graduate School of Nanobiosciences, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama, Kanagawa, 236-0027, Japan
| | - Jiro F Mori
- Department of Life and Environmental System Science, Graduate School of Nanobiosciences, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama, Kanagawa, 236-0027, Japan
| | - Robert A Kanaly
- Department of Life and Environmental System Science, Graduate School of Nanobiosciences, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama, Kanagawa, 236-0027, Japan.
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Luo J, Li Y, Cao H, Zhu Y, Liu X, Li H, Liao X. Variations of microbiota in three types of typical military contaminated sites: Diversities, structures, influence factors, and co-occurrence patterns. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130290. [PMID: 36335906 DOI: 10.1016/j.jhazmat.2022.130290] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/15/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Contamination with energetic compounds (ECs) is common in military sites and poses a great risk to the environment and human health. However, its effects on the soil bacterial communities remain unclear. This study assessed the variations of bacterial communities, co-occurrence patterns, and their influence factors in three types of typical military-contaminated sites (artillery range, military-industrial site, and ammunition destruction site). The results showed that the most polluted sites were ammunition destruction sites, followed by military-industrial sites, whereas pollution in the artillery ranges was minimal. The average concentrations of ECs including 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in the study sites ranged 120-1.67 × 105, 20-7.20 × 104, and 180-2.38 × 105 μg/kg, respectively. Bacterial diversity and community structure in military-industrial and ammunition destruction sites were significantly changed, but not in artillery ranges. TNT, pH, and soil moisture are the critical factors affecting bacterial communities in contaminated military sites. Co-occurrence network analysis indicated that the pressure of ECs affected bacterial interactions and microbiota function. Our findings provide new insights into the variations in bacterial communities in EC-contaminated military sites and references for the bioremediation of ECs.
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Affiliation(s)
- Junpeng Luo
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - You Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China.
| | - Hongying Cao
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China
| | - Yongbing Zhu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
| | - Xiaodong Liu
- Anhui Province Key Laboratory of Polar Environment and Global Change, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Haonan Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyong Liao
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing 100101, China.
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In situ bioremediation of petroleum hydrocarbon–contaminated soil: isolation and application of a Rhodococcus strain. Int Microbiol 2022; 26:411-421. [PMID: 36484911 DOI: 10.1007/s10123-022-00305-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/04/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022]
Abstract
Due to low consumption and high efficiency, in situ microbial remediation of petroleum hydrocarbons (PHs)-contaminated sites in in-service petrochemical enterprises has attracted more and more attention. In this study, a degrading strain was isolated from oil depot-contaminated soil with soil extract (PHs) as the sole carbon source, identified and named Rhodococcus sp. OBD-3. Strain OBD-3 exhibited wide adaptability and degradability over a wide range of temperatures (15-37 °C), pH (6.0-9.0), and salinities (1-7% NaCl) to degrade 60.6-86.6% of PHs. Under extreme conditions (15 °C and 3-7% salinity), PHs were degraded by 60.6 ± 8.2% and more than 82.1% respectively. In OBD-3, the alkane monooxygenase genes alkB1 and alkB2 (GenBank accession numbers: MZ688386 and MZ688387) were found, which belonged to Rhodococcus by sequence alignment. Moreover, strain OBD-3 was used in lab scale remediation in which the contaminated soil with OBD-3 was isolated as the remediation object. The PHs were removed at 2,809 ± 597 mg/kg within 2 months, and the relative abundances of Sphingobium and Pseudomonas in soil increased more than fivefold. This study not only established a system for the isolation and identification of indigenous degrading strains that could efficiently degrade pollutants in the isolated environment but also enabled the isolated degrading strains to have potential application prospects in the in situ bioremediation of PHs-contaminated soils.
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Duque E, Udaondo Z, Molina L, de la Torre J, Godoy P, Ramos JL. Providing octane degradation capability to Pseudomonas putida KT2440 through the horizontal acquisition of oct genes located on an integrative and conjugative element. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:934-946. [PMID: 35651318 PMCID: PMC9795978 DOI: 10.1111/1758-2229.13097] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/09/2022] [Accepted: 05/16/2022] [Indexed: 05/17/2023]
Abstract
The extensive use of petrochemicals has produced serious environmental pollution problems; fortunately, bioremediation is considered an efficient way to fight against pollution. In line with Synthetic Biology is that robust microbial chassis with an expanded ability to remove environmental pollutants are desirable. Pseudomonas putida KT2440 is a robust lab microbe that has preserved the ability to survive in the environment and is the natural host for the self-transmissible TOL plasmid, which allows metabolism of toluene and xylenes to central metabolism. We show that the P. putida KT2440 (pWW0) acquired the ability to use octane as the sole C-source after acquisition of an almost 62-kb ICE from a microbial community that harbours an incomplete set of octane metabolism genes. The ICE bears genes for an alkane monooxygenase, a PQQ-dependent alcohol dehydrogenase and aldehyde dehydrogenase but lacks the electron donor enzymes required for the monooxygenase to operate. Host rubredoxin and rubredoxin reductase allow metabolism of octane to octanol. Proteomic assays and mutants unable to grow on octane or octanoic acid revealed that metabolism of octane is mediated by redundant host and ICE enzymes. Octane is oxidized to octanol, octanal and octanoic acid, the latter is subsequently acylated and oxidized to yield acetyl-CoA that is assimilated via the glyoxylate shunt; in fact, a knockout mutant in the aceA gene, encoding isocitrate lyase was unable to grow on octane or octanoic acid.
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Affiliation(s)
- Estrella Duque
- Department of Environmental ProtectionEstación Experimental del Zaidín, CSICGranadaSpain
| | - Zulema Udaondo
- Department of Biomedical InformaticsUniversity of Arkansas for Medical ScienceLittle RockArkansasUSA
| | - Lázaro Molina
- Department of Environmental ProtectionEstación Experimental del Zaidín, CSICGranadaSpain
| | - Jesús de la Torre
- Department of Environmental ProtectionEstación Experimental del Zaidín, CSICGranadaSpain
| | - Patricia Godoy
- Department of Environmental ProtectionEstación Experimental del Zaidín, CSICGranadaSpain
| | - Juan L. Ramos
- Department of Environmental ProtectionEstación Experimental del Zaidín, CSICGranadaSpain
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Comprehensive Genomic Characterization of Marine Bacteria Thalassospira spp. Provides Insights into Their Ecological Roles in Aromatic Hydrocarbon-Exposed Environments. Microbiol Spectr 2022; 10:e0314922. [PMID: 36190412 PMCID: PMC9604089 DOI: 10.1128/spectrum.03149-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The marine bacterial genus Thalassospira has often been identified as an abundant member of polycyclic aromatic hydrocarbon (PAH)-exposed microbial communities. However, despite their potential usability for biotechnological applications, functional genes that are conserved in their genomes have barely been investigated. Thus, the goal of this study was to comprehensively examine the functional genes that were potentially responsible for aromatic hydrocarbon biodegradation in the Thalassospira genomes available from databases, including a new isolate of Thalassospira, strain GO-4, isolated from a phenanthrene-enriched marine bacterial consortium. Strain GO-4 was used in this study as a model organism to link the genomic data and their metabolic functions. Strain GO-4 growth assays confirmed that it utilized a common phenanthrene biodegradation intermediate 2-carboxybenzaldehyde (CBA) as the sole source of carbon and energy, but did not utilize phenanthrene. Consistently, strain GO-4 was found to possess homologous genes of phdK, pht, and pca that encode enzymes for biodegradation of CBA, phthalic acid, and protocatechuic acid, respectively. Further comprehensive genomic analyses for 33 Thalassospira genomes from databases showed that a gene cluster that consisted of phdK and pht homologs was conserved in 13 of the 33 strains. pca gene homologs were found in all examined genomes; however, homologs of the known PAH-degrading genes, such as the pah, phn, or nah genes, were not found. Possibly Thalassospira spp. co-occupy niches with other PAH-degrading bacteria that provide them with PAH degradation intermediates and facilitated their inhabitation in PAH-exposed microbial ecosystems. IMPORTANCE Comprehensive investigation of multiple genomic data sets from targeted microbial taxa deposited in databases may provide substantial information to predict metabolic capabilities and ecological roles in different environments. This study is the first report that details the functional profiling of Thalassospira spp. that have repeatedly been found in polycyclic aromatic hydrocarbon (PAH)-exposed marine bacterial communities by using genomic data from a new isolate, Thalassospira strain GO-4, and other strains in databases. Through screening of functional genes potentially involved in aromatic hydrocarbon biodegradation across 33 Thalassospira genomes and growth assays for strain GO-4, it was suggested that Thalassospira spp. unexceptionally conserved the ability to metabolize single-ring, PAH biodegradation intermediates, while being incapable of utilizing PAHs. This expanded our understanding of this potentially important contributing member to PAH-degrading microbial ecosystems; such species are considered to be specialized in driving downstream reactions of PAH biodegradation.
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11
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Nnabuife OO, Ogbonna JC, Anyanwu C, Ike AC, Eze CN, Enemuor SC. Mixed bacterial consortium can hamper the efficient degradation of crude oil hydrocarbons. Arch Microbiol 2022; 204:306. [PMID: 35532873 DOI: 10.1007/s00203-022-02915-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 04/07/2022] [Accepted: 04/10/2022] [Indexed: 11/24/2022]
Abstract
Crude oil degradation efficiency can be improved because of co-metabolism that exists when bacterial consortium is applied. However, because of possible vulnerability to environmental conditions and/or antagonistic interactions among members of the consortium, the degradation efficiency can be hampered. In this laboratory-based study, the biodegradation potentials of pure bacterial isolates namely Pseudomonas aeruginosa strain W15 (MW320658), Providencia vermicola strain W8 (MW320661) and Serratia marcescens strain W13 (MW320662) earlier isolated from crude oil-contaminated site and their consortium were evaluated using 3% crude oil-supplemented Bushnell Haas media. The efficiency was evaluated based on the viable cell count, biosurfactant analyses, percentage hydrocarbon degradation using gravimetric analysis and gas chromatography-mass spectrophotometry (GC-MS) analysis. There was decline in the population of W13 and predominance of W15 in the consortium as the incubation period progressed. Accelerated biodegradation of the crude oil hydrocarbons through co-metabolism was not achieved with the consortium; neither was there any improved resilience nor resistance to environmental changes of strain W13. The GC-MS analyses showed that the highest degradation was produced by W15 (48.23%) compared to W8 (46.04%), W13 (45.24%) and the Consortium (28.51%). The biodegradation of the crude oil hydrocarbons by W15, W8, W13 axenic cultures and their consortium treatments demonstrated that the bacterial constituent in a consortium can influence the synergistic effect that improves bioremediation. Future research that focuses on evaluating possible improvement in bioremediation through maintenance of diversity by continuous bioaugmentation using vulnerable but efficient degraders in a consortium is necessary to further understand the application of consortia for bioremediation improvement.
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Affiliation(s)
- Obianuju Obiajulu Nnabuife
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria.
| | - James Chukwuma Ogbonna
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Chukwudi Anyanwu
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Anthony Chibuogwu Ike
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Chibuzor Nwadibe Eze
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Simeon Chukwuemeka Enemuor
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
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Mori JF, Kanaly RA. Natural Chromosome-Chromid Fusion across rRNA Operons in a Burkholderiaceae Bacterium. Microbiol Spectr 2022; 10:e0222521. [PMID: 34985328 PMCID: PMC8729776 DOI: 10.1128/spectrum.02225-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/07/2021] [Indexed: 12/31/2022] Open
Abstract
Chromids (secondary chromosomes) in bacterial genomes that are present in addition to the main chromosome appear to be evolutionarily conserved in some specific bacterial groups. In rare cases among these groups, a small number of strains from Rhizobiales and Vibrionales were shown to possess a naturally fused single chromosome that was reported to have been generated through intragenomic homologous recombination between repeated sequences on the chromosome and chromid. Similar examples have never been reported in the family Burkholderiaceae, a well-documented group that conserves chromids. Here, an in-depth genomic characterization was performed on a Burkholderiaceae bacterium that was isolated from a soil bacterial consortium maintained on diesel fuel and mutagenic benzo[a]pyrene. This organism, Cupriavidus necator strain KK10, was revealed to carry a single chromosome with unexpectedly large size (>6.6 Mb), and results of comparative genomics with the genome of C. necator N-1T indicated that the single chromosome of KK10 was generated through fusion of the prototypical chromosome and chromid at the rRNA operons. This fusion hypothetically occurred through homologous recombination with a crossover between repeated rRNA operons on the chromosome and chromid. Some metabolic functions that were likely expressed from genes on the prototypical chromid region were indicated to be retained. If this phenomenon-the bacterial chromosome-chromid fusion across the rRNA operons through homologous recombination-occurs universally in prokaryotes, the multiple rRNA operons in bacterial genomes may not only contribute to the robustness of ribosome function, but also provide more opportunities for genomic rearrangements through frequent recombination. IMPORTANCE A bacterial chromosome that was naturally fused with the secondary chromosome, or "chromid," and presented as an unexpectedly large single replicon was discovered in the genome of Cupriavidus necator strain KK10, a biotechnologically useful member of the family Burkholderiaceae. Although Burkholderiaceae is a well-documented group that conserves chromids in their genomes, this chromosomal fusion event has not been previously reported for this family. This fusion has hypothetically occurred through intragenomic homologous recombination between repeated rRNA operons and, if so, provides novel insight into the potential of multiple rRNA operons in bacterial genomes to lead to chromosome-chromid fusion. The harsh conditions under which strain KK10 was maintained-a genotoxic hydrocarbon-enriched milieu-may have provided this genotype with a niche in which to survive.
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Affiliation(s)
- Jiro F. Mori
- Graduate School of Nanobiosicences, Yokohama City University, Yokohama, Japan
| | - Robert A. Kanaly
- Graduate School of Nanobiosicences, Yokohama City University, Yokohama, Japan
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Microbial Consortia Are Needed to Degrade Soil Pollutants. Microorganisms 2022; 10:microorganisms10020261. [PMID: 35208716 PMCID: PMC8874626 DOI: 10.3390/microorganisms10020261] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/30/2021] [Accepted: 01/07/2022] [Indexed: 12/10/2022] Open
Abstract
Soil pollution is one of the most serious environmental problems globally due to the weak self-purification ability, long degradation time, and high cost of cleaning soil pollution. The pollutants in the soil can be transported into the human body through water or dust, causing adverse effects on human health. The latest research has shown that the clean-up of soil pollutants through microbial consortium is a very promising method. This review provides an in-depth discussion on the efficient removal, bio-adsorption, or carbonated precipitation of organic and inorganic pollutants by the microbial consortium, including PAHs, BPS, BPF, crude oil, pyrene, DBP, DOP, TPHP, PHs, butane, DON, TC, Mn, and Cd. In view of the good degradation ability of the consortium compared to single strains, six different synergistic mechanisms and corresponding microorganisms are summarized. The microbial consortium obtains such activities through enhancing synergistic degradation, reducing the accumulation of intermediate products, generating the crude enzyme, and self-regulating, etc. Furthermore, the degradation efficiency of pollutants can be greatly improved by adding chemical materials such as the surfactants Tween 20, Tween 80, and SDS. This review provides insightful information regarding the application of microbial consortia for soil pollutant removal.
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Complete Genome Sequence of Cupriavidus necator KK10, an Azaarene-Degrading and Polyhydroxyalkanoate-Producing Soil Bacterium. Microbiol Resour Announc 2021; 10:e0042321. [PMID: 34264105 PMCID: PMC8280871 DOI: 10.1128/mra.00423-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cupriavidus necator KK10 has been investigated in azaarene and diesel fuel biodegradation studies and is capable of polyhydroxyalkanoate (PHA) production. Its complete genome sequence revealed two closed circular sequences, the chromosome (6.68 Mb) and plasmid (1.67 Mb). The KK10 genome carries functional genes potentially responsible for azaarene biodegradation and polyhydroxyalkanoate biosynthesis.
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Complete Genome Sequence of Sphingobium barthaii KK22, a High-Molecular-Weight Polycyclic Aromatic Hydrocarbon-Degrading Soil Bacterium. Microbiol Resour Announc 2021; 10:10/1/e01250-20. [PMID: 33414343 PMCID: PMC8407719 DOI: 10.1128/mra.01250-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Sphingobium barthaii KK22T is a high-molecular-weight polycyclic aromatic hydrocarbon-degrading soil bacterium that has been investigated in biotransformation, microbial ecology, and DNA damage studies. The complete genome sequence of S. barthaii revealed four closed circular sequences, including two chromosomes, a megaplasmid, and a smaller plasmid, by hybrid assembly using short- and long-read sequencing technologies. Sphingobium barthaii KK22T is a high-molecular-weight polycyclic aromatic hydrocarbon-degrading soil bacterium that has been investigated in biotransformation, microbial ecology, and DNA damage studies. The complete genome sequence of S. barthaii revealed four closed circular sequences, including two chromosomes, a megaplasmid, and a smaller plasmid, by hybrid assembly using short- and long-read sequencing technologies.
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