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Bell E, Chen J, Richardson WDL, Fustic M, Hubert CRJ. Denitrification genotypes of endospore-forming Bacillota. ISME COMMUNICATIONS 2024; 4:ycae107. [PMID: 39263550 PMCID: PMC11388526 DOI: 10.1093/ismeco/ycae107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 08/14/2024] [Accepted: 08/19/2024] [Indexed: 09/13/2024]
Abstract
Denitrification is a key metabolic process in the global nitrogen cycle and is performed by taxonomically diverse microorganisms. Despite the widespread importance of this metabolism, challenges remain in identifying denitrifying populations and predicting their metabolic end-products based on their genotype. Here, genome-resolved metagenomics was used to explore the denitrification genotype of Bacillota enriched in nitrate-amended high temperature incubations with confirmed N2O and N2 production. A set of 12 hidden Markov models (HMMs) was created to target the diversity of denitrification genes in members of the phylum Bacillota. Genomic potential for complete denitrification was found in five metagenome-assembled genomes from nitrate-amended enrichments, including two novel members of the Brevibacillaceae family. Genomes of complete denitrifiers encode N2O reductase gene clusters with clade II-type nosZ and often include multiple variants of the nitric oxide reductase gene. The HMM set applied to all genomes of Bacillota from the Genome Taxonomy Database identified 17 genera inferred to contain complete denitrifiers based on their gene content. Among complete denitrifiers it was common for three distinct nitric oxide reductases to be present (qNOR, bNOR, and sNOR) that may reflect the metabolic adaptability of Bacillota in environments with variable redox conditions.
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Affiliation(s)
- Emma Bell
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Jianwei Chen
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - William D L Richardson
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Milovan Fustic
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
- Department of Geology, Nazarbayev University, 53 Kabanbay Batyr Ave, Astana 010000, Kazakhstan
| | - Casey R J Hubert
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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Das J, Kumar R, Yadav SK, Jha G. The alternative sigma factors, rpoN1 and rpoN2 are required for mycophagous activity of Burkholderia gladioli strain NGJ1. Environ Microbiol 2021; 24:2781-2796. [PMID: 34766435 DOI: 10.1111/1462-2920.15836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 11/26/2022]
Abstract
Bacteria utilize RpoN, an alternative sigma factor (σ54) to grow in diverse habitats, including nitrogen-limiting conditions. Here, we report that a rice-associated mycophagous bacterium Burkholderia gladioli strain NGJ1 encodes two paralogues of rpoN viz. rpoN1 and rpoN2. Both of them are upregulated during 24 h of mycophagous interaction with Rhizoctonia solani, a polyphagous fungal pathogen. Disruption of either one of rpoNs renders the mutant NGJ1 bacterium defective in mycophagy, whereas ectopic expression of respective rpoN genes restores mycophagy in the complementing strains. NGJ1 requires rpoN1 and rpoN2 for efficient biocontrol to prevent R. solani to establish disease in rice and tomato. Further, we have identified 17 genes having RpoN regulatory motif in NGJ1, majority of them encode potential type III secretion system (T3SS) effectors, nitrogen assimilation, and cellular transport-related functions. Several of these RpoN regulated genes as well as certain previously reported T3SS apparatus (hrcC and hrcN) and effector (Bg_9562 and endo-β-1,3-glucanase) encoding genes are upregulated in NGJ1 but not in ΔrpoN1 or ΔrpoN2 mutant bacterium, during mycophagous interaction with R. solani. This highlights that RpoN1 and RpoN2 modulate T3SS, nitrogen assimilation as well as cellular transport systems in NGJ1 and thereby promote bacterial mycophagy.
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Affiliation(s)
- Joyati Das
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
| | - Rahul Kumar
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
| | - Sunil Kumar Yadav
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
| | - Gopaljee Jha
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, 110067, India
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Liu G, Vijayaraman SB, Dong Y, Li X, Andongmaa BT, Zhao L, Tu J, He J, Lin L. Bacillus velezensis LG37: transcriptome profiling and functional verification of GlnK and MnrA in ammonia assimilation. BMC Genomics 2020; 21:215. [PMID: 32143571 PMCID: PMC7060608 DOI: 10.1186/s12864-020-6621-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 02/25/2020] [Indexed: 11/14/2022] Open
Abstract
Background In recent years, interest in Bacillus velezensis has increased significantly due to its role in many industrial water bioremediation processes. In this study, we isolated and assessed the transcriptome of Bacillus velezensis LG37 (from an aquaculture pond) under different nitrogen sources. Since Bacillus species exhibit heterogeneity, it is worth investigating the molecular mechanism of LG37 through ammonia nitrogen assimilation, where nitrogen in the form of molecular ammonia is considered toxic to aquatic organisms. Results Here, a total of 812 differentially expressed genes (DEGs) from the transcriptomic sequencing of LG37 grown in minimal medium supplemented with ammonia (treatment) or glutamine (control) were obtained, from which 56 had Fold Change ≥2. BLAST-NCBI and UniProt databases revealed 27 out of the 56 DEGs were potentially involved in NH4+ assimilation. Among them, 8 DEGs together with the two-component regulatory system GlnK/GlnL were randomly selected for validation by quantitative real-time RT-PCR, and the results showed that expression of all the 8 DEGs are consistent with the RNA-seq data. Moreover, the transcriptome and relative expression analysis were consistent with the transporter gene amtB and it is not involved in ammonia transport, even in the highest ammonia concentrations. Besides, CRISPR-Cas9 knockout and overexpression glnK mutants further evidenced the exclusion of amtB regulation, suggesting the involvement of alternative transporter. Additionally, in the transcriptomic data, a novel ammonium transporter mnrA was expressed significantly in increased ammonia concentrations. Subsequently, OEmnrA and ΔmnrA LG37 strains showed unique expression pattern of specific genes compared to that of wild-LG37 strain. Conclusion Based on the transcriptome data, regulation of nitrogen related genes was determined in the newly isolated LG37 strain to analyse the key regulating factors during ammonia assimilation. Using genomics tools, the novel MnrA transporter of LG37 became apparent in ammonia transport instead of AmtB, which transports ammonium nitrogen in other Bacillus strains. Collectively, this study defines heterogeneity of B. velezensis LG37 through comprehensive transcriptome analysis and subsequently, by genome editing techniques, sheds light on the enigmatic mechanisms controlling the functional genes under different nitrogen sources also reveals the need for further research.
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Affiliation(s)
- Guangxin Liu
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China.,Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China
| | - Sarath Babu Vijayaraman
- Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China
| | - Yanjun Dong
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Binda Tembeng Andongmaa
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Lijuan Zhao
- Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China
| | - Jiagang Tu
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China.
| | - Li Lin
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China. .,Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China. .,Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology, Qingdao, 266071, Shandong, China.
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Perazzoli S, de Santana Neto JP, Soares HM. Anoxic-biocathode microbial desalination cell as a new approach for wastewater remediation and clean water production. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 81:550-563. [PMID: 32385209 DOI: 10.2166/wst.2020.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Bioelectrochemical systems are emerging as a promising and friendly alternative to convert the energy stored in wastewater directly into electricity by microorganisms and utilize it in situ to drive desalination. To better understand such processes, we propose the development of an anoxic biocathode microbial desalination Cell for the conversion of carbon- and nitrogen-rich wastewaters into bioenergy and to perform salt removal. Our results demonstrate a power output of 0.425 W m-3 with desalination, organic matter removal and nitrate conversion efficiencies of 43.69, 99.85 and 92.11% respectively. Microbiological analysis revealed Proteobacteria as the dominant phylum in the anode (88.45%) and biocathode (97.13%). While a relatively higher bacterial abundance was developed in the anode chamber, the biocathode showed a greater variety of microorganisms, with a predominance of Paracoccus (73.2%), which are related to the denitrification process. These findings are promising and provide new opportunities for the development and application of this technology in the field of wastewater treatment to produce cleaner water and conserve natural resources.
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Affiliation(s)
- Simone Perazzoli
- Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88034-001 Florianópolis, SC, Brazil E-mail:
| | - José Pedro de Santana Neto
- Department of Mechanical Engineering, Federal University of Santa Catarina, 88034-001 Florianópolis, SC, Brazil
| | - Hugo M Soares
- Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88034-001 Florianópolis, SC, Brazil E-mail:
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Niu T, Lv X, Liu Z, Li J, Du G, Liu L. Synergetic engineering of central carbon and nitrogen metabolism for the production ofN‐acetylglucosamine inBacillus subtilis. Biotechnol Appl Biochem 2020; 67:123-132. [DOI: 10.1002/bab.1845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Tengfei Niu
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Zhenmin Liu
- State Key Laboratory of Dairy BiotechnologyShanghai Engineering Research Center of Dairy BiotechnologyDairy Research InstituteBright Dairy & Food Co., Ltd. Shanghai People's Republic of China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
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Sun Y, De Vos P, Willems A. Influence of nitrate and nitrite concentration on N 2 O production via dissimilatory nitrate/nitrite reduction to ammonium in Bacillus paralicheniformis LMG 6934. Microbiologyopen 2018; 7:e00592. [PMID: 29504271 PMCID: PMC6079178 DOI: 10.1002/mbo3.592] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 12/17/2017] [Accepted: 12/29/2017] [Indexed: 12/28/2022] Open
Abstract
Until now, the exact mechanisms for N2 O production in dissimilatory nitrate/nitrite reduction to ammonium (DNRA) remain underexplored. Previously, we investigated this mechanism in Bacillus licheniformis and Bacillus paralicheniformis, ubiquitous gram-positive bacteria with many industrial applications, and observed significant strain dependency and media dependency in N2 O production which was thought to correlate with high residual NO2- . Here, we further studied the influence of several physicochemical factors on NO3- (or NO2- ) partitioning and N2 O production in DNRA to shed light on the possible mechanisms of N2 O production. The effects of NO3- concentrations under variable or fixed C/N-NO3- ratios, NO2- concentrations under variable or fixed C/N-NO2- ratios, and NH4+ concentrations under fixed C/N-NO3- ratios were tested during anaerobic incubation of soil bacterium B. paralicheniformis LMG 6934 (previously known as B. licheniformis), a strain with a high nitrite reduction capacity. Monitoring of growth, NO3- , NO2- , NH4+ concentration, and N2 O production in physiological tests revealed that NO3- as well as NO2- concentration showed a linear correlation with N2 O production. Increased NO3- concentration under fixed C/N-NO3- ratios, NO2- concentration, and NH4+ concentration had a significant positive effect on NO3- (or NO2- ) partitioning ([N-NH4+ ]/[N-N2 O]) toward N2 O, which may be a consequence of the (transient) accumulation and subsequent detoxification of NO2- . These findings extend the information on several physiological parameters affecting DNRA and provide a basis for further study on N2 O production during this process.
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Affiliation(s)
- Yihua Sun
- Laboratory of MicrobiologyDepartment of Biochemistry and MicrobiologyGhent UniversityGentBelgium
| | - Paul De Vos
- Laboratory of MicrobiologyDepartment of Biochemistry and MicrobiologyGhent UniversityGentBelgium
| | - Anne Willems
- Laboratory of MicrobiologyDepartment of Biochemistry and MicrobiologyGhent UniversityGentBelgium
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