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Wei X, Yang L, Chen Z, Xia W, Chen Y, Cao M, He N. Molecular weight control of poly-γ-glutamic acid reveals novel insights into extracellular polymeric substance synthesis in Bacillus licheniformis. Biotechnol Biofuels Bioprod 2024; 17:60. [PMID: 38711141 DOI: 10.1186/s13068-024-02501-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/04/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from Bacillus species. The function of γ-PGA varies with its molecular weight (Mw). RESULTS Herein, different endogenous promoters in Bacillus licheniformis were selected to regulate the expression levels of pgdS, resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 103 to 2.03 × 104 kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the pgdS engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the pgdS engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield. CONCLUSIONS Here, we present a novel insight that increased pgdS expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in B. licheniformis and provided an effective strategy for the controlled synthesis of extracellular polymeric substances.
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Affiliation(s)
- Xiaoyu Wei
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Lijie Yang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Zhen Chen
- College of Life Science, Xinyang Normal University, Xinyang, 464000, China.
| | - Wenhao Xia
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Yongbin Chen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China.
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China.
| | - Ning He
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China.
- The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, People's Republic of China.
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2
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Fiedler SM, Graumann PL. Dynamics of cell wall-binding proteins at a single molecule level: B. subtilis autolysins show different kinds of motion. Mol Biol Cell 2024; 35:ar55. [PMID: 38381561 PMCID: PMC11064672 DOI: 10.1091/mbc.e23-10-0387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/23/2024] [Accepted: 02/13/2024] [Indexed: 02/23/2024] Open
Abstract
The bacterial cell wall is a meshwork of crosslinked peptidoglycan strands, with a thickness of up to 50 nm in Firmicutes. Little is known about how proteins move through the cell wall to find sites of enzymatic activity. Cell wall synthesis for cell elongation involves the integration of new peptidoglycan strands by integral membrane proteins, as well as the degradation of existing strands by so-called autolysins, soluble proteins that are secreted through the cell membrane. Autolysins comprise different classes of proteases and glucanases and mostly contain cell-wall binding domains in addition to their catalytic domain. We have studied dynamics of Bacillus subtilis autolysins LytC, a major endopeptidase required for lateral cell wall growth, and LytF, a peptidase acting at the newly formed division site in order to achieve separation of daughter cells. We show that both proteins, fused to moxVenus are present as three distinct populations of different diffusion constants. The fastest population is compatible with free diffusion in a crowded liquid environment, that is similar to that of cytosolic enzymes, likely reflecting autolysins diffusing through the periplasm. The medium mobile fraction can be explained by constrained motion through a polymeric substance, indicating mobility of autolysins through the wall similar to that of DNA-binding proteins within the nucleoid. The slow-mobile fraction are most likely autolysins bound to their specific substrate sites. We show that LytF is more static during exponential phase, while LytC appears to be more active during the transition to stationary phase. Both autolysins became more static in backgrounds lacking redundant other autolysins, suggesting stochastic competition for binding sites. On the other hand, lack of inhibitor IseA or autolysin CwlS lead to an altered preference for polar localization of LytF within the cell wall, revealing that inhibitors and autolysins also affect each other's pattern of localization, in addition to their activity.
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Affiliation(s)
- Svenja M. Fiedler
- Fachbereich Chemie und Zentrum für Synthetische Mikrobiologie, SYNMIKRO, Philipps-Universität Marburg, Hans-Meerwein Strasse 4, 35043 Marburg, Germany
| | - Peter L. Graumann
- Fachbereich Chemie und Zentrum für Synthetische Mikrobiologie, SYNMIKRO, Philipps-Universität Marburg, Hans-Meerwein Strasse 4, 35043 Marburg, Germany
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3
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Wilson SA, Tank RKJ, Hobbs JK, Foster SJ, Garner EC. An exhaustive multiple knockout approach to understanding cell wall hydrolase function in Bacillus subtilis. mBio 2023; 14:e0176023. [PMID: 37768080 PMCID: PMC10653849 DOI: 10.1128/mbio.01760-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/03/2023] [Indexed: 09/29/2023] Open
Abstract
IMPORTANCE In order to grow, bacterial cells must both create and break down their cell wall. The enzymes that are responsible for these processes are the target of some of our best antibiotics. Our understanding of the proteins that break down the wall- cell wall hydrolases-has been limited by redundancy among the large number of hydrolases many bacteria contain. To solve this problem, we identified 42 cell wall hydrolases in Bacillus subtilis and created a strain lacking 40 of them. We show that cells can survive using only a single cell wall hydrolase; this means that to understand the growth of B. subtilis in standard laboratory conditions, it is only necessary to study a very limited number of proteins, simplifying the problem substantially. We additionally show that the ∆40 strain is a research tool to characterize hydrolases, using it to identify three "helper" hydrolases that act in certain stress conditions.
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Affiliation(s)
- Sean A. Wilson
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
- Center for Systems Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Raveen K. J. Tank
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Jamie K. Hobbs
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Simon J. Foster
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Ethan C. Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
- Center for Systems Biology, Harvard University, Cambridge, Massachusetts, USA
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4
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Griffin ME, Klupt S, Espinosa J, Hang HC. Peptidoglycan NlpC/P60 peptidases in bacterial physiology and host interactions. Cell Chem Biol 2023; 30:436-456. [PMID: 36417916 PMCID: PMC10192474 DOI: 10.1016/j.chembiol.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/15/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The bacterial cell wall is composed of a highly crosslinked matrix of glycopeptide polymers known as peptidoglycan that dictates bacterial cell morphology and protects against environmental stresses. Regulation of peptidoglycan turnover is therefore crucial for bacterial survival and growth and is mediated by key protein complexes and enzyme families. Here, we review the prevalence, structure, and activity of NlpC/P60 peptidases, a family of peptidoglycan hydrolases that are crucial for cell wall turnover and division as well as interactions with antibiotics and different hosts. Understanding the molecular functions of NlpC/P60 peptidases should provide important insight into bacterial physiology, their interactions with different kingdoms of life, and the development of new therapeutic approaches.
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Affiliation(s)
- Matthew E Griffin
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Steven Klupt
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Juliel Espinosa
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA; Department of Chemistry, Scripps Research, La Jolla, CA 92037, USA.
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5
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Tandukar S, Kwon E, Kim DY. Structural insights into the regulation of peptidoglycan DL-endopeptidases by inhibitory protein IseA. Structure 2023; 31:619-628.e4. [PMID: 36963396 DOI: 10.1016/j.str.2023.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/29/2023] [Accepted: 02/27/2023] [Indexed: 03/26/2023]
Abstract
Peptidoglycan, a physical barrier that protects bacteria from the environment, is constantly degraded and resynthesized for remodeling during cell growth and division. Because excessive or insufficient peptidoglycan hydrolysis affects bacterial homeostasis and viability, peptidoglycan degradation must be precisely regulated. In Bacillus subtilis, DL-endopeptidases play an essential role in peptidoglycan remodeling, and their activity is regulated by IseA. Here, we report the crystal structure of peptidoglycan DL-endopeptidase LytE complexed with IseA. In the crystal structure, the inhibitory loop connecting the two lobes of IseA blocks the active site of LytE by mimicking its substrate. Consistently, mutations in the inhibitory loop resulted in the loss of IseA activity. The structure also shows that conformational rearrangements in both LytE and IseA restrict access of the inhibitory loop to the LytE catalytic site. These results reveal an inhibition mechanism of peptidoglycan DL-endopeptidase in which the inhibitory protein mimics the substrate but is not degraded.
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Affiliation(s)
| | - Eunju Kwon
- College of Pharmacy, Yeungnam University, Gyeongsan 38541, South Korea.
| | - Dong Young Kim
- College of Pharmacy, Yeungnam University, Gyeongsan 38541, South Korea.
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6
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Hoffmann K, Halmschlag B, Briel S, Sieben M, Putri S, Fukusaki E, Blank LM, Büchs J. Online measurement of the viscosity in shake flasks enables monitoring of γ-PGA production in depolymerase knockout mutants of Bacillus subtilis with the phosphate-starvation inducible promoter P pst. Biotechnol Prog 2023; 39:e3293. [PMID: 36081345 DOI: 10.1002/btpr.3293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/26/2022] [Accepted: 08/11/2022] [Indexed: 11/10/2022]
Abstract
Poly-γ-glutamic acid (γ-PGA) is a biopolymer with a wide range of applications, mainly produced using Bacillus strains. The formation and concomitant secretion of γ-PGA increases the culture broth viscosity, while enzymatic depolymerisation and degradation of γ-PGA decreases the culture broth viscosity. In this study, the recently published ViMOS (Viscosity Monitoring Online System) is applied for optical online measurements of broth viscosity in eight parallel shake flasks. It is shown that the ViMOS is suitable to monitor γ-PGA production and degradation online in shake flasks. This online monitoring enables the detailed analysis of the Ppst promoter and γ-PGA depolymerase knockout mutants in genetically modified Bacillus subtilis 168. The Ppst promoter becomes active under phosphate starvation. The different single depolymerase knockout mutants are ∆ggt, ∆pgdS, ∆cwlO and a triple knockout mutant. An increase in γ-PGA yield in gγ-PGA /gglucose of 190% could be achieved with the triple knockout mutant compared to the Ppst reference strain. The single cwlO knockout also increased γ-PGA production, while the other single knockouts of ggt and pgdS showed no impact. Partial depolymerisation of γ-PGA occurred despite the triple knockout. The online measured data are confirmed with offline measurements. The online viscosity system directly reflects γ-PGA synthesis, γ-PGA depolymerisation, and changes in the molecular weight. Thus, the ViMOS has great potential to rapidly gain detailed and reliable information about new strains and cultivation conditions. The broadened knowledge will facilitate the further optimization of γ-PGA production.
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Affiliation(s)
- Kyra Hoffmann
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Birthe Halmschlag
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Simon Briel
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Michaela Sieben
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Sastia Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Lars M Blank
- Institute of Applied Microbiology - iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University, Aachen, Germany
| | - Jochen Büchs
- AVT - Biochemical Engineering, RWTH Aachen University, Aachen, Germany
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7
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Caballero V, Estévez M, Tomás-Barberán FA, Morcuende D, Martín I, Delgado J. Biodegradation of Punicalagin into Ellagic Acid by Selected Probiotic Bacteria: A Study of the Underlying Mechanisms by MS-Based Proteomics. J Agric Food Chem 2022; 70:16273-16285. [PMID: 36519204 PMCID: PMC9801417 DOI: 10.1021/acs.jafc.2c06585] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 05/31/2023]
Abstract
Pomegranate (Punica granatum L.) is a well-known source of bioactive phenolic compounds such as ellagitannins, anthocyanins, and flavanols. Punicalagin, one of the main constituents of pomegranate, needs to be biodegraded by bacteria to yield metabolites of medicinal interest. In this work, we tested 30 lactic acid bacteria (LAB) and their capacity to transform punicalagin from a punicalagin-rich pomegranate extract into smaller bioactive molecules, namely, ellagic acid and urolithins. These were identified and quantified by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS2). Further, we evaluated the molecular mechanism governing this transformation through label-free comparative MS-based proteomics. All tested LAB strains were capable of transforming punicalagin into ellagic acid, while the biosynthesis of urolithins was not observed. Proteomic analysis revealed an increase of generic transglycosylases that might have a hydrolytic role in the target phenolic molecule, coupled with an increase in the quantity of ATP-binding cassette (ABC) transporters, which might play a relevant role in transporting the resulting byproducts in and out of the cell.
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Affiliation(s)
- Víctor Caballero
- Food
Technology, IPROCAR Research Institute, Universidad de Extremadura, 10003Cáceres, Spain
- Food
Hygiene and Safety, IPROCAR Research Institute, Universidad de Extremadura, 10003Cáceres, Spain
| | - Mario Estévez
- Food
Technology, IPROCAR Research Institute, Universidad de Extremadura, 10003Cáceres, Spain
| | | | - David Morcuende
- Food
Technology, IPROCAR Research Institute, Universidad de Extremadura, 10003Cáceres, Spain
| | - Irene Martín
- Food
Hygiene and Safety, IPROCAR Research Institute, Universidad de Extremadura, 10003Cáceres, Spain
| | - Josué Delgado
- Food
Hygiene and Safety, IPROCAR Research Institute, Universidad de Extremadura, 10003Cáceres, Spain
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8
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Wei X, Yang L, Wang H, Chen Z, Xu Y, Weng Y, Cao M, Li Q, He N. Genomic and metabolomic analysis of Bacillus licheniformis with enhanced poly-γ-glutamic acid production through atmospheric and room temperature plasma mutagenesis. Front Chem Sci Eng 2022. [DOI: 10.1007/s11705-022-2211-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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9
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Zhang J, Zhu B, Xu X, Liu Y, Li Q, Li Y, Lu F. Remodeling Bacillus amyloliquefaciens Cell Wall Rigidity to Reduce Cell Lysis and Increase the Yield of Heterologous Proteins. J Agric Food Chem 2022; 70:10552-10562. [PMID: 35984403 DOI: 10.1021/acs.jafc.2c04454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Bacillus amyloliquefaciens has great potential as a host for heterologous protein production, but its severe autolytic behavior has precluded its industrial application to date. Because d,l-endopeptidase activity-guided cell wall rigidity is considered essential for autolysis resistance, we investigated the effects of d,l-endopeptidase genes lytE, lytF, cwlO, and cwlS play on the growth, lysis, and morphology remodeling of B. amyloliquefaciens strain TCCC11018. Individual and combinatorial deletion of lytE, lytF, and cwlS enhanced the cell growth and delayed cell lysis. For the best mutant with the lytF and cwlS double deletion, the viable cell number at 24 h increased by 11.90% and the cell wall thickness at 6 h increased by 25.87%. Transcriptomic and proteomic analyses indicated that the improvement was caused by enhanced peptidoglycan synthesis. With the lytF and cwlS double deletion, the extracellular green fluorescent protein and phospholipase D expression levels increased by 113 and 55.89%, respectively. This work broadens our understanding of the relationship between d,l-endopeptidases and B. amyloliquefaciens cell characteristics, which provides an effective strategy to improve the heterologous protein expression in B. amyloliquefaciens-based cell factories.
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Affiliation(s)
- Jinfang Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Baoyue Zhu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Xiaojian Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Yihan Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Qinggang Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Yu Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
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10
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Wang G, Li S, Yan Q, Guo R, Zhang Y, Chen F, Tian X, Lv Q, Jin H, Ma X, Ma Y. Optimization and evaluation of viral metagenomic amplification and sequencing procedures toward a genome-level resolution of the human fecal DNA virome. J Adv Res 2022:S2090-1232(22)00192-8. [PMID: 35995413 DOI: 10.1016/j.jare.2022.08.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 08/12/2022] [Accepted: 08/14/2022] [Indexed: 10/15/2022] Open
Abstract
INTRODUCTION Viruses in the human gut have been linked to health and disease. Deciphering the gut virome is dependent on metagenomic sequencing of the virus-like particles (VLPs) purified from the fecal specimens. A major limitation of conventional viral metagenomic sequencing is the low recoverability of viral genomes from the metagenomic dataset. OBJECTIVES To develop an optimal method for viral amplification and metagenomic sequencing for maximizing the recovery of viral genomes. METHODS We performed parallel virus enrichment and DNA extraction to generate ∼ 30 viral DNA samples from each of 5 fresh fecal specimens and conducted the experiments including 1) optimizing the cycle number for high-fidelity enzyme-based PCR amplification, 2) evaluating the reproducibility of the optimally whole viral metagenomic experimental process, 3) evaluating the reliability of multiple displacement amplification (MDA), 4) testing the capability of long-read sequencing for improving viral metagenomic assembly, and 5) comparing the differences between viral metagenomic and bulk metagenomic approaches. RESULTS Our results revealed that the optimal cycle number for PCR amplification is 15. We verified the reliability of MDA and the effectiveness of long-read sequencing. Based on our optimized results, we generated 151 high-quality viruses using the dataset combined from short-read and long-read sequencing. Genomic analysis of these viruses found that most (60.3%) of them were previously unknown and showed a remarkable diversity of viral functions, especially the existence of 206 viral auxiliary metabolic genes. Finally, we uncovered significant differences in the efficiency and coverage of viral identification between viral metagenomic and bulk metagenomic approaches. CONCLUSIONS Our study demonstrates the potential of optimized experiment and sequencing strategies in uncovering viral genomes from fecal specimens, which will facilitate future research about the genome-level characterization of complex viral communities.
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Affiliation(s)
- Guangyang Wang
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Shenghui Li
- Puensum Genetech Institute, Wuhan 430076, China; Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China
| | - Qiulong Yan
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Ruochun Guo
- Puensum Genetech Institute, Wuhan 430076, China
| | - Yue Zhang
- Puensum Genetech Institute, Wuhan 430076, China
| | - Fang Chen
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Xiangge Tian
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China; Pharmaceutical Research Center, Second Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Qingbo Lv
- Puensum Genetech Institute, Wuhan 430076, China
| | - Hao Jin
- Puensum Genetech Institute, Wuhan 430076, China
| | - Xiaochi Ma
- Pharmaceutical Research Center, Second Affiliated Hospital, Dalian Medical University, Dalian, China
| | - Yufang Ma
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China.
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11
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Cheng JH, Wang Y, Zhang XY, Sun ML, Zhang X, Song XY, Zhang YZ, Zhang Y, Chen XL. Characterization and Diversity Analysis of the Extracellular Proteases of Thermophilic Anoxybacillus caldiproteolyticus 1A02591 From Deep-Sea Hydrothermal Vent Sediment. Front Microbiol 2021; 12:643508. [PMID: 33796092 PMCID: PMC8007923 DOI: 10.3389/fmicb.2021.643508] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/24/2021] [Indexed: 11/13/2022] Open
Abstract
Protease-producing bacteria play key roles in the degradation of marine organic nitrogen. Although some deep-sea bacteria are found to produce proteases, there has been no report on protease-secreting Anoxybacillus from marine hydrothermal vent regions. Here, we analyzed the diversity and functions of the proteases, especially the extracellular proteases, of Anoxybacillus caldiproteolyticus 1A02591, a protease-secreting strain isolated from a deep-sea hydrothermal vent sediment of the East Pacific Ocean. Strain 1A02591 is a thermophilic bacterium with a strong protease-secreting ability, which displayed the maximum growth rate (0.139 h–1) and extracellular protease production (307.99 U/mL) at 55°C. Strain 1A02591 contains 75 putative proteases, including 65 intracellular proteases and 10 extracellular proteases according to signal peptide prediction. When strain 1A02591 was cultured with casein, 12 proteases were identified in the secretome, in which metalloproteases (6/12) and serine proteases (4/12) accounted for the majority, and a thermolysin-like protease of the M4 family was the most abundant, suggesting that strain 1A02591 mainly secreted a thermophilic metalloprotease. Correspondingly, the secreted proteases of strain 1A02591 showed the highest activity at the temperature as high as 70°C, and was inhibited 70% by metalloprotease inhibitor o-phenanthroline and 50% by serine protease inhibitor phenylmethylsulfonyl fluoride. The secreted proteases could degrade different proteins, suggesting the role of strain 1A02591 in organic nitrogen degradation in deep-sea hydrothermal ecosystem. These results provide the first insight into the proteases of an Anoxybacillus strain from deep-sea hydrothermal ecosystem, which is helpful in understanding the function of Anoxybacillus in the marine biogeochemical cycle.
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Affiliation(s)
- Jun-Hui Cheng
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Yan Wang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Xiao-Yu Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Mei-Ling Sun
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xia Zhang
- Department of Molecular Biology, Qingdao Vland Biotech Inc., Qingdao, China
| | - Xiao-Yan Song
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yi Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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Abstract
The NlpC/p60-family of peptidoglycan hydrolases are key enzymes that facilitate bacterial cell division and also modulate microbe-host interactions. These endopeptidases utilize conserved Cys-His residues in their active site and are expressed in most bacterial species as well as some eukaryotes. Here we describe methods for biochemical analysis of Enterococcus faecium SagA-NlpC/p60 peptidoglycan hydrolase activity (Kim et al., 2019; Rangan et al., 2016), which includes recombinant protein preparation and biochemical analysis using both gel-based and LC-MS profiling of peptidoglycan fragments. These protocols should also facilitate the biochemical analysis of other NlpC/p60 peptidoglycan hydrolases.
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Duchêne MC, Rolain T, Knoops A, Courtin P, Chapot-Chartier MP, Dufrêne YF, Hallet BF, Hols P. Distinct and Specific Role of NlpC/P60 Endopeptidases LytA and LytB in Cell Elongation and Division of Lactobacillus plantarum. Front Microbiol 2019; 10:713. [PMID: 31031721 PMCID: PMC6473061 DOI: 10.3389/fmicb.2019.00713] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 03/21/2019] [Indexed: 11/22/2022] Open
Abstract
Peptidoglycan (PG) is an essential lattice of the bacterial cell wall that needs to be continuously remodeled to allow growth. This task is ensured by the concerted action of PG synthases that insert new material in the pre-existing structure and PG hydrolases (PGHs) that cleave the PG meshwork at critical sites for its processing. Contrasting with Bacillus subtilis that contains more than 35 PGHs, Lactobacillus plantarum is a non-sporulating rod-shaped bacterium that is predicted to possess a minimal set of 12 PGHs. Their role in morphogenesis and cell cycle remains mostly unexplored, except for the involvement of the glucosaminidase Acm2 in cell separation and the NlpC/P60 D, L-endopeptidase LytA in cell shape maintenance. Besides LytA, L. plantarum encodes three additional NlpC/P60 endopeptidases (i.e., LytB, LytC and LytD). The in silico analysis of these four endopeptidases suggests that they could have redundant functions based on their modular organization, forming two pairs of paralogous enzymes. In this work, we investigate the role of each Lyt endopeptidase in cell morphogenesis in order to evaluate their distinct or redundant functions, and eventually their synthetic lethality. We show that the paralogous LytC and LytD enzymes are not required for cell shape maintenance, which may indicate an accessory role such as in PG recycling. In contrast, LytA and LytB appear to be key players of the cell cycle. We show here that LytA is required for cell elongation while LytB is involved in the spatio-temporal regulation of cell division. In addition, both PGHs are involved in the proper positioning of the division site. The absence of LytA activity is responsible for the asymmetrical positioning of septa in round cells while the lack of LytB results in a lateral misplacement of division planes in rod-shaped cells. Finally, we show that the co-inactivation of LytA and LytB is synthetically affecting cell growth, which confirms the key roles played by both enzymes in PG remodeling during the cell cycle of L. plantarum. Based on the large distribution of NlpC/P60 endopeptidases in low-GC Gram-positive bacteria, these enzymes are attractive targets for the discovery of novel antimicrobial compounds.
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Affiliation(s)
- Marie-Clémence Duchêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Thomas Rolain
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Adrien Knoops
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Pascal Courtin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | | | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Bernard F Hallet
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Pascal Hols
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
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