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Elbediwi M, Rolff J. Metabolic pathways and antimicrobial peptide resistance in bacteria. J Antimicrob Chemother 2024; 79:1473-1483. [PMID: 38742645 DOI: 10.1093/jac/dkae128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024] Open
Abstract
Antimicrobial resistance is a pressing concern that poses a significant threat to global public health, necessitating the exploration of alternative strategies to combat drug-resistant microbial infections. Recently, antimicrobial peptides (AMPs) have gained substantial attention as possible replacements for conventional antibiotics. Because of their pharmacodynamics and killing mechanisms, AMPs display a lower risk of bacterial resistance evolution compared with most conventional antibiotics. However, bacteria display different mechanisms to resist AMPs, and the role of metabolic pathways in the resistance mechanism is not fully understood. This review examines the intricate relationship between metabolic genes and AMP resistance, focusing on the impact of metabolic pathways on various aspects of resistance. Metabolic pathways related to guanosine pentaphosphate (pppGpp) and guanosine tetraphosphate (ppGpp) [collectively (p)ppGpp], the tricarboxylic acid (TCA) cycle, haem biosynthesis, purine and pyrimidine biosynthesis, and amino acid and lipid metabolism influence in different ways metabolic adjustments, biofilm formation and energy production that could be involved in AMP resistance. By targeting metabolic pathways and their associated genes, it could be possible to enhance the efficacy of existing antimicrobial therapies and overcome the challenges exhibited by phenotypic (recalcitrance) and genetic resistance toward AMPs. Further research in this area is needed to provide valuable insights into specific mechanisms, uncover novel therapeutic targets, and aid in the fight against antimicrobial resistance.
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Affiliation(s)
- Mohammed Elbediwi
- Evolutionary Biology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
- Animal Health Research Institute, Agriculture Research Centre, 12618 Cairo, Egypt
| | - Jens Rolff
- Evolutionary Biology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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Jiang J, Zhao Y, Chen A, Sun J, Zhou M, Hu J, Cao X, Dai N, Liang Z, Feng S. Efficient markerless genetic manipulation of Pasteurella multocida using lacZ and pheSm as selection markers. Appl Environ Microbiol 2024; 90:e0204323. [PMID: 38547470 PMCID: PMC11022533 DOI: 10.1128/aem.02043-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/07/2024] [Indexed: 04/18/2024] Open
Abstract
Pasteurella multocida is a zoonotic conditional pathogen that infects multiple livestock species, causing substantial economic losses in the animal husbandry industry. An efficient markerless method for gene manipulation may facilitate the investigations of P. multocida gene function and pathogenesis of P. multocida. Herein, a temperature-sensitive shuttle vector was constructed using lacZ as a selection marker, and markerless glgB, opa, and hyaE mutants of P. multocida were subsequently constructed through blue-white colony screening. The screening efficiency of markerless deletion strains was improved by the lacZ system, and the method could be used for multiple gene deletions. However, the fur mutant was unavailable via this method. Therefore, we constructed a pheSm screening system based on mutated phenylalanine tRNA synthetase as a counterselection marker to achieve fur deletion mutant. The transformed strain was sensitive to 20 mM p-chloro-phenylalanine, demonstrating the feasibility of pheSm as a counter-selective marker. The pheSm system was used for markerless deletions of glgB, opa, and hyaE as well as fur that could not be screened by the lacZ system. A comparison of screening efficiencies of the system showed that the pheSm counterselection system was more efficient than the lacZ system and broadly applicable for mutant screening. The methods developed herein may provide valuable tools for genetic manipulation of P. multocida.IMPORTANCEPasteurella multocida is a highly contagious zoonotic pathogen. An understanding of its underlying pathogenic mechanisms is of considerable importance and requires efficient species-specific genetic tools. Herein, we propose a screening system for P. multocida mutants using lacZ or pheSm screening markers. We evaluated the efficiencies of both systems, which were used to achieve markerless deletion of multiple genes. The results of this study support the use of lacZ or pheSm as counterselection markers to improve counterselection efficiency in P. multocida. This study provides an effective genetic tool for investigations of the virulence gene functions and pathogenic mechanisms of P. multocida.
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Affiliation(s)
- Jinfei Jiang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yishan Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Aihua Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Juan Sun
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Mengruo Zhou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jialian Hu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xuewei Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Ning Dai
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zhaoping Liang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, Guangzhou, China
- Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture and Rural Affairs, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
| | - Saixiang Feng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, Guangzhou, China
- Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture and Rural Affairs, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
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Luo Z, Yan Y, Du S, Zhu Y, Pan F, Wang R, Xu Z, Xu X, Li S, Xu H. Recent advances and prospects of Bacillus amyloliquefaciens as microbial cell factories: from rational design to industrial applications. Crit Rev Biotechnol 2023; 43:1073-1091. [PMID: 35997331 DOI: 10.1080/07388551.2022.2095499] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/02/2022] [Indexed: 11/03/2022]
Abstract
Bacillus amyloliquefaciens is one of the most characterized Gram-positive bacteria. This species has unique characteristics that are beneficial for industrial applications, including its utilization of: cheap carbon as a substrate, a transparent genetic background, and large-scale robustness in fermentation. Indeed, the productivity characteristics of B. amyloliquefaciens have been thoroughly analyzed and further optimized through systems biology and synthetic biology techniques. Following the analysis of multiple engineering design strategies, B. amyloliquefaciens is now considered an efficient cell factory capable of producing large quantities of multiple products from various raw materials. In this review, we discuss the significant potential advantages offered by B. amyloliquefaciens as a platform for metabolic engineering and industrial applications. In addition, we systematically summarize the recent laboratory research and industrial application of B. amyloliquefaciens, including: relevant advances in systems and synthetic biology, various strategies adopted to improve the cellular performances of synthetic chemicals, as well as the latest progress in the synthesis of certain important products by B. amyloliquefaciens. Finally, we propose the current challenges and essential strategies to usher in an era of broader B. amyloliquefaciens use as microbial cell factories.
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Affiliation(s)
- Zhengshan Luo
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Yifan Yan
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Shanshan Du
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Yifan Zhu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Fei Pan
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Rui Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Zheng Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Xiaoqi Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
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Wu P, Tao Q, Liu Y, Zeng C, Li Y, Yan X. Efficient secretion of mussel adhesion proteins using a chaperone protein Spy as fusion tag in Bacillus subtilis. Biotechnol J 2023; 18:e2200582. [PMID: 37357718 DOI: 10.1002/biot.202200582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Mussel foot proteins (Mfps) are considered as remarkable materials due to their extraordinary adhesive capability. Recombinant expression is an ideal way to synthesis these proteins at large scale. However, secretory expression of Mfps into culture medium has not been achieved in a heterologous host. METHODS AND RESULTS Here, to realize the secretion of Mfp3 and Mfp5 in Bacillus subtilis, signal peptide screening was first performed. Minimal Mfp3-6×His was targeted into the growth medium with AmyE signal peptide. We found that a small chaperone protein Spy was secreted efficiently in B. subtilis, and the fusion proteins Spy-Mfp3-6×His and Spy-Mfp5-6×His could also be delivered into growth medium well. The yield of Spy-Mfp3-6×His and Spy-Mfp5-6×His reached 255 and 119 mg L-1 at shake flask conditions, respectively. Mfp3-6×His and Mfp5-6×His were finally purified via TEV protease cleavage and NTA affinity chromatography. CONCLUSION Mfp3-6×His and Mfp5-6×His could be efficiently secreted using a chaperone protein Spy as fusion tag in B. subtilis.
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Affiliation(s)
- Panpan Wu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Qing Tao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Yuxuan Liu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Caiting Zeng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Yu Li
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Xin Yan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
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Li T, Liu P, Guo G, Liu Z, Zhong L, Guo L, Chen C, Hao N, Ouyang P. Production of acetoin and its derivative tetramethylpyrazine from okara hydrolysate with Bacillus subtilis. AMB Express 2023; 13:25. [PMID: 36853576 PMCID: PMC9975146 DOI: 10.1186/s13568-023-01532-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/21/2023] [Indexed: 03/01/2023] Open
Abstract
Okara, a renewable biomass resource, is a promising fermentative raw material for the bio-production of value-added chemicals due to its abundance and low-costs. we developed a process for the enzymatic hydrolysis of okara, and then engineered Bacillus subtilis to utilize mixed sugars to produce acetoin in okara hydrolysis without the addition of a supplemental nitrogen source. Okara was initially hydrolyzed with cellulase, β-glucosidase, and pectinase to obtain okara hydrolysate containing mixed sugars (32.78 ± 0.23 g/L glucose, 1.43 ± 0.064 g/L arabinose, 7.74 ± 0.11 g/L galactose) and amino acids. In this study, Bacillus subtilis 168 was used as the acetoin-producing strain, and the key genes bdhA and acoA of the acetoin catabolism pathway were knocked out to improve the fermentation yield of acetoin. In order to utilize the galactose in the hydrolysate, the recombinant strain BS03 (Bacillus subtilis168∆bdhA∆acoA) was used to overexpress the arabinose transporter-encoding gene (araE) drive heterologous expression of the Leloir pathway gene (galKTE). The corn dry powder concentration was optimized to 29 g/L in the reducing sugar okara hydrolysate. The results show that the recombinant bacterium BS03 could still synthesize 11.79 g/L acetoin without using corn dry powder as a nitrogen source. Finally, using okara enzymatic hydrolysate as the carbon and nitrogen source, 11.11 g/L and 29.7 g/L acetoin were obtained by batch fermentation and fed-batch fermentation, respectively, which was further converted to 5.33 g/L and 13.37 g/L tetramethylpyrazine (TTMP) by reaction with an ammonium salt.
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Affiliation(s)
- Tao Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Ping Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Gege Guo
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Zhaoxing Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Lei Zhong
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Lianxia Guo
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Cheng Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Ning Hao
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China.
| | - Pingkai Ouyang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
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Dong X, Tu C, Liu Y, Zhang R, Liu Y. Identification of the core c-di-GMP turnover proteins responsible for root colonization of Bacillus velezensis. iScience 2022; 25:105294. [PMID: 36300004 PMCID: PMC9589206 DOI: 10.1016/j.isci.2022.105294] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/19/2022] [Accepted: 10/03/2022] [Indexed: 11/17/2022] Open
Abstract
Root colonization by beneficial rhizobacteria determines their plant beneficial effects. The messenger c-di-GMP is involved in the bacterial transition process between motility and biofilm, which are crucial to the colonization ability of the rhizobacteria. In this study, we identified three GGDEF domain-containing proteins (YdaK, YhcK, and YtrP) and two EAL domain-containing proteins (YuxH and YkuI) in beneficial rhizobacterium Bacillus velezensis SQR9. We found that deficiency of ytrP or ykuI in SQR9 led to impaired biofilm formation, while deficiency of yuxH led to weakened motility. Further investigation showed that YtrP, YuxH, and YkuI all contributed to the root colonization of SQR9 on cucumber root. Further bioinformatics analysis showed that YtrP and YuxH are conserved in plant beneficial Bacillus group, while they do not occur in animal pathogenic Bacillus. This research will be useful for enhancing the beneficial function of Bacillus spp. in agricultural application. C-di-GMP is involved in root colonization of B. velezensis YtrP and YkuI enhance the root colonization by regulating biofilm of B velezensis YuxH enhances the root colonization by affecting the motility of B. velezensis YtrP and YuxH are conserved in plant beneficial Bacillus group
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Affiliation(s)
- Xiaoyan Dong
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, P.R. China,Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Chen Tu
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, P.R. China
| | - Yanan Liu
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, P.R. China
| | - Ruifu Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China,College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Yunpeng Liu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China,Corresponding author
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Gao G, Wei D, Li G, Chen P, Wu L, Liu S, Zhang Y. Highly Effective Markerless Genetic Manipulation of Streptococcus suis Using a Mutated PheS-Based Counterselectable Marker. Front Microbiol 2022; 13:947821. [PMID: 35910605 PMCID: PMC9329067 DOI: 10.3389/fmicb.2022.947821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Streptococcus suis is an important zoonotic pathogen, however, an efficient markerless genetic manipulation system is still lacking for further physiological and pathological studies on this bacterium. Several techniques have been developed for markerless genetic manipulation of S. suis utilizing either a temperature-sensitive vector or a counterselectable markers (CSMs), however, at present, the efficiency of these techniques is not very satisfactory. In this study, we developed a strategy for markerless genetic manipulation of S. suis employing a CSM based on a conditionally lethal mutant allele of pheS, which encodes the α-subunit of phenylalanyl-tRNA synthetase (PheS). This mutant pheS, mPheS, was constructed by introducing site-directed mutations for a T261S/A315G double-substitution and a number of silent mutations to decrease its similarity with the endogenous wild type pheS gene (wtPheS). Additionally, five potentially strong promoters from S. suis were screened for their ability to drive high-level expression of mPheS, thus endowing the carrier strain with sufficient sensitivity to the phenylalanine analog p-chloro-phenylalanine (p-Cl-phe). Insertion of these P-mPheS cassettes into a vector or into the chromosomal locus via a linked erythromycin resistance gene revealed that mPheS allele driven by promoters P0530 and P1503 renders S. suis sensitive to as low as 0.01% (or 0.5 mM) of p-Cl-phe. This offers two potential CSMs for S. suis with p-Cl-phe as a counterselective agent. P1503-mPheS was revealed to be 100% efficient for counter-selection in S. suis by application in a precise gene deletion. Using P1503-mPheS as a CSM, a two-step insertion and excision strategy for markerless genetic manipulation of S. suis were developed, supplying a powerful tool for markerless genetic manipulation of S. suis.
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Annulment of Bacterial Antagonism Improves Plant Beneficial Activity of a Bacillus velezensis Consortium. Appl Environ Microbiol 2022; 88:e0024022. [PMID: 35380452 DOI: 10.1128/aem.00240-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bacillus sp. strains that are beneficial to plants are widely used in commercial biofertilizers and biocontrol agents for sustainable agriculture. Generally, functional Bacillus strains are applied as single-strain communities since the principles of synthetic microbial consortia constructed with Bacillus strains remain largely unclear. Here, we demonstrated that the mutual compatibility directly affects the survival and function of two-member consortia composed of Bacillus velezensis SQR9 and FZB42 in the rhizosphere. A mutation in the global regulator Spo0A of SQR9 markedly reduced the boundary phenotype (appearance of a visible boundary line at the meeting point of two swarms) with wild-type FZB42, and the combined use of the SQR9(△spo0A) mutant and FZB42 improved biofilm formation, root colonization, and the production of secondary metabolites that are beneficial to plants. Furthermore, alleviation of antagonistic interactions of two-member Bacillus consortia improved its beneficial effects to cucumber in a greenhouse experiment. Our results provide evidence that social interactions among bacteria could be an influencing factor for achieving a desired community-level function. IMPORTANCE Bacillus velezensis is one of the most widely applied bacteria in biofertilizers in China and Europe. Additionally, the molecular mechanisms of plant growth promotion and disease suppression by representative model strains are well established, such as B. velezensis SQR9 and FZB42. However, it remains extremely challenging to design efficient consortia based on these model strains. Here, we showed that swarm encounter phenotype is one of the major determinants that affects the performance of two-member Bacillus consortia in vitro and in the rhizosphere. Deletion in global regulatory gene spo0A of SQR9 reduced the strength of boundary formation with FZB42 and resulted in the improved plant growth promotion performance of the dual consortium. This knowledge provides new insights into efficient probiotics consortia design in Bacillus spp.
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Bacillus velezensis stimulates resident rhizosphere Pseudomonas stutzeri for plant health through metabolic interactions. THE ISME JOURNAL 2022; 16:774-787. [PMID: 34593997 PMCID: PMC8483172 DOI: 10.1038/s41396-021-01125-3] [Citation(s) in RCA: 121] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 02/08/2023]
Abstract
Trophic interactions play a central role in driving microbial community assembly and function. In gut or soil ecosystems, successful inoculants are always facilitated by efficient colonization; however, the metabolite exchanges between inoculants and resident bacteria are rarely studied, particularly in the rhizosphere. Here, we used bioinformatic, genetic, transcriptomic, and metabonomic analyses to uncover syntrophic cooperation between inoculant (Bacillus velezensis SQR9) and plant-beneficial indigenous Pseudomonas stutzeri in the cucumber rhizosphere. We found that the synergistic interaction of these two species is highly environmental dependent, the emergence of syntrophic cooperation was only evident in a static nutrient-rich niche, such as pellicle biofilm in addition to the rhizosphere. Our results identified branched-chain amino acids (BCAAs) biosynthesis pathways are involved in syntrophic cooperation. Genome-scale metabolic modeling and metabolic profiling also demonstrated metabolic facilitation among the bacterial strains. In addition, biofilm matrix components from Bacillus were essential for the interaction. Importantly, the two-species consortium promoted plant growth and helped plants alleviate salt stress. In summary, we propose a mechanism in which synergic interactions between a biocontrol bacterium and a partner species promote plant health.
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Xia L, Miao Y, Cao A, Liu Y, Liu Z, Sun X, Xue Y, Xu Z, Xun W, Shen Q, Zhang N, Zhang R. Biosynthetic gene cluster profiling predicts the positive association between antagonism and phylogeny in Bacillus. Nat Commun 2022; 13:1023. [PMID: 35197480 PMCID: PMC8866423 DOI: 10.1038/s41467-022-28668-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 02/01/2022] [Indexed: 01/23/2023] Open
Abstract
Understanding the driving forces and intrinsic mechanisms of microbial competition is a fundamental question in microbial ecology. Despite the well-established negative correlation between exploitation competition and phylogenetic distance, the process of interference competition that is exemplified by antagonism remains controversial. Here, we studied the genus Bacillus, a commonly recognized producer of multifarious antibiotics, to explore the role of phylogenetic patterns of biosynthetic gene clusters (BGCs) in mediating the relationship between antagonism and phylogeny. Comparative genomic analysis revealed a positive association between BGC distance and phylogenetic distance. Antagonistic tests demonstrated that the inhibition phenotype positively correlated with both phylogenetic and predicted BGC distance, especially for antagonistic strains possessing abundant BGCs. Mutant-based verification showed that the antagonism was dependent on the BGCs that specifically harbored by the antagonistic strain. These findings highlight that BGC-phylogeny coherence regulates the positive correlation between congeneric antagonism and phylogenetic distance, which deepens our understanding of the driving force and intrinsic mechanism of microbial interactions.
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Affiliation(s)
- Liming Xia
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Youzhi Miao
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - A'li Cao
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Yan Liu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Zihao Liu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Xinli Sun
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Yansheng Xue
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Zhihui Xu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Weibing Xun
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Qirong Shen
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China
| | - Nan Zhang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Nanjing Agricultural University, 210095, Nanjing, Jiangsu, P. R. China.
| | - Ruifu Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 100081, Beijing, P. R. China.
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11
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Huang R, Feng H, Xu Z, Zhang N, Liu Y, Shao J, Shen Q, Zhang R. Identification of Adhesins in Plant Beneficial Rhizobacteria Bacillus velezensis SQR9 and Their Effect on Root Colonization. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:64-72. [PMID: 34698535 DOI: 10.1094/mpmi-09-21-0234-r] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Probiotic Bacillus colonization of plant root surfaces has been reported to improve its beneficial effect. Chemotaxis, adhesion, aggregation, and biofilm formation are the four steps of root colonization by plant growth-promoting rhizobacteria (PGPRs). Compared with the other three well-studied processes, adhesion of PGPRs is less known. In this study, using mutant strains deleted for potential adhesin genes in PGPR strain Bacillus velezensis SQR9, adherence to both cucumber root surface and abiotic surface by those strains was evaluated. Results showed that deletion mutations ΔlytB, ΔV529_10500, ΔfliD, ΔyhaN, and ΔsacB reduced the adhesion to root surfaces, while, among them, only ΔfliD had significant defects in adhesion to abiotic surfaces (glass and polystyrene). In addition, B. velevzensis SQR9 mutants defective in adhesion to root surfaces showed a deficiency in rhizosphere colonization. Among the encoded proteins, FliD and YhaN played vital roles in root adhesion. This research systematically explored the potential adhesins in a well-studied PGPR strain and also indicated that adhesion progress was required for root colonization, which will help to enhance rhizosphere colonization and beneficial function of PGPRs in agricultural production.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Rong Huang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Haichao Feng
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Zhihui Xu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Nan Zhang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Yunpeng Liu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Jiahui Shao
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Qirong Shen
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Ruifu Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
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12
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Hu F, Cai W, Lin J, Wang W, Li S. Genetic engineering of the precursor supply pathway for the overproduction of the nC 14-surfactin isoform with promising MEOR applications. Microb Cell Fact 2021; 20:96. [PMID: 33964901 PMCID: PMC8105922 DOI: 10.1186/s12934-021-01585-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/24/2021] [Indexed: 11/25/2022] Open
Abstract
Background Surfactin, a representative biosurfactant of lipopeptide mainly produced by Bacillus subtilis, consists of a cyclic heptapeptide linked to a β-hydroxy fatty acid chain. The functional activity of surfactin is closely related to the length and isomerism of the fatty acid chain. Results In this study, the fatty acid precursor supply pathway in Bacillus subtilis 168 for surfactin production was strengthened through two steps. Firstly, pathways competing for the precursors were eliminated with inactivation of pps and pks. Secondly, the plant medium-chain acyl-carrier protein (ACP) thioesterase (BTE) from Umbellularia californica was overexpressed. As a result, the surfactin titer after 24 h of cultivation improved by 34%, and the production rate increased from 0.112 to 0.177 g/L/h. The isoforms identified by RP-HPLC and GC–MS showed that the proportion of nC14-surfactin increased 6.4 times compared to the control strain. A comparison of further properties revealed that the product with more nC14-surfactin had higher surface activity and better performance in oil-washing. Finally, the product with more nC14-surfactin isoform had a higher hydrocarbon-emulsification index, and it increased the water-wettability of the oil-saturated silicate surface. Conclusion The obtained results identified that enhancing the supply of fatty acid precursor is very essential for the synthesis of surfactin. At the same time, this study also proved that thioesterase BTE can promote the production of nC14-surfactin and experimentally demonstrated its higher surface activity and better performance in oil-washing. These results are of great significance for the MEOR application of surfactin. Graphic abstract ![]()
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Affiliation(s)
- Fangxiang Hu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Weijie Cai
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Junzhang Lin
- Oil Production Research Institute, Shengli Oil Field Ltd. Co. Sinopec, Dongying, 257000, PR China
| | - Weidong Wang
- Oil Production Research Institute, Shengli Oil Field Ltd. Co. Sinopec, Dongying, 257000, PR China
| | - Shuang Li
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China.
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13
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Xu Z, Mandic-Mulec I, Zhang H, Liu Y, Sun X, Feng H, Xun W, Zhang N, Shen Q, Zhang R. Antibiotic Bacillomycin D Affects Iron Acquisition and Biofilm Formation in Bacillus velezensis through a Btr-Mediated FeuABC-Dependent Pathway. Cell Rep 2020; 29:1192-1202.e5. [PMID: 31665633 DOI: 10.1016/j.celrep.2019.09.061] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 05/31/2019] [Accepted: 09/19/2019] [Indexed: 02/06/2023] Open
Abstract
Bacillus spp. produce a wide range of secondary metabolites, including antibiotics, which have been well studied for their antibacterial properties but less so as signaling molecules. Previous results indicated that the lipopeptide bacillomycin D is a signal that promotes biofilm development of Bacillus velezensis SQR9. However, the mechanism behind this signaling is still unknown. Here, we show that bacillomycin D promotes biofilm development by promoting the acquisition of iron. Bacillomycin D promotes the transcription of the iron ABC transporter FeuABC by binding to its transcription factor, Btr. These actions increase intracellular iron concentration and activate the KinB-Spo0A-SinI-SinR-dependent synthesis of biofilm matrix components. We demonstrate that this strategy is beneficial for biofilm development and competition with the Pseudomonas fluorescens PF-5. Our results unravel an antibiotic-dependent signaling mechanism that links iron acquisition to biofilm development and ecological competition.
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Affiliation(s)
- Zhihui Xu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Ines Mandic-Mulec
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Huihui Zhang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Yan Liu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Xinli Sun
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Haichao Feng
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Weibing Xun
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Nan Zhang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Qirong Shen
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China
| | - Ruifu Zhang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Peoples R China; Key Laboratory of Microbial Resource Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agriculture Sciences, Beijing, Peoples R China.
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14
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Efficient production of surfactin from xylose-rich corncob hydrolysate using genetically modified Bacillus subtilis 168. Appl Microbiol Biotechnol 2020; 104:4017-4026. [DOI: 10.1007/s00253-020-10528-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/28/2020] [Accepted: 03/05/2020] [Indexed: 01/04/2023]
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15
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Liu Y, Feng H, Fu R, Zhang N, Du W, Shen Q, Zhang R. Induced root-secreted D-galactose functions as a chemoattractant and enhances the biofilm formation of Bacillus velezensis SQR9 in an McpA-dependent manner. Appl Microbiol Biotechnol 2019; 104:785-797. [PMID: 31813049 DOI: 10.1007/s00253-019-10265-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/09/2019] [Accepted: 11/22/2019] [Indexed: 12/26/2022]
Abstract
Chemotaxis towards root exudates and subsequent biofilm formation are very important for root colonization and for providing the beneficial functions of plant growth-promoting rhizobacteria (PGPRs). In this study, in comparison with other root-secreted compounds, D-galactose in the root exudates of cucumber was found to be a strong chemoattractant at the concentration of 1 μM for Bacillus velezensis SQR9. Chemotaxis assays with methyl-accepting chemotaxis proteins (MCPs) deletion strains demonstrated that McpA was solely responsible for chemotaxis towards D-galactose. Interestingly, D-galactose significantly enhanced the biofilm formation of SQR9 in an McpA-dependent manner. Further experiment showed that D-galactose also enhanced root colonization by SQR9. In addition, the secretion of D-galactose by cucumber roots could be induced by inoculation with SQR9, indicating that D-galactose may be an important signal in the interaction between plant and SQR9. These findings suggested that the root-secreted D-galactose was a signal, the secretion of which was induced by the beneficial bacteria, and which in turn induced colonization of the bacteria.
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Affiliation(s)
- Yunpeng Liu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Haichao Feng
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Ruixin Fu
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Nan Zhang
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Wenbin Du
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
| | - Qirong Shen
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Ruifu Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
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16
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Ni H, Li N, Qian M, He J, Chen Q, Huang Y, Zou L, Long ZE, Wang F. Identification of a Novel Nitroreductase LNR and Its Role in Pendimethalin Catabolism in Bacillus subtilis Y3. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:12816-12823. [PMID: 31675231 DOI: 10.1021/acs.jafc.9b04354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Microbial degradation plays a major role in the dissipation of pendimethalin, and nitroreduction is an initial and detoxicating step. Previously, a pendimethalin nitroreductase, PNR, was identified in Bacillus subtilis Y3. Here, another pendimethalin nitroreductase from strain Y3, LNR, was identified. LNR shares only 40% identity with PNR and reduces the aromatic ring C-6 nitro group of pendimethalin and both nitro groups of trifluralin, butralin, and oryzalin. The catalytic activities against the four dinitroanilines were much higher for LNR than for PNR. lnr deletion significantly reduced the pendimethalin-reduction activity (60% activity loss), while pnr deletion led to only 30% activity loss, indicating that both LNR and PNR were involved in pendimethalin nitroreduction in strain Y3; however, LNR played the major role. This study facilitates the elucidation of pendimethalin catabolism and provides degrading enzyme resources for the removal of dinitroaniline herbicide residues in environment and agricultural products.
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Affiliation(s)
- Haiyan Ni
- College of Life Sciences , Jiangxi Normal University , Nanchang , Jiangxi 330022 , China
| | - Na Li
- School of Life Science and Technology , Nanyang Normal University , Nanyang , Henan 473061 , China
| | - Meng Qian
- Laboratory Center of Life Science, College of Life Sciences , Nanjing Agricultural University , Nanjing , Jiangsu 210095 , China
| | - Jian He
- Laboratory Center of Life Science, College of Life Sciences , Nanjing Agricultural University , Nanjing , Jiangsu 210095 , China
| | - Qing Chen
- College of Life Sciences , Zaozhuang University , Zaozhuang , Shandong 277160 , China
| | - Yunhong Huang
- College of Life Sciences , Jiangxi Normal University , Nanchang , Jiangxi 330022 , China
| | - Long Zou
- College of Life Sciences , Jiangxi Normal University , Nanchang , Jiangxi 330022 , China
| | - Zhong-Er Long
- College of Life Sciences , Jiangxi Normal University , Nanchang , Jiangxi 330022 , China
| | - Fei Wang
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering , Jiangxi Agricultural University , Nanchang , Jiangxi 330045 , China
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17
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Isolation of Enterococcus faecium, characterization of its antimicrobial metabolites and viability in probiotic Minas Frescal cheese. Journal of Food Science and Technology 2019; 56:5128-5137. [PMID: 31741537 DOI: 10.1007/s13197-019-03985-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/11/2019] [Accepted: 07/24/2019] [Indexed: 12/21/2022]
Abstract
The aim of this study was to isolate Enterococcus faecium from raw milk samples, to characterize its antimicrobial metabolites, and to evaluate its viability in a probiotic Minas Frescal cheese. For this, antagonist activity against Listeria monocytogenes, safety aspects and biochemical, genotypic, and probiotic characteristics of the isolates were evaluated. Minas Frescal cheese was manufactured with the isolate that showed the best characteristics in vitro, and its viability in the product was evaluated. It was observed that of the 478 lactic acid bacteria isolates, only isolate E297 presented antagonist activity, genes encoding for enterocin production and absence of virulence factors. Besides that, E297 presented probiotic characteristics in vitro, and maintained its viability (8.09 log CFU mL-1) for 14 days of cold storage, when it was added to cheese. Therefore, isolate E297 can be considered a promising microorganism for the manufacture of probiotic foods, especially Minas Frescal cheese.
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18
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Schuster CF, Howard SA, Gründling A. Use of the counter selectable marker PheS* for genome engineering in Staphylococcus aureus. Microbiology (Reading) 2019; 165:572-584. [DOI: 10.1099/mic.0.000791] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Christopher F. Schuster
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Sophie A. Howard
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Angelika Gründling
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
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19
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Zhao L, Ye B, Zhang Q, Cheng D, Zhou C, Cheng S, Yan X. Construction of second generation protease-deficient hosts of Bacillus subtilis for secretion of foreign proteins. Biotechnol Bioeng 2019; 116:2052-2060. [PMID: 30989640 DOI: 10.1002/bit.26992] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/18/2019] [Accepted: 04/11/2019] [Indexed: 12/23/2022]
Abstract
Although one of the major factors limiting the application of Bacillus subtilis as an expression host has been its production of at least eight extracellular proteases, researchers have also noticed that some proteases benefited the secretion of foreign proteins at times. Therefore, to maximize the yield of a foreign protein, the proteases should be selectively inactivated. This raises a new question that how to identify the favorable and unfavorable proteases for a target protein. Here, an evaluation system containing nine mutant strains of B. subtilis 168 was developed to address this question. The mutant strain PD8 has all the eight proteases inactivated whereas each of the other eight mutant strains expresses only one kind of these eight proteases. The target protein is secreted in these nine mutant strains; if the production of target protein in a mutant strain is higher than that in strain PD8, the corresponding protease is regarded as favorable. Accordingly, the optimal protease-deficient host is constructed through inactivating the unfavorable proteases. The effectiveness of this system was confirmed by expressing three foreign proteins. This study provides a strategy for improving the secretion of a foreign protein in B. subtilis through tailoring a personalized protease-deficient host.
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Affiliation(s)
- Leizhen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Bin Ye
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Qi Zhang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Dan Cheng
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Chaoyang Zhou
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Shan Cheng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Xin Yan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China.,Provincial Key Laboratory of Agrobiology, Institute of Agro-biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, People's Republic of China
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20
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Qiu Y, Zhu Y, Zhang Y, Sha Y, Xu Z, Li S, Feng X, Xu H. Characterization of a Regulator pgsR on Endogenous Plasmid p2Sip and Its Complementation for Poly(γ-glutamic acid) Accumulation in Bacillus amyloliquefaciens. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:3711-3722. [PMID: 30866628 DOI: 10.1021/acs.jafc.9b00332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Bacillus amyloliquefaciens NX-2S154 is a promising poly(γ-glutamic acid) (γ-PGA) producing strain discovered in previous studies. However, the wild-type strain contains an unknown endogenous plasmid, p2Sip, which causes low transformation efficiency and instability of exogenous plasmids. In our study, p2Sip is 5622 bp with 41% G+C content and contains four putative open reading frames (ORFs), including genes repB, hsp, and mobB and γ-PGA-synthesis regulator, pgsR. Elimination of p2Sip from strain NX-2S154 delayed γ-PGA secretion and decreased production of γ-PGA by 18.1%. Integration of a pgsR expression element into the genomic BamHI locus using marker-free manipulation based on pheS* increased the γ-PGA titer by 8%. pgsR overexpression upregulated the expression of γ-PGA synthase pgsB, regulator degQ, and glutamic acid synthase gltA, thus increasing the γ-PGA production in B. amyloliquefaciens NB. Our results indicated that pgsR from p2Sip plays an important regulatory role in γ-PGA synthesis in B. amyloliquefaciens.
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Affiliation(s)
- Yibin Qiu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Yifan Zhu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Yatao Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Yuanyuan Sha
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Zongqi Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Xiaohai Feng
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing 211816 , China
- College of Food Science and Light Industry , Nanjing Tech University , Nanjing 211816 , China
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Bacillus velezensis Wall Teichoic Acids Are Required for Biofilm Formation and Root Colonization. Appl Environ Microbiol 2019; 85:AEM.02116-18. [PMID: 30552189 DOI: 10.1128/aem.02116-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/03/2018] [Indexed: 12/21/2022] Open
Abstract
Rhizosphere colonization by plant growth-promoting rhizobacteria (PGPR) along plant roots facilitates the ability of PGPR to promote plant growth and health. Thus, an understanding of the molecular mechanisms of the root colonization process by plant-beneficial Bacillus strains is essential for the use of these strains in agriculture. Here, we observed that an sfp gene mutant of the plant growth-promoting rhizobacterium Bacillus velezensis SQR9 was unable to form normal biofilm architecture, and differential protein expression was observed by proteomic analysis. A minor wall teichoic acid (WTA) biosynthetic protein, GgaA, was decreased over 4-fold in the Δsfp mutant, and impairment of the ggaA gene postponed biofilm formation and decreased cucumber root colonization capabilities. In addition, we provide evidence that the major WTA biosynthetic enzyme GtaB is involved in both biofilm formation and root colonization. The deficiency in biofilm formation of the ΔgtaB mutant may be due to an absence of UDP-glucose, which is necessary for the synthesis of biofilm matrix exopolysaccharides (EPS). These observations provide insights into the root colonization process by a plant-beneficial Bacillus strain, which will help improve its application as a biofertilizer.IMPORTANCE Bacillus velezensis is a Gram-positive plant-beneficial bacterium which is widely used in agriculture. Additionally, Bacillus spp. are some of the model organisms used in the study of biofilms, and as such, the molecular networks and regulation systems of biofilm formation are well characterized. However, the molecular processes involved in root colonization by plant-beneficial Bacillus strains remain largely unknown. Here, we showed that WTAs play important roles in the plant root colonization process. The loss of the gtaB gene affects the ability of B. velezensis SQR9 to sense plant polysaccharides, which are important environmental cues that trigger biofilm formation and colonization in the rhizosphere. This knowledge provides new insights into the Bacillus root colonization process and can help improve our understanding of plant-rhizobacterium interactions.
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Feng H, Zhang N, Fu R, Liu Y, Krell T, Du W, Shao J, Shen Q, Zhang R. Recognition of dominant attractants by key chemoreceptors mediates recruitment of plant growth-promoting rhizobacteria. Environ Microbiol 2019; 21:402-415. [PMID: 30421582 DOI: 10.1111/1462-2920.14472] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 10/09/2018] [Accepted: 11/05/2018] [Indexed: 12/16/2022]
Abstract
Chemotaxis to plant root exudates is supposed to be a prerequisite for efficient root colonization by rhizobacteria. This is a highly multifactorial process since root exudates are complex compound mixtures of which components are recognized by different chemoreceptors. Little information is available as to the key components in root exudates and their receptors that drive colonization related chemotaxis. We present here the first global assessment of this issue using the plant growth-promoting rhizobacterium (PGPR) Bacillus velezensis SQR9 (formerly B. amyloliquefaciens). This strain efficiently colonizes cucumber roots, and here, we show that chemotaxis to cucumber root exudates was essential in this process. We conducted chemotaxis assays using cucumber root exudates at different concentrations, individual exudate components as well as recomposed exudates, taking into account their concentrations detected in root exudates. Results indicated that two key chemoreceptors, McpA and McpC, were essential for root exudate chemotaxis and root colonization. Both receptors possess a broad ligand range and recognize most of the exudate key components identified (malic, fumaric, gluconic and glyceric acids, Lys, Ser, Ala and mannose). The remaining six chemoreceptors did not contribute to exudate chemotaxis. This study provides novel insight into the evolution of the chemotaxis system in rhizobacteria.
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Affiliation(s)
- Haichao Feng
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China.,Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Nan Zhang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ruixin Fu
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yunpeng Liu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008, Granada, Spain
| | - Wenbin Du
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jiahui Shao
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qirong Shen
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ruifu Zhang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China.,Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
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23
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Xu Z, Xie J, Zhang H, Wang D, Shen Q, Zhang R. Enhanced Control of Plant Wilt Disease by a Xylose-Inducible degQ Gene Engineered into Bacillus velezensis Strain SQR9XYQ. PHYTOPATHOLOGY 2019; 109:36-43. [PMID: 29927357 DOI: 10.1094/phyto-02-18-0048-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bacillus velezensis SQR9 (former B. amyloliquefaciens SQR9) is a plant-growth-promoting rhizobacterium (PGPR) that promotes plant growth and health. The colonization of PGPR strains along plant roots is a prerequisite for them to execute their specific functions. However, one problem of microbial introduction in practice is that the applied PGPR strains do not always successfully colonize the rhizosphere. In Bacillus spp., two-component signal transduction system (TCS) DegS/U regulates flagellar motility, biofilm formation and antibiotic production. Phosphorylation of DegU by DegS is positively affected by DegQ protein. In this study, we constructed a xylose-inducible degQ genetically engineered strain SQR9XYQ to improve the biocontrol activity. The results from in vitro, root in situ, greenhouse experiments and RT-qPCR studies demonstrate that (i) the phosphorylation of DegU in SQR9XYQ can be gradually activated by xylose, which is a component of both cucumber and tomato root exudates, and (ii) biofilm formation, antibiotic expression, colonization activity, and biocontrol efficiency were improved in SQR9XYQ compared with the wild-type strain SQR9. These results suggest that colonization trait is important to biocontrol strains for maintenance of plant health.
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Affiliation(s)
- Zhihui Xu
- First, second, third, fourth, and fifth authors: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 210095, China; and sixth author: Nanjing Agricultural University, College of Resources and Environmental Sciences, Weigang 1#, Nanjing, Jiangsu, China, 210095
| | - Jiyu Xie
- First, second, third, fourth, and fifth authors: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 210095, China; and sixth author: Nanjing Agricultural University, College of Resources and Environmental Sciences, Weigang 1#, Nanjing, Jiangsu, China, 210095
| | - Huihui Zhang
- First, second, third, fourth, and fifth authors: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 210095, China; and sixth author: Nanjing Agricultural University, College of Resources and Environmental Sciences, Weigang 1#, Nanjing, Jiangsu, China, 210095
| | - Dandan Wang
- First, second, third, fourth, and fifth authors: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 210095, China; and sixth author: Nanjing Agricultural University, College of Resources and Environmental Sciences, Weigang 1#, Nanjing, Jiangsu, China, 210095
| | - Qirong Shen
- First, second, third, fourth, and fifth authors: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 210095, China; and sixth author: Nanjing Agricultural University, College of Resources and Environmental Sciences, Weigang 1#, Nanjing, Jiangsu, China, 210095
| | - Ruifu Zhang
- First, second, third, fourth, and fifth authors: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 210095, China; and sixth author: Nanjing Agricultural University, College of Resources and Environmental Sciences, Weigang 1#, Nanjing, Jiangsu, China, 210095
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24
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Efficient Counterselection for Methylococcus capsulatus (Bath) by Using a Mutated pheS Gene. Appl Environ Microbiol 2018; 84:AEM.01875-18. [PMID: 30266726 DOI: 10.1128/aem.01875-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/22/2018] [Indexed: 11/20/2022] Open
Abstract
Methylococcus capsulatus (Bath) is a representative gammaproteobacterial methanotroph that has been studied extensively in diverse research fields. The sacB gene, which encodes levansucrase, causing cell death in the presence of sucrose, is widely used as a counterselectable marker for disruption of a target gene in Gram-negative bacteria. However, sacB is not applicable to all Gram-negative bacteria, and its efficiency for the counterselection of M. capsulatus (Bath) is low. Here, we report the construction of an alternative counterselectable marker, pheS*, by introduction of two point mutations (A306G and T252A) into the pheS gene from M. capsulatus (Bath), which encodes the α-subunit of phenylalanyl-tRNA synthetase. The transformant harboring pheS* on an expression plasmid showed sensitivity to 10 mM p-chloro-phenylalanine, whereas the transformant harboring an empty plasmid showed no sensitivity, indicating the availability of pheS* as a counterselectable marker in M. capsulatus (Bath). To validate the utility of the pheS* marker in counterselection, we attempted to obtain an unmarked mutant of xoxF, a gene encoding the major subunit of Xox methanol dehydrogenase, which we failed to obtain by counterselection using the sacB marker. PCR, immunodetection using an anti-XoxF antiserum, and a cell growth assay in the absence of calcium demonstrated successful disruption of the xoxF gene in M. capsulatus (Bath). The difference in counterselection efficiencies of the markers indicated that pheS* is more suitable than sacB for counterselection in M. capsulatus (Bath). This study provides a new genetic tool enabling efficient counterselection in M. capsulatus (Bath).IMPORTANCE Methanotrophs have long been considered promising strains for biologically reducing methane from the environment and converting it into valuable products, because they can oxidize methane at ambient temperatures and pressures. Although several methodologies and tools for the genetic manipulation of methanotrophs have been developed, their mutagenic efficiency remains lower than that of tractable strains such as Escherichia coli Therefore, further improvements are still desired. The significance of our study is that we increased the efficiency of counterselection in M. capsulatus (Bath) by employing pheS*, which was newly constructed as a counterselectable marker. This will allow for the efficient production of gene-disrupted and gene-integrated mutants of M. capsulatus (Bath). We anticipate that this counterselection system will be utilized widely by the methanotroph research community, leading to improved productivity of methane-based bioproduction and new insights into methanotrophy.
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25
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Feng H, Zhang N, Du W, Zhang H, Liu Y, Fu R, Shao J, Zhang G, Shen Q, Zhang R. Identification of Chemotaxis Compounds in Root Exudates and Their Sensing Chemoreceptors in Plant-Growth-Promoting Rhizobacteria Bacillus amyloliquefaciens SQR9. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:995-1005. [PMID: 29714096 DOI: 10.1094/mpmi-01-18-0003-r] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Chemotaxis-mediated response to root exudates, initiated by sensing-specific ligands through methyl-accepting chemotaxis proteins (MCP), is very important for root colonization and beneficial functions of plant-growth-promoting rhizobacteria (PGPR). Systematic identification of chemoattractants in complex root exudates and their sensing chemoreceptors in PGPR is helpful for enhancing their recruitment and colonization. In this study, 39 chemoattractants and 5 chemorepellents, including amino acids, organic acids, and sugars, were identified from 98 tested components of root exudates for the well-studied PGPR strain Bacillus amyloliquefaciens SQR9. Interestingly, mutant stain SQR9Δ8mcp, with all eight putative chemoreceptors completely deleted, lost the chemotactic responses to those 44 compounds. Gene complementation, chemotaxis assay, and isothermal titration calorimetry analysis revealed that McpA was mainly responsible for sensing organic acids and amino acids, while McpC was mostly for amino acids. These two chemoreceptors may play important roles in the rhizosphere chemotaxis of SQR9. In contrast, the B. amyloliquefaciens-unique chemoreceptor McpR was specifically responsible for arginine, and residues Tyr-78, Thr-131, and Asp-162 were critical for arginine binding. This study not only deepened our insights into PGPR-root interaction but also provided useful information to enhance the rhizosphere chemotaxis mobility and colonization of PGPR, which will promote their application in agricultural production.
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Affiliation(s)
- Haichao Feng
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
- 2 Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China; and
| | - Nan Zhang
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Wenbin Du
- 3 State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huihui Zhang
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Yunpeng Liu
- 2 Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China; and
| | - Ruixin Fu
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Jiahui Shao
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Guishan Zhang
- 2 Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China; and
| | - Qirong Shen
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Ruifu Zhang
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China
- 2 Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China; and
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26
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Multiple genetic tools for editing the genome of Riemerella anatipestifer using a counterselectable marker. Appl Microbiol Biotechnol 2018; 102:7475-7488. [PMID: 29951859 DOI: 10.1007/s00253-018-9181-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/12/2018] [Accepted: 06/14/2018] [Indexed: 02/07/2023]
Abstract
Riemerella anatipestifer (R. anatipestifer, RA) is an important bacterial pathogen of ducks and other birds; infection with RA causes high poultry mortality and heavy economic losses in the poultry industry. However, the pathogenesis of this bacterium is poorly understood, in part due to the lack of a suitable array of methods for genetic manipulation. In this study, we first examined the efficacy of the mutated pheS gene (pheS*) as a counterselectable marker in R. anatipestifer. A suicide vector carrying pheS*, pOES, was constructed and used for markerless deletion of the gene RA0C_2053 which encode a putative TonB-dependent receptor in RA ATCC11845. The suicide plasmid pOES was also used to introduce a "knock-in" Myc-tag into the C-terminus of RA0C_1912 which encode a putative Fur protein. Using pheS* as a counterselectable marker, markerless mutagenesis and "knock-in" genetic manipulation techniques were also developed based on natural transformation. Furthermore, this marker was used to generate a point mutation in the RA0C_1912 gene of the RA ATCC11845 genome. The genetic methods developed in this study provide new and useful tools required to investigate the physiology and pathogenic mechanisms of this bacterium. These techniques may also have wider application in many other members of the Flavobacteria.
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27
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pheS* as a counter-selectable marker for marker-free genetic manipulations in Bacillus anthracis. J Microbiol Methods 2018; 151:35-38. [PMID: 29859216 DOI: 10.1016/j.mimet.2018.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/18/2018] [Accepted: 05/29/2018] [Indexed: 12/28/2022]
Abstract
Several genetic tools have been developed for use in Bacillus anthracis, but there is still a need for a more marker-free gene inactivation protocols. Thus, we report a method to generate unmarked mutations in B. anthracis. This approach was based on the counter-selectable pheS* gene with assistance by the I-SceI homing endonuclease. Using this strategy, the NprR gene, a transcriptional activator of B. anthracis, was deleted at an extremely high efficiency. Our study indicates that mutated pheS is a useful counter-selective marker to design a valuable genetic tool for in-frame and unmarked gene deletions of B. anthracis.
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28
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Zhao X, Xu J, Tan M, Yu Z, Yang S, Zheng H, Song H. Construction of a plasmid interspecific transfer system in Bacillus species with the counter-selectable marker mazF. J Ind Microbiol Biotechnol 2018; 45:417-428. [PMID: 29737437 DOI: 10.1007/s10295-018-2038-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/25/2018] [Indexed: 11/29/2022]
Abstract
Bacillus sp. strains as attractive hosts for the production of heterologous secretory proteins usually play important roles in bio-industry. However, low transformation efficiency of exogenous plasmids limited the application of Bacillus species. Here, a novel plasmid interspecific transfer system, with high transformation efficiency, high positive rate, and convenient manipulation, has been successfully constructed. A high electrotransformation efficiency strain Bacillus subtilis F-168 containing the counter-selectable marker mazF was used as the plasmid donor strain in this transfer method. A shuttled plasmid pBE980 and its recombinant plasmids pBE980::pulA and pBE980::HSPA were successfully transferred into the recipient Bacillus strains (Bacillus amyloliquefaciens 66, Bacillus licheniformis 124 and Bacillus megaterium 258) by this method. After co-culturing the donor cells (OD600nm = 1.3-1.7) and the recipient cells (OD600nm = 0.5-0.9) for 24 h in 22 °C, more than 1.0 × 105 positive transformants were obtained and a interspecific transformation efficiency of 1.0 × 10-3. It would provide a new approach for genetic manipulation in Bacillus strains and accelerate the research progress of the wild Bacillus strains in bio-industry.
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Affiliation(s)
- XingYa Zhao
- University of Chinese Academy of Sciences, Beijing, 100049, China.,Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - JianYong Xu
- Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,Tianjin Key Laboratory for Industrial Biological, Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Ming Tan
- Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,Tianjin Key Laboratory for Industrial Biological, Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - ZhenXiao Yu
- University of Chinese Academy of Sciences, Beijing, 100049, China.,Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - ShiBin Yang
- University of Chinese Academy of Sciences, Beijing, 100049, China.,Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - HongChen Zheng
- Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,Tianjin Key Laboratory for Industrial Biological, Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
| | - Hui Song
- University of Chinese Academy of Sciences, Beijing, 100049, China. .,Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,Tianjin Key Laboratory for Industrial Biological, Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
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29
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Kharchenko MS, Teslya PN, Babaeva MN, Zakataeva NP. Improving the selection efficiency of the counter-selection marker pheS* for the genetic engineering of Bacillus amyloliquefaciens. J Microbiol Methods 2018; 148:18-21. [PMID: 29596960 DOI: 10.1016/j.mimet.2018.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 03/22/2018] [Indexed: 11/28/2022]
Abstract
Bacillus subtilis pheS was genetically modified to obtain a counter-selection marker with high selection efficiency in Bacillus amyloliquefaciens. The application of the new replication-thermosensitive integrative vector pNZTM1, containing this marker, pheSBsT255S/A309G, with a two-step replacement recombination procedure provides an effective tool for the genetic engineering of industrially important Bacillus species.
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Affiliation(s)
| | - Petr N Teslya
- Ajinomoto-Genetika Research Institute, Moscow, Russia
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30
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Xuan C, Haixia L, Xian P, Ling Z. [Construction of srtA-deletion mutant of Streptococcus mutans by an in-frame deletion system]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2017; 35:588-592. [PMID: 29333770 DOI: 10.7518/hxkq.2017.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To construct srtA-gene deletion mutant of Streptococcus mutans (S. mutans) UA159 with IFDC2 cassette through overlapping polymerase chain reaction (PCR) and allelic homologous recombination. METHODS First, the upstream and downstream fragments surrounding the srtA and IFDC2 cassette were PCR amplified and ligated through overlapping PCR. The resulting amplicon was transformed into UA159, and positive transformants were selected on BHI plates containing erythromycin. Second, upstream and downstream fragments of srtA with overlap regions were generated by PCR and were overlapped to create upΔ-down amplicon. Then, the upΔ-down amplicon was transformed into the aforementioned positive transformants and selected on BHI plates containing p-Cl-Phe. RESULTS The PCR analysis and DNA sequencing results indicated that the coding region of the srtA was completely deleted, and the upstream and downstream regions flanking the srtA were ligated seamlessly. CONCLUSIONS The markerless srtA-deletion mutant of S. mutans was constructed successfully, which laid a foundation for further study of its biological function and influence on the biofilm formation of S. mutans.
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Affiliation(s)
- Chen Xuan
- State Key Laboratory of Oral Diseases & Dept. of Conservative Dentistry and Endodontics, National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Liu Haixia
- State Key Laboratory of Oral Diseases & Dept. of Conservative Dentistry and Endodontics, National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Peng Xian
- State Key Laboratory of Oral Diseases & Dept. of Conservative Dentistry and Endodontics, National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Zou Ling
- State Key Laboratory of Oral Diseases & Dept. of Conservative Dentistry and Endodontics, National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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31
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Guo Y, Hu D, Guo J, Li X, Guo J, Wang X, Xiao Y, Jin H, Liu M, Li Z, Bi D, Zhou Z. The Role of the Regulator Fur in Gene Regulation and Virulence of Riemerella anatipestifer Assessed Using an Unmarked Gene Deletion System. Front Cell Infect Microbiol 2017; 7:382. [PMID: 28971067 PMCID: PMC5609570 DOI: 10.3389/fcimb.2017.00382] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/09/2017] [Indexed: 11/29/2022] Open
Abstract
Riemerella anatipestifer, an avian pathogen, has resulted in enormous economic losses to the duck industry globally. Notwithstanding, little is known regarding the physiological, pathogenic and virulence mechanisms of Riemerella anatipestifer (RA) infection. However, the role of Ferric uptake regulator (Fur) in the virulence of R. anatipestifer has not, to date, been demonstrated. Using a genetic approach, unmarked gene deletion system, we evaluated the function of fur gene in the virulence of R. anatipestifer. For this purpose, we constructed a suicide vector containing pheS as a counter selectable marker for unmarked deletion of fur gene to investigate its role in the virulence. After successful transformation of the newly constructed vector, a mutant strain was characterized for genes regulated by iron and Fur using RNA-sequencing and a comparison was made between wild type and mutant strains in both iron restricted and enriched conditions. RNA-seq analysis of the mutant strain in a restricted iron environment showed the downregulation and upregulation of genes which were involved in either important metabolic pathways, transport processes, growth or cell membrane synthesis. Electrophoretic mobility shift assay was performed to identify the putative sequences recognized by Fur. The putative Fur-box sequence was 5′-GATAATGATAATCATTATC-3′. Lastly, the median lethal dose and histopathological investigations of animal tissues also illustrated mild pathological lesions produced by the mutant strain as compared to the wild type RA strain, hence showing declined virulence. Conclusively, an unmarked gene deletion system was successfully developed for RA and the role of the fur gene in virulence was explored comprehensively.
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Affiliation(s)
- Yunqing Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Di Hu
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Jie Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Xiaowen Li
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Jinyue Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Xiliang Wang
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Yuncai Xiao
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Hui Jin
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
| | - Mei Liu
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Zili Li
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Dingren Bi
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
| | - Zutao Zhou
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
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Zhang S, Zou Z, Kreth J, Merritt J. Recombineering in Streptococcus mutans Using Direct Repeat-Mediated Cloning-Independent Markerless Mutagenesis (DR-CIMM). Front Cell Infect Microbiol 2017; 7:202. [PMID: 28589101 PMCID: PMC5440470 DOI: 10.3389/fcimb.2017.00202] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 05/08/2017] [Indexed: 01/13/2023] Open
Abstract
Studies of the dental caries pathogen Streptococcus mutans have benefitted tremendously from its sophisticated genetic system. As part of our own efforts to further improve upon the S. mutans genetic toolbox, we previously reported the development of the first cloning-independent markerless mutagenesis (CIMM) system for S. mutans and illustrated how this approach could be adapted for use in many other organisms. The CIMM approach only requires overlap extension PCR (OE-PCR) protocols to assemble counterselectable allelic replacement mutagenesis constructs, and thus greatly increased the speed and efficiency with which markerless mutations could be introduced into S. mutans. Despite its utility, the system is still subject to a couple limitations. Firstly, CIMM requires negative selection with the conditionally toxic phenylalanine analog p-chlorophenylalanine (4-CP), which is efficient, but never perfect. Typically, 4-CP negative selection results in a small percentage of naturally resistant background colonies. Secondly, CIMM requires two transformation steps to create markerless mutants. This can be inherently problematic if the transformability of the strain is negatively impacted after the first transformation step, which is used to insert the counterselection cassette at the mutation site on the chromosome. In the current study, we develop a next-generation counterselection cassette that eliminates 4-CP background resistance and combine this with a new direct repeat-mediated cloning-independent markerless mutagenesis (DR-CIMM) system to specifically address the limitations of the prior approach. DR-CIMM is even faster and more efficient than CIMM for the creation of all types of deletions, insertions, and point mutations and is similarly adaptable for use in a wide range of genetically tractable bacteria.
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Affiliation(s)
- Shan Zhang
- Department of Restorative Dentistry, Oregon Health and Science UniversityPortland, OR, United States.,State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of SciencesBeijing, China
| | - Zhengzhong Zou
- Department of Restorative Dentistry, Oregon Health and Science UniversityPortland, OR, United States
| | - Jens Kreth
- Department of Restorative Dentistry, Oregon Health and Science UniversityPortland, OR, United States
| | - Justin Merritt
- Department of Restorative Dentistry, Oregon Health and Science UniversityPortland, OR, United States.,Department of Molecular Microbiology and Immunology, Oregon Health and Science UniversityPortland, OR, United States
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Chen L, Liu Y, Wu G, Zhang N, Shen Q, Zhang R. Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 Induces Plant Salt Tolerance through Spermidine Production. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:423-432. [PMID: 28291380 DOI: 10.1094/mpmi-02-17-0027-r] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The inoculation of plants with plant-growth-promoting rhizobacterium has been an effective strategy for enhancing plant salt tolerance to diminish the loss of agricultural productivity caused by salt stress; however, the signal transmitted from bacteria to the plant under salt stress is poorly understood. In this study, the salt tolerance of Arabidopsis thaliana and Zea mays was enhanced by inoculation with Bacillus amyloliquefaciens SQR9. Using dialysis bags with different molecular weight cutoffs, we sorted through the molecules secreted by SQR9 and found that spermidine is responsible for enhancing plant salt tolerance. An SQR9 ΔspeB mutant deficient in spermidine production failed to induce plant salt tolerance. However, the induction of plant salt tolerance was disrupted by mutating genes involved in reduced glutathione (GSH) biosynthesis and the salt overly sensitive pathway in Arabidopsis. Using quantitative real-time polymerase chain reaction, this study demonstrated that spermidine produced by SQR9 leads to increased glutamine synthetase and glutathione reductase gene expression, leading to increased levels of GSH, which is critical for scavenging reactive oxygen species. SQR9-derived spermidine also upregulates the expression of NHX1 and NHX7, which sequesters Na+ into vacuoles and expels Na+ from the cell, thereby reducing ion toxicity.
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Affiliation(s)
- Lin Chen
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China; and
| | - Yunpeng Liu
- 2 Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Gengwei Wu
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China; and
| | - Nan Zhang
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China; and
| | - Qirong Shen
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China; and
| | - Ruifu Zhang
- 1 Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, P.R. China; and
- 2 Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
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