1
|
Phillips EK, Cannon JA, Zhou Y, Bonifer KS, Reynolds TB. Conjugation-Mediated Plasmid Transfer Enables Genetic Modification of Diverse Bacillus Species. Microbiol Spectr 2023; 11:e0370022. [PMID: 36975796 PMCID: PMC10101014 DOI: 10.1128/spectrum.03700-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 02/17/2023] [Indexed: 03/29/2023] Open
Abstract
Performing genetic manipulations in Bacillus strains is often hindered by difficulty in identifying conditions appropriate for DNA uptake. This shortcoming limits our understanding of the functional diversity within this genus and the practical application of new strains. We have developed a simple method for increasing the genetic tractability of Bacillus spp. through conjugation-mediated plasmid transfer via a diaminopimelic acid (DAP) auxotrophic Escherichia coli donor strain. We observe transfer into representatives of the Bacillus clades subtilis, cereus, galactosidilyticus, and Priestia megaterium and successfully applied this protocol to 9 out of 12 strains attempted. We utilized the BioBrick 2.0 plasmids pECE743 and pECE750, as well as the CRISPR plasmid pJOE9734.1, to generate a xylose-inducible green-fluorescent protein (GFP)-expressing conjugal vector, pEP011. The use of xylose-inducible GFP ensures ease of confirming transconjugants, which enables users to quickly rule out false positives. Additionally, our plasmid backbone offers the flexibility to be used in other contexts, including transcriptional fusions and overexpression, with only a few modifications. IMPORTANCE Bacillus species are widely used to produce proteins and to understand microbial differentiation. Unfortunately, outside a few lab strains, genetic manipulation is difficult and can prevent thorough dissection of useful phenotypes. We developed a protocol that utilizes conjugation (plasmids that initiate their own transfer) to introduce plasmids into a diverse range of Bacillus spp. This will facilitate a deeper study of wild isolates for both industrial and pure research uses.
Collapse
Affiliation(s)
- Elise K. Phillips
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
| | - Jordan A. Cannon
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
| | - Yue Zhou
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
| | - Kyle S. Bonifer
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
| | - Todd B. Reynolds
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
| |
Collapse
|
2
|
Appelbaum M, Schweder T. Metabolic Engineering of
Bacillus
– New Tools, Strains, and Concepts. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
3
|
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 ![]()
Collapse
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.
| |
Collapse
|
4
|
Liu YC, Han LL, Chen TY, Lu YB, Feng H. Characterization of a Protease Hyper-Productive Mutant of Bacillus pumilus by Comparative Genomic and Transcriptomic Analysis. Curr Microbiol 2020; 77:3612-3622. [PMID: 32749522 DOI: 10.1007/s00284-020-02154-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 07/28/2020] [Indexed: 01/06/2023]
Abstract
Bacillus pumilus BA06 has great potential for the production of alkaline proteases. To improve the protease yield, classical mutagenesis to combine the physical and chemical mutagens was performed to obtain a protease hyper-productive mutant SCU11. The full genome sequences of BA06 and SCU11 strains were assembled through DNA sequencing using the PacBio sequencing platform. By comparative genomics analysis, 147 SNPs and 15 InDels were found between these two genomes, which lead to alternation of coding sequence in 15 genes. Noticeable, the gene (kinA) encoding sporulation kinase A is interrupted by introducing a stop codon in its coding region in BA06. Interestedly, this gene is reversely corrected in SCU11. Furthermore, comparative transcriptome analysis revealed that kinA and two positive regulatory genes (DegU and Spo0A) were upregulated in transcription in SCU11. In terms of the transcriptional data, upregulation of a phosphorylation cascade starting with KinA may enhance Spo0A phosphorylation, and thus activate expression of the gene aprE (encoding major extracellular protease) through repression of AbrB (a repressor of aprE) and activation of SinI, an antagonist of SinR (a repressor of aprE). In addition, the other genes involved in various metabolic pathways, especially of membrane transport and sporulation, were altered in transcription between these two strains. Conclusively, our transcriptome data suggested that upregulation degU and spo0A, as well as kinA, may at least partially contribute to the high production of alkaline protease in SCU11.
Collapse
Affiliation(s)
- Yong-Cheng Liu
- College of Life Sciences, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China
| | - Lin-Li Han
- College of Life Sciences, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China
| | - Tian-Yu Chen
- College of Life Sciences, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China
| | - Yan-Bing Lu
- College of Life Sciences, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China
| | - Hong Feng
- College of Life Sciences, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, Sichuan University, Chengdu, 610064, Sichuan, People's Republic of China.
| |
Collapse
|
5
|
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]
|
6
|
Han LL, Liu YC, Miao CC, Feng H. Disruption of the pleiotropic gene scoC causes transcriptomic and phenotypical changes in Bacillus pumilus BA06. BMC Genomics 2019; 20:327. [PMID: 31039790 PMCID: PMC6492404 DOI: 10.1186/s12864-019-5671-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 04/08/2019] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Bacillus pumilus is a Gram-positive and endospore-forming bacterium broadly existing in a variety of environmental niches. Because it produces and secrets many industrially useful enzymes, a lot of studies have been done to understand the underlying mechanisms. Among them, scoC was originally identified as a pleiotropic transcription factor negatively regulating protease production and sporulation in B. subtilis. Nevertheless, its role in B. pumilus largely remains unknown. RESULTS In this study we successfully disrupted scoC gene in B. pumilus BA06 and found increased total extracellular protease activity in scoC mutant strain. Surprisingly, we also found that scoC disruption reduced cell motility possibly by affecting flagella formation. To better understand the underlying mechanism, we performed transcriptome analysis with RNA sequencing. The result showed that more than one thousand genes were alternated at transcriptional level across multiple growth phases, and among them the largest number of differentially expressed genes (DEGs) were identified at the transition time point (12 h) between the exponential growth and the stationary growth phases. In accordance with the altered phenotype, many protease genes especially the aprE gene encoding alkaline protease were transcriptionally regulated. In contrast to the finding in B. subtilis, the aprN gene encoding neutral protease was transcriptionally downregulated in B. pumilus, implicating that scoC plays strain-specific roles. CONCLUSIONS The pleiotropic transcription factor ScoC plays multiple roles in various cellular processes in B. pumilus, some of which were previously reported in B. subtilis. The supervising finding is the identification of ScoC as a positive regulator for flagella formation and bacterial motility. Our transcriptome data may provide hints to understand the underlying mechanism.
Collapse
Affiliation(s)
- Lin-Li Han
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Yong-Cheng Liu
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Cui-Cui Miao
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Hong Feng
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, People's Republic of China.
| |
Collapse
|
7
|
Ye B, Zhou C, Zhao L, Cheng S, Cheng D, Yan X. Unmarked genetic manipulation in Bacillus subtilis by natural co-transformation. J Biotechnol 2018; 284:57-62. [PMID: 30092237 DOI: 10.1016/j.jbiotec.2018.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 07/27/2018] [Accepted: 08/05/2018] [Indexed: 01/14/2023]
Abstract
Bacillus subtilis is well known as both a model organism and as a microbial cell factory. Simple and scarless gene modification is a desirable tool for basic research and industrial applications of B. subtilis. It has been demonstrated that naturally competent strains of B. subtilis can uptake multiple different DNA molecules, a phenomenon called co-transformation. Here, we describe a co-transformation-based method for generating unmarked mutants of B. subtilis. The PCR product containing the desired mutant allele is introduced into B. subtilis through co-transformation of the plasmid pUS20, which harbours a spectinomycin-resistant marker (Spcr). The target mutation is acquired by screening transformants for integration of pUS20 by resistance to spectinomycin. Due to its unstable replication in B. subtilis, pUS20 is easily cured from transformants in the absence of spectinomycin. This method allows for point mutation delivery at frequencies of approximately 30%. Deletions and insertions of long DNA fragments can also be carried out efficiently using this method. Moreover, this method is also successful in Bacillus velezensis, indicating that it may be extended to other Bacillus species that can form natural competence.
Collapse
Affiliation(s)
- Bin Ye
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Chaoyang Zhou
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Leizhen Zhao
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Shan Cheng
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Dan Cheng
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China
| | - Xin Yan
- Jiangsu Provincial Key Lab for Solid Organic Wastes Utilization, Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.
| |
Collapse
|
8
|
The restriction modification system of Bacillus licheniformis MS1 and generation of a readily transformable deletion mutant. Appl Microbiol Biotechnol 2017; 101:7933-7944. [PMID: 28942561 DOI: 10.1007/s00253-017-8532-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 01/19/2023]
Abstract
Restriction modification systems (R-M systems), consisting of a restriction endonuclease and a cognate methyltransferase, constitute an effective means of a cell to protect itself from foreign DNA. Identification, characterization, and deletion of the restriction modification system BliMSI, a putative isoschizomer of ClaI from Caryophanon latum, were performed in the wild isolate Bacillus licheniformis MS1. BliMSI was produced as recombinant protein in Escherichia coli, purified, and in vitro analysis demonstrated identical restriction endonuclease activity as for ClaI. A recombinant E. coli strain, expressing the heterologous bliMSIM gene, was constructed and used as the host for in vivo methylation of plasmids prior to their introduction into B. licheniformis to improve transformation efficiencies. The establishment of suicide plasmids in the latter was rendered possible. The subsequent deletion of the restriction endonuclease encoding gene, bliMSIR, caused doubled transformation efficiencies in the respective mutant B. licheniformis MS2 (∆bliMSIR). Along with above in vivo methylation, the establishment of further gene deletions (∆upp, ∆yqfD) was performed. The constructed triple mutant (∆bliMSIR, ∆upp, ∆yqfD) enables rapid genome manipulation, a requirement for genetic engineering of industrially important strains.
Collapse
|
9
|
Han LL, Shao HH, Liu YC, Liu G, Xie CY, Cheng XJ, Wang HY, Tan XM, Feng H. Transcriptome profiling analysis reveals metabolic changes across various growth phases in Bacillus pumilus BA06. BMC Microbiol 2017; 17:156. [PMID: 28693413 PMCID: PMC5504735 DOI: 10.1186/s12866-017-1066-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/04/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Bacillus pumilus can secret abundant extracellular enzymes, and may be used as a potential host for the industrial production of enzymes. It is necessary to understand the metabolic processes during cellular growth. Here, an RNA-seq based transcriptome analysis was applied to examine B. pumilus BA06 across various growth stages to reveal metabolic changes under two conditions. RESULTS Based on the gene expression levels, changes to metabolism pathways that were specific to various growth phases were enriched by KEGG analysis. Upon entry into the transition from the exponential growth phase, striking changes were revealed that included down-regulation of the tricarboxylic acid cycle, oxidative phosphorylation, flagellar assembly, and chemotaxis signaling. In contrast, the expression of stress-responding genes was induced when entering the transition phase, suggesting that the cell may suffer from stress during this growth stage. As expected, up-regulation of sporulation-related genes was continuous during the stationary growth phase, which was consistent with the observed sporulation. However, the expression pattern of the various extracellular proteases was different, suggesting that the regulatory mechanism may be distinct for various proteases. In addition, two protein secretion pathways were enriched with genes responsive to the observed protein secretion in B. pumilus. However, the expression of some genes that encode sporulation-related proteins and extracellular proteases was delayed by the addition of gelatin to the minimal medium. CONCLUSIONS The transcriptome data depict global alterations in the genome-wide transcriptome across the various growth phases, which will enable an understanding of the physiology and phenotype of B. pumilus through gene expression.
Collapse
Affiliation(s)
- Lin-Li Han
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Huan-Huan Shao
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Yong-Cheng Liu
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Gang Liu
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Chao-Ying Xie
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Xiao-Jie Cheng
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Hai-Yan Wang
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Xue-Mei Tan
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| | - Hong Feng
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
- College of Life Sciences, Sichuan University, Chengdu, 610064 Sichuan People’s Republic of China
| |
Collapse
|
10
|
How to transform a recalcitrant Paenibacillus strain: From culture medium to restriction barrier. J Microbiol Methods 2016; 131:135-143. [PMID: 27780731 DOI: 10.1016/j.mimet.2016.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/11/2016] [Accepted: 10/21/2016] [Indexed: 11/20/2022]
Abstract
Paenibacillus riograndensis SBR5T is a plant growth-promoting bacterium isolated from the wheat rhizosphere. Its recalcitrance to genetic manipulation is a major bottleneck for molecular studies, as has been reported for other Paenibacillus environmental isolates. An efficient electroporation protocol was established by evaluating diverse parameters and optimizing the culture medium, culture growth phase, electroporation solution, recovery medium, DNA input, and electric field strength. Efficiencies of approximately 2.8×104transformantsμg-1 of plasmid DNA were obtained. The optimized protocol was tested with other Paenibacillus species, and the relevance of bypassing the restriction DNA defense system to transform Paenibacillus was highlighted. This protocol is the tool needed to deepen molecular studies with this strain and will aid in the manipulation of other new environmental isolates that also exhibit recalcitrant transformation difficulties.
Collapse
|
11
|
Zhou C, Shi L, Ye B, Feng H, Zhang J, Zhang R, Yan X. pheS * , an effective host-genotype-independent counter-selectable marker for marker-free chromosome deletion in Bacillus amyloliquefaciens. Appl Microbiol Biotechnol 2016; 101:217-227. [PMID: 27730334 DOI: 10.1007/s00253-016-7906-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/15/2016] [Accepted: 09/25/2016] [Indexed: 12/22/2022]
Abstract
Aside from applications in the production of commercial enzymes and metabolites, Bacillus amyloliquefaciens is also an important group of plant growth-promoting rhizobacteria that supports plant growth and suppresses phytopathogens. A host-genotype-independent counter-selectable marker would enable rapid genetic manipulation and metabolic engineering, accelerating the study of B. amyloliquefaciens and its development as both a microbial cell factory and plant growth-promoting rhizobacteria. Here, a host-genotype-independent counter-selectable marker pheS * was constructed through a point mutation of the gene pheS, which encodes the α-subunit of phenylalanyl-tRNA synthetase in Bacillus subtilis strain 168. In the presence of 5 mM p-chloro-phenylalanine, 100 % of B. amyloliquefaciens strain SQR9 cells carrying pheS * were killed, whereas the wild-type strain SQR9 showed resistance to p-chloro-phenylalanine. A simple pheS * and overlap-PCR-based strategy was developed to create the marker-free deletion of the amyE gene as well as a 37-kb bmy cluster in B. amyloliquefaciens SQR9. The effectiveness of pheS * as a counter-selectable marker in B. amyloliquefaciens was further confirmed through the deletion of amyE genes in strains B. amyloliquefaciens FZB42 and NJN-6. In addition, the potential use of pheS * in other Bacillus species was preliminarily assessed. The expression of PheS* in B. subtilis strain 168 and B. cereus strain ATCC 14579 caused pronounced sensitivity of both hosts to p-chloro-phenylalanine, indicating that pheS * could be used as a counter-selectable marker (CSM) in these strains.
Collapse
Affiliation(s)
- Chaoyang Zhou
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Lingling Shi
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Bin Ye
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Haichao Feng
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Ji Zhang
- Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials, School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huaian, 223300, People's Republic of China
| | - Ruifu Zhang
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Xin Yan
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, Jiangsu, 210095, People's Republic of China.
| |
Collapse
|
12
|
Artificial induction of genetic competence in Bacillus amyloliquefaciens isolates. Biotechnol Lett 2016; 38:2109-2117. [DOI: 10.1007/s10529-016-2194-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/18/2016] [Indexed: 12/22/2022]
|
13
|
Jakobs M, Meinhardt F. What renders Bacilli genetically competent? A gaze beyond the model organism. Appl Microbiol Biotechnol 2014; 99:1557-70. [DOI: 10.1007/s00253-014-6316-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 12/20/2022]
|
14
|
The two putative comS homologs of the biotechnologically important Bacillus licheniformis do not contribute to competence development. Appl Microbiol Biotechnol 2014; 99:2255-66. [PMID: 25520171 DOI: 10.1007/s00253-014-6291-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/28/2014] [Accepted: 12/02/2014] [Indexed: 01/17/2023]
Abstract
In Bacillus subtilis, natural genetic competence is subject to complex genetic regulation and quorum sensing dependent. Upon extracellular accumulation of the peptide-pheromone ComX, the membrane-bound sensor histidine kinase ComP initiates diverse signaling pathways by activating-among others-DegQ and ComS. While DegQ favors the expression of extracellular enzymes rather than competence development, ComS is crucial for competence development as it prevents proteolytic degradation of ComK, the key transcriptional activator of all genes required for the uptake and integration of DNA. In Bacillus licheniformis, ComX/ComP sensed cell density negatively influences competence development, suggesting differences from the quorum-sensing-dependent control mechanism in Bacillus subtilis. Here, we show that each of six investigated strains possesses both of two different, recently identified putative comS genes. When expressed from an inducible promoter, none of the comS candidate genes displayed an impact on competence development neither in B. subtilis nor in B. licheniformis. Moreover, disruption of the genes did not reduce transformation efficiency. While the putative comS homologs do not contribute to competence development, we provide evidence that the degQ gene as for B. subtilis negatively influences genetic competency in B. licheniformis.
Collapse
|
15
|
Handtke S, Volland S, Methling K, Albrecht D, Becher D, Nehls J, Bongaerts J, Maurer KH, Lalk M, Liesegang H, Voigt B, Daniel R, Hecker M. Cell physiology of the biotechnological relevant bacterium Bacillus pumilus-an omics-based approach. J Biotechnol 2014; 192 Pt A:204-14. [PMID: 25281541 DOI: 10.1016/j.jbiotec.2014.08.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/15/2014] [Accepted: 08/22/2014] [Indexed: 12/18/2022]
Abstract
Members of the species Bacillus pumilus get more and more in focus of the biotechnological industry as potential new production strains. Based on exoproteome analysis, B. pumilus strain Jo2, possessing a high secretion capability, was chosen for an omics-based investigation. The proteome and metabolome of B. pumilus cells growing either in minimal or complex medium was analyzed. In total, 1542 proteins were identified in growing B. pumilus cells, among them 1182 cytosolic proteins, 297 membrane and lipoproteins and 63 secreted proteins. This accounts for about 43% of the 3616 proteins encoded in the B. pumilus Jo2 genome sequence. By using GC-MS, IP-LC/MS and H NMR methods numerous metabolites were analyzed and assigned to reconstructed metabolic pathways. In the genome sequence a functional secretion system including the components of the Sec- and Tat-secretion machinery was found. Analysis of the exoproteome revealed secretion of about 70 proteins with predicted secretion signals. In addition, selected production-relevant genome features such as restriction modification systems and NRPS clusters of B. pumilus Jo2 are discussed.
Collapse
Affiliation(s)
- Stefan Handtke
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Sonja Volland
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany.
| | - Karen Methling
- Institute of Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Dirk Albrecht
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Dörte Becher
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Jenny Nehls
- Institute of Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Johannes Bongaerts
- Department of Chemistry and Biotechnology, Aachen University of Applied Sciences, Heinrich-Mußmannstr. 1, 52428 Jülich, Germany.
| | | | - Michael Lalk
- Institute of Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Heiko Liesegang
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany.
| | - Birgit Voigt
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany.
| | - Michael Hecker
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| |
Collapse
|
16
|
Unravelling the genetic basis for competence development of auxotrophic Bacillus licheniformis 9945A strains. Microbiology (Reading) 2014; 160:2136-2147. [DOI: 10.1099/mic.0.079236-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Bacterial natural genetic competence – well studied in Bacillus subtilis – enables cells to take up and integrate extracellularly supplied DNA into their own genome. However, little is known about competence development and its regulation in other members of the genus, although DNA uptake machineries are routinely encoded. Auxotrophic Bacillus licheniformis 9945A derivatives, obtained from repeated rounds of random mutagenesis, were long known to develop natural competence. Inspection of the colony morphology and extracellular enzyme secretion of two of these derivatives, M28 and M18, suggested that regulator genes are collaterally hit. M28 emerged as a 14 bp deletion mutant concomitantly displaying a shift in the reading frame of degS that encodes the sensor histidine kinase, which is part of the molecular switch that directs cells to genetic competence, the synthesis of extracellular enzymes or biofilm formation, while for M18, sequencing of the suspected gene revealed a 375 bp deletion in abrB, encoding the major transition state regulator. With respect to colony morphology, enzyme secretion and competence development, both of the mutations, when newly generated on the wild-type B. licheniformis 9945A genetic background, resulted in phenotypes resembling M28 and M18, respectively. All of the known naturally competent B. licheniformis representatives, hitherto thoroughly investigated in this regard, carry mutations in regulator genes, and hence genetic competence observed in domesticated strains supposedly results from deregulation.
Collapse
|
17
|
Dong H, Zhang D. Current development in genetic engineering strategies of Bacillus species. Microb Cell Fact 2014; 13:63. [PMID: 24885003 PMCID: PMC4030025 DOI: 10.1186/1475-2859-13-63] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/28/2014] [Indexed: 11/28/2022] Open
Abstract
The complete sequencing and annotation of the genomes of industrially-important Bacillus species has enhanced our understanding of their properties, and allowed advances in genetic manipulations in other Bacillus species. Post-genomic studies require simple and highly efficient tools to enable genetic manipulation. Here, we summarize the recent progress in genetic engineering strategies for Bacillus species. We review the available genetic tools that have been developed in Bacillus species, as well as methods developed in other species that may also be applicable in Bacillus. Furthermore, we address the limitations and challenges of the existing methods, and discuss the future research prospects in developing novel and useful tools for genetic modification of Bacillus species.
Collapse
Affiliation(s)
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
| |
Collapse
|
18
|
Küppers T, Steffen V, Hellmuth H, O'Connell T, Bongaerts J, Maurer KH, Wiechert W. Developing a new production host from a blueprint: Bacillus pumilus as an industrial enzyme producer. Microb Cell Fact 2014; 13:46. [PMID: 24661794 PMCID: PMC3987833 DOI: 10.1186/1475-2859-13-46] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/18/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Since volatile and rising cost factors such as energy, raw materials and market competitiveness have a significant impact on the economic efficiency of biotechnological bulk productions, industrial processes need to be steadily improved and optimized. Thereby the current production hosts can undergo various limitations. To overcome those limitations and in addition increase the diversity of available production hosts for future applications, we suggest a Production Strain Blueprinting (PSB) strategy to develop new production systems in a reduced time lapse in contrast to a development from scratch.To demonstrate this approach, Bacillus pumilus has been developed as an alternative expression platform for the production of alkaline enzymes in reference to the established industrial production host Bacillus licheniformis. RESULTS To develop the selected B. pumilus as an alternative production host the suggested PSB strategy was applied proceeding in the following steps (dedicated product titers are scaled to the protease titer of Henkel's industrial production strain B. licheniformis at lab scale): Introduction of a protease production plasmid, adaptation of a protease production process (44%), process optimization (92%) and expression optimization (114%). To further evaluate the production capability of the developed B. pumilus platform, the target protease was substituted by an α-amylase. The expression performance was tested under the previously optimized protease process conditions and under subsequently adapted process conditions resulting in a maximum product titer of 65% in reference to B. licheniformis protease titer. CONCLUSIONS In this contribution the applied PSB strategy performed very well for the development of B. pumilus as an alternative production strain. Thereby the engineered B. pumilus expression platform even exceeded the protease titer of the industrial production host B. licheniformis by 14%. This result exhibits a remarkable potential of B. pumilus to be the basis for a next generation production host, since the strain has still a large potential for further genetic engineering. The final amylase titer of 65% in reference to B. licheniformis protease titer suggests that the developed B. pumilus expression platform is also suitable for an efficient production of non-proteolytic enzymes reaching a final titer of several grams per liter without complex process modifications.
Collapse
|