1
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Giordano I, Pasolli E, Mauriello G. Transcriptomic analysis reveals differential gene expression patterns of Lacticaseibacillus casei ATCC 393 in response to ultrasound stress. ULTRASONICS SONOCHEMISTRY 2024; 107:106939. [PMID: 38843696 PMCID: PMC11214525 DOI: 10.1016/j.ultsonch.2024.106939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/14/2024] [Accepted: 05/30/2024] [Indexed: 06/19/2024]
Abstract
In recent years, there has been a growing interest in modulating the performance of probiotic, mainly Lactic Acid Bacteria (LAB), in the field of probiotic food. Attenuation, induced by sub-lethal stresses, delays the probiotic metabolism, and induces a metabolic shift as survival strategy. In this paper, RNA sequencing was used to uncover the transcriptional regulation in Lacticaseibacillus casei ATCC 393 after ultrasound-induced attenuation. Six (T) and 8 (ST) min of sonication induced a significant differential expression of 742 and 409 genes, respectively. We identified 198 up-regulated and 321 down-regulated genes in T, and similarly 321 up-regulated and 249 down-regulated in ST. These results revealed a strong defensive response at 6 min, followed by adaptation at 8 min. Ultrasound attenuation modified the expression of genes related to a series of crucial biomolecular processes including membrane transport, carbohydrate and purine metabolism, phage-related genes, and translation. Specifically, genes encoding PTS transporters and genes involved in the glycolytic pathway and pyruvate metabolism were up-regulated, indicating an increased need for energy supply, as also suggested by an increase in the transcription of purine biosynthetic genes. Instead, protein translation, a high-energy process, was inhibited with the down-regulation of ribosomal protein biosynthetic genes. Moreover, phage-related genes were down-regulated suggesting a tight transcriptional control on DNA structure. The observed phenomena highlight the cell need of ATP to cope with the multiple ultrasound stresses and the activation of processes to stabilize and preserve the DNA structure. Our work demonstrates that ultrasound has remarkable effects on the tested strain and elucidates the involvement of different pathways in its defensive stress-response and in the modification of its phenotype.
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Affiliation(s)
- Irene Giordano
- Department of Agricultural Sciences, University of Naples Federico II, 80049 Naples, Italy
| | - Edoardo Pasolli
- Department of Agricultural Sciences, University of Naples Federico II, 80049 Naples, Italy
| | - Gianluigi Mauriello
- Department of Agricultural Sciences, University of Naples Federico II, 80049 Naples, Italy.
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2
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Xu X, Liu F, Qiao W, Dong Y, Yang H, Liu F, Xu H, Qiao M. A Point Mutation in Cassette Relieves the Repression Regulation of CcpA Resulting in an Increase in the Degradation of 2,3-Butanediol in Lactococcus lactis. Microorganisms 2024; 12:773. [PMID: 38674718 PMCID: PMC11051896 DOI: 10.3390/microorganisms12040773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
In lactic acid bacteria, the global transcriptional regulator CcpA regulates carbon metabolism by repressing and activating the central carbon metabolism pathway, thus decreasing or increasing the yield of certain metabolites to maximize carbon flow. However, there are no reports on the deregulation of the inhibitory effects of CcpA on the metabolism of secondary metabolites. In this study, we identified a single-base mutant strain of Lactococcus lactis N8-2 that is capable of metabolizing 2,3-butanediol. It has been established that CcpA dissociates from the catabolite responsive element (cre) site due to a mutation, leading to the activation of derepression and expression of the 2,3-butanediol dehydrogenase gene cluster (butB and butA). Transcriptome analysis and quantitative polymerase chain reaction (Q-PCR) results showed significant upregulation of transcription of butB and butA compared to the unmutated strain. Furthermore, micro-scale thermophoresis experiments confirmed that CcpA did not bind to the mutated cre. Furthermore, in a bacterial two-plasmid fluorescent hybridization system, it was similarly confirmed that the dissociation of CcpA from cre eliminated the repressive effect of CcpA on downstream genes. Finally, we investigated the differing catalytic capacities of the 2,3-butanediol dehydrogenase gene cluster in L. lactis N8-1 and L. lactis N8-2 for 2,3-butanediol. This led to increased expression of butB and butA, which were deregulated by CcpA repression. This is the first report on the elimination of the deterrent effect of CcpA in lactic acid bacteria, which changes the direction of enzymatic catalysis and alters the direction of carbon metabolism. This provides new perspectives and strategies for metabolizing 2,3-butanediol using bacteria in synthetic biology.
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Affiliation(s)
- Xian Xu
- School of Life Science, Shanxi University, Taiyuan 030006, China; (X.X.); (Y.D.); (H.Y.); (F.L.)
| | - Fulu Liu
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China;
| | - Wanjin Qiao
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China; (W.Q.); (H.X.)
| | - Yujie Dong
- School of Life Science, Shanxi University, Taiyuan 030006, China; (X.X.); (Y.D.); (H.Y.); (F.L.)
| | - Huan Yang
- School of Life Science, Shanxi University, Taiyuan 030006, China; (X.X.); (Y.D.); (H.Y.); (F.L.)
| | - Fengming Liu
- School of Life Science, Shanxi University, Taiyuan 030006, China; (X.X.); (Y.D.); (H.Y.); (F.L.)
| | - Haijin Xu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China; (W.Q.); (H.X.)
| | - Mingqiang Qiao
- School of Life Science, Shanxi University, Taiyuan 030006, China; (X.X.); (Y.D.); (H.Y.); (F.L.)
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China; (W.Q.); (H.X.)
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3
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van Belkum MJ, Aleksandrzak-Piekarczyk T, Lamer T, Vederas JC. Lactococcus lactis mutants resistant to lactococcin A and garvicin Q reveal missense mutations in the sugar transport domain of the mannose phosphotransferase system. Microbiol Spectr 2024; 12:e0313023. [PMID: 38047704 PMCID: PMC10783117 DOI: 10.1128/spectrum.03130-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/23/2023] [Indexed: 12/05/2023] Open
Abstract
IMPORTANCE Many bacteriocins target the sugar transporter mannose phosphotransferase system (man-PTS) to exert their antibacterial activity. The elucidation in recent years of the structure of man-PTS has facilitated our understanding of how bacteriocins might interact with the receptor and which domains of the transporter are involved in bacteriocin resistance. Here, we show that missense mutations in the sugar-binding domain of the man-PTS not only impede the uptake of sugars but also prevent the antibacterial activity of the bacteriocins lactococcin A and garvicin Q.
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Affiliation(s)
| | | | - Tess Lamer
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - John C. Vederas
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
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4
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Douwenga S, van Olst B, Boeren S, Luo Y, Lai X, Teusink B, Vervoort J, Kleerebezem M, Bachmann H. The hierarchy of sugar catabolization in Lactococcus cremoris. Microbiol Spectr 2023; 11:e0224823. [PMID: 37888986 PMCID: PMC10715065 DOI: 10.1128/spectrum.02248-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/21/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE The availability of nutrients to microorganisms varies considerably between different environments, and changes can occur rapidly. As a general rule, a fast growth rate-typically growth on glucose-is associated with the repression of other carbohydrate utilization genes, but it is not clear to what extent catabolite repression is exerted by other sugars. We investigated the hierarchy of sugar utilization after substrate transitions in Lactococcus cremoris. For this, we determined the proteome and carbohydrate utilization capacity after growth on different sugars. The results show that the preparedness of cells for the utilization of "slower" sugars is not strictly determined by the growth rate. The data point to individual proteins relevant for various sugar transitions and suggest that the evolutionary history of the organism might be responsible for deviations from a strictly growth rate-related sugar catabolization hierarchy.
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Affiliation(s)
- Sieze Douwenga
- TI Food and Nutrition, Wageningen, the Netherlands
- Systems Biology Lab, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Berdien van Olst
- TI Food and Nutrition, Wageningen, the Netherlands
- Host-Microbe Interactomics, Wageningen University & Research, Wageningen, the Netherlands
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands
| | - Sjef Boeren
- TI Food and Nutrition, Wageningen, the Netherlands
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands
| | - Yanzhang Luo
- MAGNEtic resonance research FacilitY (MAGNEFY), Wageningen University & Research, Wageningen, the Netherlands
| | - Xin Lai
- Systems Biology Lab, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Bas Teusink
- TI Food and Nutrition, Wageningen, the Netherlands
- Systems Biology Lab, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Jacques Vervoort
- TI Food and Nutrition, Wageningen, the Netherlands
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands
| | - Michiel Kleerebezem
- TI Food and Nutrition, Wageningen, the Netherlands
- Host-Microbe Interactomics, Wageningen University & Research, Wageningen, the Netherlands
| | - Herwig Bachmann
- TI Food and Nutrition, Wageningen, the Netherlands
- Systems Biology Lab, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Microbiology Department, NIZO Food Research, Ede, the Netherlands
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5
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Kosiorek K, Koryszewska-Bagińska A, Skoneczny M, Aleksandrzak-Piekarczyk T. Control of Bacterial Phenotype and Chromosomal Gene Expression by Single Plasmids of Lactococcus lactis IL594. Int J Mol Sci 2023; 24:9877. [PMID: 37373024 DOI: 10.3390/ijms24129877] [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: 04/18/2023] [Revised: 06/04/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Plasmid-free Lactococcus lactis IL1403 is one of the best-characterized representatives of lactic acid bacteria (LAB), intensively used in broad microbiology worldwide. Its parent strain, L. lactis IL594, contains seven plasmids (pIL1-pIL7) with resolved DNA sequences and an indicated role for overall plasmid load in enhancing host-adaptive potential. To determine how individual plasmids manipulate the expression of phenotypes and chromosomal genes, we conducted global comparative phenotypic analyses combined with transcriptomic studies in plasmid-free L. lactis IL1403, multiplasmid L. lactis IL594, and its single-plasmid derivatives. The presence of pIL2, pIL4, and pIL5 led to the most pronounced phenotypic differences in the metabolism of several carbon sources, including some β-glycosides and organic acids. The pIL5 plasmid also contributed to increased tolerance to some antimicrobial compounds and heavy metal ions, especially those in the toxic cation group. Comparative transcriptomics showed significant variation in the expression levels of up to 189 chromosomal genes due to the presence of single plasmids and 435 unique chromosomal genes that were resultant of the activity of all plasmids, which may suggest that the observed phenotypic changes are not only the result of a direct action of their own genes but also originate from indirect actions through crosstalk between plasmids and the chromosome. The data obtained here indicate that plasmid maintenance leads to the development of important mechanisms of global gene regulation that provide changes in the central metabolic pathways and adaptive properties of L. lactis and suggest the possibility of a similar phenomenon among other groups of bacteria.
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Affiliation(s)
- Katarzyna Kosiorek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106 Warsaw, Poland
| | | | - Marek Skoneczny
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106 Warsaw, Poland
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6
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Ekkers DM, Tusso S, Moreno-Gamez S, Rillo MC, Kuipers OP, van Doorn GS. Trade-offs predicted by metabolic network structure give rise to evolutionary specialization and phenotypic diversification. Mol Biol Evol 2022; 39:msac124. [PMID: 35679426 PMCID: PMC9206417 DOI: 10.1093/molbev/msac124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Mitigating trade-offs between different resource-utilization functions is key to an organism's ecological and evolutionary success. These trade-offs often reflect metabolic constraints with a complex molecular underpinning; therefore, their consequences for evolutionary processes have remained elusive. Here, we investigate how metabolic architecture induces resource utilization constraints and how these constraints, in turn, elicit evolutionary specialization and diversification. Guided by the metabolic network structure of the bacterium Lactococcus cremoris, we selected two carbon sources (fructose and galactose) with predicted co-utilization constraints. By evolving L. cremoris on either fructose, galactose or a mix of both sugars, we imposed selection favoring divergent metabolic specializations or co-utilization of both resources, respectively. Phenotypic characterization revealed the evolution of either fructose or galactose specialists in the single-sugar treatments. In the mixed sugar regime, we observed adaptive diversification: both specialists coexisted, and no generalist evolved. Divergence from the ancestral phenotype occurred at key pathway junctions in the central carbon metabolism. Fructose specialists evolved mutations in the fbp and pfk genes that appear to balance anabolic and catabolic carbon fluxes. Galactose specialists evolved increased expression of pgmA (the primary metabolic bottleneck of galactose metabolism) and silencing of ptnABCD (the main glucose transporter) and ldh (regulator/enzyme of downstream carbon metabolism). Overall, our study shows how metabolic network architecture and historical contingency serve to predict targets of selection and inform the functional interpretation of evolved mutations. The elucidation of the relationship between molecular constraints and phenotypic trade-offs contributes to an integrative understanding of evolutionary specialization and diversification.
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Affiliation(s)
- David M Ekkers
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Sergio Tusso
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany
- Science for Life Laboratories and Department of Evolutionary Biology, Norbyvägen 18D, Uppsala University, 75236 Uppsala, Sweden
| | - Stefany Moreno-Gamez
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Marina C Rillo
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg, Schleusenstr. 1, 26382 Wilhelmshaven, Germany
| | - Oscar P Kuipers
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - G Sander van Doorn
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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7
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Woo JKK, McIver KS, Federle MJ. Carbon catabolite repression on the Rgg2/3 quorum sensing system in Streptococcus pyogenes is mediated by PTS Man and Mga. Mol Microbiol 2022; 117:525-538. [PMID: 34923680 PMCID: PMC8844239 DOI: 10.1111/mmi.14866] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 02/03/2023]
Abstract
Streptococcus pyogenes, also known as group A Streptococcus or GAS, is a human-restricted pathogen causing a diverse array of infections. The ability to adapt to different niches requires GAS to adjust gene expression in response to environmental cues. We previously identified the abundance of biometals and carbohydrates led to natural induction of the Rgg2/3 cell-cell communication system (quorum sensing, QS). Here we determined the mechanism by which the Rgg2/3 QS system is stimulated exclusively by mannose and repressed by glucose, a phenomenon known as carbon catabolite repression (CCR). Instead of carbon catabolite protein A, the primary mediator of CCR in Gram-positive bacteria; CCR of Rgg2/3 requires the PTS regulatory domain (PRD)-containing transcriptional regulator Mga. Deletion of Mga led to carbohydrate-independent activation of Rgg2/3 by down-regulating rgg3, the QS repressor. Through phosphoablative and phosphomimetic substitutions within Mga PRDs, we demonstrated that selective phosphorylation of PRD1 conferred repression of the Rgg2/3 system. Moreover, given the carbohydrate specificity mediating Mga-dependent governance over Rgg2/3, we tested mannose-specific PTS components and found the EIIA/B subunit ManL was required for Mga-dependent repression. These findings provide newfound connections between PTSMan , Mga, and QS, and further demonstrate that Mga is a central regulatory nexus for integrating nutritional status and virulence.
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Affiliation(s)
- Jerry K. K. Woo
- Department of Biopharmaceutical Sciences, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Kevin S. McIver
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA
| | - Michael J. Federle
- Department of Biopharmaceutical Sciences, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60607, USA,For correspondence. ; Tel. 312-413-0213; Fax. 312-413-9303
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8
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Raturi S, Nair AV, Shinoda K, Singh H, Bai B, Murakami S, Fujitani H, van Veen HW. Engineered MATE multidrug transporters reveal two functionally distinct ion-coupling pathways in NorM from Vibrio cholerae. Commun Biol 2021; 4:558. [PMID: 33976372 PMCID: PMC8113278 DOI: 10.1038/s42003-021-02081-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 04/01/2021] [Indexed: 11/09/2022] Open
Abstract
Multidrug and toxic compound extrusion (MATE) transport proteins confer multidrug resistance on pathogenic microorganisms and affect pharmacokinetics in mammals. Our understanding of how MATE transporters work, has mostly relied on protein structures and MD simulations. However, the energetics of drug transport has not been studied in detail. Many MATE transporters utilise the electrochemical H+ or Na+ gradient to drive substrate efflux, but NorM-VC from Vibrio cholerae can utilise both forms of metabolic energy. To dissect the localisation and organisation of H+ and Na+ translocation pathways in NorM-VC we engineered chimaeric proteins in which the N-lobe of H+-coupled NorM-PS from Pseudomonas stutzeri is fused to the C-lobe of NorM-VC, and vice versa. Our findings in drug binding and transport experiments with chimaeric, mutant and wildtype transporters highlight the versatile nature of energy coupling in NorM-VC, which enables adaptation to fluctuating salinity levels in the natural habitat of V. cholerae.
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Affiliation(s)
- Sagar Raturi
- Department of Pharmacology, University of Cambridge, Cambridge, UK
- University College Dublin Clinical Research Centre, St. Vincent's University Hospital, Dublin, Ireland
| | - Asha V Nair
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Keiko Shinoda
- Microbial Membrane Transport Engineering, Biotechnology Research Center, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Himansha Singh
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Boyan Bai
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Satoshi Murakami
- Department of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, Japan
| | - Hideaki Fujitani
- Laboratories for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
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9
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Kleerebezem M, Bachmann H, van Pelt-KleinJan E, Douwenga S, Smid EJ, Teusink B, van Mastrigt O. Lifestyle, metabolism and environmental adaptation in Lactococcus lactis. FEMS Microbiol Rev 2021; 44:804-820. [PMID: 32990728 DOI: 10.1093/femsre/fuaa033] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022] Open
Abstract
Lactococcus lactis serves as a paradigm organism for the lactic acid bacteria (LAB). Extensive research into the molecular biology, metabolism and physiology of several model strains of this species has been fundamental for our understanding of the LAB. Genomic studies have provided new insights into the species L. lactis, including the resolution of the genetic basis of its subspecies division, as well as the control mechanisms involved in the fine-tuning of growth rate and energy metabolism. In addition, it has enabled novel approaches to study lactococcal lifestyle adaptations to the dairy application environment, including its adjustment to near-zero growth rates that are particularly relevant in the context of cheese ripening. This review highlights various insights in these areas and exemplifies the strength of combining experimental evolution with functional genomics and bacterial physiology research to expand our fundamental understanding of the L. lactis lifestyle under different environmental conditions.
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Affiliation(s)
- Michiel Kleerebezem
- Host-Microbe Interactomics Group, Animal Sciences Department, Wageningen University, De Elst 1, 6708 WD Wageningen, the Netherlands
| | - Herwig Bachmann
- Systems Bioinformatics, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands.,NIZO food research, Kernhemseweg 2, 6718 ZB Ede, the Netherlands
| | - Eunice van Pelt-KleinJan
- Systems Bioinformatics, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands.,TiFN Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, the Netherlands
| | - Sieze Douwenga
- Systems Bioinformatics, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands.,TiFN Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, the Netherlands
| | - Eddy J Smid
- Laboratory of Food Microbiology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands
| | - Bas Teusink
- Systems Bioinformatics, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands
| | - Oscar van Mastrigt
- Laboratory of Food Microbiology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands
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10
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Ruiz-Villafán B, Cruz-Bautista R, Manzo-Ruiz M, Passari AK, Villarreal-Gómez K, Rodríguez-Sanoja R, Sánchez S. Carbon catabolite regulation of secondary metabolite formation, an old but not well-established regulatory system. Microb Biotechnol 2021; 15:1058-1072. [PMID: 33675560 PMCID: PMC8966007 DOI: 10.1111/1751-7915.13791] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 11/28/2022] Open
Abstract
Secondary microbial metabolites have various functions for the producer microorganisms, which allow them to interact and survive in adverse environments. In addition to these functions, other biological activities may have clinical relevance, as diverse as antimicrobial, anticancer and hypocholesterolaemic effects. These metabolites are usually formed during the idiophase of growth and have a wide diversity in their chemical structures. Their synthesis is under the impact of the type and concentration of the culture media nutrients. Some of the molecular mechanisms that affect the synthesis of secondary metabolites in bacteria (Gram‐positive and negative) and fungi are partially known. Moreover, all microorganisms have their peculiarities in the control mechanisms of carbon sources, even those belonging to the same genus. This regulatory knowledge is necessary to establish culture conditions and manipulation methods for genetic improvement and product fermentation. As the carbon source is one of the essential nutritional factors for antibiotic production, its study has been imperative both at the industrial and research levels. This review aims to draw the utmost recent advances performed to clarify the molecular mechanisms of the negative effect exerted by the carbon source on the secondary metabolite formation, emphasizing those found in Streptomyces, one of the genera most profitable antibiotic producers.
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Affiliation(s)
- Beatriz Ruiz-Villafán
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
| | - Rodrigo Cruz-Bautista
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
| | - Monserrat Manzo-Ruiz
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
| | - Ajit Kumar Passari
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
| | - Karen Villarreal-Gómez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
| | - Romina Rodríguez-Sanoja
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
| | - Sergio Sánchez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CdMx, México City, 04510, México
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11
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He N, Fang C, Qiu Z, Bao J. Increasing sodium lactate production by enhancement of Na + transmembrane transportation in Pediococcus acidilactici. BIORESOURCE TECHNOLOGY 2021; 323:124562. [PMID: 33360114 DOI: 10.1016/j.biortech.2020.124562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/13/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Fermentative production of sodium lactate generally is a low efficient process because of the high Na+ osmatic stress on lactic acid bacterium cells. In this study, the homogeneous genes encoding Na+/H+ antiporters were screened and overexpressed in Pediococcus acidilactici for the enhancement of Na+ transmembrane transportation. The function of the gene RS02775 was identified and its overexpressing in P. acidilactici resulted in the significantly improved sodium lactate production. The recombinant not only accelerated the sugar consumption, but also achieved the record high titer of sodium lactate by 121.1 g/L using pure sugars and 132.4 g/L using wheat straw. The transcription analysis shows that the overexpression of Na+/H+ antiporter significantly upregulated the transcription of the sugar phosphorylation genes of P. acidilactici under high Na+ stress. This study provides an effective method for high titer production of sodium lactate using both pure sugars and lignocellulose feedstocks.
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Affiliation(s)
- Niling He
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Chun Fang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Zhongyang Qiu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, 111 West Changjiang Road, Huaian, Jiangsu 223300, China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
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12
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Sørensen KI, Kjærbølling I, Neves AR, Machielsen R, Johansen E. Use of Cell Envelope Targeting Antibiotics and Antimicrobial Agents as a Powerful Tool to Select for Lactic Acid Bacteria Strains With Improved Texturizing Ability in Milk Fermentations. Front Bioeng Biotechnol 2021; 8:623700. [PMID: 33520973 PMCID: PMC7839403 DOI: 10.3389/fbioe.2020.623700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/07/2020] [Indexed: 12/03/2022] Open
Abstract
Many antibiotics and antimicrobial agents have the bacterial cell envelope as their primary target, interfering with functions such as synthesis of peptidoglycan, membrane stability and permeability, and attachment of surface components. The cell envelope is the outermost barrier of the bacterial cell, conferring protection against environmental stresses, and maintaining structural integrity and stability of the growing cell, while still allowing for required metabolism. In this work, inhibitory concentrations of several different cell envelope targeting antibiotics and antimicrobial agents were used to select for derivatives of lactic acid bacteria (LAB) with improved properties for dairy applications. Interestingly, we observed that for several LAB species a fraction of the isolates had improved milk texturizing capabilities. To further improve our understanding of the mechanisms underlying the improved rheology and to validate the efficacy of this method for strain improvement, genetic and physiological characterization of several improved derivatives was performed. The results showed that the identified genetic changes are diverse and affect also other cellular functions than the targeted cell surface. In short, this study describes a new versatile and powerful toolbox based on targeting of the cell envelope to select for LAB derivatives with improved phenotypic traits for dairy applications.
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Affiliation(s)
- Kim I Sørensen
- Discovery, Research and Development, Chr. Hansen A/S, Hørsholm, Denmark
| | - Inge Kjærbølling
- Discovery, Research and Development, Chr. Hansen A/S, Hørsholm, Denmark
| | - Ana Rute Neves
- Discovery, Research and Development, Chr. Hansen A/S, Hørsholm, Denmark
| | - Ronnie Machielsen
- Discovery, Research and Development, Chr. Hansen A/S, Hørsholm, Denmark
| | - Eric Johansen
- Emerging Technology, Chr. Hansen A/S, Hørsholm, Denmark
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13
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Qiao W, Qiao Y, Liu F, Zhang Y, Li R, Wu Z, Xu H, Saris PEJ, Qiao M. Engineering Lactococcus lactis as a multi-stress tolerant biosynthetic chassis by deleting the prophage-related fragment. Microb Cell Fact 2020; 19:225. [PMID: 33298073 PMCID: PMC7727215 DOI: 10.1186/s12934-020-01487-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/28/2020] [Indexed: 01/02/2023] Open
Abstract
Background In bioengineering, growth of microorganisms is limited because of environmental and industrial stresses during fermentation. This study aimed to construct a nisin-producing chassis Lactococcus lactis strain with genome-streamlined, low metabolic burden, and multi-stress tolerance characteristics. Results The Cre-loxP recombination system was applied to reduce the genome and obtain the target chassis strain. A prophage-related fragment (PRF; 19,739 bp) in the L. lactis N8 genome was deleted, and the mutant strain L. lactis N8-1 was chosen for multi-stress tolerance studies. Nisin immunity of L. lactis N8-1 was increased to 6500 IU/mL, which was 44.44% higher than that of the wild-type L. lactis N8 (4500 IU/mL). The survival rates of L. lactis N8-1 treated with lysozyme for 2 h and lactic acid for 1 h were 1000- and 10,000-fold higher than that of the wild-type strain, respectively. At 39 ℃, the L. lactis N8-1 could still maintain its growth, whereas the growth of the wild-type strain dramatically dropped. Scanning electron microscopy showed that the cell wall integrity of L. lactis N8-1 was well maintained after lysozyme treatment. Tandem mass tags labeled quantitative proteomics revealed that 33 and 9 proteins were significantly upregulated and downregulated, respectively, in L. lactis N8-1. These differential proteins were involved in carbohydrate and energy transport/metabolism, biosynthesis of cell wall and cell surface proteins. Conclusions PRF deletion was proven to be an efficient strategy to achieve multi-stress tolerance and nisin immunity in L. lactis, thereby providing a new perspective for industrially obtaining engineered strains with multi-stress tolerance and expanding the application of lactic acid bacteria in biotechnology and synthetic biology. Besides, the importance of PRF, which can confer vital phenotypes to bacteria, was established.
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Affiliation(s)
- Wanjin Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, China.,Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Yu Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, China
| | - Fulu Liu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, China
| | - Yating Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, China
| | - Ran Li
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Zhenzhou Wu
- State Key Laboratory of Medicinal Chemical Biology & Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin, China
| | - Haijin Xu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, China.
| | - Per Erik Joakim Saris
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | - Mingqiang Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, China.
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14
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van Tatenhove-Pel RJ, Rijavec T, Lapanje A, van Swam I, Zwering E, Hernandez-Valdes JA, Kuipers OP, Picioreanu C, Teusink B, Bachmann H. Microbial competition reduces metabolic interaction distances to the low µm-range. ISME JOURNAL 2020; 15:688-701. [PMID: 33077887 PMCID: PMC8027890 DOI: 10.1038/s41396-020-00806-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/21/2020] [Accepted: 10/02/2020] [Indexed: 01/12/2023]
Abstract
Metabolic interactions between cells affect microbial community compositions and hence their function in ecosystems. It is well-known that under competition for the exchanged metabolite, concentration gradients constrain the distances over which interactions can occur. However, interaction distances are typically quantified in two-dimensional systems or without accounting for competition or other metabolite-removal, conditions which may not very often match natural ecosystems. We here analyze the impact of cell-to-cell distance on unidirectional cross-feeding in a three-dimensional aqueous system with competition for the exchanged metabolite. Effective interaction distances were computed with a reaction-diffusion model and experimentally verified by growing a synthetic consortium of 1 µm-sized metabolite producer, receiver, and competitor cells in different spatial structures. We show that receivers cannot interact with producers located on average 15 µm away from them, as product concentration gradients flatten close to producer cells. We developed an aggregation protocol and varied the receiver cells’ product affinity, to show that within producer–receiver aggregates even low-affinity receiver cells could interact with producers. These results show that competition or other metabolite-removal of a public good in a three-dimensional system reduces metabolic interaction distances to the low µm-range, highlighting the importance of concentration gradients as physical constraint for cellular interactions.
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Affiliation(s)
- Rinke J van Tatenhove-Pel
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences, VU University Amsterdam, de Boelelaan 1108, 1081HV, Amsterdam, The Netherlands
| | - Tomaž Rijavec
- Department of Environmental Sciences, Jožef Stefan Institute, Jamova cesta 39, 1000, Ljubljana, Slovenia
| | - Aleš Lapanje
- Department of Environmental Sciences, Jožef Stefan Institute, Jamova cesta 39, 1000, Ljubljana, Slovenia
| | - Iris van Swam
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences, VU University Amsterdam, de Boelelaan 1108, 1081HV, Amsterdam, The Netherlands
| | - Emile Zwering
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences, VU University Amsterdam, de Boelelaan 1108, 1081HV, Amsterdam, The Netherlands
| | - Jhonatan A Hernandez-Valdes
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG, Groningen, The Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG, Groningen, The Netherlands
| | - Cristian Picioreanu
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ, Delft, The Netherlands
| | - Bas Teusink
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences, VU University Amsterdam, de Boelelaan 1108, 1081HV, Amsterdam, The Netherlands
| | - Herwig Bachmann
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences, VU University Amsterdam, de Boelelaan 1108, 1081HV, Amsterdam, The Netherlands. .,NIZO Food Research, Kernhemseweg 2, 6718ZB, Ede, The Netherlands.
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15
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Kumar S, Narayan KS, Shandilya S, Sood SK, Kapila S. Role of non-PTS dependent glucose permease (GlcU) in maintaining the fitness cost during acquisition of nisin resistance by Enterococcus faecalis. FEMS Microbiol Lett 2020; 366:5628326. [PMID: 31738414 DOI: 10.1093/femsle/fnz230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/15/2019] [Indexed: 11/13/2022] Open
Abstract
Nisin is used for food preservation due to its antibacterial activity. However, some bacteria survive under the prevailing conditions owing to the acquisition of resistance. This study aimed to characterize nisin-resistant Enterococcus faecalis isolated from raw buffalo milk and investigate their fitness cost. FE-SEM, biofilm and cytochrome c assay were used for characterization. Growth kinetics, HPLC, qPCR and western blotting were performed to confer their fitness cost. Results revealed that nisin-resistant E. faecalis were morphologically different from sensitive strain and internalize more glucose. However, no significant difference was observed in the growth pattern of the resistant strain compared to that of the sensitive strain. A non-phosphotransferase glucose permease (GlcU) was found to be associated with enhanced glucose uptake. Conversely, Mpt, a major phosphotransferase system responsible for glucose uptake, did not play any role, as confirmed by gene expression studies and western blot analysis of HPr protein. The phosphorylation of His-15 residue of HPr phosphoprotein was reduced, while that of the Ser-46 residue increased with progression in nisin resistance, indicating that it may be involved in the regulation of pathogenicity. In conclusion, resistance imposes a significant fitness cost and GlcU plays a key role in maintaining the fitness cost in nisin-resistant variants.
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Affiliation(s)
- Sandeep Kumar
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Kapil Singh Narayan
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Shruti Shandilya
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Shiv Kumar Sood
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Suman Kapila
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
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16
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Xiao H, Wang Q, Bang-Berthelsen CH, Jensen PR, Solem C. Harnessing Adaptive Evolution to Achieve Superior Mannitol Production by Lactococcus lactis Using Its Native Metabolism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:4912-4921. [PMID: 32233405 DOI: 10.1021/acs.jafc.0c00532] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Mannitol can be obtained as a by-product of certain heterolactic lactic acid bacteria, when grown on substrates containing fructose. Lactococcus lactis, a homolactic lactic acid bacterium, normally does not form mannitol but can be persuaded into doing so by expressing certain foreign enzyme activities. In this study, we find that L. lactis has an inherent capacity to form mannitol from glucose. By adaptively evolving L. lactis or derivatives blocked in NAD+ regenerating pathways, we manage to accelerate growth on mannitol. When cells of the adapted strains are resuspended in buffer containing glucose, 4-58% of the glucose metabolized is converted into mannitol, in contrast to nonadapted strains. The highest conversion was obtained for a strain lacking all major NAD+ regenerating pathways. Mannitol had an inhibitory effect on the conversion, which we speculated was due to the mannitol uptake system. After its inactivation, 60% of the glucose was converted into mannitol by cells suspended in glucose buffer. Using a two-stage setup, where biomass first was accumulated by aerated culturing, followed by a nonaerated phase (static conditions), it was possible to obtain 6.1 g/L mannitol, where 60% of the glucose had been converted into mannitol, which is the highest yield reported for L. lactis.
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Affiliation(s)
- Hang Xiao
- National Food Institute, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Qi Wang
- National Food Institute, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
| | | | - Peter Ruhdal Jensen
- National Food Institute, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Christian Solem
- National Food Institute, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
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17
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Lysis of a Lactococcus lactis Dipeptidase Mutant and Rescue by Mutation in the Pleiotropic Regulator CodY. Appl Environ Microbiol 2020; 86:AEM.02937-19. [PMID: 32005740 PMCID: PMC7117943 DOI: 10.1128/aem.02937-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
Lactococcus lactis subsp. cremoris MG1363 is a model for the lactic acid bacteria (LAB) used in the dairy industry. The proteolytic system, consisting of a proteinase, several peptide and amino acid uptake systems, and a host of intracellular peptidases, plays a vital role in nitrogen metabolism and is of eminent importance for flavor formation in dairy products. The dipeptidase PepV functions in the last stages of proteolysis. A link between nitrogen metabolism and peptidoglycan (PG) biosynthesis was underlined by the finding that deletion of the dipeptidase gene pepV (creating strain MGΔpepV) resulted in a prolonged lag phase when the mutant strain was grown with a high concentration of glycine. In addition, most MGΔpepV cells lyse and have serious defects in their shape. This phenotype is due to a shortage of alanine, since adding alanine can rescue the growth and shape defects. Strain MGΔpepV is more resistant to vancomycin, an antibiotic targeting peptidoglycan d-Ala-d-Ala ends, which confirmed that MGΔpepV has an abnormal PG composition. A mutant of MGΔpepV was obtained in which growth inhibition and cell shape defects were alleviated. Genome sequencing showed that this mutant has a single point mutation in the codY gene, resulting in an arginine residue at position 218 in the DNA-binding motif of CodY being replaced by a cysteine residue. Thus, this strain was named MGΔpepVcodY R218C Transcriptome sequencing (RNA-seq) data revealed a dramatic derepression in peptide uptake and amino acid utilization in MGΔpepVcodY R218C A model of the connections among PepV activity, CodY regulation, and PG synthesis of L. lactis is proposed.IMPORTANCE Precise control of peptidoglycan synthesis is essential in Gram-positive bacteria for maintaining cell shape and integrity as well as resisting stresses. Although neither the dipeptidase PepV nor alanine is essential for L. lactis MG1363, adequate availability of either ensures proper cell wall synthesis. We broaden the knowledge about the dipeptidase PepV, which acts as a linker between nitrogen metabolism and cell wall synthesis in L. lactis.
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18
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Proteomic analysis reveals potential factors associated with enhanced EPS production in Streptococcus thermophilus ASCC 1275. Sci Rep 2020; 10:807. [PMID: 31964939 PMCID: PMC6972726 DOI: 10.1038/s41598-020-57665-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 12/24/2019] [Indexed: 11/12/2022] Open
Abstract
Streptococcus thermophilus ASCC 1275 has two chain length determining genes - epsC and epsD- in its eps gene cluster, and produces two times more EPS in sucrose medium than that in glucose and lactose. Hence, we investigated the influence of sugars (glucose, sucrose and lactose), at log phase (5 h) and stationary phase (10 h), on the global proteomics of S. thermophilus 1275 to understand the differentially expressed proteins (DEPs) during EPS production using isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis. Among 98 DEPs in sucrose medium, most of them were mapped into EPS biosynthesis pathway and other related metabolisms. There was an upregulation of several proteins involved in sugar transport (phosphoenolpyruvate (PEP) phosphotransferase system), EPS assembly (epsG1D) and amino acid metabolism (methionine, cysteine/arginine metabolism) in sucrose medium. This study showed that increased EPS production in S. thermophilus 1275 requires a well-co-ordinated regulation of pathway involved in both EPS assembly and amino acid metabolism along with the availability of sugars. Thus, it provided valuable insights into the biosynthesis and regulation of EPS in S. thermophilus 1275, and potential gene targets for understanding high-EPS strains.
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19
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Liu J, Chan SHJ, Chen J, Solem C, Jensen PR. Systems Biology - A Guide for Understanding and Developing Improved Strains of Lactic Acid Bacteria. Front Microbiol 2019; 10:876. [PMID: 31114552 PMCID: PMC6503107 DOI: 10.3389/fmicb.2019.00876] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/04/2019] [Indexed: 12/15/2022] Open
Abstract
Lactic Acid Bacteria (LAB) are extensively employed in the production of various fermented foods, due to their safe status, ability to affect texture and flavor and finally due to the beneficial effect they have on shelf-life. More recently, LAB have also gained interest as production hosts for various useful compounds, particularly compounds with sensitive applications, such as food ingredients and therapeutics. As for all industrial microorganisms, it is important to have a good understanding of the physiology and metabolism of LAB in order to fully exploit their potential, and for this purpose, many systems biology approaches are available. Systems metabolic engineering, an approach that combines optimization of metabolic enzymes/pathways at the systems level, synthetic biology as well as in silico model simulation, has been used to build microbial cell factories for production of biofuels, food ingredients and biochemicals. When developing LAB for use in foods, genetic engineering is in general not an accepted approach. An alternative is to screen mutant libraries for candidates with desirable traits using high-throughput screening technologies or to use adaptive laboratory evolution to select for mutants with special properties. In both cases, by using omics data and data-driven technologies to scrutinize these, it is possible to find the underlying cause for the desired attributes of such mutants. This review aims to describe how systems biology tools can be used for obtaining both engineered as well as non-engineered LAB with novel and desired properties.
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Affiliation(s)
- Jianming Liu
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Siu Hung Joshua Chan
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States
| | - Jun Chen
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Christian Solem
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Peter Ruhdal Jensen
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Denmark
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20
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Price CE, Branco Dos Santos F, Hesseling A, Uusitalo JJ, Bachmann H, Benavente V, Goel A, Berkhout J, Bruggeman FJ, Marrink SJ, Montalban-Lopez M, de Jong A, Kok J, Molenaar D, Poolman B, Teusink B, Kuipers OP. Adaption to glucose limitation is modulated by the pleotropic regulator CcpA, independent of selection pressure strength. BMC Evol Biol 2019; 19:15. [PMID: 30630406 PMCID: PMC6327505 DOI: 10.1186/s12862-018-1331-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 12/14/2018] [Indexed: 11/23/2022] Open
Abstract
Background A central theme in (micro)biology is understanding the molecular basis of fitness i.e. which strategies are successful under which conditions; how do organisms implement such strategies at the molecular level; and which constraints shape the trade-offs between alternative strategies. Highly standardized microbial laboratory evolution experiments are ideally suited to approach these questions. For example, prolonged chemostats provide a constant environment in which the growth rate can be set, and the adaptive process of the organism to such environment can be subsequently characterized. Results We performed parallel laboratory evolution of Lactococcus lactis in chemostats varying the quantitative value of the selective pressure by imposing two different growth rates. A mutation in one specific amino acid residue of the global transcriptional regulator of carbon metabolism, CcpA, was selected in all of the evolution experiments performed. We subsequently showed that this mutation confers predictable fitness improvements at other glucose-limited growth rates as well. In silico protein structural analysis of wild type and evolved CcpA, as well as biochemical and phenotypic assays, provided the underpinning molecular mechanisms that resulted in the specific reprogramming favored in constant environments. Conclusion This study provides a comprehensive understanding of a case of microbial evolution and hints at the wide dynamic range that a single fitness-enhancing mutation may display. It demonstrates how the modulation of a pleiotropic regulator can be used by cells to improve one trait while simultaneously work around other limiting constraints, by fine-tuning the expression of a wide range of cellular processes. Electronic supplementary material The online version of this article (10.1186/s12862-018-1331-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Claire E Price
- Molecular Genetics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.,Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.,Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands.,Present address: DSM Biotechnology Centre, Alexander Fleminglaan 1, 2613 AX, Delft, The Netherlands
| | - Filipe Branco Dos Santos
- Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands.,Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.,Molecular Microbial Physiology Group, Faculty of Life Science, Swammerdam Institute of Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, Netherlands
| | - Anne Hesseling
- Molecular Genetics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Jaakko J Uusitalo
- Molecular Dynamics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Herwig Bachmann
- Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands.,Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Vera Benavente
- Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Anisha Goel
- Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands.,Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.,Present address: Chr. Hansen, Boege Allé 10-12, 2970, Hoersholm, Denmark
| | - Jan Berkhout
- Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Frank J Bruggeman
- Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Siewert-Jan Marrink
- Molecular Dynamics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Manolo Montalban-Lopez
- Molecular Genetics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Anne de Jong
- Molecular Genetics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Jan Kok
- Molecular Genetics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Douwe Molenaar
- Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands.,Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Bas Teusink
- Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands. .,Systems Bioinformatics, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
| | - Oscar P Kuipers
- Molecular Genetics Group, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands. .,Kluyver Center for Genomics of Industrial Fermentations/NCSB, Julianalaan 67, 2628 BC, Delft, The Netherlands.
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21
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Xu J, Xie YD, Liu L, Guo S, Su YL, Li AX. Virulence regulation of cel-EIIB protein mediated PTS system in Streptococcus agalactiae in Nile tilapia. JOURNAL OF FISH DISEASES 2019; 42:11-19. [PMID: 30374993 DOI: 10.1111/jfd.12907] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
Streptococcus agalactiae is a major pathogen of tilapia causing significant economic losses for the global aquatic industry yearly. To elucidate the role of cel-EIIB protein-mediated phosphotransferase systems (PTS) in the virulence regulation of S. agalactiae, cel-EIIB gene deletion in a virulent strain THN0901 was achieved by homologous recombination. The cellobiose utilization of △cel-EIIB strain was significantly decreased relative to S.a.THN0901 strain incubating in LB with 10 mg/ml cellobiose (p < 0.05). The biofilm formation ability of △cel-EIIB strain was also significantly decreased when cultured in BHI medium (p < 0.05). Under a lower infection dose, the accumulative mortality of tilapia caused by △cel-EIIB strain was dramatically decreased (20%), of which S.a.THN0901 strain and △cel-EIIB::i strain were 53.33% and 50%, respectively. The competition experience using tilapia model indicated the invasion and colonization ability of △cel-EIIB strain was significantly weaker than that of S.a.THN0901 strain (p < 0.05). Compared to △cel-EIIB::i strain, the mRNA expression of csrS, csrR, rgfA, rgfC, bgrR and bgrS was significantly downregulated in △cel-EIIB strain (p < 0.05). In conclusion, cel-EIIB protein-mediated cel-PTS not only contributes to biofilm formation and virulence regulation, but also plays an important role in the invasion and colonization of S. agalactiae.
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Affiliation(s)
- Jun Xu
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Lab for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Yun-Dan Xie
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong Province, China
| | - Ling Liu
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Lab for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Song Guo
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Lab for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - You-Lu Su
- College of Fisheries, Tianjin Agricultural University, Tianjin, China
| | - An-Xing Li
- State Key Laboratory of Biocontrol/Guangdong Provincial Key Lab for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
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Wu H, Zhao Y, Du Y, Miao S, Liu J, Li Y, Caiyin Q, Qiao J. Quantitative proteomics of Lactococcus lactis F44 under cross-stress of low pH and lactate. J Dairy Sci 2018; 101:6872-6884. [DOI: 10.3168/jds.2018-14594] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/13/2018] [Indexed: 12/12/2022]
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23
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Daba GM, Ishibashi N, Gong X, Taki H, Yamashiro K, Lim YY, Zendo T, Sonomoto K. Characterisation of the action mechanism of a Lactococcus-specific bacteriocin, lactococcin Z. J Biosci Bioeng 2018; 126:603-610. [PMID: 29929768 DOI: 10.1016/j.jbiosc.2018.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/14/2018] [Accepted: 05/24/2018] [Indexed: 11/25/2022]
Abstract
Lactococcin Z is a novel Lactococcus-specific bacteriocin produced by Lactococcus lactis QU 7 that shares 55.6% identity with lactococcin A. To identify the receptor targeted by lactococcin Z, several lactococcin Z-resistant mutants were generated from the sensitive strain, L. lactis IL1403. The resistant mutants showed difficulties in utilising mannose and glucose as sole carbon sources, contrary to their pattern of growth in the presence of galactose as a sole carbon source. Mutations were found in the ptnC and ptnD genes of lactococcin Z-resistant mutants, which encode the mannose phosphotransferase system (Man-PTS) components, IIC and IID, respectively; therefore, IIC and IID are proposed as potential receptors employed by lactococcin Z and are the same receptors targeted by lactococcin A. Both lactococcins A and Z share a high percentage identity in their N-termini regions in contrast to their C-termini that show less similarity; this may explain the difference in their action mechanisms as well as the lack of cross-immunity between them. Although lactococcin Z showed bactericidal activity, it neither dissipated membrane potential nor formed pores on the membranes of sensitive cells, in sharp contrast to the pore-forming lactococcin A.
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Affiliation(s)
- Ghoson Mosbah Daba
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Naoki Ishibashi
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Xiao Gong
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Hiroya Taki
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Keisuke Yamashiro
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Yen Yi Lim
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Takeshi Zendo
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
| | - Kenji Sonomoto
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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24
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Low affinity uniporter carrier proteins can increase net substrate uptake rate by reducing efflux. Sci Rep 2018; 8:5576. [PMID: 29615663 PMCID: PMC5883050 DOI: 10.1038/s41598-018-23528-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 03/09/2018] [Indexed: 01/25/2023] Open
Abstract
Many organisms have several similar transporters with different affinities for the same substrate. Typically, high-affinity transporters are expressed when substrate is scarce and low-affinity ones when it is abundant. The benefit of using low instead of high-affinity transporters remains unclear, especially when additional nutrient sensors are present. Here, we investigate two hypotheses. It was previously hypothesized that there is a trade-off between the affinity and the catalytic efficiency of transporters, and we find some but no definitive support for it. Additionally, we propose that for uptake by facilitated diffusion, at saturating substrate concentrations, lowering the affinity enhances the net uptake rate by reducing substrate efflux. As a consequence, there exists an optimal, external-substrate-concentration dependent transporter affinity. A computational model of Saccharomyces cerevisiae glycolysis shows that using the low affinity HXT3 transporter instead of the high affinity HXT6 enhances the steady-state flux by 36%. We tried to test this hypothesis with yeast strains expressing a single glucose transporter modified to have either a high or a low affinity. However, due to the intimate link between glucose perception and metabolism, direct experimental proof for this hypothesis remained inconclusive. Still, our theoretical results provide a novel reason for the presence of low-affinity transport systems.
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25
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Sundar GS, Islam E, Braza RD, Silver AB, Le Breton Y, McIver KS. Route of Glucose Uptake in the Group a Streptococcus Impacts SLS-Mediated Hemolysis and Survival in Human Blood. Front Cell Infect Microbiol 2018; 8:71. [PMID: 29594067 PMCID: PMC5861209 DOI: 10.3389/fcimb.2018.00071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 02/27/2018] [Indexed: 12/29/2022] Open
Abstract
The transport and metabolism of glucose has been shown to have far reaching consequences in the transcriptional profile of many bacteria. As glucose is most often the preferred carbon source for bacteria, its presence in the environment leads to the repression of many alternate carbohydrate pathways, a condition known as carbon catabolite repression (CCR). Additionally, the expression of many virulence factors is also dependent on the presence of glucose. Despite its importance, little is known about the transport routes of glucose in the human pathogen Streptococcus pyogenes. Considering that Streptococcus pyogenes is an important human pathogen responsible for over 500,000 deaths every year, we characterized the routes of glucose transport in an effort to understand its importance in GAS pathogenesis. Using a deletion of glucokinase (ΔnagC) to block utilization of glucose imported by non-PTS pathways, we determined that of the two glucose transport pathways in GAS (PTS and non-PTS), the non-PTS pathway played a more significant role in glucose transport. However, the expression of both pathways is linked by a currently unknown mechanism, as blocking the non-PTS uptake of glucose reduces ptsI (EI) expression. Similar to the effects of the deletion of the PTS pathway, lack of the non-PTS pathway also leads to the early activity of Streptolysin S. However, this early activity did not adversely or favorably affect survival of ΔnagC in whole human blood. In a subcutaneous murine infection model, ΔnagC-infected mice showed increased lesion severity at the local site of infection; although, lesion size and dissemination from the site of infection was similar to wild type. Here, we show that glucose transport in GAS is primarily via a non-PTS pathway. The route of glucose transport differentially affects the survival of GAS in whole human blood, as well as the lesion size at the local site of infection in a murine skin infection model.
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Affiliation(s)
- Ganesh S Sundar
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, United States
| | - Emrul Islam
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, United States
| | - Rezia D Braza
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, United States
| | - Aliyah B Silver
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, United States
| | - Yoann Le Breton
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, United States
| | - Kevin S McIver
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, United States
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26
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Abstract
Characterization of PTS-IIC, an endogenous constitutive promoter from L. lactis.. Cellobiose enhances activity from PTS-IIC promoter. PTS-IIC promoter mediates protein expression in B. subtilis and E coli Nissle 1917.
Constitutively active promoter elements for heterologous protein production in Lactococcus lactis are scarce. Here, the promoter of the PTS-IIC gene cluster from L. lactis NZ3900 is described. This promoter was cloned upstream of an enhanced green fluorescent protein, GFPmut3a, and transformed into L. lactis. Transformants produced up to 13.5 μg of GFPmut3a per milliliter of log phase cells. Addition of cellobiose further increased the production of GFPmut3a by up to two-fold when compared to glucose. Analysis of mutations at two specific positions in the PTS-IIC promoter showed that a ‘T’ to ‘G’ mutation within the −35 element resulted in constitutive expression in glucose, while a ‘C’ at nucleotide 7 in the putative cre site enhanced promoter activity in cellobiose. Finally, this PTS-IIC promoter is capable of mediating protein expression in Bacillus subtilis and Escherichia coli Nissle 1917, suggesting the potential for future biotechnological applications of this element and its derivatives.
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Key Words
- ELISA, enzyme-linked immunosorbent assay
- GFP, green fluorescent protein
- Heterologous protein expression
- LAB, lactic acid bacteria
- LB, Luria-Bertani media
- Lactococcus lactis
- OD600, optical density at 600 nm
- PBS, phosphate buffered saline
- Probiotics
- Promoter
- RFU, relative fluorescence unit
- ccpA, catabolite control protein A
- celA, cellobiose-specific phosphor-β-glucosidase
- cre, catabolite-responsive element
- noxE, NADH oxidase promoter
- nt, nucleotide
- ptcC, cellobiose-specific PTS IIC component
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27
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Zhang X, de Maat V, Guzmán Prieto AM, Prajsnar TK, Bayjanov JR, de Been M, Rogers MRC, Bonten MJM, Mesnage S, Willems RJL, van Schaik W. RNA-seq and Tn-seq reveal fitness determinants of vancomycin-resistant Enterococcus faecium during growth in human serum. BMC Genomics 2017; 18:893. [PMID: 29162049 PMCID: PMC5699109 DOI: 10.1186/s12864-017-4299-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/13/2017] [Indexed: 12/30/2022] Open
Abstract
Background The Gram-positive bacterium Enterococcus faecium is a commensal of the human gastrointestinal tract and a frequent cause of bloodstream infections in hospitalized patients. The mechanisms by which E. faecium can survive and grow in blood during an infection have not yet been characterized. Here, we identify genes that contribute to growth of E. faecium in human serum through transcriptome profiling (RNA-seq) and a high-throughput transposon mutant library sequencing approach (Tn-seq). Results We first sequenced the genome of E. faecium E745, a vancomycin-resistant clinical isolate, using a combination of short- and long read sequencing, revealing a 2,765,010 nt chromosome and 6 plasmids, with sizes ranging between 9.3 kbp and 223.7 kbp. We then compared the transcriptome of E. faecium E745 during exponential growth in rich medium and in human serum by RNA-seq. This analysis revealed that 27.8% of genes on the E. faecium E745 genome were differentially expressed in these two conditions. A gene cluster with a role in purine biosynthesis was among the most upregulated genes in E. faecium E745 upon growth in serum. The E. faecium E745 transposon mutant library was then used to identify genes that were specifically required for growth of E. faecium in serum. Genes involved in de novo nucleotide biosynthesis (including pyrK_2, pyrF, purD, purH) and a gene encoding a phosphotransferase system subunit (manY_2) were thus identified to be contributing to E. faecium growth in human serum. Transposon mutants in pyrK_2, pyrF, purD, purH and manY_2 were isolated from the library and their impaired growth in human serum was confirmed. In addition, the pyrK_2 and manY_2 mutants were tested for their virulence in an intravenous zebrafish infection model and exhibited significantly attenuated virulence compared to E. faecium E745. Conclusions Genes involved in carbohydrate metabolism and nucleotide biosynthesis of E. faecium are essential for growth in human serum and contribute to the pathogenesis of this organism. These genes may serve as targets for the development of novel anti-infectives for the treatment of E. faecium bloodstream infections. Electronic supplementary material The online version of this article (10.1186/s12864-017-4299-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xinglin Zhang
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China.,Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Vincent de Maat
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Ana M Guzmán Prieto
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Tomasz K Prajsnar
- Krebs Institute, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Jumamurat R Bayjanov
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Mark de Been
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Malbert R C Rogers
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Marc J M Bonten
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Stéphane Mesnage
- Krebs Institute, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands. .,Institute of Microbiology and Infection, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, B15 2TT, United Kingdom.
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28
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Zeidan AA, Poulsen VK, Janzen T, Buldo P, Derkx PMF, Øregaard G, Neves AR. Polysaccharide production by lactic acid bacteria: from genes to industrial applications. FEMS Microbiol Rev 2017; 41:S168-S200. [DOI: 10.1093/femsre/fux017] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/29/2017] [Indexed: 01/14/2023] Open
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29
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Zhu D, Fu Y, Liu F, Xu H, Saris PEJ, Qiao M. Enhanced heterologous protein productivity by genome reduction in Lactococcus lactis NZ9000. Microb Cell Fact 2017; 16:1. [PMID: 28049473 PMCID: PMC5210298 DOI: 10.1186/s12934-016-0616-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 12/15/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The implementation of novel chassis organisms to be used as microbial cell factories in industrial applications is an intensive research field. Lactococcus lactis, which is one of the most extensively studied model organisms, exhibits superior ability to be used as engineered host for fermentation of desirable products. However, few studies have reported about genome reduction of L. lactis as a clean background for functional genomic studies and a model chassis for desirable product fermentation. RESULTS Four large nonessential DNA regions accounting for 2.83% in L. lactis NZ9000 (L. lactis 9 k) genome (2,530,294 bp) were deleted using the Cre-loxP deletion system as the first steps toward a minimized genome in this study. The mutants were compared with the parental strain in several physiological traits and evaluated as microbial cell factories for heterologous protein production (intracellular and secretory expression) with the red fluorescent protein (RFP) and the bacteriocin leucocin C (LecC) as reporters. The four mutants grew faster, yielded enhanced biomass, achieved increased adenosine triphosphate content, and diminished maintenance demands compared with the wild strain in the two media tested. In particular, L. lactis 9 k-4 with the largest deletion was identified as the optimum candidate host for recombinant protein production. With nisin induction, not only the transcriptional efficiency but also the production levels of the expressed reporters were approximately three- to fourfold improved compared with the wild strain. The expression of lecC gene controlled with strong constitutive promoters P5 and P8 in L. lactis 9 k-4 was also improved significantly. CONCLUSIONS The genome-streamlined L. lactis 9 k-4 outcompeted the parental strain in several physiological traits assessed. Moreover, L. lactis 9 k-4 exhibited good properties as platform organism for protein production. In future works, the genome of L. lactis will be maximally reduced by using our specific design to provide an even more clean background for functional genomics studies than L. lactis 9 k-4 constructed in this study. Furthermore, an improved background will be potentially available for use in biotechology.
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Affiliation(s)
- Duolong Zhu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China.,Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Yuxin Fu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Fulu Liu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Haijin Xu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Per Erik Joakim Saris
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Mingqiang Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China. .,College of Life Sciences, Nankai University, Room 301, Tianjin, China.
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30
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Dolatshahi S, Fonseca LL, Voit EO. New insights into the complex regulation of the glycolytic pathway in Lactococcus lactis. II. Inference of the precisely timed control system regulating glycolysis. MOLECULAR BIOSYSTEMS 2016; 12:37-47. [PMID: 26609780 DOI: 10.1039/c5mb00726g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dairy bacterium Lactococcus lactis has to master a complicated task. It must control its essentially linear glycolytic pathway in such a fashion that, when the substrate, glucose, runs out, it retains enough phosphoenolpyruvate and fructose-1,6-bisphosphate to be able to restart glycolysis as soon as new glucose becomes available. Although glycolysis is arguably the best-studied metabolic pathway, its details in L. lactis are still unclear, and it is, in particular, not understood how the bacterium manages the stop-and-start task. The primary purpose of this paper and its companion is a clarification of some of the details of the governing regulatory strategies with which L. lactis manages to retain the necessary metabolites for the restart of glycolysis after periods of starvation. The paper furthermore discusses how the bacterium changes these strategies when it is subjected to aerobic rather than anaerobic conditions.
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Affiliation(s)
- Sepideh Dolatshahi
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Luis L Fonseca
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Eberhard O Voit
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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31
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Ohba T, Uemura K, Nabetani H. Moderate pulsed electric field treatment enhances exopolysaccharide production by Lactococcus lactis subspecies cremoris. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.05.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Expanded Glucose Import Capability Affords Staphylococcus aureus Optimized Glycolytic Flux during Infection. mBio 2016; 7:mBio.00296-16. [PMID: 27329749 PMCID: PMC4916373 DOI: 10.1128/mbio.00296-16] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acquisition of numerous virulence determinants affords Staphylococcus aureus greater pathogenicity than other skin-colonizing staphylococci in humans. Additionally, the metabolic adaptation of S. aureus to nonrespiratory conditions encountered during infection (e.g., hypoxia, nitric oxide, iron chelation) has been implicated as contributing to S. aureus virulence. Specifically, S. aureus has been shown to ferment glycolytic substrates in nonrespiratory environments encountered within the host. Here, we show that S. aureus has acquired unique carbohydrate transporters that facilitate the maximal uptake of host sugars and serve to support nonrespiratory growth in inflamed tissue. The carbohydrate substrates of 11 S. aureus transporters were identified, and at least four of their genes encode S. aureus glucose transporters (glcA, glcB, glcC, and glcU). Moreover, two transporter genes (glcA and glcC) are unique to S. aureus and contribute disproportionately to the nonrespiratory growth of S. aureus on glucose. Targeted inactivation of sugar transporters reduced glucose uptake and attenuated S. aureus in a murine model of skin and soft tissue infections. These data expand the evidence for metabolic adaptation of S. aureus to invasive infection and demonstrate the specific requirement for the fermentation of glucose over all other available carbohydrates. Ultimately, acquisition of foreign genes allows S. aureus to adopt a metabolic strategy resembling that of infiltrating host immune cells: high glycolytic flux coupled to lactate excretion. The bacterial pathogen Staphylococcus aureus causes a wide range of human infections that are costly and difficult to treat. S. aureus differs from closely related commensal staphylococci in its ability to flourish following the invasion of deeper tissue from the skin surface. There, S. aureus primarily uses glucose to grow under respiration-limiting conditions imposed by the immune system. It was previously unclear how S. aureus thrives in this environment when other Staphylococcus species cannot. Our results provide evidence that S. aureus has acquired an expanded repertoire of carbohydrate transporters. In particular, four glucose transporters contribute to efficient S. aureus growth during infection. Thus, S. aureus has evolved to maximize its glucose uptake abilities for enhanced glycolytic flux during tissue invasion. This dependence on glucose acquisition for S. aureus virulence may also explain links between serious infectious complications associated with diabetic patients exhibiting elevated blood glucose levels.
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33
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Enhancing the Sweetness of Yoghurt through Metabolic Remodeling of Carbohydrate Metabolism in Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. Appl Environ Microbiol 2016; 82:3683-3692. [PMID: 27107115 DOI: 10.1128/aem.00462-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/06/2016] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are used in the fermentation of milk to produce yoghurt. These species normally metabolize only the glucose moiety of lactose, secreting galactose and producing lactic acid as the main metabolic end product. We used multiple serial selection steps to isolate spontaneous mutants of industrial strains of S. thermophilus and L. delbrueckii subsp. bulgaricus that secreted glucose rather than galactose when utilizing lactose as a carbon source. Sequencing revealed that the S. thermophilus strains had mutations in the galKTEM promoter, the glucokinase gene, and genes encoding elements of the glucose/mannose phosphotransferase system (PTS). These strains metabolize galactose but are unable to phosphorylate glucose internally or via the PTS. The L. delbrueckii subsp. bulgaricus mutants had mutations in genes of the glucose/mannose PTS and in the pyruvate kinase gene. These strains cannot grow on exogenous glucose but are proficient at metabolizing internal glucose released from lactose by β-galactosidase. The resulting strains can be combined to ferment milk, producing yoghurt with no detectable lactose, moderate levels of galactose, and high levels of glucose. Since glucose tastes considerably sweeter than either lactose or galactose, the sweetness of the yoghurt is perceptibly enhanced. These strains were produced without the use of recombinant DNA technology and can be used for the industrial production of yoghurt with enhanced intrinsic sweetness and low residual levels of lactose. IMPORTANCE Based on a good understanding of the physiology of the lactic acid bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, we were able, by selecting spontaneously occurring mutants, to change dramatically the metabolic products secreted into the growth medium. These mutants consume substantially more of the lactose, metabolize some of the galactose, and secrete the remaining galactose and most of the glucose back into the milk. This allows production of yoghurt with very low lactose levels and enhanced natural sweetness, because humans perceive glucose as sweeter than either lactose or galactose.
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34
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Zhu D, Li R, Liu F, Xu H, Li B, Yuan Y, Saris P, Qiao M. Mu insertion in feuD
triggers the increase in nisin immunity in Lactococcus lactis
subsp. lactis
N8. J Appl Microbiol 2016; 120:402-12. [DOI: 10.1111/jam.13015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 10/21/2015] [Accepted: 11/20/2015] [Indexed: 11/29/2022]
Affiliation(s)
- D. Zhu
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
| | - R. Li
- School of Life Sciences and Technology; ShanghaiTech University; Shanghai China
| | - F. Liu
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
| | - H. Xu
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
| | - B. Li
- Key Laboratory of Systems Bioengineering; Ministry of Education; Department of Pharmaceutical Engineering; Tianjin University; Tianjin China
| | - Y. Yuan
- Key Laboratory of Systems Bioengineering; Ministry of Education; Department of Pharmaceutical Engineering; Tianjin University; Tianjin China
| | - P.E.J. Saris
- Department of Food and Environmental Sciences; University of Helsinki; Helsinki Finland
| | - M. Qiao
- Key Laboratory of Molecular Microbiology and Technology; Ministry of Education; Nankai University; Tianjin China
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35
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Dolatshahi S, Fonseca LL, Voit EO. New insights into the complex regulation of the glycolytic pathway in Lactococcus lactis. I. Construction and diagnosis of a comprehensive dynamic model. MOLECULAR BIOSYSTEMS 2016; 12:23-36. [DOI: 10.1039/c5mb00331h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This article and the companion paper use computational systems modeling to decipher the complex coordination of regulatory signals controlling the glycolytic pathway in the dairy bacterium Lactococcus lactis.
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Affiliation(s)
- Sepideh Dolatshahi
- Department of Biomedical Engineering
- Georgia Institute of Technology
- Atlanta
- USA
| | - Luis L. Fonseca
- Department of Biomedical Engineering
- Georgia Institute of Technology
- Atlanta
- USA
| | - Eberhard O. Voit
- Department of Biomedical Engineering
- Georgia Institute of Technology
- Atlanta
- USA
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Paixão L, Caldas J, Kloosterman TG, Kuipers OP, Vinga S, Neves AR. Transcriptional and metabolic effects of glucose on Streptococcus pneumoniae sugar metabolism. Front Microbiol 2015; 6:1041. [PMID: 26500614 PMCID: PMC4595796 DOI: 10.3389/fmicb.2015.01041] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/14/2015] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae is a strictly fermentative human pathogen that relies on carbohydrate metabolism to generate energy for growth. The nasopharynx colonized by the bacterium is poor in free sugars, but mucosa lining glycans can provide a source of sugar. In blood and inflamed tissues glucose is the prevailing sugar. As a result during progression from colonization to disease S. pneumoniae has to cope with a pronounced shift in carbohydrate nature and availability. Thus, we set out to assess the pneumococcal response to sugars found in glycans and the influence of glucose (Glc) on this response at the transcriptional, physiological, and metabolic levels. Galactose (Gal), N-acetylglucosamine (GlcNAc), and mannose (Man) affected the expression of 8 to 14% of the genes covering cellular functions including central carbon metabolism and virulence. The pattern of end-products as monitored by in vivo13C-NMR is in good agreement with the fermentation profiles during growth, while the pools of phosphorylated metabolites are consistent with the type of fermentation observed (homolactic vs. mixed) and regulation at the metabolic level. Furthermore, the accumulation of α-Gal6P and Man6P indicate metabolic bottlenecks in the metabolism of Gal and Man, respectively. Glc added to cells actively metabolizing other sugar(s) was readily consumed and elicited a metabolic shift toward a homolactic profile. The transcriptional response to Glc was large (over 5% of the genome). In central carbon metabolism (most represented category), Glc exerted mostly negative regulation. The smallest response to Glc was observed on a sugar mix, suggesting that exposure to varied sugars improves the fitness of S. pneumoniae. The expression of virulence factors was negatively controlled by Glc in a sugar-dependent manner. Overall, our results shed new light on the link between carbohydrate metabolism, adaptation to host niches and virulence.
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Affiliation(s)
- Laura Paixão
- Laboratory of Lactic Acid Bacteria and In Vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - José Caldas
- Center of Intelligent Systems, Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
| | - Tomas G Kloosterman
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Susana Vinga
- Center of Intelligent Systems, Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
| | - Ana R Neves
- Laboratory of Lactic Acid Bacteria and In Vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
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37
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Chen J, Shen J, Ingvar Hellgren L, Ruhdal Jensen P, Solem C. Adaptation of Lactococcus lactis to high growth temperature leads to a dramatic increase in acidification rate. Sci Rep 2015; 5:14199. [PMID: 26388459 PMCID: PMC4585701 DOI: 10.1038/srep14199] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 08/21/2015] [Indexed: 01/17/2023] Open
Abstract
Lactococcus lactis is essential for most cheese making, and this mesophilic bacterium has its growth optimum around 30 °C. We have, through adaptive evolution, isolated a mutant TM29 that grows well up to 39 °C, and continuous growth at 40 °C is possible if pre-incubated at a slightly lower temperature. At the maximal permissive temperature for the wild-type, 38 °C, TM29 grows 33% faster and has a 12% higher specific lactate production rate than its parent MG1363, which results in fast lactate accumulation. Genome sequencing was used to reveal the mutations accumulated, most of which were shown to affect thermal tolerance. Of the mutations with more pronounced effects, two affected expression of single proteins (chaperone; riboflavin transporter), two had pleiotropic effects (RNA polymerase) which changed the gene expression profile, and one resulted in a change in the coding sequence of CDP-diglyceride synthase. A large deletion containing 10 genes was also found to affect thermal tolerance significantly. With this study we demonstrate a simple approach to obtain non-GMO derivatives of the important L. lactis that possess properties desirable by the industry, e.g. thermal robustness and increased rate of acidification. The mutations we have identified provide a genetic basis for further investigation of thermal tolerance.
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Affiliation(s)
- Jun Chen
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Jing Shen
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Lars Ingvar Hellgren
- Department of Systems Biology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Peter Ruhdal Jensen
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Christian Solem
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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38
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Hartmann A, Lemos JM, Vinga S. Modeling multiple experiments using regularized optimization: A case study on bacterial glucose utilization dynamics. Comput Biol Med 2015; 63:301-9. [DOI: 10.1016/j.compbiomed.2014.08.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 06/27/2014] [Accepted: 08/28/2014] [Indexed: 11/26/2022]
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39
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Zhu D, Liu F, Xu H, Bai Y, Zhang X, Saris PEJ, Qiao M. Isolation of strong constitutive promoters from Lactococcus lactis subsp. lactis N8. FEMS Microbiol Lett 2015; 362:fnv107. [PMID: 26156144 DOI: 10.1093/femsle/fnv107] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2015] [Indexed: 11/13/2022] Open
Abstract
The synthesis of heterologous proteins in Lactococcus lactis is strongly influenced by the promoter selected for the expression. The nisin A promoter is commonly used for induced expression of proteins in L. lactis, whereas few constitutive promoters (P45 and the weaker P32) have been used for protein expression studies. In this study, eight different putative strong constitutive promoters were identified through transcriptional analysis of L. lactis N8 and were investigated for their capability to drive nisZ gene expression with promoters P45 and P32 as control. Four strong promoters (P8, P5, P3 and P2) were identified as having a transcriptional activity that was higher than that of P45 through RT-qPCR and agar-diffusion experiments. In addition, these four promoters were fused to the erythromycin resistant gene (ermC) with promoter P45 as control and inserted into the backbone of the pNZ8048 vector. The transcriptional efficiencies of promoters P8, P5, P2 and P3 were all higher than promoter P45 based on the obtained MIC50 values and they all showed different activity levels. In conclusion, four strong constitutive promoters with a wide range of promoter activities were identified and are suitable for protein production in L. lactis.
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Affiliation(s)
- Duolong Zhu
- College of Life Sciences, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Fulu Liu
- College of Life Sciences, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Haijin Xu
- College of Life Sciences, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Yanling Bai
- College of Life Sciences, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | - Xiuming Zhang
- College of Life Sciences, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
| | | | - Mingqiang Qiao
- College of Life Sciences, The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin, China
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40
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Eiteman MA, Ramalingam S. Microbial production of lactic acid. Biotechnol Lett 2015; 37:955-72. [PMID: 25604523 DOI: 10.1007/s10529-015-1769-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
Abstract
Lactic acid is an important commodity chemical having a wide range of applications. Microbial production effectively competes with chemical synthesis methods because biochemical synthesis permits the generation of either one of the two enantiomers with high optical purity at high yield and titer, a result which is particularly beneficial for the production of poly(lactic acid) polymers having specific properties. The commercial viability of microbial lactic acid production relies on utilization of inexpensive carbon substrates derived from agricultural or waste resources. Therefore, optimal lactic acid formation requires an understanding and engineering of both the competing pathways involved in carbohydrate metabolism, as well as pathways leading to potential by-products which both affect product yield. Recent research leverages those biochemical pathways, while researchers also continue to seek strains with improved tolerance and ability to perform under desirable industrial conditions, for example, of pH and temperature.
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Affiliation(s)
- Mark A Eiteman
- BioChemical Engineering Program, College of Engineering, University of Georgia, Athens, GA, 30602, USA,
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41
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Lactate dehydrogenase is the key enzyme for pneumococcal pyruvate metabolism and pneumococcal survival in blood. Infect Immun 2014; 82:5099-109. [PMID: 25245810 DOI: 10.1128/iai.02005-14] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Streptococcus pneumoniae is a fermentative microorganism and causes serious diseases in humans, including otitis media, bacteremia, meningitis, and pneumonia. However, the mechanisms enabling pneumococcal survival in the host and causing disease in different tissues are incompletely understood. The available evidence indicates a strong link between the central metabolism and pneumococcal virulence. To further our knowledge on pneumococcal virulence, we investigated the role of lactate dehydrogenase (LDH), which converts pyruvate to lactate and is an essential enzyme for redox balance, in the pneumococcal central metabolism and virulence using an isogenic ldh mutant. Loss of LDH led to a dramatic reduction of the growth rate, pinpointing the key role of this enzyme in fermentative metabolism. The pattern of end products was altered, and lactate production was totally blocked. The fermentation profile was confirmed by in vivo nuclear magnetic resonance (NMR) measurements of glucose metabolism in nongrowing cell suspensions of the ldh mutant. In this strain, a bottleneck in the fermentative steps is evident from the accumulation of pyruvate, revealing LDH as the most efficient enzyme in pyruvate conversion. An increase in ethanol production was also observed, indicating that in the absence of LDH the redox balance is maintained through alcohol dehydrogenase activity. We also found that the absence of LDH renders the pneumococci avirulent after intravenous infection and leads to a significant reduction in virulence in a model of pneumonia that develops after intranasal infection, likely due to a decrease in energy generation and virulence gene expression.
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42
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Petrova O, Gorshkov V, Daminova A, Ageeva M, Moleleki LN, Gogolev Y. Stress response in Pectobacterium atrosepticum SCRI1043 under starvation conditions: adaptive reactions at a low population density. Res Microbiol 2014; 165:119-27. [DOI: 10.1016/j.resmic.2013.11.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 11/19/2013] [Indexed: 11/27/2022]
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43
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Availability of public goods shapes the evolution of competing metabolic strategies. Proc Natl Acad Sci U S A 2013; 110:14302-7. [PMID: 23940318 DOI: 10.1073/pnas.1308523110] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tradeoffs provide a rationale for the outcome of natural selection. A prominent example is the negative correlation between the growth rate and the biomass yield in unicellular organisms. This tradeoff leads to a dilemma, where the optimization of growth rate is advantageous for an individual, whereas the optimization of the biomass yield would be advantageous for a population. High-rate strategies are observed in a broad variety of organisms such as Escherichia coli, yeast, and cancer cells. Growth in suspension cultures favors fast-growing organisms, whereas spatial structure is of importance for the evolution of high-yield strategies. Despite this realization, experimental methods to directly select for increased yield are lacking. We here show that the serial propagation of a microbial population in a water-in-oil emulsion allows selection of strains with increased biomass yield. The propagation in emulsion creates a spatially structured environment where the growth-limiting substrate is privatized for populations founded by individual cells. Experimental evolution of several isogenic Lactococcus lactis strains demonstrated the existence of a tradeoff between growth rate and biomass yield as an apparent Pareto front. The underlying mutations altered glucose transport and led to major shifts between homofermentative and heterofermentative metabolism, accounting for the changes in metabolic efficiency. The results demonstrated the impact of privatizing a public good on the evolutionary outcome between competing metabolic strategies. The presented approach allows the investigation of fundamental questions in biology such as the evolution of cooperation, cell-cell interactions, and the relationships between environmental and metabolic constraints.
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44
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Carvalho AL, Turner DL, Fonseca LL, Solopova A, Catarino T, Kuipers OP, Voit EO, Neves AR, Santos H. Metabolic and transcriptional analysis of acid stress in Lactococcus lactis, with a focus on the kinetics of lactic acid pools. PLoS One 2013; 8:e68470. [PMID: 23844205 PMCID: PMC3700934 DOI: 10.1371/journal.pone.0068470] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 05/29/2013] [Indexed: 01/27/2023] Open
Abstract
The effect of pH on the glucose metabolism of non-growing cells of L. lactis MG1363 was studied by in vivo NMR in the range 4.8 to 6.5. Immediate pH effects on glucose transporters and/or enzyme activities were distinguished from transcriptional/translational effects by using cells grown at the optimal pH of 6.5 or pre-adjusted to low pH by growth at 5.1. In cells grown at pH 5.1, glucose metabolism proceeds at a rate 35% higher than in non-adjusted cells at the same pH. Besides the upregulation of stress-related genes (such as dnaK and groEL), cells adjusted to low pH overexpressed H(+)-ATPase subunits as well as glycolytic genes. At sub-optimal pHs, the total intracellular pool of lactic acid reached approximately 500 mM in cells grown at optimal pH and about 700 mM in cells grown at pH 5.1. These high levels, together with good pH homeostasis (internal pH always above 6), imply intracellular accumulation of the ionized form of lactic acid (lactate anion), and the concomitant export of the equivalent protons. The average number, n, of protons exported with each lactate anion was determined directly from the kinetics of accumulation of intra- and extracellular lactic acid as monitored online by (13)C-NMR. In cells non-adjusted to low pH, n varies between 2 and 1 during glucose consumption, suggesting an inhibitory effect of intracellular lactate on proton export. We confirmed that extracellular lactate did not affect the lactate: proton stoichiometry. In adjusted cells, n was lower and varied less, indicating a different mix of lactic acid exporters less affected by the high level of intracellular lactate. A qualitative model for pH effects and acid stress adaptation is proposed on the basis of these results.
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Affiliation(s)
- Ana Lúcia Carvalho
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - David L. Turner
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Luís L. Fonseca
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Integrative BioSystems Institute and the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Ana Solopova
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands
| | - Teresa Catarino
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Departamento de Química, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, Caparica, Oeiras, Portugal
| | - Oscar P. Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands
| | - Eberhard O. Voit
- Integrative BioSystems Institute and the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Ana Rute Neves
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Helena Santos
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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45
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Akyol I. Proteomics analysis of the Flp regulon in Lactococcus lactis subsp. cremoris. Electrophoresis 2013; 34:2218-28. [PMID: 23712609 DOI: 10.1002/elps.201300002] [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: 10/12/2012] [Revised: 03/30/2013] [Accepted: 04/03/2013] [Indexed: 11/09/2022]
Abstract
Lactococcus lactis subsp. cremoris MG1363 genome sequence was completed and encodes two flp genes flpA and flpB. Research carried out has suggested that the flpB proteins are transcriptional regulators that respond to the environmental oxygen level. A variety of flp deletion mutant strains with single and double mutation were created. Wild-type (MG1363) and its flp(-) derivatives were compared by 2DE to identify changes in protein intensity under different aerobic/anaerobic growth conditions. In total, 416 ± 20 and 444 ± 32 protein spots were quantified from anaerobic and aerobic cells, respectively, on pH 4-7 gels. Forty-five protein spots that changed were excised from 2DE gel, digested with trypsin and identified from their MALDI-TOF MS Peptide Mass Fingerprint. A variety of proteins were affected by the flp mutations and oxygen level. Some proteins were controlled by FlpA and FlpB independently and some required both FlpA and B for regulation. The identified proteins that are regulated by the Flp proteins can be grouped by biochemical function. These groups are oxidative stress, electron transfer, sugars, cell wall, ABC transporters, arginine metabolism, and pyrimidine biosynthesis pathway.
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Affiliation(s)
- Ismail Akyol
- Department of Agricultural Biotechnology, Faculty of Agriculture, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey.
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46
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Distribution and functions of phosphotransferase system genes in the genome of the lactic acid bacterium Oenococcus oeni. Appl Environ Microbiol 2013; 79:3371-9. [PMID: 23524676 DOI: 10.1128/aem.00380-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Oenococcus oeni, the lactic acid bacterium primarily responsible for malolactic fermentation in wine, is able to grow on a large variety of carbohydrates, but the pathways by which substrates are transported and phosphorylated in this species have been poorly studied. We show that the genes encoding the general phosphotransferase proteins, enzyme I (EI) and histidine protein (HPr), as well as 21 permease genes (3 isolated ones and 18 clustered into 6 distinct loci), are highly conserved among the strains studied and may form part of the O. oeni core genome. Additional permease genes differentiate the strains and may have been acquired or lost by horizontal gene transfer events. The core pts genes are expressed, and permease gene expression is modulated by the nature of the bacterial growth substrate. Decryptified O. oeni cells are able to phosphorylate glucose, cellobiose, trehalose, and mannose at the expense of phosphoenolpyruvate. These substrates are present at low concentrations in wine at the end of alcoholic fermentation. The phosphotransferase system (PTS) may contribute to the perfect adaptation of O. oeni to its singular ecological niche.
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47
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Ferreira MT, Manso AS, Gaspar P, Pinho MG, Neves AR. Effect of oxygen on glucose metabolism: utilization of lactate in Staphylococcus aureus as revealed by in vivo NMR studies. PLoS One 2013; 8:e58277. [PMID: 23472168 PMCID: PMC3589339 DOI: 10.1371/journal.pone.0058277] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 02/01/2013] [Indexed: 01/25/2023] Open
Abstract
The ability to successfully adapt to changing host conditions is crucial for full virulence of bacterial pathogens. Staphylococcus aureus has to cope with fluctuating oxygen concentrations during the course of infection. Hence, we studied the effect of oxygen on glucose metabolism in non-growing S. aureus COL-S cells by in vivo13C-NMR. Glucose catabolism was probed at different oxygen concentrations in suspensions of cells grown aerobically (direct effects on metabolism) or anaerobically (transcriptional adjustment to oxygen deprivation). In aerobically-grown cells, the rate of glucose consumption diminished progressively with decreasing oxygen concentrations. Additionally, oxygen deprivation resulted in biphasic glucose consumption, with the second phase presenting a higher rate. The fructose-1,6-bisphosphate pool peaked while glucose was still abundant, but the transient maximum varied with the oxygen concentration. As oxygen became limiting mannitol/mannitol-1-phosphate were detected as products of glucose catabolism. Under anoxic conditions, accumulation of mannitol-1-phosphate ceased with the switch to higher glucose consumption rates, which implies the activation of a more efficient means by which NAD+ can be regenerated. The distribution of end-products deriving from glucose catabolism was dramatically affected by oxygen: acetate increased and lactate decreased with the oxygen concentration; ethanol was formed only anaerobically. Moreover, oxygen promoted the energetically favourable conversion of lactate into acetate, which was particularly noticeable under fully oxygenated conditions. Interestingly, under aerobiosis growing S. aureus cells also converted lactate to acetate, used simultaneously glucose and lactate as substrates for growth, and grew considerably well on lactate-medium. We propose that the efficient lactate catabolism may endow S. aureus with a metabolic advantage in its ecological niche.
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Affiliation(s)
- Maria Teresa Ferreira
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana S. Manso
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Paula Gaspar
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana Rute Neves
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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48
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Martinussen J, Solem C, Holm AK, Jensen PR. Engineering strategies aimed at control of acidification rate of lactic acid bacteria. Curr Opin Biotechnol 2012; 24:124-9. [PMID: 23266099 DOI: 10.1016/j.copbio.2012.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 11/21/2012] [Accepted: 11/22/2012] [Indexed: 10/27/2022]
Abstract
The ability of lactic acid bacteria to produce lactic acid from various sugars plays an important role in food fermentations. Lactic acid is derived from pyruvate, the end product of glycolysis and thus a fast lactic acid production rate requires a high glycolytic flux. In addition to lactic acid, alternative end products--ethanol, acetic acid and formic acid--are formed by many species. The central role of glycolysis in lactic acid bacteria has provoked numerous studies aiming at identifying potential bottleneck(s) since knowledge about flux control could be important not only for optimizing food fermentation processes, but also for novel applications of lactic acid bacteria, such as cell factories for the production of green fuels and chemicals. With respect to the control and regulation of the fermentation mode, some progress has been made, but the question of which component(s) control the main glycolytic flux remains unanswered.
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Affiliation(s)
- Jan Martinussen
- Center for Systems Microbiology, Department of Systems Biology, Technical University of Denmark, Matematiktorvet, Building 301, 2800 Kgs. Lyngby, Denmark
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49
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Levering J, Kummer U, Becker K, Sahle S. Glycolytic oscillations in a model of a lactic acid bacterium metabolism. Biophys Chem 2012; 172:53-60. [PMID: 23357412 DOI: 10.1016/j.bpc.2012.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 11/12/2012] [Accepted: 11/12/2012] [Indexed: 11/16/2022]
Abstract
Glycolytic oscillations in yeast have been extensively studied. It is still unclear, if these oscillations are caused by the allosteric enzyme phosphofructokinase or the stoichiometry of glycolysis which contains an autocatalysis with respect to ATP. Bacterial glycolysis shows a different stoichiometry, however, also containing a stoichiometric autocatalysis. For Escherichia coli, the regulation of the enzyme phosphofructokinase is also assumed to be a major reason for oscillations to occur. We investigated glycolytic oscillations in a quantitative kinetic model for Streptococcus pyogenes set-up on the basis of experimental data. We found oscillations within physiologically feasible parameter ranges. We investigated the origin of these oscillations and conclude that, again, both the stoichiometry of the system, as well as its allosterically regulated enzymes can give rise to these oscillations. For the analysis we employed established and new optimization methods for finding oscillatory regimes and present these in the context of this study.
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Affiliation(s)
- Jennifer Levering
- Department of Modeling of Biological Processes, COS Heidelberg/BioQuant, University Heidelberg, 69120 Heidelberg, Germany.
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50
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The putative lactococcal extracytoplasmic function anti-sigma factor llmg2447 determines resistance to the cell wall-active bacteriocin lcn972. Antimicrob Agents Chemother 2012; 56:5520-7. [PMID: 22890757 DOI: 10.1128/aac.01206-12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Lactococcin 972 (Lcn972) is a cell wall-active bacteriocin that inhibits cell wall biosynthesis in Lactococcus lactis. In this work, the transcriptomes of the Lcn972-resistant (Lcn(r)) mutant L. lactis D1 and its parent strain were compared to identify factors involved in Lcn972 resistance. Upregulated genes included members of the cell envelope stress (CesSR) regulon, the penicillin-binding protein pbpX gene and gene llmg2447, which may encode a putative extracytoplasmic function (ECF) anti-sigma factor. The gene llmg2447 is located downstream of the nonfunctional ECF gene sigX(pseudo). Nisin-controlled expression of llmg2447 led to high Lcn972 resistance in L. lactis, with no cross-resistance to other cell wall-active antimicrobials. Upregulation of llmg2447 in L. lactis D1 (Lcn(r)) was linked to the integration of insertion element IS981 into the llmg2447 promoter region, replacing the native -35 box and activating the otherwise silent promoter P(2447). This is the first example of an orphan ECF anti-sigma factor involved in bacteriocin resistance. This new role in neutralizing cell wall-active compounds (e.g., Lcn972) could have evolved from a putative primary function of Llmg2447 in sensing cell envelope stress.
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