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Wang H, Ai LZ, Xia YJ, Wang GQ, Xiong ZQ, Song X. Characterization of a Panel of Constitutive Promoters from Lactococcus cremoris for Fine-Tuning Gene Expression. ACS Synth Biol 2024; 13:1365-1372. [PMID: 38518262 DOI: 10.1021/acssynbio.4c00087] [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] [Indexed: 03/24/2024]
Abstract
Lactococcus cremoris (homotypic synonym: Lactococcus lactis) is receiving increasing attention as a prominent vehicle for the delivery of live vaccines. This can hardly be achieved without developing tools for the genetic manipulation of L. cremoris, and the paucity of studies on L. cremoris endogenous promoters has attracted our attention. Here, we report the discovery and characterization of 29 candidate promoters identified from L. cremoris subsp. cremoris NZ9000 by RNA sequencing analysis. Furthermore, 18 possible constitutive promoters were obtained by RT-qPCR screening from these 29 candidate promoters. Then, these 18 promoters were cloned and characterized by a reporter gene, gusA, encoding β-glucuronidase. Eventually, eight endogenous constitutive promoters of L. cremoris were obtained, which can be applied to genetic manipulation of lactic acid bacteria.
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Affiliation(s)
- Hui Wang
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Lian-Zhong Ai
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Yong-Jun Xia
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Guang-Qiang Wang
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Zhi-Qiang Xiong
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Xin Song
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
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Wang H, Ai L, Xia Y, Wang G, Xiong Z, Song X. Software-based screening for efficient sgRNAs in Lactococcus lactis. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:1200-1206. [PMID: 37647419 DOI: 10.1002/jsfa.12946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/23/2023] [Accepted: 08/30/2023] [Indexed: 09/01/2023]
Abstract
BACKGROUND The two essential editing elements in the clustered regularly interspaced short palindromic repeats (CRISPR) editing system are promoter and single-guide RNA (sgRNA), the latter of which determines whether Cas protein can precisely target a specific location to edit the targeted gene. Therefore, the selection of sgRNA is crucial to the efficiency of the CRISPR editing system. Various online prediction tools for sgRNA are currently available. These tools can predict all possible sgRNAs of the targeted gene and rank sgRNAs according to certain scoring criteria according to the demands of the user. RESULTS We designed sgRNAs for Lactococcus lactis NZ9000 LLNZ_RS02020 (ldh) and LLNZ_RS10925 (upp) individually using online prediction software - CRISPOR - and successfully constructed a series of knockout strains to allow comparison of the knockout efficiency of each sgRNA and analyze the differences between software predictions and actual experimental results. CONCLUSION Our experimental results showed that the actual editing efficiency of the screened sgRNAs did not match the predicted results - a phenomenon that suggests that established findings from eukaryotic studies are not universally applicable to prokaryotes. Software prediction can still be used as a tool for the initial screening of sgRNAs before further selection of suitable sgRNAs through experimental experience. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Hui Wang
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Lianzhong Ai
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Yongjun Xia
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Guangqiang Wang
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Zhiqiang Xiong
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Xin Song
- Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
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Wu F, Xie X, Du T, Jiang X, Miao W, Wang T. Lactococcus lactis, a bacterium with probiotic functions and pathogenicity. World J Microbiol Biotechnol 2023; 39:325. [PMID: 37776350 DOI: 10.1007/s11274-023-03771-5] [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: 07/31/2023] [Accepted: 09/16/2023] [Indexed: 10/02/2023]
Abstract
Lactococcus lactis (L. lactis) is the primary organism for lactic acid bacteria (LAB) and is a globally recognized safe microorganism for the regulation of the intestinal micro-ecological balance of animals and improving the immune performance of the host. L. lactis is known to play a commercially important role in feed fortification, milk fermentation, and vaccine production, but pathogenic L. lactis has been isolated from many clinical cases in recent years, such as the brain of silver carp with Lactococcosis, the liver and spleen of diseased waterfowl, milk samples and padding materials with cow mastitis, and blood and urine from human patients with endocarditis. In dairy farming, where L. lactis has been used as a probiotic in the past, however, some studies have found that L. lactis can cause mastitis in cows, but the lack of understanding of the pathogenesis of mastitis in cows caused by L. lactis has become a new problem. The main objective of this review is to analyze the increasingly serious clinical mastitis caused by L. lactis and combined with the wide application of L. lactis as probiotics, to comprehensively discuss the characteristics and diversity of L. lactis.
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Affiliation(s)
- Fan Wu
- College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
| | - Xinmei Xie
- Elanco (Shanghai)Animal Health Co, Ltd, No.1, Field Middle Road, Wusi Farm, Fengxian District, Shanghai, China
| | - Tao Du
- College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
| | - Xiaodan Jiang
- College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
| | - Wei Miao
- College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
| | - Tiancheng Wang
- College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China.
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Markakiou S, Neves AR, Zeidan AA, Gaspar P. Development of a Tetracycline-Inducible System for Conditional Gene Expression in Lactococcus lactis and Streptococcus thermophilus. Microbiol Spectr 2023; 11:e0066823. [PMID: 37191512 PMCID: PMC10269922 DOI: 10.1128/spectrum.00668-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/21/2023] [Indexed: 05/17/2023] Open
Abstract
Inducible gene expression systems are invaluable tools for the functional characterization of genes and in the construction of protein overexpression hosts. Controllable expression is especially important for the study of essential and toxic genes or genes where the level of expression tightly influences their cellular effect. Here, we implemented the well-characterized tetracycline-inducible expression system in two industrially important lactic acid bacteria, Lactococcus lactis and Streptococcus thermophilus. Using a fluorescent reporter gene, we show that optimization of the repression level is necessary for efficient induction using anhydrotetracycline in both organisms. Random mutagenesis in the ribosome binding site of the tetracycline repressor TetR in Lactococcus lactis indicated that altering the expression levels of TetR was necessary for efficient inducible expression of the reporter gene. Through this approach, we achieved plasmid-based, inducer-responsive, and tight gene expression in Lactococcus lactis. We then verified the functionality of the optimized inducible expression system in Streptococcus thermophilus following its chromosomal integration using a markerless mutagenesis approach and a novel DNA fragment assembly tool presented herein. This inducible expression system holds several advantages over other described systems in lactic acid bacteria, although more efficient techniques for genetic engineering are still needed to realize these advantages in industrially relevant species, such as S. thermophilus. Our work expands the molecular toolbox of these bacteria, which can accelerate future physiological studies. IMPORTANCE Lactococcus lactis and Streptococcus thermophilus are two industrially important lactic acid bacteria globally used in dairy fermentations and, therefore, are of considerable commercial interest to the food industry. Moreover, due to their general history of safe usage, these microorganisms are increasingly being explored as hosts for the production of heterologous proteins and various chemicals. Development of molecular tools in the form of inducible expression systems and mutagenesis techniques facilitates their in-depth physiological characterization as well as their exploitation in biotechnological applications.
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Affiliation(s)
- Sofia Markakiou
- R&D Department, Chr. Hansen A/S, Hørsholm, Denmark
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | | | | | - Paula Gaspar
- R&D Department, Chr. Hansen A/S, Hørsholm, Denmark
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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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Wu J, Tian X, Xu X, Gu X, Kong J, Guo T. Engineered Probiotic Lactococcus lactis for Lycopene Production against ROS Stress in Intestinal Epithelial Cells. ACS Synth Biol 2022; 11:1568-1576. [PMID: 35289165 DOI: 10.1021/acssynbio.1c00639] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lactococcus lactis is a food-grade chassis for delivery of bioactive molecules to the intestinal mucosa in situ, while its ability to produce lycopene for detoxification of reactive oxidative species (ROS) is not realized yet. Here, L. lactis NZ9000 was engineered to synthesize lycopene by heterologous expression of a gene cluster crtEBI in plasmids or chromosomes, yielding the recombinant strains NZ4 and NZ5 with 0.59 and 0.54 mg/L lycopene production, respectively. To reroute the pyruvate flux to lycopene, the main lactate dehydrogenase and α-acetolactate synthase pathways were sequentially disrupted. The resultant strains NZΔldh-1 and NZΔldhΔals-1 increased lycopene accumulation to 0.70 and 0.73 mg/L, respectively, while their biomasses were reduced by 12.42% and the intracellular NADH/NAD+ ratios increased by 3.05- and 2.10-fold. To increase the biomasses of these engineered strains, aerobic respiration was activated and tuned by the addition of exogenous heme and oxygen. As a result, the engineered L. lactis strains partly recovered the growth and redox balance, yielding the lycopene levels of 0.91-1.09 mg/L. The engineered L. lactis strain protected the intestinal epithelial cells NCM460 against H2O2 challenge, with a 30.09% increase of cell survival and a 29.2% decrease of the intracellular ROS level compared with strain NZ9000 treatment. In summary, this work established the use of the engineered probiotic L. lactis for lycopene production and prospected its potential in the prevention of intestinal oxidative damage.
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Affiliation(s)
- Jiapeng Wu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Xingfang Tian
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Xiaoning Xu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Xinyi Gu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Tingting Guo
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
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Structural and biochemical characterization of in vivo assembled Lactococcus lactis CRISPR-Csm complex. Commun Biol 2022; 5:279. [PMID: 35351985 PMCID: PMC8964682 DOI: 10.1038/s42003-022-03187-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/14/2022] [Indexed: 12/15/2022] Open
Abstract
The small RNA-mediated immunity in bacteria depends on foreign RNA-activated and self RNA-inhibited enzymatic activities. The multi-subunit Type III-A CRISPR-Cas effector complex (Csm) exemplifies this principle and is in addition regulated by cellular metabolites such as divalent metals and ATP. Recognition of the foreign or cognate target RNA (CTR) triggers its single-stranded deoxyribonuclease (DNase) and cyclic oligoadenylate (cOA) synthesis activities. The same activities remain dormant in the presence of the self or non-cognate target RNA (NTR) that differs from CTR only in its 3′-protospacer flanking sequence (3′-PFS). Here we employ electron cryomicroscopy (cryoEM), functional assays, and comparative cross-linking to study in vivo assembled mesophilic Lactococcus lactis Csm (LlCsm) at the three functional states: apo, the CTR- and the NTR-bound. Unlike previously studied Csm complexes, we observed binding of 3′-PFS to Csm in absence of bound ATP and analyzed the structures of the four RNA cleavage sites. Interestingly, comparative crosslinking results indicate a tightening of the Csm3-Csm4 interface as a result of CTR but not NTR binding, reflecting a possible role of protein dynamics change during activation. This study presents Cryo-EM structures of the Lactococcus lactis Type III-A CRISPR-Cas effector complex in three functional states, including bound forms with cognate and non-cognate target RNA. The results suggest changing protein dynamics during effector complex activation.
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8
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Anastasiou R, Kazou M, Georgalaki M, Aktypis A, Zoumpopoulou G, Tsakalidou E. Omics Approaches to Assess Flavor Development in Cheese. Foods 2022; 11:188. [PMID: 35053920 PMCID: PMC8775153 DOI: 10.3390/foods11020188] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/03/2022] [Accepted: 01/09/2022] [Indexed: 12/27/2022] Open
Abstract
Cheese is characterized by a rich and complex microbiota that plays a vital role during both production and ripening, contributing significantly to the safety, quality, and sensory characteristics of the final product. In this context, it is vital to explore the microbiota composition and understand its dynamics and evolution during cheese manufacturing and ripening. Application of high-throughput DNA sequencing technologies have facilitated the more accurate identification of the cheese microbiome, detailed study of its potential functionality, and its contribution to the development of specific organoleptic properties. These technologies include amplicon sequencing, whole-metagenome shotgun sequencing, metatranscriptomics, and, most recently, metabolomics. In recent years, however, the application of multiple meta-omics approaches along with data integration analysis, which was enabled by advanced computational and bioinformatics tools, paved the way to better comprehension of the cheese ripening process, revealing significant associations between the cheese microbiota and metabolites, as well as their impact on cheese flavor and quality.
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Affiliation(s)
- Rania Anastasiou
- Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece; (M.K.); (M.G.); (A.A.); (G.Z.); (E.T.)
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Riboswitch RS thiT as a molecular tool in Lactococcus lactis. Appl Environ Microbiol 2021; 88:e0176421. [PMID: 34936833 PMCID: PMC8862789 DOI: 10.1128/aem.01764-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Previous RNA sequencing has allowed the identification of 129 long 5′ untranslated regions (UTRs) in the Lactococcus lactis MG1363 transcriptome. These sequences potentially harbor cis-acting riboswitches. One of the identified extended 5′ UTRs is a putative thiamine pyrophosphate (TPP) riboswitch. It is located immediately upstream of the thiamine transporter gene thiT (llmg_0334). To confirm this assumption, the 5′-UTR sequence was placed upstream of the gene encoding the superfolder green fluorescent protein (sfGFP), sfgfp, allowing the examination of the expression of sfGFP in the presence or absence of thiamine in the medium. The results show that this sequence indeed represents a thiamine-responsive TPP riboswitch. This RNA-based genetic control device was used to successfully restore the mutant phenotype of an L. lactis strain lacking the major autolysin gene, acmA. The L. lactisthiT TPP riboswitch (RSthiT) is a useful molecular genetic tool enabling the gradual downregulation of the expression of genes under its control by adjusting the thiamine concentration. IMPORTANCE The capacity of microbes with biotechnological importance to adapt to and survive under quickly changing industrial conditions depends on their ability to adequately control gene expression. Riboswitches are important RNA-based elements involved in rapid and precise gene regulation. Here, we present the identification of a natural thiamine-responsive riboswitch of Lactococcus lactis, a bacterium used worldwide in the production of dairy products. We used it to restore a genetic defect in an L. lactis mutant and show that it is a valuable addition to the ever-expanding L. lactis genetic toolbox.
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Brandsma JB, Rustandi N, Brinkman J, Wolkers‐Rooijackers JCM, Zwietering MH, Smid EJ. Pivotal role of cheese salting method for the production of 3‐methylbutanal by
Lactococcus lactis. INT J DAIRY TECHNOL 2021. [DOI: 10.1111/1471-0307.12839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - Marcel H Zwietering
- Wageningen University & Research Food Microbiology P.O. Box 17 6700 AA Wageningen The Netherlands
| | - Eddy J Smid
- Wageningen University & Research Food Microbiology P.O. Box 17 6700 AA Wageningen The Netherlands
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Wang P, Wang T, Ismael M, Wang X, Yi Y, Lü X. Development of an electroporation method and expression patterns of bacteriocin-encoding genes in Companilactobacillus crustorum MN047. FOOD BIOSCI 2021. [DOI: 10.1016/j.fbio.2021.101420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Song X, Liu L, Liu XX, Xiong ZQ, Xie CL, Wang SJ, Ai LZ. Single-plasmid systems based on CRISPR-Cas9 for gene editing in Lactococcus lactis. J Dairy Sci 2021; 104:10576-10585. [PMID: 34275631 DOI: 10.3168/jds.2020-19901] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 03/15/2021] [Indexed: 01/20/2023]
Abstract
Lactococcus lactis is a food-grade lactic acid bacterial species that is widely used in food and medical industries. Due to its relatively small genome and simple metabolism, L. lactis is commonly engineered to produce large quantities of recombinant proteins. The most common single-gene knockout strategy in L. lactis involves RecA-dependent homologous double-crossover recombination, which is relatively time-consuming and laborious. In this study, a precise and efficient genome-editing plasmid for L. lactis NZ9000 genome engineering, pLL, was established based on clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 technology. By studying the effects of different single guide RNA (sgRNA) promoters, the efficiency of gene deletion was optimized. For LLNZ_02045 (ldh), gene deletion efficiency of up to 50% was achieved. Effective sequential gene deletion of LLNZ_11240 (upp) and LLNZ_04580 (upp1) was also demonstrated using this tool. Additionally, the gene that encodes for uracil phosphoribosyltransferase was identified using this system. Similar robust gene deletion efficiencies of sgRNA that targeted different regions of a single gene suggested that gene deletion was not affected by the location of sgRNA binding. Thus, our study established a new gene-editing tool that may allow further investigation and understanding of the L. lactis NZ9000 genome.
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Affiliation(s)
- Xin Song
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Lu Liu
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Xin-Xin Liu
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Zhi-Qiang Xiong
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Chun-Liang Xie
- Institute of Bast Fiber Crop, Chinese Academy of Agricultural Sciences, Changsha 410205, China
| | - Shij-Jie Wang
- College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang 050018, Hebei, China; Shijiazhuang Junlebao Dairy Co. Ltd., Shijiazhuang 050211, China
| | - Lian-Zhong Ai
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
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Cataldo PG, Klemm P, Thüring M, Saavedra L, Hebert EM, Hartmann RK, Lechner M. Insights into 6S RNA in lactic acid bacteria (LAB). BMC Genom Data 2021; 22:29. [PMID: 34479493 PMCID: PMC8414754 DOI: 10.1186/s12863-021-00983-2] [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: 06/21/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 6S RNA is a regulator of cellular transcription that tunes the metabolism of cells. This small non-coding RNA is found in nearly all bacteria and among the most abundant transcripts. Lactic acid bacteria (LAB) constitute a group of microorganisms with strong biotechnological relevance, often exploited as starter cultures for industrial products through fermentation. Some strains are used as probiotics while others represent potential pathogens. Occasional reports of 6S RNA within this group already indicate striking metabolic implications. A conceivable idea is that LAB with 6S RNA defects may metabolize nutrients faster, as inferred from studies of Echerichia coli. This may accelerate fermentation processes with the potential to reduce production costs. Similarly, elevated levels of secondary metabolites might be produced. Evidence for this possibility comes from preliminary findings regarding the production of surfactin in Bacillus subtilis, which has functions similar to those of bacteriocins. The prerequisite for its potential biotechnological utility is a general characterization of 6S RNA in LAB. RESULTS We provide a genomic annotation of 6S RNA throughout the Lactobacillales order. It laid the foundation for a bioinformatic characterization of common 6S RNA features. This covers secondary structures, synteny, phylogeny, and product RNA start sites. The canonical 6S RNA structure is formed by a central bulge flanked by helical arms and a template site for product RNA synthesis. 6S RNA exhibits strong syntenic conservation. It is usually flanked by the replication-associated recombination protein A and the universal stress protein A. A catabolite responsive element was identified in over a third of all 6S RNA genes. It is known to modulate gene expression based on the available carbon sources. The presence of antisense transcripts could not be verified as a general trait of LAB 6S RNAs. CONCLUSIONS Despite a large number of species and the heterogeneity of LAB, the stress regulator 6S RNA is well-conserved both from a structural as well as a syntenic perspective. This is the first approach to describe 6S RNAs and short 6S RNA-derived transcripts beyond a single species, spanning a large taxonomic group covering multiple families. It yields universal insights into this regulator and complements the findings derived from other bacterial model organisms.
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Affiliation(s)
- Pablo Gabriel Cataldo
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Paul Klemm
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Marietta Thüring
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Lucila Saavedra
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Elvira Maria Hebert
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Roland K Hartmann
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Marcus Lechner
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany. .,Philipps-Universität Marburg, Center for Synthetic Microbiology (Synmikro), Hans-Meerwein-Straße 6, Marburg, 35043, Germany.
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14
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Ma M, Zhao Z, Liang Q, Shen H, Zhao Z, Chen Z, He R, Feng S, Cao D, Gan G, Ye H, Qiu W, Deng J, Ming F, Jia J, Sun C, Li J, Zhang L. Overexpression of pEGF improved the gut protective function of Clostridium butyricum partly through STAT3 signal pathway. Appl Microbiol Biotechnol 2021; 105:5973-5991. [PMID: 34396488 DOI: 10.1007/s00253-021-11472-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 12/25/2022]
Abstract
Clostridium butyricum (C. butyricum) is a probiotic that could promote animal growth and protect gut health. So far, current studies mainly keep up with the basic biological functions of C. butyricum, missing the effective strategy to further improve its protective efficiency. A recent report about C. butyricum alleviating intestinal injury through epidermal growth factor receptor (EGFR) inspired us to bridge this gap by porcine epidermal growth factor (EGF) overexpression. Lacking a secretory overexpression system, we constructed the recombinant strains overexpressing pEGF in C. butyricum for the first time and obtained 4 recombinant strains for highly efficient secretion of pEGF (BC/pPD1, BC/pSPP, BC/pGHF, and BC/pDBD). Compared to the wild-type strain, we confirmed that the expression level ranges of the intestinal development-related genes (Claudin-1, GLUT-2, SUC, GLP2R, and EGFR) and anti-inflammation-related gene (IL-10) in IPECs were upregulated under recombinant strain stimulation, and the growth of Staphylococcus aureus and Salmonella typhimurium was significantly inhibited as well. Furthermore, a particular inhibitor (stattic) was used to block STAT3 tyrosine phosphorylation, resulting in the downregulation on antibacterial effect of recombinant strains. This study demonstrated that the secretory overexpression of pEGF in C. butyricum could upregulate the expression level of EGFR, consequently improving the intestinal protective functions of C. butyricum partly following STAT3 signal activation in IPECs and making it a positive loop. These findings on the overexpression strains pointed out a new direction for further development and utilization of C. butyricum. KEY POINTS: • By 12 signal peptide screening in silico, 4 pEGF overexpression strains of C. butyricum/pMTL82151-pEGF for highly efficient secretion of pEGF were generated for the first time. • The secretory overexpression of pEGF promoted the intestinal development, antimicrobial action, and anti-inflammatory function of C. butyricum. • The overexpressed pEGF upregulated the expression level of EGFR and further magnified the gut protective function of recombinant strains which in turn partly depended on STAT3 signal pathway in IPECs.
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Affiliation(s)
- Miaopeng Ma
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Zitong Zhao
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Qianyi Liang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Haokun Shen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Zengjue Zhao
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Zhiyang Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Rongxiao He
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Saixiang Feng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Ding Cao
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Guanhua Gan
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Hejia Ye
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Weihong Qiu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Jinbo Deng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Feiping Ming
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Junhao Jia
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Chongjun Sun
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Jiayi Li
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China
| | - Linghua Zhang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, 510642, Guangdong, China.
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15
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Dorau R, Liu J, Solem C, Jensen PR. Metabolic Engineering of Lactic Acid Bacteria. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Chen Y, van Pelt‐KleinJan E, van Olst B, Douwenga S, Boeren S, Bachmann H, Molenaar D, Nielsen J, Teusink B. Proteome constraints reveal targets for improving microbial fitness in nutrient-rich environments. Mol Syst Biol 2021; 17:e10093. [PMID: 33821549 PMCID: PMC8022198 DOI: 10.15252/msb.202010093] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 11/28/2022] Open
Abstract
Cells adapt to different conditions via gene expression that tunes metabolism for maximal fitness. Constraints on cellular proteome may limit such expression strategies and introduce trade-offs. Resource allocation under proteome constraints has explained regulatory strategies in bacteria. It is unclear, however, to what extent these constraints can predict evolutionary changes, especially for microorganisms that evolved under nutrient-rich conditions, i.e., multiple available nitrogen sources, such as Lactococcus lactis. Here, we present a proteome-constrained genome-scale metabolic model of L. lactis (pcLactis) to interpret growth on multiple nutrients. Through integration of proteomics and flux data, in glucose-limited chemostats, the model predicted glucose and arginine uptake as dominant constraints at low growth rates. Indeed, glucose and arginine catabolism were found upregulated in evolved mutants. At high growth rates, pcLactis correctly predicted the observed shutdown of arginine catabolism because limited proteome availability favored lactate for ATP production. Thus, our model-based analysis is able to identify and explain the proteome constraints that limit growth rate in nutrient-rich environments and thus form targets of fitness improvement.
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Affiliation(s)
- Yu Chen
- Department of Biology and Biological EngineeringChalmers University of TechnologyGothenburgSweden
- Novo Nordisk Foundation Center for BiosustainabilityChalmers University of TechnologyGothenburgSweden
| | - Eunice van Pelt‐KleinJan
- TiFNWageningenthe Netherlands
- Systems Biology LabAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Berdien van Olst
- TiFNWageningenthe Netherlands
- Host‐Microbe InteractomicsWageningen University & ResearchWageningenThe Netherlands
- Laboratory of BiochemistryWageningen University & ResearchWageningenThe Netherlands
| | - Sieze Douwenga
- TiFNWageningenthe Netherlands
- Systems Biology LabAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Sjef Boeren
- TiFNWageningenthe Netherlands
- Laboratory of BiochemistryWageningen University & ResearchWageningenThe Netherlands
| | - Herwig Bachmann
- TiFNWageningenthe Netherlands
- Systems Biology LabAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamAmsterdamThe Netherlands
- NIZO Food ResearchEdeThe Netherlands
| | - Douwe Molenaar
- TiFNWageningenthe Netherlands
- Systems Biology LabAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Jens Nielsen
- Department of Biology and Biological EngineeringChalmers University of TechnologyGothenburgSweden
- Novo Nordisk Foundation Center for BiosustainabilityChalmers University of TechnologyGothenburgSweden
- Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkLyngbyDenmark
- BioInnovation InstituteCopenhagen NDenmark
| | - Bas Teusink
- TiFNWageningenthe Netherlands
- Systems Biology LabAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamAmsterdamThe Netherlands
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17
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Martínez B, Rodríguez A, Kulakauskas S, Chapot-Chartier MP. Cell wall homeostasis in lactic acid bacteria: threats and defences. FEMS Microbiol Rev 2021; 44:538-564. [PMID: 32495833 PMCID: PMC7476776 DOI: 10.1093/femsre/fuaa021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/03/2020] [Indexed: 12/16/2022] Open
Abstract
Lactic acid bacteria (LAB) encompasses industrially relevant bacteria involved in food fermentations as well as health-promoting members of our autochthonous microbiota. In the last years, we have witnessed major progresses in the knowledge of the biology of their cell wall, the outermost macrostructure of a Gram-positive cell, which is crucial for survival. Sophisticated biochemical analyses combined with mutation strategies have been applied to unravel biosynthetic routes that sustain the inter- and intra-species cell wall diversity within LAB. Interplay with global cell metabolism has been deciphered that improved our fundamental understanding of the plasticity of the cell wall during growth. The cell wall is also decisive for the antimicrobial activity of many bacteriocins, for bacteriophage infection and for the interactions with the external environment. Therefore, genetic circuits involved in monitoring cell wall damage have been described in LAB, together with a plethora of defence mechanisms that help them to cope with external threats and adapt to harsh conditions. Since the cell wall plays a pivotal role in several technological and health-promoting traits of LAB, we anticipate that this knowledge will pave the way for the future development and extended applications of LAB.
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Affiliation(s)
- Beatriz Martínez
- DairySafe research group. Department of Technology and Biotechnology of Dairy Products. Instituto de Productos Lácteos de Asturias, IPLA-CSIC. Paseo Río Linares s/n. 33300 Villaviciosa, Spain
| | - Ana Rodríguez
- DairySafe research group. Department of Technology and Biotechnology of Dairy Products. Instituto de Productos Lácteos de Asturias, IPLA-CSIC. Paseo Río Linares s/n. 33300 Villaviciosa, Spain
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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18
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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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19
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Exploring the synthetic biology potential of bacteriophages for engineering non-model bacteria. Nat Commun 2020; 11:5294. [PMID: 33082347 PMCID: PMC7576135 DOI: 10.1038/s41467-020-19124-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/25/2020] [Indexed: 12/26/2022] Open
Abstract
Non-model bacteria like Pseudomonas putida, Lactococcus lactis and other species have unique and versatile metabolisms, offering unique opportunities for Synthetic Biology (SynBio). However, key genome editing and recombineering tools require optimization and large-scale multiplexing to unlock the full SynBio potential of these bacteria. In addition, the limited availability of a set of characterized, species-specific biological parts hampers the construction of reliable genetic circuitry. Mining of currently available, diverse bacteriophages could complete the SynBio toolbox, as they constitute an unexplored treasure trove for fully adapted metabolic modulators and orthogonally-functioning parts, driven by the longstanding co-evolution between phage and host. Non-model bacteria offer unique and versatile metabolisms for synthetic biology. In this Perspective, the authors explore the limited availability of well-characterised biological parts in these species and argue that bacteriophages represent a diverse trove of orthogonal parts.
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20
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Liu JM, Chen L, Dorau R, Lillevang SK, Jensen PR, Solem C. From Waste to Taste-Efficient Production of the Butter Aroma Compound Acetoin from Low-Value Dairy Side Streams Using a Natural (Nonengineered) Lactococcus lactis Dairy Isolate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:5891-5899. [PMID: 32363876 DOI: 10.1021/acs.jafc.0c00882] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Lactococcus lactis subsp. lactis biovar diacetylactis is widely used in dairy fermentations as it can form the butter aroma compounds acetoin and diacetyl from citrate in milk. Here, we explore the possibility of producing acetoin from the more abundant lactose. Starting from a dairy isolate of L. lactis biovar diacetylactis, we obtained a series of mutants with low lactate dehydrogenase (ldh) activity. One isolate, RD1M5, only had a single insertion mutation in the ldh gene compared to its parental strain as revealed by whole genome resequencing. We tested the ability of RD1M5 to produce acetoin in milk. With aeration, all the lactose could be consumed, and the only product was acetoin. In a simulated cheese fermentation, a 50% increase in acetoin concentration could be achieved. RD1M5 turned out to be an excellent cell factory for acetoin and was able to convert lactose in dairy waste into acetoin with high titer (41 g/L) and high yield (above 90% of the theoretical yield). Summing up, RD1M5 was found to be highly robust and to grow excellently in milk or dairy waste. Being natural in origin opens up for applications within dairies as well as for safe production of food-grade acetoin from low-cost substrates.
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Affiliation(s)
- Jian-Ming Liu
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Lin Chen
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Robin Dorau
- National Food Institute, 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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21
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Genetics of Lactococci. Microbiol Spectr 2020; 7. [PMID: 31298208 DOI: 10.1128/microbiolspec.gpp3-0035-2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lactococcus lactis is the best characterized species among the lactococci, and among the most consumed food-fermenting bacteria worldwide. Thanks to their importance in industrialized food production, lactococci are among the lead bacteria understood for fundamental metabolic pathways that dictate growth and survival properties. Interestingly, lactococci belong to the Streptococcaceae family, which includes food, commensal and virulent species. As basic metabolic pathways (e.g., respiration, metal homeostasis, nucleotide metabolism) are now understood to underlie virulence, processes elucidated in lactococci could be important for understanding pathogen fitness and synergy between bacteria. This chapter highlights major findings in lactococci and related bacteria, and covers five themes: distinguishing features of lactococci, metabolic capacities including the less known respiration metabolism in Streptococcaceae, factors and pathways modulating stress response and fitness, interbacterial dialogue via metabolites, and novel applications in health and biotechnology.
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22
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van Tilburg AY, Cao H, van der Meulen SB, Solopova A, Kuipers OP. Metabolic engineering and synthetic biology employing Lactococcus lactis and Bacillus subtilis cell factories. Curr Opin Biotechnol 2019; 59:1-7. [DOI: 10.1016/j.copbio.2019.01.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/05/2018] [Accepted: 01/16/2019] [Indexed: 12/11/2022]
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23
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Pangallo D, Kraková L, Puškárová A, Šoltys K, Bučková M, Koreňová J, Budiš J, Kuchta T. Transcription activity of lactic acid bacterial proteolysis-related genes during cheese maturation. Food Microbiol 2019; 82:416-425. [DOI: 10.1016/j.fm.2019.03.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/18/2019] [Accepted: 03/12/2019] [Indexed: 12/11/2022]
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24
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Gómez de Cadiñanos LP, García-Cayuela T, Martínez-Cuesta MC, Peláez C, Requena T. Expression of amino acid converting enzymes and production of volatile compounds by Lactococcus lactis IFPL953. Int Dairy J 2019. [DOI: 10.1016/j.idairyj.2019.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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25
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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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26
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Guo T, Xin Y, Zhang Y, Gu X, Kong J. A rapid and versatile tool for genomic engineering in Lactococcus lactis. Microb Cell Fact 2019; 18:22. [PMID: 30704485 PMCID: PMC6357491 DOI: 10.1186/s12934-019-1075-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/24/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Lactococcus lactis is one of the most extensively characterized lactic acid bacteria, from physiological traits to industrial exploitation. Since last decade, L. lactis has been developed into cell factories for the production of bioactive compounds such as enzymes, vaccine antigens and natural products. However, its precise and efficient genome editing tools is still required to make L. lactis more suitable candidate for engineered functionality. RESULTS A high active recombinase, RecT of Enterococcus faecalis ATCC14506, was selected from six candidates and mediated homologous recombination between single-stranded DNA (ssDNA) and the L. lactis chromosomal rpoB locus with an efficiency of 100% after rifampin selection. To screen mutants without an externally selectable phenotype, the CRISPR/Cas9 system was used for counterselection, yielding an upp mutant with an efficiency of 46%. By optimization of the copy number of plasmid carrying the CRISPR/Cas9 system and the length of spacer sequence, the off-target efficiency of the recA, galK, hemN and noxD genes were eliminated. The ability of this optimized tool to perform sequential point mutation was demonstrated using the upp and galK gene loci as targets with improved efficiencies > 75%. Moreover, seamless genomic DNA deletions (50/100 bp) or insertion (a loxP site, 34 bp) was efficiently accomplished within 72 h. CONCLUSIONS The work provided a rapid, versatile and precise tool for L. lactis genomic engineering by combination of ssDNA recombineering with improved CRISPR/Cas9 counterselection. This tool will simplify the production of isogenic strains for assessment of gene function or construction of biosynthetic host.
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Affiliation(s)
- Tingting Guo
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Yongping Xin
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Yi Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Xinyi Gu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, People's Republic of China.
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27
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Afshari R, Pillidge CJ, Dias DA, Osborn AM, Gill H. Cheesomics: the future pathway to understanding cheese flavour and quality. Crit Rev Food Sci Nutr 2018; 60:33-47. [DOI: 10.1080/10408398.2018.1512471] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Roya Afshari
- School of Science, RMIT University, Bundoora, Victoria, Australia
| | | | - Daniel A. Dias
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - A. Mark Osborn
- School of Science, RMIT University, Bundoora, Victoria, Australia
| | - Harsharn Gill
- School of Science, RMIT University, Bundoora, Victoria, Australia
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28
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Aucouturier A, Chain F, Langella P, Bidnenko E. Characterization of a Prophage-Free Derivative Strain of Lactococcus lactis ssp. lactis IL1403 Reveals the Importance of Prophages for Phenotypic Plasticity of the Host. Front Microbiol 2018; 9:2032. [PMID: 30233519 PMCID: PMC6127208 DOI: 10.3389/fmicb.2018.02032] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022] Open
Abstract
Lactococcus lactis is a lactic acid bacterium of major importance for the dairy industry and for human health. Recent sequencing surveys of this species have provided evidence that all lactococcal genomes contain prophages and prophage-like elements. The prophage-related sequences encompass up to 10% of the bacterial chromosomes and thus contribute significantly to the genetic diversity of lactococci. However, the impact of these resident prophages on the physiology of L. lactis is presently unknown. The genome of the first sequenced prototype strain, L. lactis ssp. lactis IL1403, contains six prophage-like elements which together represent 6.7% of the IL1403 chromosome. Diverse prophage genes other than those encoding phage repressors have been shown to be expressed in lysogenic conditions, suggesting that prophage genes are indeed able to modulate the physiology of their host. To elucidate the effect of resident prophages on the behavior of L. lactis in different growth conditions, we constructed and characterized, for the first time, a derivative strain of IL1403 that is prophage-free. This strain provides unique experimental opportunities for the study of different aspects of lactococcal physiology using the well-defined genetic background of IL1403. Here, we show that resident prophages modify the growth and survival of the host strain to a considerable extent in different conditions, including in the gastrointestinal environment. They also may affect cellular autolytic properties and the host cells' susceptibility to virulent bacteriophages and antimicrobial agents. It thus appears that prophages contribute significantly to lactococcal cell physiology and might play an important role in the adaptation of L. lactis to cultivation and environmental conditions.
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Affiliation(s)
- Anne Aucouturier
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Florian Chain
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Philippe Langella
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Elena Bidnenko
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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Bron PA, Kleerebezem M. Lactic Acid Bacteria for Delivery of Endogenous or Engineered Therapeutic Molecules. Front Microbiol 2018; 9:1821. [PMID: 30123213 PMCID: PMC6085456 DOI: 10.3389/fmicb.2018.01821] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 07/20/2018] [Indexed: 12/12/2022] Open
Abstract
Food-grade lactic acid bacteria (LAB) are considered suitable vehicles for the production and/or delivery of health promoting or therapeutic, bioactive molecules. The molecules considered for health-beneficial use include the endogenous effector molecules produced by probiotics (mostly lactobacilli), as well as heterologous bioactives that can be produced in LAB by genetic engineering (mostly using lactococci). Both strategies aim to deliver appropriate dosages of specific bioactive molecules to the site of action. This review uses specific examples of both strategies to illustrate the different avenues of research involved in these applications as well as their translation to human health-promoting applications. These examples pinpoint that despite the promising perspectives of these approaches, the evidence for their effective applications in human populations is lagging behind.
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Affiliation(s)
- Peter A Bron
- NIZO Food Research BV, Ede, Netherlands.,BE-Basic Foundation, Delft, Netherlands
| | - Michiel Kleerebezem
- BE-Basic Foundation, Delft, Netherlands.,Host-Microbe Interactomics Group, Department of Animal Sciences, Wageningen University & Research, Wageningen, Netherlands
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van der Els S, James JK, Kleerebezem M, Bron PA. Versatile Cas9-Driven Subpopulation Selection Toolbox for Lactococcus lactis. Appl Environ Microbiol 2018; 84:e02752-17. [PMID: 29453254 PMCID: PMC5881059 DOI: 10.1128/aem.02752-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/08/2018] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas9 technology has been exploited for the removal or replacement of genetic elements in a wide range of prokaryotes and eukaryotes. Here, we describe the extension of the Cas9 application toolbox to the industrially important dairy species Lactococcus lactis The Cas9 expression vector pLABTarget, encoding the Streptocccus pyogenes Cas9 under the control of a constitutive promoter, was constructed, allowing plug and play introduction of short guide RNA (sgRNA) sequences to target specific genetic loci. Introduction of a pepN-targeting derivative of pLABTarget into L. lactis strain MG1363 led to a strong reduction in the number of transformants obtained, which did not occur in a pepN deletion derivative of the same strain, demonstrating the specificity and lethality of the Cas9-mediated double-strand breaks in the lactococcal chromosome. Moreover, the same pLABTarget derivative allowed the selection of a pepN deletion subpopulation from its corresponding single-crossover plasmid integrant precursor, accelerating the construction and selection of gene-specific deletion derivatives in L. lactis Finally, pLABTarget, which contained sgRNAs designed to target mobile genetic elements, allowed the effective curing of plasmids, prophages, and integrative conjugative elements (ICEs). These results establish that pLABTarget enables the effective exploitation of Cas9 targeting in L. lactis, while the broad-host-range vector used suggests that this toolbox could readily be expanded to other Gram-positive bacteria.IMPORTANCE Mobile genetic elements in Lactococcus lactis and other lactic acid bacteria (LAB) play an important role in dairy fermentation, having both positive and detrimental effects during the production of fermented dairy products. The pLABTarget vector offers an efficient cloning platform for Cas9 application in lactic acid bacteria. Targeting Cas9 toward mobile genetic elements enabled their effective curing, which is of particular interest in the context of potentially problematic prophages present in a strain. Moreover, Cas9 targeting of other mobile genetic elements enables the deciphering of their contribution to dairy fermentation processes and further establishment of their importance for product characteristics.
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Affiliation(s)
- Simon van der Els
- Host-Microbe Interactomics Group, Animal Sciences, Wageningen University & Research, Wageningen, The Netherlands
- NIZO B.V., Ede, The Netherlands
- BE-Basic Foundation, Delft, The Netherlands
| | | | - Michiel Kleerebezem
- Host-Microbe Interactomics Group, Animal Sciences, Wageningen University & Research, Wageningen, The Netherlands
- BE-Basic Foundation, Delft, The Netherlands
| | - Peter A Bron
- NIZO B.V., Ede, The Netherlands
- BE-Basic Foundation, Delft, The Netherlands
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Complete Genome Sequence of Lactococcus lactis subsp. lactis G50 with Immunostimulating Activity, Isolated from Napier Grass. GENOME ANNOUNCEMENTS 2018; 6:6/8/e00069-18. [PMID: 29472335 PMCID: PMC5823991 DOI: 10.1128/genomea.00069-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Lactococcus lactis subsp. lactis G50 is a strain with immunostimulating activity, isolated from Napier grass (Pennisetum purpureum). We determined the complete genome sequence of this strain using the PacBio RS II platform. The single circular chromosome consists of 2,346,663 bp, with 35.03% G+C content and no plasmids.
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