1
|
Jeeva P, Jayaprakash SR, Jayaraman G. Hyaluronic acid production is enhanced by harnessing the heme-induced respiration in recombinant Lactococcus lactis cultures. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
2
|
Li Q, Zhang J, Yang J, Jiang Y, Yang S. Recent progress on n-butanol production by lactic acid bacteria. World J Microbiol Biotechnol 2021; 37:205. [PMID: 34698975 DOI: 10.1007/s11274-021-03173-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 10/13/2021] [Indexed: 11/26/2022]
Abstract
n-Butanol is an essential chemical intermediate produced through microbial fermentation. However, its toxicity to microbial cells has limited its production to a great extent. The anaerobe lactic acid bacteria (LAB) are the most resistant to n-butanol, so it should be the first choice for improving n-butanol production. The present article aims to review the following aspects of n-butanol production by LAB: (1) the tolerance of LAB to n-butanol, including its tolerance level and potential tolerance mechanisms; (2) genome editing tools in the n-butanol-resistant LAB; (3) methods of LAB modification for n-butanol production and the production levels after modification. This review will provide a theoretical basis for further research on n-butanol production by LAB.
Collapse
Affiliation(s)
- Qi Li
- College of Life Sciences, Sichuan Normal University, Chengdu, 610101, China
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Jieze Zhang
- Department of Chemistry, University of Southern California, Los Angeles, CA, 90089, USA
| | - Junjie Yang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Yu Jiang
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou, 313000, China
- Shanghai Taoyusheng Biotechnology Company Ltd, Shanghai, 200032, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou, 313000, China.
| |
Collapse
|
3
|
Suo F, Liu J, Chen J, Li X, Solem C, Jensen PR. Efficient Production of Pyruvate Using Metabolically Engineered Lactococcus lactis. Front Bioeng Biotechnol 2021; 8:611701. [PMID: 33490054 PMCID: PMC7815928 DOI: 10.3389/fbioe.2020.611701] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022] Open
Abstract
Microbial production of commodity chemicals has gained increasing attention and most of the focus has been on reducing the production cost. Selecting a suitable microorganism, which can grow rapidly on cheap feedstocks, is of key importance when developing an economically feasible bioprocess. We chose Lactococcus lactis, a well-characterized lactic acid bacterium, as our microbial host to produce pyruvate, which is a commodity chemical with various important applications. Here we report the engineering of Lactococcus lactis into becoming an efficient microbial platform for producing pyruvate. The strain obtained, FS1076 (MG1363 Δ3 ldh Δpta ΔadhE Δals), was able to produce pyruvate as the sole product. Since all the competitive pathways had been knocked out, we achieved growth-coupled production of pyruvate with high yield. More than 80 percent of the carbon flux was directed toward pyruvate, and a final titer of 54.6 g/L was obtained using a fed-batch fermentation setup. By introducing lactose catabolism into FS1076, we obtained the strain FS1080, which was able to generate pyruvate from lactose. We then demonstrated the potential of FS1080 for valorizing lactose contained in dairy side-streams, by achieving a high titer (40.1 g/L) and high yield (78.6%) of pyruvate using residual whey permeate (RWP) as substrate. The results obtained, show that the L. lactis platform is well-suited for transforming lactose in dairy waste into food-grade pyruvate, and the yields obtained are the highest reported in the literature. These results demonstrate that it is possible to achieve sustainable bioconversion of waste products from the dairy industry (RWP) to valuable products.
Collapse
Affiliation(s)
- Fan Suo
- Division of Production and Microbiology, National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - Jianming Liu
- Division of Production and Microbiology, National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - Jun Chen
- Division of Production and Microbiology, National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - Xuanji Li
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Christian Solem
- Division of Production and Microbiology, National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - Peter R. Jensen
- Division of Production and Microbiology, National Food Institute, Technical University of Denmark, Lyngby, Denmark
| |
Collapse
|
4
|
Özcan E, Seven M, Şirin B, Çakır T, Nikerel E, Teusink B, Toksoy Öner E. Dynamic co-culture metabolic models reveal the fermentation dynamics, metabolic capacities and interplays of cheese starter cultures. Biotechnol Bioeng 2020; 118:223-237. [PMID: 32926401 PMCID: PMC7971941 DOI: 10.1002/bit.27565] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/19/2020] [Accepted: 09/09/2020] [Indexed: 01/06/2023]
Abstract
In this study, we have investigated the cheese starter culture as a microbial community through a question: can the metabolic behaviour of a co-culture be explained by the characterized individual organism that constituted the co-culture? To address this question, the dairy-origin lactic acid bacteria Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Streptococcus thermophilus and Leuconostoc mesenteroides, commonly used in cheese starter cultures, were grown in pure and four different co-cultures. We used a dynamic metabolic modelling approach based on the integration of the genome-scale metabolic networks of the involved organisms to simulate the co-cultures. The strain-specific kinetic parameters of dynamic models were estimated using the pure culture experiments and they were subsequently applied to co-culture models. Biomass, carbon source, lactic acid and most of the amino acid concentration profiles simulated by the co-culture models fit closely to the experimental results and the co-culture models explained the mechanisms behind the dynamic microbial abundance. We then applied the co-culture models to estimate further information on the co-cultures that could not be obtained by the experimental method used. This includes estimation of the profile of various metabolites in the co-culture medium such as flavour compounds produced and the individual organism level metabolic exchange flux profiles, which revealed the potential metabolic interactions between organisms in the co-cultures.
Collapse
Affiliation(s)
- Emrah Özcan
- Systems Biology, Amsterdam Institute of Molecular and Life Sciences (AIMMS), VU Amsterdam, Amsterdam, The Netherlands.,Department of Bioengineering, IBSB, Marmara University, Istanbul, Turkey
| | - Merve Seven
- Genetics and Bioengineering Department, Yeditepe University, Istanbul, Turkey
| | - Burcu Şirin
- Genetics and Bioengineering Department, Yeditepe University, Istanbul, Turkey
| | - Tunahan Çakır
- Department of Bioengineering, Gebze Technical University, Gebze, Kocaeli, Turkey
| | - Emrah Nikerel
- Genetics and Bioengineering Department, Yeditepe University, Istanbul, Turkey
| | - Bas Teusink
- Systems Biology, Amsterdam Institute of Molecular and Life Sciences (AIMMS), VU Amsterdam, Amsterdam, The Netherlands
| | - Ebru Toksoy Öner
- Department of Bioengineering, IBSB, Marmara University, Istanbul, Turkey
| |
Collapse
|
5
|
Chen Y, Sun Y, Liu Z, Dong F, Li Y, Wang Y. Genome-scale modeling for Bacillus coagulans to understand the metabolic characteristics. Biotechnol Bioeng 2020; 117:3545-3558. [PMID: 32648961 DOI: 10.1002/bit.27488] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/01/2020] [Accepted: 07/09/2020] [Indexed: 12/14/2022]
Abstract
Lactic acid is widely used in many industries, especially in the production of poly-lactic acid. Bacillus coagulans is a promising lactic acid producer in industrial fermentation due to its thermophilic property. In this study, we developed the first genome-scale metabolic model (GEM) of B. coagulans iBag597, together with an enzyme-constrained model ec-iBag597. We measured strain-specific biomass composition and integrated the data into a biomass equation. Then, we validated iBag597 against experimental data generated in this study, including amino acid requirements and carbon source utilization, showing that simulations were generally consistent with the experimental results. Subsequently, we carried out chemostats to investigate the effects of specific growth rate and culture pH on metabolism of B. coagulans. Meanwhile, we used iBag597 to estimate the intracellular metabolic fluxes for those conditions. The results showed that B. coagulans was capable of generating ATP via multiple pathways, and switched among them in response to various conditions. With ec-iBag597, we estimated the protein cost and protein efficiency for each ATP-producing pathway to investigate the switches. Our models pave the way for systems biology of B. coagulans, and our findings suggest that maintaining a proper growth rate and selecting an optimal pH are beneficial for lactate fermentation.
Collapse
Affiliation(s)
- Yu Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yan Sun
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Zhihao Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Fengqing Dong
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yuanyuan Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yonghong Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| |
Collapse
|
6
|
Investigation of genomic characteristics and carbohydrates' metabolic activity of Lactococcus lactis subsp. lactis during ripening of a Swiss-type cheese. Food Microbiol 2019; 87:103392. [PMID: 31948633 DOI: 10.1016/j.fm.2019.103392] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/04/2019] [Accepted: 11/20/2019] [Indexed: 01/08/2023]
Abstract
Genetic diversity and metabolic properties of Lactococcus lactis subsp. lactis were explored using phylogenetic, pan-genomic and metatranscriptomic analysis. The genomes, used in the current study, were available and downloaded from the GenBank which were primarily related with microorganisms isolated from dairy products and secondarily from other foodstuffs. To study the genetic diversity of the microorganism, various bioinformatics tools were employed such as average nucleotide identity, digital DNA-DNA hybridization, phylogenetic analysis, clusters of orthologous groups analysis, KEGG orthology analysis and pan-genomic analysis. The results showed that Lc. lactis subsp. lactis strains cannot be sufficiently separated into phylogenetic lineages based on the 16S rRNA gene sequences and core genome-based phylogenetic analysis was more appropriate. Pan-genomic analysis of the strains indicated that the core, accessory and unique genome comprised of 1036, 3146 and 1296 genes, respectively. Considering the results of pan-genomic and KEGG orthology analyses, the metabolic network of Lc. lactis subsp. lactis was rebuild regarding its carbohydrates' metabolic capabilities. Based on the metatranscriptomic data during the ripening of the Swiss-type Maasdam cheese at 20 °C and 5 °C, it was shown that the microorganism performed mixed acid fermentation producing lactate, formate, acetate, ethanol and 2,3-butanediol. Mixed acid fermentation was more pronounced at higher ripening temperatures. At lower ripening temperatures, the genes involved in mixed acid fermentation were repressed while lactate production remained unaffected resembling to a homolactic fermentation. Comparative genomics and metatranscriptomic analysis are powerful tools to gain knowledge on the genomic diversity of the lactic acid bacteria used as starter cultures as well as on the metabolic activities occurring in fermented dairy products.
Collapse
|
7
|
Marques Da Silva W, Oliveira LC, Soares SC, Sousa CS, Tavares GC, Resende CP, Pereira FL, Ghosh P, Figueiredo H, Azevedo V. Quantitative Proteomic Analysis of the Response of Probiotic Putative Lactococcus lactis NCDO 2118 Strain to Different Oxygen Availability Under Temperature Variation. Front Microbiol 2019; 10:759. [PMID: 31031733 PMCID: PMC6470185 DOI: 10.3389/fmicb.2019.00759] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/26/2019] [Indexed: 02/06/2023] Open
Abstract
Lactococcus lactis is a gram positive facultative anaerobe widely used in the dairy industry and human health. L. lactis subsp. lactis NCDO 2118 is a strain that exhibits anti-inflammatory and immunomodulatory properties. In this study, we applied a label-free shotgun proteomic approach to characterize and quantify the NCDO 2118 proteome in response to variations of temperature and oxygen bioavailability, which constitute the environmental conditions found by this bacterium during its passage through the host gastro-intestinal tract and in other industrial processes. From this proteomic analysis, a total of 1,284 non-redundant proteins of NCDO 2118 were characterized, which correspond to approximately 54% of its predicted proteome. Comparative proteomic analysis identified 149 and 136 proteins in anaerobic (30°C and 37°C) and non-aerated (30°C and 37°C) conditions, respectively. Our label-free proteomic analysis quantified a total of 1,239 proteins amongst which 161 proteins were statistically differentially expressed. Main differences were observed in cellular metabolism, stress response, transcription and proteins associated to cell wall. In addition, we identified six strain-specific proteins of NCDO 2118. Altogether, the results obtained in our study will help to improve the understanding about the factors related to both physiology and adaptive processes of L. lactis NCDO 2118 under changing environmental conditions.
Collapse
Affiliation(s)
- Wanderson Marques Da Silva
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Leticia Castro Oliveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - Siomar Castro Soares
- Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - Cassiana Severiano Sousa
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | - Felipe Luis Pereira
- AQUACEN, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Preetam Ghosh
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA, United States
| | - Henrique Figueiredo
- AQUACEN, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vasco Azevedo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| |
Collapse
|
8
|
Quantitative physiology and aroma formation of a dairy Lactococcus lactis at near-zero growth rates. Food Microbiol 2018. [DOI: 10.1016/j.fm.2018.01.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
9
|
Hagi T, Kobayashi M, Nomura M. Whole-transcriptome analysis of oxidative stress response genes in carotenoid-producing Enterococcus gilvus. Biosci Biotechnol Biochem 2017; 82:1053-1057. [PMID: 29161967 DOI: 10.1080/09168451.2017.1399790] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Whole-transcriptome analysis of aerobic stress response gene in Enterococcus gilvus was performed using RNA-sequencing to identify carotenoid-based stress response genes in lactic acid bacteria. The expression of gene responsible for pyruvate dehydrogenase complex synthesis was highly upregulated after aerobic treatment. In addition, the expression of transcriptional regulator spx and genes encoding UvrABC system protein was also upregulated.
Collapse
Affiliation(s)
- Tatsuro Hagi
- a Animal Products Research Division, Institute of Livestock and Grassland Science , National Agriculture and Food Research Organization (NARO) , Ibaraki , Japan
| | - Miho Kobayashi
- a Animal Products Research Division, Institute of Livestock and Grassland Science , National Agriculture and Food Research Organization (NARO) , Ibaraki , Japan
| | - Masaru Nomura
- a Animal Products Research Division, Institute of Livestock and Grassland Science , National Agriculture and Food Research Organization (NARO) , Ibaraki , Japan
| |
Collapse
|
10
|
Oxygen-Inducible Conversion of Lactate to Acetate in Heterofermentative Lactobacillus brevis ATCC 367. Appl Environ Microbiol 2017; 83:AEM.01659-17. [PMID: 28842545 DOI: 10.1128/aem.01659-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 08/23/2017] [Indexed: 11/20/2022] Open
Abstract
Lactobacillus brevis is an obligatory heterofermentative lactic acid bacterium that produces high levels of acetate, which improve the aerobic stability of silages against deterioration caused by yeasts and molds. However, the mechanism involved in acetate accumulation has yet to be elucidated. Here, experimental evidence indicated that aerobiosis resulted in the conversion of lactate to acetate after glucose exhaustion in L. brevis ATCC 367 (GenBank accession number NC_008497). To elucidate the conversion pathway, in silico analysis showed that lactate was first converted to pyruvate by the reverse catalytic reaction of lactate dehydrogenase (LDH); subsequently, pyruvate conversion to acetate might be mediated by pyruvate dehydrogenase (PDH) or pyruvate oxidase (POX). Transcriptional analysis indicated that the pdh and pox genes of L. brevis ATCC 367 were upregulated 37.92- and 18.32-fold, respectively, by oxygen and glucose exhaustion, corresponding to 5.32- and 2.35-fold increases in the respective enzyme activities. Compared with the wild-type strain, the transcription and enzymatic activity of PDH remained stable in the Δpox mutant, while those of POX increased significantly in the Δpdh mutant. More lactate but less acetate was produced in the Δpdh mutant than in the wild-type and Δpox mutant strains, and more H2O2 (a product of the POX pathway) was produced in the Δpdh mutant. We speculated that the high levels of aerobic acetate accumulation in L. brevis ATCC 367 originated mainly from the reuse of lactate to produce pyruvate, which was further converted to acetate by the predominant and secondary functions of PDH and POX, respectively.IMPORTANCE PDH and POX are two possible key enzymes involved in aerobic acetate accumulation in lactic acid bacteria (LAB). It is currently thought that POX plays the major role in aerobic growth in homofermentative LAB and some heterofermentative LAB, while the impact of PDH remains unclear. In this study, we reported that both PDH and POX worked in the aerobic conversion of lactate to acetate in L. brevis ATCC 367, in dominant and secondary roles, respectively. Our findings will further develop the theory of aerobic metabolism by LAB.
Collapse
|
11
|
Azizan KA, Ressom HW, Mendoza ER, Baharum SN. 13C based proteinogenic amino acid (PAA) and metabolic flux ratio analysis of Lactococcus lactis reveals changes in pentose phosphate (PP) pathway in response to agitation and temperature related stresses. PeerJ 2017; 5:e3451. [PMID: 28695065 PMCID: PMC5501154 DOI: 10.7717/peerj.3451] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 05/19/2017] [Indexed: 11/20/2022] Open
Abstract
Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To gain insights into cellular metabolism, 13C metabolic flux analysis and gas chromatography mass spectrometry (GC-MS) were used to measure the flux ratios of active pathways in the central metabolism of L. lactis when subjected to three conditions varying in temperature (30°C, 37°C) and agitation (with and without agitation at 150 rpm). Collectively, the concentrations of proteinogenic amino acids (PAAs) and free fatty acids (FAAs) were compared, and Pearson correlation analysis (r) was calculated to measure the pairwise relationship between PAAs. Branched chain and aromatic amino acids, threonine, serine, lysine and histidine were correlated strongly, suggesting changes in flux regulation in glycolysis, the pentose phosphate (PP) pathway, malic enzyme and anaplerotic reaction catalysed by pyruvate carboxylase (pycA). Flux ratio analysis revealed that glucose was mainly converted by glycolysis, highlighting the stability of L. lactis’ central carbon metabolism despite different conditions. Higher flux ratios through oxaloacetate (OAA) from pyruvate (PYR) reaction in all conditions suggested the activation of pyruvate carboxylate (pycA) in L. lactis, in response to acid stress during exponential phase. Subsequently, more significant flux ratio differences were seen through the oxidative and non-oxidative pentose phosphate (PP) pathways, malic enzyme, and serine and C1 metabolism, suggesting NADPH requirements in response to environmental stimuli. These reactions could play an important role in optimization strategies for metabolic engineering in L. lactis. Overall, the integration of systematic analysis of amino acids and flux ratio analysis provides a systems-level understanding of how L. lactis regulates central metabolism under various conditions.
Collapse
Affiliation(s)
- Kamalrul Azlan Azizan
- Metabolomics Research Laboratory, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, Malaysia
| | - Habtom W Ressom
- Departments of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D.C., United States of America
| | - Eduardo R Mendoza
- Institute of Mathematics, University of the Philippines Diliman, Quezon City, Metro Manila, Philippines.,Membrane Biochemistry Group, Max Planck Institute of Biochemistry, Planegg, Germany
| | - Syarul Nataqain Baharum
- Metabolomics Research Laboratory, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, Malaysia
| |
Collapse
|
12
|
Delpech P, Rifa E, Ball G, Nidelet S, Dubois E, Gagne G, Montel MC, Delbès C, Bornes S. New Insights into the Anti-pathogenic Potential of Lactococcus garvieae against Staphylococcus aureus Based on RNA Sequencing Profiling. Front Microbiol 2017; 8:359. [PMID: 28337182 PMCID: PMC5340753 DOI: 10.3389/fmicb.2017.00359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/21/2017] [Indexed: 11/13/2022] Open
Abstract
The bio-preservation potential of Lactococcus garvieae lies in its capacity to inhibit the growth of staphylococci, especially Staphylococcus aureus, in dairy products and in vitro. In vitro, inhibition is modulated by the level of aeration, owing to hydrogen peroxide (H2O2) production by L. garvieae under aeration. The S. aureus response to this inhibition has already been studied. However, the molecular mechanisms of L. garvieae underlying the antagonism against S. aureus have never been explored. This study provides evidence of the presence of another extracellular inhibition effector in vitro. This effector was neither a protein, nor a lipid, nor a polysaccharide, nor related to an L-threonine deficiency. To better understand the H2O2-related inhibition mechanism at the transcriptome level and to identify other mechanisms potentially involved, we used RNA sequencing to determine the transcriptome response of L. garvieae to different aeration levels and to the presence or absence of S. aureus. The L. garvieae transcriptome differed radically between different aeration levels mainly in biological processes related to fundamental functions and nutritional adaptation. The transcriptomic response of L. garvieae to aeration level differed according to the presence or absence of S. aureus. The higher concentration of H2O2 with high aeration was not associated with a higher expression of L. garvieae H2O2-synthesis genes (pox, sodA, and spxA1) but rather with a repression of L. garvieae H2O2-degradation genes (trxB1, ahpC, ahpF, and gpx). We showed that L. garvieae displayed an original, previously undiscovered, H2O2 production regulation mechanism among bacteria. In addition to the key factor H2O2, the involvement of another extracellular effector in the antagonism against S. aureus was shown. Future studies should explore the relation between H2O2-metabolism, H2O2-producing LAB and the pathogen they inhibit. The nature of the other extracellular effector should also be determined.
Collapse
Affiliation(s)
- Pierre Delpech
- Université Clermont Auvergne, INRA, UMRF Aurillac, France
| | - Etienne Rifa
- Université Clermont Auvergne, INRA, UMRF Aurillac, France
| | - Graham Ball
- John van Geest Cancer Research Centre, School of Science and Technology, Nottingham Trent University Nottingham, UK
| | - Sabine Nidelet
- Montpellier GenomiX, Institut de Génomique Fonctionnelle Montpellier, France
| | - Emeric Dubois
- Montpellier GenomiX, Institut de Génomique Fonctionnelle Montpellier, France
| | | | | | - Céline Delbès
- Université Clermont Auvergne, INRA, UMRF Aurillac, France
| | | |
Collapse
|
13
|
Kandasamy V, Liu J, Dantoft SH, Solem C, Jensen PR. Synthesis of (3R)-acetoin and 2,3-butanediol isomers by metabolically engineered Lactococcus lactis. Sci Rep 2016; 6:36769. [PMID: 27857195 PMCID: PMC5114678 DOI: 10.1038/srep36769] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/20/2016] [Indexed: 12/18/2022] Open
Abstract
The potential that lies in harnessing the chemical synthesis capabilities inherent in living organisms is immense. Here we demonstrate how the biosynthetic machinery of Lactococcus lactis, can be diverted to make (3R)-acetoin and the derived 2,3-butanediol isomers meso-(2,3)-butanediol (m-BDO) and (2R,3R)-butanediol (R-BDO). Efficient production of (3R)-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBDH from Enterobacter cloacae or SadB from Achromobacter xylosooxidans, it was possible to achieve high-yield production of m-BDO or R-BDO respectively. To achieve biosustainable production of these chemicals from dairy waste, we transformed the above strains with the lactose plasmid pLP712. This enabled efficient production of (3R)-acetoin, m-BDO and R-BDO from processed whey waste, with titers of 27, 51, and 32 g/L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell factory for transforming lactose containing dairy waste into value added chemicals.
Collapse
Affiliation(s)
| | - Jianming Liu
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Shruti Harnal Dantoft
- 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
| | - Peter Ruhdal Jensen
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| |
Collapse
|
14
|
Liu J, Chan SHJ, Brock-Nannestad T, Chen J, Lee SY, Solem C, Jensen PR. Combining metabolic engineering and biocompatible chemistry for high-yield production of homo-diacetyl and homo-(S,S)-2,3-butanediol. Metab Eng 2016; 36:57-67. [DOI: 10.1016/j.ymben.2016.02.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 02/10/2016] [Accepted: 02/23/2016] [Indexed: 10/22/2022]
|
15
|
Homola P, Kurák T, Illeová V, Polakovič M. Cultivation of Pichia capsulata as a whole-cell biocatalyst with NADH-dependent alcohol dehydrogenase activity for R -1-phenylethanol production. FOOD AND BIOPRODUCTS PROCESSING 2015. [DOI: 10.1016/j.fbp.2015.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
16
|
Cloning and Overexpression of the als, pflA, and adhB Genes in Streptococcus thermophilus and Their Effects on Metabolite Formation. Mol Biotechnol 2015; 57:923-30. [DOI: 10.1007/s12033-015-9882-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
17
|
Ianniello R, Zheng J, Zotta T, Ricciardi A, Gänzle M. Biochemical analysis of respiratory metabolism in the heterofermentativeLactobacillus spicheriandLactobacillus reuteri. J Appl Microbiol 2015; 119:763-75. [DOI: 10.1111/jam.12853] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/27/2015] [Accepted: 05/12/2015] [Indexed: 01/01/2023]
Affiliation(s)
- R.G. Ianniello
- Department of Agricultural, Food and Nutritional Science; University of Alberta; Edmonton AB Canada
- Scuola di Scienze Agrarie; Forestali, Alimentari e Ambientali; Università degli Studi della Basilicata; Potenza Italy
| | - J. Zheng
- State Key Laboratory of Agricultural Microbiology; Huazhong Agricultural University; Wuhan Hubei China
| | - T. Zotta
- Istituto di Scienze dell'Alimentazione-CNR; Avellino Italy
| | - A. Ricciardi
- Scuola di Scienze Agrarie; Forestali, Alimentari e Ambientali; Università degli Studi della Basilicata; Potenza Italy
| | - M.G. Gänzle
- Department of Agricultural, Food and Nutritional Science; University of Alberta; Edmonton AB Canada
| |
Collapse
|
18
|
Early adaptation to oxygen is key to the industrially important traits of Lactococcus lactis ssp. cremoris during milk fermentation. BMC Genomics 2014; 15:1054. [PMID: 25467604 PMCID: PMC4289295 DOI: 10.1186/1471-2164-15-1054] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 11/18/2014] [Indexed: 11/17/2022] Open
Abstract
Background Lactococcus lactis is the most used species in the dairy industry. Its ability to adapt to technological stresses, such as oxidative stress encountered during stirring in the first stages of the cheese-making process, is a key factor to measure its technological performance. This study aimed to understand the response to oxidative stress of Lactococcus lactis subsp. cremoris MG1363 at the transcriptional and metabolic levels in relation to acidification kinetics and growth conditions, especially at an early stage of growth. For those purposes, conditions of hyper-oxygenation were initially fixed for the fermentation. Results Kinetics of growth and acidification were not affected by the presence of oxygen, indicating a high resistance to oxygen of the L. lactis MG1363 strain. Its resistance was explained by an efficient consumption of oxygen within the first 4 hours of culture, leading to a drop of the redox potential. The efficient consumption of oxygen by the L. lactis MG1363 strain was supported by a coherent and early adaptation to oxygen after 1 hour of culture at both gene expression and metabolic levels. In oxygen metabolism, the over-expression of all the genes of the nrd (ribonucleotide reductases) operon or fhu (ferrichrome ABC transports) genes was particularly significant. In carbon metabolism, the presence of oxygen led to an early shift at the gene level in the pyruvate pathway towards the acetate/2,3-butanediol pathway confirmed by the kinetics of metabolite production. Finally, the MG1363 strain was no longer able to consume oxygen in the stationary growth phase, leading to a drastic loss of culturability as a consequence of cumulative stresses and the absence of gene adaptation at this stage. Conclusions Combining metabolic and transcriptomic profiling, together with oxygen consumption kinetics, yielded new insights into the whole genome adaptation of L. lactis to initial oxidative stress. An early and transitional adaptation to oxidative stress was revealed for L. lactis subsp. cremoris MG1363 in the presence of initially high levels of oxygen. This enables the cells to maintain key traits that are of great importance for industry, such as rapid acidification and reduction of the redox potential of the growth media. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1054) contains supplementary material, which is available to authorized users.
Collapse
|
19
|
Serebrennikov VM, Kotova LN, Glazunov AV. α-Acetolactate overexpression from glucose in the diacetyl producer Lactococcus lactis ssp. lactis bv. diacetylactis B2103, a natural mutant lacking α-acetolactate decarboxylase. APPL BIOCHEM MICRO+ 2014. [DOI: 10.1134/s0003683814070059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
20
|
Abstract
When bacteria grow in a medium with two sugars, they first use the preferred sugar and only then start metabolizing the second one. After the first exponential growth phase, a short lag phase of nongrowth is observed, a period called the diauxie lag phase. It is commonly seen as a phase in which the bacteria prepare themselves to use the second sugar. Here we reveal that, in contrast to the established concept of metabolic adaptation in the lag phase, two stable cell types with alternative metabolic strategies emerge and coexist in a culture of the bacterium Lactococcus lactis. Only one of them continues to grow. The fraction of each metabolic phenotype depends on the level of catabolite repression and the metabolic state-dependent induction of stringent response, as well as on epigenetic cues. Furthermore, we show that the production of alternative metabolic phenotypes potentially entails a bet-hedging strategy. This study sheds new light on phenotypic heterogeneity during various lag phases occurring in microbiology and biotechnology and adjusts the generally accepted explanation of enzymatic adaptation proposed by Monod and shared by scientists for more than half a century.
Collapse
|
21
|
|
22
|
Aller K, Adamberg K, Timarova V, Seiman A, Feštšenko D, Vilu R. Nutritional requirements and media development for Lactococcus lactis IL1403. Appl Microbiol Biotechnol 2014; 98:5871-81. [PMID: 24626960 DOI: 10.1007/s00253-014-5641-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/21/2014] [Accepted: 02/28/2014] [Indexed: 11/29/2022]
Abstract
Lactic acid bacteria are extensively used in food technology and for the production of various compounds, but they are fastidious in nutrient requirements. In order to elucidate the role of each component precisely, defined multicomponent media are required. This study focuses on determining nutrient auxotrophies and minimizing media components (amino acids, vitamins, metal ions, buffers and additional compounds) for the cultivation of Lactococcus lactis subsp. lactis IL1403, using microtitre plates and test tubes. It was shown that glutamine and asparagine were the most important media components for achieving higher biomass yields while the branched-chain amino acids were necessary to increase specific growth rate. The amino acid and glucose ratio was reduced to achieve minimal residual concentration of amino acids in the medium after the growth of cells, whereas the specific growth rate and biomass yield of cells were not considerably affected. As the percentage of each consumed amino acid compared to initial amount is larger than measurement error, these optimized media are important for achieving more precise data about amino acid utilization and metabolism.
Collapse
Affiliation(s)
- Kadri Aller
- The Competence Center of Food and Fermentation Technologies (CCFFT), Akadeemia tee 15A, 12618, Tallinn, Estonia,
| | | | | | | | | | | |
Collapse
|
23
|
Pessione A, Zapponi M, Mandili G, Fattori P, Mangiapane E, Mazzoli R, Pessione E. Enantioselective lactic acid production by an Enterococcus faecium strain showing potential in agro-industrial waste bioconversion: Physiological and proteomic studies. J Biotechnol 2014; 173:31-40. [DOI: 10.1016/j.jbiotec.2014.01.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/09/2014] [Accepted: 01/13/2014] [Indexed: 11/25/2022]
|
24
|
Genome-scale metabolic model for Lactococcus lactis MG1363 and its application to the analysis of flavor formation. Appl Microbiol Biotechnol 2013; 97:8729-39. [DOI: 10.1007/s00253-013-5140-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 07/15/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
|
25
|
Oxidative stress at high temperatures in Lactococcus lactis due to an insufficient supply of Riboflavin. Appl Environ Microbiol 2013; 79:6140-7. [PMID: 23913422 DOI: 10.1128/aem.01953-13] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lactococcus lactis MG1363 was found to be unable to grow at temperatures above 37°C in a defined medium without riboflavin, and the cause was identified to be dissolved oxygen introduced during preparation of the medium. At 30°C, growth was unaffected by dissolved oxygen and oxygen was consumed quickly. Raising the temperature to 37°C resulted in severe growth inhibition and only slow removal of dissolved oxygen. Under these conditions, an abnormally low intracellular ratio of [ATP] to [ADP] (1.4) was found (normally around 5), which indicates that the cells are energy limited. By adding riboflavin to the medium, it was possible to improve growth and oxygen consumption at 37°C, and this also normalized the [ATP]-to-[ADP] ratio. A codon-optimized redox-sensitive green fluorescent protein (GFP) was introduced into L. lactis and revealed a more oxidized cytoplasm at 37°C than at 30°C. These results indicate that L. lactis suffers from heat-induced oxidative stress at increased temperatures. A decrease in intracellular flavin adenine dinucleotide (FAD), which is derived from riboflavin, was observed with increasing growth temperature, but the presence of riboflavin made the decrease smaller. The drop was accompanied by a decrease in NADH oxidase and pyruvate dehydrogenase activities, both of which depend on FAD as a cofactor. By overexpressing the riboflavin transporter, it was possible to improve FAD biosynthesis, which resulted in increased NADH oxidase and pyruvate dehydrogenase activities and improved fitness at high temperatures in the presence of oxygen.
Collapse
|
26
|
Goel A, Wortel MT, Molenaar D, Teusink B. Metabolic shifts: a fitness perspective for microbial cell factories. Biotechnol Lett 2012; 34:2147-60. [PMID: 22936303 PMCID: PMC3487007 DOI: 10.1007/s10529-012-1038-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 08/16/2012] [Indexed: 04/28/2023]
Abstract
Performance of industrial microorganisms as cell factories is limited by the capacity to channel nutrients to desired products, of which optimal production usually requires careful manipulation of process conditions, or strain improvement. The focus in process improvement is often on understanding and manipulating the regulation of metabolism. Nonetheless, one encounters situations where organisms are remarkably resilient to further optimization or their properties become unstable. Therefore it is important to understand the origin of these apparent limitations to find whether and how they can be improved. We argue that by considering fitness effects of regulation, a more generic explanation for certain behaviour can be obtained. In this view, apparent process limitations arise from trade-offs that cells faced as they evolved to improve fitness. A deeper understanding of such trade-offs using a systems biology approach can ultimately enhance performance of cell factories.
Collapse
Affiliation(s)
- Anisha Goel
- Systems Bioinformatics IBIVU, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | | | | | | |
Collapse
|
27
|
Engineering the central pathways in Lactococcus lactis: Functional expression of the phosphofructokinase (pfk) and alternative oxidase (aox1) genes from Aspergillus niger in Lactococcus lactis facilitates improved carbon conversion rates under oxidizing conditions. Enzyme Microb Technol 2012; 51:125-30. [DOI: 10.1016/j.enzmictec.2012.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/23/2012] [Accepted: 04/23/2012] [Indexed: 11/21/2022]
|
28
|
Guo T, Kong J, Zhang L, Zhang C, Hu S. Fine tuning of the lactate and diacetyl production through promoter engineering in Lactococcus lactis. PLoS One 2012; 7:e36296. [PMID: 22558426 PMCID: PMC3338672 DOI: 10.1371/journal.pone.0036296] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 03/30/2012] [Indexed: 01/08/2023] Open
Abstract
Lactococcus lactis is a well-studied bacterium widely used in dairy fermentation and capable of producing metabolites with organoleptic and nutritional characteristics. For fine tuning of the distribution of glycolytic flux at the pyruvate branch from lactate to diacetyl and balancing the production of the two metabolites under aerobic conditions, a constitutive promoter library was constructed by randomizing the promoter sequence of the H2O-forming NADH oxidase gene in L. lactis. The library consisted of 30 promoters covering a wide range of activities from 7,000 to 380,000 relative fluorescence units using a green fluorescent protein as reporter. Eleven typical promoters of the library were selected for the constitutive expression of the H2O-forming NADH oxidase gene in L. lactis, and the NADH oxidase activity increased from 9.43 to 58.17-fold of the wild-type strain in small steps of activity change under aerobic conditions. Meanwhile, the lactate yield decreased from 21.15±0.08 mM to 9.94±0.07 mM, and the corresponding diacetyl production increased from 1.07±0.03 mM to 4.16±0.06 mM with the intracellular NADH/NAD+ ratios varying from 0.711±0.005 to 0.383±0.003. The results indicated that the reduced pyruvate to lactate flux was rerouted to the diacetyl with an almost linear flux variation via altered NADH/NAD+ ratios. Therefore, we provided a novel strategy to precisely control the pyruvate distribution for fine tuning of the lactate and diacetyl production through promoter engineering in L. lactis. Interestingly, the increased H2O-forming NADH oxidase activity led to 76.95% lower H2O2 concentration in the recombinant strain than that of the wild-type strain after 24 h of aerated cultivation. The viable cells were significantly elevated by four orders of magnitude within 28 days of storage at 4°C, suggesting that the increased enzyme activity could eliminate H2O2 accumulation and prolong cell survival.
Collapse
Affiliation(s)
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China
- * E-mail:
| | | | | | | |
Collapse
|
29
|
Price CE, Zeyniyev A, Kuipers OP, Kok J. From meadows to milk to mucosa - adaptation of Streptococcus and Lactococcus species to their nutritional environments. FEMS Microbiol Rev 2012; 36:949-71. [PMID: 22212109 DOI: 10.1111/j.1574-6976.2011.00323.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 12/20/2011] [Accepted: 12/21/2011] [Indexed: 01/20/2023] Open
Abstract
Lactic acid bacteria (LAB) are indigenous to food-related habitats as well as associated with the mucosal surfaces of animals. The LAB family Streptococcaceae consists of the genera Lactococcus and Streptococcus. Members of the family include the industrially important species Lactococcus lactis, which has a long history safe use in the fermentative food industry, and the disease-causing streptococci Streptococcus pneumoniae and Streptococcus pyogenes. The central metabolic pathways of the Streptococcaceae family have been extensively studied because of their relevance in the industrial use of some species, as well as their influence on virulence of others. Recent developments in high-throughput proteomic and DNA-microarray techniques, in in vivo NMR studies, and importantly in whole-genome sequencing have resulted in new insights into the metabolism of the Streptococcaceae family. The development of cost-effective high-throughput sequencing has resulted in the publication of numerous whole-genome sequences of lactococcal and streptococcal species. Comparative genomic analysis of these closely related but environmentally diverse species provides insight into the evolution of this family of LAB and shows that the relatively small genomes of members of the Streptococcaceae family have been largely shaped by the nutritionally rich environments they inhabit.
Collapse
Affiliation(s)
- Claire E Price
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands; Biochemistry Department, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands; Kluyver Centre for Genomics of Industrial Fermentation, Delft, The Netherlands; Netherlands Consortium for Systems Biology, Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
30
|
Papagianni M, Avramidis N. Cloning and functional expression of the mitochondrial alternative oxidase gene (aox1) of Aspergillus niger in Lactococcus lactis and its induction by oxidizing conditions. Enzyme Microb Technol 2012; 50:17-21. [DOI: 10.1016/j.enzmictec.2011.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/23/2011] [Accepted: 09/26/2011] [Indexed: 10/16/2022]
|
31
|
Growth rate-dependent control in Enterococcus faecalis: effects on the transcriptome and proteome, and strong regulation of lactate dehydrogenase. Appl Environ Microbiol 2011; 78:170-6. [PMID: 22038603 DOI: 10.1128/aem.06604-11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis V583 was grown in a glucose-limited chemostat at three different growth rates (0.05, 0.15, and 0.4 h⁻¹). The fermentation pattern changed with growth rate, from a mostly homolactic profile at a high growth rate to a fermentation dominated by formate, acetate, and ethanol production at a low growth rate. A number of amino acids were consumed at the lower growth rates but not by fast-growing cells. The change in metabolic profile was caused mainly by decreased flux through lactate dehydrogenase. The transcription of ldh-1, encoding the principal lactate dehydrogenase, showed very strong growth rate dependence and differed by three orders of magnitude between the highest and the lowest growth rates. Despite the increase in ldh-1 transcript, the content of the Ldh-1 protein was the same under all conditions. Using microarrays and quantitative PCR, the levels of 227 gene transcripts were found to be affected by the growth rate, and 56 differentially expressed proteins were found by proteomic analyses. Few genes or proteins showed a growth rate-dependent increase or decrease in expression across the whole range of conditions, and many showed a maximum or minimum at the middle growth rate (i.e., 0.15 h⁻¹). For many gene products, a discrepancy between transcriptomic and proteomic data were seen, indicating posttranscriptional regulation of expression.
Collapse
|
32
|
Zhu J, Sánchez A, Bennett GN, San KY. Manipulating respiratory levels in Escherichia coli for aerobic formation of reduced chemical products. Metab Eng 2011; 13:704-12. [PMID: 22001430 DOI: 10.1016/j.ymben.2011.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 09/20/2011] [Accepted: 09/22/2011] [Indexed: 11/17/2022]
Abstract
Optimizing the productivity of bioengineered strains requires balancing ATP generation and carbon atom conservation through fine-tuning cell respiration and metabolism. Traditional approaches manipulate cell respiration by altering air feeding, which are technically difficult especially in large bioreactors. An approach based on genetic regulation may better serve this purpose. With excess oxygen supply to the culture, we efficiently manipulated Escherichia coli cell respiration by adding different amount of coenzyme Q1 to strains lacking the ubiCA genes, which encode two critical enzymes for ubiquinone synthesis. As a proof-of-concept, the metabolic effect of the ubiCA gene knockout and coenzyme Q1 supplementation were characterized, and the metabolic profiles of the experimental strains showed clear correlations with coenzyme Q1 concentrations. Further proof-of-principle experiments were performed to illustrate that the approach can be used to optimize cell respiration for the production of chemicals of interest such as ethanol. This study showed that controlled respiration through genetic manipulation can be exploited to allow much larger operating windows for reduced product formation even under fully aerobic conditions.
Collapse
Affiliation(s)
- Jiangfeng Zhu
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, China
| | | | | | | |
Collapse
|
33
|
de Arauz LJ, Jozala AF, Baruque-Ramos J, Mazzola PG, Pessoa A, Penna TCV. Culture medium of diluted skimmed milk for the production of nisin in batch cultivations. ANN MICROBIOL 2011. [DOI: 10.1007/s13213-011-0278-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
34
|
Identification of a conserved sequence in flavoproteins essential for the correct conformation and activity of the NADH oxidase NoxE of Lactococcus lactis. J Bacteriol 2011; 193:3000-8. [PMID: 21498647 DOI: 10.1128/jb.01466-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Water-forming NADH oxidases (encoded by noxE, nox2, or nox) are flavoproteins generally implicated in the aerobic survival of microaerophilic bacteria, such as lactic acid bacteria. However, some natural Lactococcus lactis strains produce an inactive NoxE. We examined the role of NoxE in the oxygen tolerance of L. lactis in the rich synthetic medium GM17. Inactivation of noxE suppressed 95% of NADH oxidase activity but only slightly affected aerobic growth, oxidative stress resistance, and NAD regeneration. However, noxE inactivation strongly impaired oxygen consumption and mixed-acid fermentation. We found that the A303T mutation is responsible for the loss of activity of a naturally occurring variant of NoxE. Replacement of A303 with T or G or of G307 with S or A by site-directed mutagenesis led to NoxE aggregation and the total loss of activity. We demonstrated that L299 is involved in NoxE activity, probably contributing to positioning flavin adenine dinucleotide (FAD) in the active site. These residues are part of the strongly conserved sequence LA(T)XXAXXXG included in an alpha helix that is present in other flavoprotein disulfide reductase (FDR) family flavoproteins that display very similar three-dimensional structures.
Collapse
|
35
|
Transcriptome, proteome, and metabolite analyses of a lactate dehydrogenase-negative mutant of Enterococcus faecalis V583. Appl Environ Microbiol 2011; 77:2406-13. [PMID: 21296946 DOI: 10.1128/aem.02485-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A constructed lactate dehydrogenase (LDH)-negative mutant of Enterococcus faecalis V583 grows at the same rate as the wild type but ferments glucose to ethanol, formate, and acetoin. Microarray analysis showed that LDH deficiency had profound transcriptional effects: 43 genes in the mutant were found to be upregulated, and 45 were found to be downregulated. Most of the upregulated genes encode enzymes of energy metabolism or transport. By two-dimensional (2D) gel analysis, 45 differentially expressed proteins were identified. A comparison of transcriptomic and proteomic data suggested that for several proteins the level of expression is regulated beyond the level of transcription. Pyruvate catabolic genes, including the truncated ldh gene, showed highly increased transcription in the mutant. These genes, along with a number of other differentially expressed genes, are preceded by sequences with homology to binding sites for the global redox-sensing repressor, Rex, of Staphylococcus aureus. The data indicate that the genes are transcriptionally regulated by the NADH/NAD ratio and that this ratio plays an important role in the regulatory network controlling energy metabolism in E. faecalis.
Collapse
|
36
|
Stoyanova. New Antifungal Bacteriocin-Synthesizing Strains of Lactococcus lactis ssp. lactis as the Perspective Biopreservatives for Protection of Raw Smoked Sausages. ACTA ACUST UNITED AC 2010. [DOI: 10.3844/ajabssp.2010.477.485] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
37
|
Cesselin B, Derré-Bobillot A, Fernandez A, Lamberet G, Lechardeur D, Yamamoto Y, Pedersen MB, Garrigues C, Gaudu P. Respiration, a strategy to avoid oxidative stress in Lactococcus lactis, is regulated by the heme status. ACTA ACUST UNITED AC 2010. [DOI: 10.4109/jslab.21.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
38
|
Lahtvee PJ, Valgepea K, Nahku R, Abner K, Adamberg K, Vilu R. Steady state growth space study of Lactococcus lactis in D-stat cultures. Antonie Van Leeuwenhoek 2009; 96:487-96. [PMID: 19603284 DOI: 10.1007/s10482-009-9363-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 06/24/2009] [Indexed: 10/20/2022]
Abstract
Growth space of Lactococcus lactis subsp. lactis IL1403 was studied at constant growth rate using D-stat cultivation technique. Starting from steady state conditions in a chemostat culture (mu = 0.2 h(-1)), the pH and/or temperature were continuously changed in the range of 5.4-6.4 and 26-34 degrees C, respectively, followed by the return to the initial environmental conditions. Based on substrate consumption and product formation yields and expression changes of 1,920 genes, it was shown that changes of physiological state were not dependent on the direction of movement (from pH 6.3 to 5.4 or from 5.4 to 6.3), showing that quasi steady state values in D-stat corresponded to the steady state values in chemostats. Relative standard deviation of growth characteristics in triplicate D-stat experiments was below 10%. Continuing the experiment and reestablishing initial growth conditions revealed in average 7% difference (hysteresis) in growth characteristics when comparing chemostat steady state cultures prior and after the change of environmental conditions. Similarly, shifts were also seen at gene expression levels. The large amount of quantitatively reliable data obtained in this study provided a new insight into dynamic properties of bacterial physiology, and can be used for describing the growth space of microorganisms by modeling cell metabolism.
Collapse
Affiliation(s)
- Petri-Jaan Lahtvee
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | | | | | | | | | | |
Collapse
|
39
|
Jeanson S, Hilgert N, Coquillard MO, Seukpanya C, Faiveley M, Neveu P, Abraham C, Georgescu V, Fourcassié P, Beuvier E. Milk acidification by Lactococcus lactis is improved by decreasing the level of dissolved oxygen rather than decreasing redox potential in the milk prior to inoculation. Int J Food Microbiol 2009; 131:75-81. [DOI: 10.1016/j.ijfoodmicro.2008.09.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 09/22/2008] [Accepted: 09/26/2008] [Indexed: 11/30/2022]
|
40
|
Multiple control of the acetate pathway in Lactococcus lactis under aeration by catabolite repression and metabolites. Appl Microbiol Biotechnol 2009; 82:1115-22. [PMID: 19214497 DOI: 10.1007/s00253-009-1897-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 01/25/2009] [Accepted: 01/26/2009] [Indexed: 10/21/2022]
Abstract
To explore the factors controlling metabolite formation under aeration in Lactococcus lactis, metabolic patterns, enzymatic activities, and transcriptional profiles of genes involved in the aerobic pathway for acetate anabolism were compared between a parental L. lactis strain and its NADH-oxidase-overproducer derivative. Deregulated catabolite repression mutans in the ccpA or pstH genes, encoding CcpA or its co-activator HPr, respectively, were compared with a parental strain, as well. Although the NADH-oxidase activity was derepressed in ccpA, but not in the pstH background, a mixed fermentation was displayed by either mutant, with a higher acetate production in the pstH variant. Moreover, transcription of genes encoding phosphotransacetylase and acetate kinase were derepressed, and the corresponding enzymatic activities increased, in both catabolite repression mutants. These results and the dependence on carbon source for acetate production in the NADH-oxidase-overproducer support the conclusion that catabolite repression, rather than NADH oxidation, plays a critical role to control acetate production. Furthermore, fructose 1,6-bisphosphate influenced the in vitro phosphotransacetylase and acetate kinase activities, while the former was sensitive to diacetyl. Our study strongly supports the model that, under aerobic conditions, the homolactic fermentation in L. lactis MG1363 is maintained by CcpA-mediated repression of mixed acid fermentation.
Collapse
|
41
|
Adamberg K, Lahtvee PJ, Valgepea K, Abner K, Vilu R. Quasi steady state growth of Lactococcus lactis in glucose-limited acceleration stat (A-stat) cultures. Antonie van Leeuwenhoek 2009; 95:219-26. [PMID: 19184516 DOI: 10.1007/s10482-009-9305-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 01/09/2009] [Indexed: 11/29/2022]
Abstract
Quasi steady state growth of Lactococcus lactis IL 1403 was studied in glucose-limited A-stat cultivation experiments with acceleration rates (a) from 0.003 to 0.06 h(-2) after initial stabilization of the cultures in chemostat at D = 0.2-0.3 h(-1). It was shown that the high limit of quasi steady state growth rate depended on the acceleration rate used-at an acceleration rate 0.003 h(-2) the quasi steady state growth was observed until mu (crit) = 0.59 h(-1), which is also the mu (max) value for the culture. Lower values of mu (crit) were observed at higher acceleration rates. The steady state growth of bacteria stabilized at dilution rate 0.2 h(-1) was immediately disrupted after initiating acceleration at the highest acceleration rate studied-0.06 h(-2). Observation was made that differences [Delta(mu - D)] of the specific growth rates from pre-programmed dilution rates were the lowest using an acceleration rate of 0.003 h(-2) (< 4% of preset changing growth rate). The adaptability of cells to follow preprogrammed growth rate was found to decrease with increasing dilution rate-it was shown that lower acceleration rates should be applied at higher growth rates to maintain the culture in the quasi steady state. The critical specific growth rate and the biomass yields based on glucose consumption were higher if the medium contained S (0) = 5 g L(-1) glucose instead of S (0) = 10 g L(-1). It was assumed that this was due to the inhibitory effect of lactate accumulating at higher concentrations in the latter cultures. Parallel A-stat experiments at the same acceleration and dilution rates showed good reproducibility-Delta(mu - D) was less than 5%, standard deviations of biomass yields per ATP produced (Y (ATP)), and biomass yields per glucose consumed (Y (XS)) were less than 15%.
Collapse
Affiliation(s)
- Kaarel Adamberg
- Department of Food Processing, Tallinn University of Technology, Ehitajate tee 5, Tallinn, Estonia
| | | | | | | | | |
Collapse
|
42
|
Papagianni M, Avramidis N, Filiousis G. Glycolysis and the regulation of glucose transport in Lactococcus lactis spp. lactis in batch and fed-batch culture. Microb Cell Fact 2007; 6:16. [PMID: 17521452 PMCID: PMC1890298 DOI: 10.1186/1475-2859-6-16] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 05/24/2007] [Indexed: 11/10/2022] Open
Abstract
Background Despite the fact that many reports deal with glycolysis in Lactococcus lactis, there is not much information on the regulation of uptake of glucose itself. The aim of the present work was to investigate the effect of the glucose level on its specific uptake rate. Results Studies on aeration levels in pH controlled L. lactis spp. lactis batch cultures on glucose (55 mM) showed that product formation is extremely homolactic and the highest yield of lactate on glucose is obtained under microaerobic conditions (5% dissolved oxygen). Microaerobic conditions were therefore applied in experiments carried out to investigate the regulation of the uptake of glucose. The tool of glucostat fed-batch culture was employed, in which glucose was added at a rate suitable to maintain a stable concentration throughout the runs with glucose concentration ranging from 13.75 to 555 mM. The glucostat experiments showed that the concentration of glucose influences its specific uptake rate and consequently the glycolytic flux, as well as the fermentation pattern. The highest specific activities of the key glycolytic enzymes PFK, PYK and the LDH were obtained at 55 mM glucose, the area of the highest observed glycolytic flux. Reduction of the glycolytic flux by 55% in the 277 mM glucostat corresponded to an almost identical reduction in PFK activity, indicating a certain controlling influence of this enzyme on the flux, through the glucose effect. Conclusion Determination of intracellular metabolites' pools showed that FBP cannot be regarded as a direct regulator of product formation, since almost identical concentrations were obtained at both low (13.75 mM) and high (138 mM) glucose levels, at which neither the glucose uptake rates and the glycolytic flux, nor the fermentation patterns were similar (mixed acids vs homolactic, respectively). Glucostat data showed instead that the control of the flux through the glycolytic pathway under the examined conditions, resides to a large extent in processes outside the pathway, like the ATP consuming reactions and glucose transport. A regulation mechanism is proposed governed by the energy state of the cell by which L. lactis can handle the glycolytic flux through the allosteric properties of key enzymes, with PFK having a significant influence on the control.
Collapse
Affiliation(s)
- Maria Papagianni
- Department of Hygiene and Technology of Food of Animal Origin, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 54006, Greece
| | - Nicholaos Avramidis
- Department of Hygiene and Technology of Food of Animal Origin, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 54006, Greece
| | - George Filiousis
- Department of Hygiene and Technology of Food of Animal Origin, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 54006, Greece
| |
Collapse
|
43
|
Papagianni M, Avramidis N, Filiousis G. Investigating the relationship between the specific glucose uptake rate and nisin production in aerobic batch and fed-batch glucostat cultures of Lactococcus lactis. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2006.10.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
44
|
Adamberg K, Adamberg S, Laht TM, Ardö Y, Paalme T. Study of Cheese Associated Lactic Acid Bacteria Under Carbohydrate-Limited Conditions Using D-Stat Cultivation. FOOD BIOTECHNOL 2006. [DOI: 10.1080/08905430600709412] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
45
|
Gößner AS, Küsel K, Schulz D, Trenz S, Acker G, Lovell CR, Drake HL. Trophic interaction of the aerotolerant anaerobe Clostridium intestinale and the acetogen Sporomusa rhizae sp. nov. isolated from roots of the black needlerush Juncus roemerianus. Microbiology (Reading) 2006; 152:1209-1219. [PMID: 16549683 DOI: 10.1099/mic.0.28725-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Acetogens were enumerated from root homogenates of the black needlerushJuncus roemerianusobtained from a nearly pristine salt marsh. An isolated colony, ST1, yielded acetogenic activity and was initially thought to be a pure culture; however, ST1 was subsequently found to be composed of an aerotolerant fermentative anaerobe (RC) and an acetogen (RST) (Tindicates type strain). The two spore-forming mesophiles were separated by selective cultivation under conditions favouring the growth of either RC or RST. The 16S rRNA gene sequence of RC was 99 % similar to that ofClostridium intestinale, indicating that RC was a new isolate of this clostridial species. The rRNA gene sequence most similar to that of RSTwas only 96 % similar to that of RSTand was from a species of the acetogenic genusSporomusa, indicating that RSTwas a new sporomusal species; the nameSporomusa rhizaesp. nov. is proposed. RC grew at the expense of saccharides. H2-forming butyrate fermentation was the primary catabolism utilized by RC under anoxic conditions, while homolactate fermentation was the primary catabolism under oxic conditions. RC consumed O2and tolerated 20 % O2in the headspace of shaken broth cultures. In contrast, RSTwas acetogenic, utilized H2, lactate and formate, did not utilize saccharides, and could not tolerate high concentrations of O2. RSTgrew by trophic interaction with RC on saccharides via the uptake of H2, and, to a lesser extent, lactate and formate produced by RC. Co-cultures of the two organisms yielded high amounts of acetate. These results indicate that (i) previously uncharacterized species ofSporomusaare associated withJuncusroots and (ii) trophic links to O2-consuming aerotolerant anaerobes might contribute to thein situactivities and survival strategies of acetogens in salt marsh rhizospheres, a habitat subject to gradients of plant-derived O2.
Collapse
MESH Headings
- Acetic Acid/metabolism
- Butyrates/metabolism
- Carbohydrate Metabolism
- Clostridium/classification
- Clostridium/isolation & purification
- Clostridium/metabolism
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Fermentation
- Formates/metabolism
- Hydrogen/metabolism
- Lactic Acid/metabolism
- Magnoliopsida/microbiology
- Microscopy, Electron, Transmission
- Molecular Sequence Data
- Oxygen Consumption
- Phylogeny
- Plant Roots/microbiology
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Veillonellaceae/classification
- Veillonellaceae/isolation & purification
- Veillonellaceae/metabolism
Collapse
Affiliation(s)
- Anita S Gößner
- Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany
| | - Kirsten Küsel
- Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany
| | - Daria Schulz
- Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany
| | - Sonja Trenz
- Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany
| | - George Acker
- Electron Microscopy Laboratory, University of Bayreuth, 95440 Bayreuth, Germany
| | - Charles R Lovell
- Department of Biological Sciences, University of South Carolina, Columbus, SC 29208, USA
| | - Harold L Drake
- Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany
| |
Collapse
|
46
|
Wagner N, Tran QH, Richter H, Selzer PM, Unden G. Pyruvate fermentation by Oenococcus oeni and Leuconostoc mesenteroides and role of pyruvate dehydrogenase in anaerobic fermentation. Appl Environ Microbiol 2005; 71:4966-71. [PMID: 16151074 PMCID: PMC1214600 DOI: 10.1128/aem.71.9.4966-4971.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The heterofermentative lactic acid bacteria Oenococcus oeni and Leuconostoc mesenteroides are able to grow by fermentation of pyruvate as the carbon source (2 pyruvate --> 1 lactate + 1 acetate + 1 CO(2)). The growth yields amount to 4.0 and 5.3 g (dry weight)/mol of pyruvate, respectively, suggesting formation of 0.5 mol ATP/mol pyruvate. Pyruvate is oxidatively decarboxylated by pyruvate dehydrogenase to acetyl coenzyme A, which is then converted to acetate, yielding 1 mol of ATP. For NADH reoxidation, one further pyruvate molecule is reduced to lactate. The enzymes of the pathway were present after growth on pyruvate, and genome analysis showed the presence of the corresponding structural genes. The bacteria contain, in addition, pyruvate oxidase activity which is induced under microoxic conditions. Other homo- or heterofermentative lactic acid bacteria showed only low pyruvate fermentation activity.
Collapse
Affiliation(s)
- Nicole Wagner
- Johannes Gutenberg-Universität Mainz, Institut für Mikrobiologie und Weinforschung, Becherweg 15, 55099 Mainz, Germany
| | | | | | | | | |
Collapse
|
47
|
Nissen L, Pérez-Martínez G, Yebra MJ. Sorbitol synthesis by an engineered Lactobacillus casei strain expressing a sorbitol-6-phosphate dehydrogenase gene within the lactose operon. FEMS Microbiol Lett 2005; 249:177-83. [PMID: 16002237 DOI: 10.1016/j.femsle.2005.06.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 06/02/2005] [Accepted: 06/07/2005] [Indexed: 10/25/2022] Open
Abstract
Sorbitol is claimed to have important health-promoting effects and Lactobacillus casei is a lactic acid bacterium relevant as probiotic and used as a cheese starter culture. A sorbitol-producing L. casei strain might therefore be of considerable interest in the food industry. A recombinant strain of L. casei was constructed by the integration of a d-sorbitol-6-phosphate dehydrogenase-encoding gene (gutF) in the chromosomal lactose operon (strain BL232). gutF expression in this strain followed the same regulation as that of the lac genes, that is, it was repressed by glucose and induced by lactose. (13)C-nuclear magnetic resonance analysis of supernatants of BL232 resting cells demonstrated that, when pre-grown on lactose, cells were able to synthesize sorbitol from glucose. Inactivation of the l-lactate dehydrogenase gene in BL232 led to an increase in sorbitol production, suggesting that the engineered route provides an alternative pathway for NAD(+) regeneration.
Collapse
Affiliation(s)
- Lorenzo Nissen
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), 46100 Burjassot, Valencia, Spain
| | | | | |
Collapse
|
48
|
Neves AR, Pool WA, Kok J, Kuipers OP, Santos H. Overview on sugar metabolism and its control inLactococcus lactis— The input from in vivo NMR. FEMS Microbiol Rev 2005. [DOI: 10.1016/j.fmrre.2005.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
49
|
Smit G, Smit BA, Engels WJ. Flavour formation by lactic acid bacteria and biochemical flavour profiling of cheese products. FEMS Microbiol Rev 2005. [DOI: 10.1016/j.fmrre.2005.04.002] [Citation(s) in RCA: 536] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
50
|
Oliveira AP, Nielsen J, Förster J. Modeling Lactococcus lactis using a genome-scale flux model. BMC Microbiol 2005; 5:39. [PMID: 15982422 PMCID: PMC1185544 DOI: 10.1186/1471-2180-5-39] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Accepted: 06/27/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genome-scale flux models are useful tools to represent and analyze microbial metabolism. In this work we reconstructed the metabolic network of the lactic acid bacteria Lactococcus lactis and developed a genome-scale flux model able to simulate and analyze network capabilities and whole-cell function under aerobic and anaerobic continuous cultures. Flux balance analysis (FBA) and minimization of metabolic adjustment (MOMA) were used as modeling frameworks. RESULTS The metabolic network was reconstructed using the annotated genome sequence from L. lactis ssp. lactis IL1403 together with physiological and biochemical information. The established network comprised a total of 621 reactions and 509 metabolites, representing the overall metabolism of L. lactis. Experimental data reported in the literature was used to fit the model to phenotypic observations. Regulatory constraints had to be included to simulate certain metabolic features, such as the shift from homo to heterolactic fermentation. A minimal medium for in silico growth was identified, indicating the requirement of four amino acids in addition to a sugar. Remarkably, de novo biosynthesis of four other amino acids was observed even when all amino acids were supplied, which is in good agreement with experimental observations. Additionally, enhanced metabolic engineering strategies for improved diacetyl producing strains were designed. CONCLUSION The L. lactis metabolic network can now be used for a better understanding of lactococcal metabolic capabilities and potential, for the design of enhanced metabolic engineering strategies and for integration with other types of 'omic' data, to assist in finding new information on cellular organization and function.
Collapse
Affiliation(s)
- Ana Paula Oliveira
- Fluxome Sciences A/S, Søltofts Plads, Building 223, DK-2800 Kgs. Lyngby, Denmark
| | - Jens Nielsen
- Fluxome Sciences A/S, Søltofts Plads, Building 223, DK-2800 Kgs. Lyngby, Denmark
- Center for Microbial Biotechnology, BioCentrum-DTU, Technical University of Denmark, Building 223, DK-2800 Kgs. Lyngby, Denmark
| | - Jochen Förster
- Fluxome Sciences A/S, Søltofts Plads, Building 223, DK-2800 Kgs. Lyngby, Denmark
| |
Collapse
|