B. Cesselin, Aurélie Derré-Bobillot, Annabelle Fernandez, G. Lamberet, D. Lechardeur, Yuji Yamamoto, M. Pedersen, C. Garrigues, P. Gaudu
Lactic acid bacteria (LAB) species like L. lactis are traditionally considered as obligate fermentative bacteria because even in aerobiosis they use sugar degradation for substrate-level phosphorylation, i.e. ATP production. However, recent studies revealed that this bacterium and some other LAB are capable of activating a heme-dependent cytochrome oxidase (CydAB) and thus undergo a respiration metabolism. Nevertheless, respiratory chain activation is allowed only when cells have access to heme (and additionally menaquinone for some LAB) in the environment because they cannot synthesize these compounds. Respiration increases the biomass yield and extends the long term survival of stored cells. These benefits of respiration are explained in different ways: i) Respiratory chain activity consumes oxygen, limiting the formation of toxic reactive oxygen species. ii) Respiratory chain generates a pH gradient, which potentially increases ATP production via H+-ATPase activity. iii) Respiration metabolism decreases lactic acid production, limiting acid stress. However, LAB have to cope with heme toxicity. Although heme has clear metabolic benefits the intracellular pool of free heme must be stringently controlled to prevent damage to macromolecules like DNA. In L. lactis, a potential efflux pump system, consisting of an ATPase (YgfA) and a permease (YgfB), is specifically highly induced in response to exogenous heme. Interestingly, the ygfA and ygfB genes are in an operon with ygfC, a potential regulator of the TetR family. Our studies implicate the ygfCBA operon is involved in modulating the free heme level and is regulated by YgfC.
{"title":"Respiration, a strategy to avoid oxidative stress in Lactococcus lactis, is regulated by the heme status","authors":"B. Cesselin, Aurélie Derré-Bobillot, Annabelle Fernandez, G. Lamberet, D. Lechardeur, Yuji Yamamoto, M. Pedersen, C. Garrigues, P. Gaudu","doi":"10.4109/JSLAB.21.10","DOIUrl":"https://doi.org/10.4109/JSLAB.21.10","url":null,"abstract":"Lactic acid bacteria (LAB) species like L. lactis are traditionally considered as obligate fermentative bacteria because even in aerobiosis they use sugar degradation for substrate-level phosphorylation, i.e. ATP production. However, recent studies revealed that this bacterium and some other LAB are capable of activating a heme-dependent cytochrome oxidase (CydAB) and thus undergo a respiration metabolism. Nevertheless, respiratory chain activation is allowed only when cells have access to heme (and additionally menaquinone for some LAB) in the environment because they cannot synthesize these compounds. Respiration increases the biomass yield and extends the long term survival of stored cells. These benefits of respiration are explained in different ways: i) Respiratory chain activity consumes oxygen, limiting the formation of toxic reactive oxygen species. ii) Respiratory chain generates a pH gradient, which potentially increases ATP production via H+-ATPase activity. iii) Respiration metabolism decreases lactic acid production, limiting acid stress. However, LAB have to cope with heme toxicity. Although heme has clear metabolic benefits the intracellular pool of free heme must be stringently controlled to prevent damage to macromolecules like DNA. In L. lactis, a potential efflux pump system, consisting of an ATPase (YgfA) and a permease (YgfB), is specifically highly induced in response to exogenous heme. Interestingly, the ygfA and ygfB genes are in an operon with ygfC, a potential regulator of the TetR family. Our studies implicate the ygfCBA operon is involved in modulating the free heme level and is regulated by YgfC.","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129851966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Kobayashi, Y. Nakagawa, Y. Tashiro, Kanda Kohzo, F. Kato
{"title":"A Novel Type II Restriction Endonuclease from Leuconostoc mesenteroides in the Ariake Sea","authors":"G. Kobayashi, Y. Nakagawa, Y. Tashiro, Kanda Kohzo, F. Kato","doi":"10.4109/JSLAB.19.96","DOIUrl":"https://doi.org/10.4109/JSLAB.19.96","url":null,"abstract":"","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122136568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular technologies have facilitated detection and identification of intestinal lactobacilli and allowed insight into the occurrence, diversity and dynamics of Lactobacillus populations in the human gastrointestinal tract. These techniques showed that the majority of Lactobacillus strains found in human fecal samples are only transiently detectable and therefore likely to be allochthonous, probably originating from food or the oral cavity. Strains of some species, such as Lactobacillus reuteri and Lactobacillus ruminis, have been shown to be true inhabitants (autochthonous) and persist in significant numbers. Very little is known about the molecular traits that enable autochthonous lactobacilli to occupy a niche within the gut ecosystem. The main focus of our research has been to determine the molecular foundations of the ecological success of Lactobacillus reuteri strains that are autochthonous to the rodent gastrointestinal tract. These studies have begun to provide mechanistic explanations of the ecological success of this species as a result of the application of in vivo expression technology (IVET) and the investigation of the ecological performance of isogenic mutants in the murine gastrointestinal tract. Functional and comparative genomic studies with Lactobacillus reuteri have been initiated in order to identify phenotypic and genotypic traits essential for gut colonization and host/microbe coexistence. Research to decipher these ecological interactions is rewarding, as it not only increases fundamental knowledge about the gut ecosystem, but also provides valuable information to select lactobacilli for probiotics.
{"title":"Discovering the molecular foundations of Lactobacillus autochthony in the gastrointestinal tract","authors":"J. Walter","doi":"10.4109/JSLAB.19.9","DOIUrl":"https://doi.org/10.4109/JSLAB.19.9","url":null,"abstract":"Molecular technologies have facilitated detection and identification of intestinal lactobacilli and allowed insight into the occurrence, diversity and dynamics of Lactobacillus populations in the human gastrointestinal tract. These techniques showed that the majority of Lactobacillus strains found in human fecal samples are only transiently detectable and therefore likely to be allochthonous, probably originating from food or the oral cavity. Strains of some species, such as Lactobacillus reuteri and Lactobacillus ruminis, have been shown to be true inhabitants (autochthonous) and persist in significant numbers. Very little is known about the molecular traits that enable autochthonous lactobacilli to occupy a niche within the gut ecosystem. The main focus of our research has been to determine the molecular foundations of the ecological success of Lactobacillus reuteri strains that are autochthonous to the rodent gastrointestinal tract. These studies have begun to provide mechanistic explanations of the ecological success of this species as a result of the application of in vivo expression technology (IVET) and the investigation of the ecological performance of isogenic mutants in the murine gastrointestinal tract. Functional and comparative genomic studies with Lactobacillus reuteri have been initiated in order to identify phenotypic and genotypic traits essential for gut colonization and host/microbe coexistence. Research to decipher these ecological interactions is rewarding, as it not only increases fundamental knowledge about the gut ecosystem, but also provides valuable information to select lactobacilli for probiotics.","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"301 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132931272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many works on the biological functions of dairy lactic acid bacteria (LAB) have contributed to the application of LAB in functional foods and supplements in the global market. More recently, the new term "immunobiotics", has been proposed to identify probiotic bacteria that promote health through activation of intestinal immunity from those with strictly local immunity, and expected for an appropriate evolutionary development. We have studied specific effector molecules and their receptor targets. Recently, we found that immunostimulatory AT oligonucleotide (AT-ODN), but not CpG ODN, from Lactobacillus gasseri JCM 1131 triggered. immune responses via Toll-like receptor 9 (TLR 9), which has been identified as a particular receptor for bacterial DNA containing the specific sequence pattern of unmethylated CpG dinucleotide. Through the discovery of TLR 9, possible molecular mechanisms in immune responses through bacterial DNA have been rapidly revealed in mice. Recently, we found that ATODN from Lactobacillus gasseri, possibly induces immunoactivation in Peyer's patches (Pps) via TLR 9. We demonstrated that TLR 9 is a receptor for not only CpG but also for non-CpG AT ODN as a result of the induction of nuclear factor-k B (NF-k B) activation by gene reporter assay. This review describes our recent study on the immunostimulatory activity of LAB via TLRs, especially TLR 9 and 2 and discuss future trends in the development of "Immunobiotic Foods" through intestinal immunoregulation mediated by "Immunobiotic" LAB
乳酸菌生物学功能方面的大量研究为乳酸菌在全球功能食品和营养补充剂中的应用做出了贡献。最近，人们提出了一个新的术语“免疫益生菌”，用来识别那些通过激活肠道免疫来促进健康的益生菌，这些益生菌来自那些严格具有局部免疫的人，并期望得到适当的进化发展。我们研究了特异的效应分子及其受体靶点。最近，我们发现了免疫刺激AT寡核苷酸(AT-ODN)，而不是CpG ODN，从乳杆菌产气JCM 1131触发。toll样受体9 (tlr9)是细菌DNA的一种特殊受体，含有非甲基化CpG二核苷酸的特定序列模式。通过tlr9的发现，在小鼠中通过细菌DNA进行免疫应答的可能分子机制已被迅速揭示。最近，我们发现产干酪乳杆菌中的ATODN可能通过tlr9诱导psp的免疫激活。我们通过基因报告实验证明，tlr9不仅是CpG的受体，也是非CpG AT ODN的受体，这是由于诱导核因子-k - B (NF-k - B)激活的结果。本文综述了近年来关于乳酸菌通过TLR，特别是TLR 9和TLR 2的免疫刺激活性的研究，并讨论了“免疫生物”乳酸菌介导肠道免疫调节的“免疫生物食品”的未来发展趋势
{"title":"Immunostimulatory Activities of Lactic Acid Bacteria via Toll-like Receptors","authors":"H. Kitazawa, T. Shimosato, M. Tohno, Tadao Saito","doi":"10.4109/JSLAB1997.16.11","DOIUrl":"https://doi.org/10.4109/JSLAB1997.16.11","url":null,"abstract":"Many works on the biological functions of dairy lactic acid bacteria (LAB) have contributed to the application of LAB in functional foods and supplements in the global market. More recently, the new term \"immunobiotics\", has been proposed to identify probiotic bacteria that promote health through activation of intestinal immunity from those with strictly local immunity, and expected for an appropriate evolutionary development. We have studied specific effector molecules and their receptor targets. Recently, we found that immunostimulatory AT oligonucleotide (AT-ODN), but not CpG ODN, from Lactobacillus gasseri JCM 1131 triggered. immune responses via Toll-like receptor 9 (TLR 9), which has been identified as a particular receptor for bacterial DNA containing the specific sequence pattern of unmethylated CpG dinucleotide. Through the discovery of TLR 9, possible molecular mechanisms in immune responses through bacterial DNA have been rapidly revealed in mice. Recently, we found that ATODN from Lactobacillus gasseri, possibly induces immunoactivation in Peyer's patches (Pps) via TLR 9. We demonstrated that TLR 9 is a receptor for not only CpG but also for non-CpG AT ODN as a result of the induction of nuclear factor-k B (NF-k B) activation by gene reporter assay. This review describes our recent study on the immunostimulatory activity of LAB via TLRs, especially TLR 9 and 2 and discuss future trends in the development of \"Immunobiotic Foods\" through intestinal immunoregulation mediated by \"Immunobiotic\" LAB","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"425 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133829813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Co-culture systems of lactic acid bacteria and yeasts for bioproduction are described with two typical examples. A novel control method exploiting microbial interaction in the co-culture system is introduced as the first example. In order to control pH in an antimicrobial peptide (nisin) production process by Lactococcus lactis subsp. lactis (ATCC 11454), microbial interaction between L-lactate production by L. lactis and its assimilation by Kluyveromyces marxianus was utilized. A cascade pH controller coupled with DO control was newly developed and the specific lactate consumption rate of K. marxianus was controlled by changing the dissolved oxygen (DO) concentration. pH and lactate were kept at constant levels and nisin accumulated in medium to high levels, compared with other pH control strategies, such as processes without pH control and with pH control by addition of alkali. The second example is polysaccharide kefiran production by co-culture of Lactobacillus kefiranofaciens and Saccharomyces cerevisiae. Productivity of kefiran was increased in the co-culture system of S. cerevisiae under an aerobic condition. Not only the effect of removal of lactic acid but also the additional effect of S. cerevisiae are discussed through the simulation of the system.
{"title":"Development of Co-Culture Systems of Lactic Acid Bacteria and Yeasts for Bioproduction","authors":"H. Shimizu, B. Cheirsilp, S. Shioya","doi":"10.4109/JSLAB1997.16.2","DOIUrl":"https://doi.org/10.4109/JSLAB1997.16.2","url":null,"abstract":"Co-culture systems of lactic acid bacteria and yeasts for bioproduction are described with two typical examples. A novel control method exploiting microbial interaction in the co-culture system is introduced as the first example. In order to control pH in an antimicrobial peptide (nisin) production process by Lactococcus lactis subsp. lactis (ATCC 11454), microbial interaction between L-lactate production by L. lactis and its assimilation by Kluyveromyces marxianus was utilized. A cascade pH controller coupled with DO control was newly developed and the specific lactate consumption rate of K. marxianus was controlled by changing the dissolved oxygen (DO) concentration. pH and lactate were kept at constant levels and nisin accumulated in medium to high levels, compared with other pH control strategies, such as processes without pH control and with pH control by addition of alkali. The second example is polysaccharide kefiran production by co-culture of Lactobacillus kefiranofaciens and Saccharomyces cerevisiae. Productivity of kefiran was increased in the co-culture system of S. cerevisiae under an aerobic condition. Not only the effect of removal of lactic acid but also the additional effect of S. cerevisiae are discussed through the simulation of the system.","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121345465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New approach to isolation and characterization of uncultured microorganisms","authors":"Y. Kamagata","doi":"10.4109/JSLAB1997.15.62","DOIUrl":"https://doi.org/10.4109/JSLAB1997.15.62","url":null,"abstract":"","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129020854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kimchi is a Korean fermented food that is prepared through a series of processes including pretreatment of Chinese cabbage, salting, blending with various spices and other ingredients, and fermentation. The characteristics of kimchi differ depending on the kimchi variety, raw materials, processing methods, and fermentation conditions. Kimchi fermentation is initiated by the various lactic acid bacteria (LAB) present in the raw materials. Sugars in raw materials are converted to lactic acid, acetic acid, carbon dioxide, and ethanol by hetero and homo fermentative LAB during kimchi fermentation, along with other chemical changes. Many physicochemical and biological factors influence kimchi fermentation. This review covers in some detail the factors affecting kimchi fermentation.
{"title":"Factors Affecting Kimchi Fermentation","authors":"T. Mheen","doi":"10.4109/JSLAB1997.14.56","DOIUrl":"https://doi.org/10.4109/JSLAB1997.14.56","url":null,"abstract":"Kimchi is a Korean fermented food that is prepared through a series of processes including pretreatment of Chinese cabbage, salting, blending with various spices and other ingredients, and fermentation. The characteristics of kimchi differ depending on the kimchi variety, raw materials, processing methods, and fermentation conditions. Kimchi fermentation is initiated by the various lactic acid bacteria (LAB) present in the raw materials. Sugars in raw materials are converted to lactic acid, acetic acid, carbon dioxide, and ethanol by hetero and homo fermentative LAB during kimchi fermentation, along with other chemical changes. Many physicochemical and biological factors influence kimchi fermentation. This review covers in some detail the factors affecting kimchi fermentation.","PeriodicalId":117947,"journal":{"name":"Japanese Journal of Lactic Acid Bacteria","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124015337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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