Lactic Acid Bacteria and Bifidobacteria: Current Progress in Advanced Research | BookPublisher: Caister Academic Press
Editor: Kenji Sonomoto and Atsushi Yokota Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan and Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Hokkaido, Japan
Pages: x + 286
Publication date: July 2011Buy book
Price: GB £159 or US $319
Lactic acid bacteria (LAB) and bifidobacteria are amongst the most important groups of microorganisms used in the food industry. For example, LAB are used in the production of fermented products, such as yoghurts, cheese and pickled vegetables. In addition LAB can inhibit the growth of spoilage microbes and/or pathogens in their environment by lowering the pH and/or through the production of antimicrobial peptides, called bacteriocins. Both LAB and bifidobacteria are also thought to have health-promoting abilities and many are used as probiotics for the prevention, alleviation and treatment of intestinal disorders in humans and animals.
In this comprehensive book, expert international authors review the most recent cutting-edge research in these areas. Topics include: Lactobacillus genomics; Bifidobacterium gene manipulation technologies; metabolism of human milk oligosaccharides in bifidobacteria; proton-motive metabolic cycles; oxidative stress and oxygen metabolism; Bifidobacterium response to O2; bile acid stress in LAB and bifidobacteria; protein structure quality control; bacteriocin classification and diversity; lactococcal bacteriocins; lactobacilli bacteriocins; other bacteriocins; production of optically pure lactic acid; antihypertensive metabolites from LAB; the anti-H. pylori effect of Lactobacillus gasseri; probiotics for allergic rhinitis; probiotics health claims in Japan and Europe. Essential reading for every researcher working with LAB, bifidobacteria and probiotics, from the PhD student to the experienced scientist.
"In this comprehensive book, expert international authors review the most recent cutting-edge research" from Food Sci. Technol. Abstr. (2011) 43(8)
"the individual contributions ... are predominantly of high scientific quality and timeliness ... chapters are highly readable, informative and well suited as a starting point for further literature searches." from Knut J. Heller (Kiel) writing in Biospektrum (2011) 17: 596-597.
"a snapshot of the current basic science" from Ref. Res. Book News (August 2011)
"This interesting book is dominated by Japanese and French contributors, but maintains an excellent standard in English usage, with the occasional unusual phrasing somehow adding to its readability ... there are interesting contributions on metabolism ... A chapter on the regulatory framework for health claims concerning probiotic supplements in Japan and Europe is very timely ... other topics in this compact and excellent book are equally worth studying" from Brian Wood (Glasgow, UK) writing in Microbiol. Today (2011) 38: 265
"the chapters are generally organized and written very clearly ... this is a well-organized book on a topic of interest to an evergrowing group of researchers worldwide. It will be of interest to both industry and academic researchers in this field and of particular interest to graduate students." from Dan O'Sullivan (University of Minnesota, USA) writing in ASM Microbe
Current Status of Bifidobacterium Gene Manipulation Technologies
Satoru Fukiya , Tohru Suzuki, Yasunobu Kano and Atsushi Yokota
Bifidobacteria are one of the beneficial intestinal bacteria that exert health-promoting effects in humans. As evidence for their beneficial effects has accumulated, the scientific and commercial importance of bifidobacteria is increasing. In contrast, the mechanisms of the beneficial effects of these bacteria have not been well-clarified primarily because the development of gene manipulation methodology in bifidobacteria is far behind that in other probiotic bacteria, such as lactobacilli. However, the recent accumulation of genomic sequence information has opened the way for the gene function analysis in this bacterium. This chapter will describe the current knowledge of bifidobacterial genetic materials, such as cryptic plasmids and transposable elements. Additionally, the current status and future perspectives on the development of gene manipulation tools in bifidobacteria will be discussed.
Metabolic Pathway of Human Milk Oligosaccharides in Bifidobacteria
Motomitsu Kitaoka , Takane Katayama, and Kenji Yamamoto
It has long been considered that human milk oligosaccharides (HMOs) are the growth-promoting factors for bifidobacteria, which makes bifidobacteria the predominant intestinal microbiota in breast-fed infants. However, the mechanism responsible for the selective growth of bifidobacteria has not yet been identified because of the difficulty caused by the complicated content of HMOs, which includes more than 100 kinds of molecules. The lacto-N-biose I (LNB) hypothesis made it possible to investigate the bifidobacterial metabolism of HMOs systematically. As predicted by the LNB hypothesis, several extracellular enzymes that liberate LNB from HMOs have been identified from Bifidobacterium bifidum JCM1254. The intracellular metabolic pathway of bifidobacteria specific to galacto-N-biose and LNB, led by β-1,3-galactosyl-N-acetylhexosamine phosphorylase, has been fully characterized. Meanwhile, a practical method to produce LNB on a large scale has been established. The long-standing enigma of the bifidus factor present in human milk might be clarified in the near future.
Energy Generation Coupled with Decarboxylation Reactions in Lactic Acid Bacteria
Kei Nanatani and Keietsu Abe
In bacteria, many biological reactions are sustained by metabolic energy present in the form of phosphoester bonds, in compounds such as ATP and phosphoenolpyruvate (PEP), or in the form of ion gradients, such as the proton motive force (PMF) and the sodium motive force. The two forms of metabolic energy can be interconverted by FoF1-ATPases, which catalyze the translocation of H+ (or Na+) concomitant with either the hydrolysis or synthesis of ATP. Nutrient transport in bacteria is usually thought to consume metabolic energy; however, over the last two decades, a new class of nutrient transport reactions has been identified, in which substrate transport generates rather than consumes energy. The reaction consists of two steps: (1) electrogenic exchange of a precursor (amino acid or other organic acid) with its intracellular metabolic product produced by decarboxylation, and (2) intracellular decarboxylation of the transported precursor. The precursor:product exchange causes a net charge movement, which generates a membrane potential of physiological polarity, and the intracellular decarboxylation consumes cytoplasmic protons to generate both a pH gradient of physiological polarity and an outward concentration gradient of the end-product, which drives precursor uptake. The combined activities constitute a metabolically-driven proton pump (proton-motive metabolic cycle), which provides sufficient energy to generate ATP in a process called "decarboxylative phosphorylation". Thus, the proton-motive metabolic cycle can be recognized as a new class of ATP generation system that is distinct from substrate-level phosphorylation, oxidative phosphorylation, and photo-phosphorylation. We consider that the proton-motive metabolic cycle could be made available as an artificial energy-supply system in various industrial fermentation organisms with the use of recombinant DNA technology in the future.
Oxidative Stress and Oxygen Metabolism in Lactic Acid Bacteria
Yuji Yamamoto, Philippe Gaudu and Alexandra Gruss
Lactic acid bacteria (LAB) are used industrially for their fermentation properties, and as such, have been generally regarded as anaerobic bacteria that contain neither a respiratory chain nor a catalase. However, most LAB can grow under aerobic conditions and consume molecular oxygen by unique flavoprotein oxidases. Some lactic acid bacteria, such as Enterococcus faecalis and Lactococcus lactis, construct a functional respiratory chain when a source of heme, an essential cofactor of cytochrome oxidases, is provided. Others, such as Lactobacillus plantarum and Streptococcus agalactiae, undergo respiration metabolism when both heme and a quinone are provided. These unique characteristics of LAB have been studied by biochemical approaches and more recently by molecular and genetic approaches. In this chapter, we present an overview of the unique features of oxygen metabolism and mechanisms of oxygen tolerance in LAB.
Response of Bifidobacterium species to oxygen
Members of the genus Bifidobacterium are classified as anaerobes that are known to be beneficial to human health. This group is expected to prove highly valuable for use in milk products, health promotion, and treatment of intestinal disorders. However, their sensitivity to O2 limits probiotic activity to solely anaerobic habitats. Recent research has reported that the Bifidobacterium strains exhibit various types of oxic growth. Low concentrations of O2 and CO2 can have a stimulatory effect on the growth of Bifidobacterium strains. Based on the growth profiles under different O2 concentrations, the Bifidobacterium species were classified into four classes; O2-hypersensitive, O2-sensitive, O2-tolerant, and microaerophilic. The primary factor responsible for aerobic growth inhibition is proposed to be the production of H2O2 in the growth medium. A H2O2-forming NADH oxidase was purified from O2-sensitive Bifidobacterium bifidum and was identified as a b-type dihydroorotate dehydrogenase. The kinetic parameters suggested that the enzyme could be involved in H2O2 production in highly aerated environments.
Bile Acid Stress in Lactic Acid Bacteria and Bifidobacteria
Abelardo Margolles and Atsushi Yokota
Bile is mainly composed of bile acids, detergent-like biological substances synthesized from cholesterol in the liver. They are involved in the generation of bile flow, and their major physiological function is to facilitate the absorption of lipophilic compounds from the diet, including vitamins and lipids. Furthermore, bile also plays a crucial role in the establishment of the intestinal microbiota in humans, since bile salts are potent antimicrobial agents and only microbial populations able to cope with physiological concentrations of bile are able to survive in the gut. Bile disturbs the cell membrane functionality in lactic acid bacteria (LAB) and bifidobacteria due to its amphipatic property. Studies on the bile stress response in LAB and bifidobacteria revealed that bile resistance is a result of integration of multi-lateral responses, which include those that protect cell membrane from direct attack by bile acids, those that restore or degrade damaged proteins, those that eliminate oxidative stress and facilitate DNA repair, and those that enhance energy generation through up-regulated sugar metabolism. This chapter summarizes the current knowledge of the molecular mechanisms used by LAB and bifidobacteria to tolerate the deleterious action of bile salts.
Quality Control of Protein Structure in Lactic Acid Bacteria
Shinya Sugimoto and Kenji Sonomoto
In order to maintain cell viability, it is essential to maintain protein homeostasis under normal conditions and during injury or stress. A network of highly conserved molecular chaperones and proteases controls the quality of cellular proteins by repairing and degrading abnormal proteins. The recently completed genome sequencing, combined with the development of advanced molecular techniques, has enabled us to identify these protein quality control systems in various lactic acid bacteria (LAB). Furthermore, mutational and biochemical studies are providing new insights into the physiological significance of protein quality control systems in LAB.
Classification and Diversity of Bacteriocin
Takeshi Zendo and Kenji Sonomoto
Many strains of lactic acid bacteria produce antimicrobial peptides, bacteriocins, which are expected to be used as safe antimicrobial agents as well as food preservatives. Since nisin A was recognized in 1928, diverse bacteriocins have been identified from various species of lactic acid bacteria. Based on their structures and characteristics, bacteriocins were classified mainly into two classes, class I (lantibiotics) and class II, and new classification schemes are being proposed according to their expanding diversity. Class I bacteriocins represented by nisin A contain posttranslationally modified amino acids such as lanthionine. Class II bacteriocins are further divided into some subclasses such as class IIa (pediocin-like bacteriocins) and class IIb (two-peptide bacteriocins).
Fuminori Yoneyama, Takeshi Zendo, and Kenji Sonomoto
Lactococcus is one of the most important genera of lactic acid bacteria (LAB), because of the widespread use in dairy fermentation foods. Since nisin produced by Lactococcus lactis was discovered in 1928 (Rogers and Whittier, 1928), many bacteriocin-producing Lactococcus strains have been reported and studied so far (Cotter et al., 2005a). Here, recent studies on lactococcal bacteriocins, mainly nisin, are summarized in their diversities and structures, biosynthesis, antimicrobial mechanisms, and applications.
Yasushi Kawai and Tadao Saito
Bacteriocins produced by lactobacilli from the lactic acid bacteria (LAB) group have been reported since about 1990 in the same time period when similar bacteriocins were reported in other bacterial species. Almost all of the bacteriocins from lactobacilli belong to class II bacteriocins except for a class III helveticin J produced by Lactobacillus helveticus 481 (37kDa, 333 amino acid residues, using an unknown antibacterial mechanism; Joerger and Klaenhammer, 1990). Interestingly, there have been few reports of class I lantibiotics from lactobacilli. In this chapter, the chemical structure, genetics, mode of action, immunity, and topics concerning lactobacilli bacteriocins are described from the recent decade. Other lactobacilli bacteriocins are referred to from many published papers and reviews.
Takeshi Zendo, Kenji Sonomoto, Yasushi Kawai and Tadao Saito
Many lactococcial and lactobacilli strains produce various available bacteriocins such as nisin, the representative bacteriocin in lactic acid bacteria (LAB), lacticin 3147, and plantaricins as mentioned in Chapter 10 and 11. Recently, pediocin PA-1/AcH (class IIa, well studied) from some Pediococcus strains and enterocin AS-48 (the first class IIc) from Enterococcus faecalis have been most likely candidates to be used for bio-preservatives as the second bacteriocin next to nisin. In this chapter, the research advances of both bacteriocins for the antibacterial spectra, mode of action, and food application in addition to the chemical structures and genes for biosynthesis and immunity, are described.
Bacteriocins: Remarks and Future Studies
Yasushi Kawai and Tadao Saito
Bacteriocins have been reported in a large number of bacteria and are used by these organisms in the struggle for survival and bacterial communication. The bacteriocins produced by lactic acid bacteria (LAB) have potential applications to prevent the growth of harmful bacteria in humans. And the bacteriocin-producing LAB strains isolated from foods and human origins are expected to be effective probiotic candidates. In this chapter, the facts, topics and problems to overcome for LAB bacteriocins and the producing strains: heterologous expression studies, nisin resistant strains and the appearance of resistant strains, applications for foods as bio-preservatives and bovine mastitis as a clinical cure, positively effects in human hosts and their microbiota, are described and discussed.
Production of Optically Pure Lactic Acid for Bioplastics
Amira M. Hamdan and Kenji Sonomoto
Lactic acid has long been used for the fermentation and preservation of foodstuffs for human consumption. Lactic acid has 2 optical isomers: L(+)-lactic acid and D(-)-lactic acid. Lactic acid is classified as GRAS (generally recognized as safe) for use as a food additive by the US FDA (Food and Drug Administration), but D(-)-lactic acid is known to be harmful to human metabolism at times, and it can result in acidosis and decalcification. The optical purity of lactic acid is crucial to the physical properties of poly(lactic acid) (PLA), and an optically pure L(+)- or D(-)-lactic acid, rather than racemic DL-lactic acid, can be polymerized to a highly crystalline PLA that is suitable for commercial uses as a bioplastic. Therefore, the biotechnological production of lactic acid has received a significant amount of interest recently, since it offers a solution to the environmental pollution caused by the petrochemical industry and an alternative to petrochemical resources, which are limited.
Antihypertensive Metabolites From Lactic Acid Bacteria
Many studies have suggested milk fermented with lactic acid bacteria has beneficial effects on the health status of animals and humans. This paper reviews the potential of antihypertensive peptides in milk fermented with lactic acid bacteria. Most of the antihypertensive effects of these peptides can be explained by their inhibition of angiotensin converting enzyme. Well characterized antihypertensive peptides released by Lactobacillus helveticus fermented milk are mainly reviewed in this chapter. Studies on Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), released in L. helveticus fermented milk, and their use in animal and clinical studies are discussed in more detail. In addition, processing of VPP and IPP by proteolytic enzymes of L. helveticus is discussed. A long peptide containing VPP and IPP sequences generated from β-casein by an extracellular proteinase was thought to be processed intracellularly by the following enzymes: an endopeptidase was expected for C-terminal processing, and an aminopeptidase and X-prolyl dipeptidyl aminopeptidase for N-terminal processing. Genome analyses of these proteolytic enzymes in L. helveticus enabled comparisons to corresponding genome sequences reported in other lactic acid bacteria; from this, it was suggested that the proteolytic system to process VPP and IPP is specific to L. helveticus. The regulatory system observed in the production of VPP and IPP during L. helveticus fermentation is also discussed.
Lactobacillus gasseri OLL2716 (LG21): Anti-Helicobacter pylori Lactic Acid Bacterium
Lactobacillus gasseri OLL2716 (LG21) was isolated from the feces of a healthy human. LG21 was selected as a probiotic against H. pylori infection by screening more than 200 Latobacillus strains by in vitro assays and animal studies. In clinical studies, the ingestion of yogurt containing LG21 decreased the number of H. pylori and IL-8 concentration in the gastric mucosa, and alleviated the mucosal inflammation in humans infected with H. pylori. LG21 was shown to be effective as a probiotic against H. pylori infection.
Effects and Mechanisms of Probiotics on the Prevention and Treatment of Allergic Rhinitis
Toshitaka Odamaki, Noriyuki Iwabuchi and Jin-zhong Xiao
Studies on probiotic bacteria in the treatment or prevention of allergic rhinitis have shown encouraging results such as improved symptoms, reduced use of relief medication and modulated immunological parameters. Bacterial cells were shown to be sampled by intestinal immunocompetent cells and hence exerted diverse immunomodulatory effects on the hosts. Clinical studies using Bifidobacterium longum BB536 to prevent or treat allergic reactions to Japanese cedar pollen demonstrated possible involvement of gut microbiota in sensitization to allergens and development of symptoms, and the potential of probiotics in stabilizing the microbiota. Based on these studies, we suggest two possible mechanisms for the antiallergic activity of probiotics: 1) immunomodulatory effects via bacterial cell components mediated by intestinal antigen-presenting cells (biogenic effects); 2) immunomodulatory effects via generating or stabilizing a balanced gut microbiota (probiotic effects). These studies suggest that probiotics may serve as an alternative treatment for allergic rhinitis, although further studies are needed to determine this conclusively.
Probiotics Health Claims in Japan and Europe
Yoichi Fukushima and Eva Hurt
Scientific evidence of health benefit of food is accumulating and health claims on food are highlighted. Food for Specified Health Use (FOSHU) was established in Japan in 1991 as the first systematic regulatory system for food health claims, and 799 FOSHU products are approved as of November 2008. Probiotics are food components scientifically well-documented, which may deliver health benefits including gut microbiota balancing, normalizing regularity, gut comfort, immune boosting, anti-infection, anti-diarrhea, anti-allergy, and skin benefits. In FOSHU, 73 products with 13 probiotic strains and/or combination of strains were approved under the "modify gastrointestinal (GI) conditions" claim category, whose criteria for scientific substantiation is clearly defined in Japan. In the European Union, a new Nutrition and Health Claims Regulation harmonises since 2007 the requirements on claims on food products, and the regulation will be fully applicable in 2010. Currently in 2009, the European Food Safety Authority (EFSA) is evaluating several thousand diet-health relationships, which will lead to a Community list of permitted claims. The 27 EU member governments have submitted the claims, including, in total, 268 proposed diet-health relationships involving probiotics. This chapter will review the health claim systems in Japan and in the European Union based on the current status in April 2009.
(EAN: 9781904455820 Subjects: [bacteriology] [microbiology] [molecular microbiology] [genomics] [probiotics] )
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