Lactic acid bacteria Holzapfel, Wilhelm H; Wood, Brian J.B
2014., 2014, 2014-04-29
eBook
Lactic Acid Bacteria Biodiversity and Taxonomy Lactic Acid Bacteria Biodiversity and Taxonomy Edited by Wilhelm H. Holzapfel and Brian J.B. Wood The lactic acid bacteria (LAB) are a group of related ...microorganisms that are enormously important in the food and beverage industries. Generally regarded as safe for human consumption (and, in the case of probiotics, positively beneficial to human health), the LAB have been used for centuries, and continue to be used worldwide on an industrial scale, in food fermentation processes, including yoghurt, cheeses, fermented meats and vegetables, where they ferment carbohydrates in the foods, producing lactic acid and creating an environment unsuitable for the survival of food spoilage organisms and pathogens. The shelf life of the product is thereby extended, but of course these foods are also enjoyed around the world for their organoleptic qualities. They are also important to the brewing and winemaking industries, where they are often undesirable intruders but can in specific cases have desirable benefits. The LAB are also used in producing silage and other agricultural animal feeds. Clinically, they can improve the digestive health of young animals, and also have human medical applications. This book provides a much-needed and comprehensive account of the current knowledge of the LAB, covering the taxonomy and relevant biochemistry, physiology and molecular biology of these scientifically and commercially important microorganisms. It is directed to bringing together the current understanding concerning the organisms' remarkable diversity within a seemingly rather constrained compass. The genera now identified as proper members of the LAB are treated in dedicated chapters, and the species properly recognized as members of each genus are listed with detailed descriptions of their principal characteristics. Each genus and species is described using a standardized format, and the relative importance of each species in food, agricultural and medical applications is assessed. In addition, certain other bacterial groups (such as Bifidobacterium) often associated with the LAB are given in-depth coverage. The book will also contribute to a better understanding and appreciation of the role of LA B in the various ecosystems and ecological niches that they occupy. In summary, this volume gathers together information designed to enable the organisms' fullest industrial, nutritional and medical applications. Lactic Acid Bacteria: Biodiversity and Taxonomy is an essential reference for research scientists, biochemists and microbiologists working in the food and fermentation industries and in research institutions. Advanced students of food science and technology will also find it an indispensable guide to the subject. Also available from Wiley Blackwell The Chemistry of Food Jan Velisek ISBN 978-1-118-38384-1 Progress in Food Preservation Edited by Rajeev Bhat, Abd Karim Alias and Gopinadham Paliyath ISBN 978-0-470-65585-6
Traditional fermented foods are a significant source of starter and/or non‐starter lactic acid bacteria (nsLAB). Moreover, these microorganisms are also known for their role as probiotics. The ...potential of nsLAB is huge; however, there are still challenges to be overcome with respect to characterization and application. In the present review, the most important steps that autochthonous lactic acid bacteria isolated from fermented foods need to overcome, to qualify as novel starter cultures, or as probiotics, in food technology and biotechnology, are considered. These different characterization steps include precise identification, detection of health‐promoting properties, and safety evaluation. Each of these features is strain specific and needs to be accurately determined. This review highlights the advantages and disadvantages of nsLAB, isolated from traditional fermented foods, discussing safety aspects and sensory impact.
Lactic acid bacteria (LAB) are capable of converting carbohydrate substrates into organic acids (mainly lactic acid) and producing a wide range of metabolites. Due to their interesting beneficial ...properties, LAB are widely used as starter cultures, as probiotics, and as microbial cell factories. Exploring LAB present in unknown niches may lead to the isolation of unique species or strains with relevant technological properties. Autochthonous rather than allochthonous starter cultures are preferred in the current industry of fermented food products, due to better adaptation and performance of autochthonous strains to the matrix they originate from. In this work, the lactic microbiota of eight different wild tropical types of fruits and four types of flowers were studied. The ability of the isolated strains to produce metabolites of interest to the food industry was evaluated. The presence of 21 species belonging to the genera
, and
was evidenced by using culture-dependent techniques. The isolated LAB corresponded to 95 genotypically differentiated strains by applying rep-PCR and sequencing of the 16S rRNA gene; subsequently, representative strains of the different isolated species were studied for technological properties, such as fast growth rate and acidifying capacity; pectinolytic and cinnamoyl esterase activities, and absence of biogenic amine biosynthesis. Additionally, the strains' capacity to produce ethyl esters as well as mannitol was evaluated. The isolated fruit- and flower-origin LAB displayed functional properties that validate their potential use in the manufacture of fermented fruit-based products setting the background for the design of novel functional foods.
Lactic acid bacteria (LAB) are members of an heterogenous group of bacteria which plays a significant role in a variety of fermentation processes. The general description of the bacteria included in ...the group is gram-positive, non-sporing, non-respiring cocci or rods. An overview of the genetics of lactococci,
, lactobacilli, pediococci, leuconostocs, enterococci and oenococciis presented with special reference to their metabolic traits. The three main pathways in which LAB are involved in the manufacture of fermented foods and the development of their flavour, are (a) glycolysis (fermentation of sugars), (b) lipolysis (degradation of fat) and (c) proteolysis (degradation of proteins). Although the major metabolic action is the production of lactic acid from the fermentation of carbohydrates, that is, the acidification of the food, LAB are involved in the production of many beneficial compounds such as organic acids, polyols, exopolysaccharides and antimicrobial compounds, and thus have a great number of applications in the food industry (i.e. starter cultures). With the advances in the genetics, molecular biology, physiology, and biochemistry and the reveal and publication of the complete genome sequence of a great number of LAB, new insights and applications for these bacteria have appeared and a variety of commercial starter, functional, bio-protective and probiotic cultures with desirable properties have marketed.
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•L. plantarum and F. sanfranciscensis produced sourdough with antifungal activity.•The antifungal activity varied depending on the substrate used and fermentation time.•The pH and ...organic acids fluctuated according to the substrate and fermentation time.•Sourdough from F. sanfranciscensis extended the shelf life of bread for 10 days.•Type III sourdough proved to be a promising biopreservative in bakery products.
The potential biopreservative role of a Type III sourdough (tIII-SD), produced by starter cultures of Fructilactobacillus sanfranciscensis and Lactiplantibacillus plantarum ATCC 8014, was assessed for its antifungal activity in baking applications. Fermentation was carried out using different substrates to enhance the production of antifungal metabolites for 24 and 48 h. The tIII-SD samples were analyzed in relation to pH, total titratable acidity (TTA) and the production of organic acids. The water/salt-soluble extract of the tIII-SD was evaluated in relation to the inhibition potential against key fungi that contaminate bakery products including Penicillium roqueforti, Penicillium chrysogenum and Aspergillus niger. Finally, breads with 10 % of the tIII-SD were prepared and the fungi contamination was evaluated throughout the shelf life period. The lowest pH value in sourdough was obtained from 48-hour fermentation by L. plantarum. The saline extracts exhibited varying degrees of inhibition in the in vitro test; however, the greatest enhancement of this effect was obtained when whole wheat grain flour was used. The tIII-SD crafted from a blend of wheat and flaxseed flours and fermented with F. sanfranciscensis for 48 h (BSWF48h-FS), demonstrated superior performance compared to other formulations. This variant exhibited a total shelf life of 10 days, suggesting that the utilization of tIII-SD could serve as a viable alternative for natural antifungal agents, proving beneficial for the bakery industry.
Novel microbes are either newly isolated genera and species from natural sources or bacterial strains derived from existing bacteria. Novel microbes are gaining increasing attention for the general ...aims to preserve and modify foods and to modulate gut microbiota. The use of novel microbes to improve health outcomes is of particular interest because growing evidence points to the importance of gut microbiota in human health. As well, some recently isolated microorganisms have promise for use as probiotics, although in-depth assessment of their safety is necessary. Recent examples of microorganisms calling for more detailed evaluation include
, fructophilic lactic acid bacteria (FLAB), and
. This paper discusses each candidate's safety evaluation for novel food or novel food ingredient approval according to European Union (EU) regulations. The factors evaluated include their beneficial properties, antibiotic resistance profiling, history of safe use (if available), publication of the genomic sequence, toxicological studies in agreement with novel food regulations, and the qualified presumptions of safety. Sufficient evidences have made possible to support and authorize the use of heat-inactivated
in the European Union. In the case of
, the discussion focuses on earlier safety studies and the strain's suitability. FLAB are also subjected to standard safety assessments, which, along with their proximity to lactic acid bacteria generally considered to be safe, may lead to novel food authorization in the future. Further research with
will increase knowledge about its safety and probiotic properties and may lead to its future use as novel food. Upcoming changes in EUU Regulation 2015/2283 on novel food will facilitate the authorization of future novel products and might increase the presence of novel microbes in the food market.
Background and Aim: In-feed antibiotics have been used as antibiotic growth promoters (AGPs) to enhance the genetic potential of poultry. However, the long-term use of AGPs is known to lead to ...bacterial resistance and antibiotic residues in poultry meat and eggs. To address these concerns, alternatives to AGPs are needed, one of which is probiotics, which can promote the health of livestock without having any negative effects. In vitro probiotic screening was performed to determine the ability of lactic acid bacteria (LAB) isolated from soymilk waste to be used as a probiotic for livestock. Materials and Methods: Four LAB isolates (designated F4, F6, F9, and F11) isolated from soymilk waste were used in this study. In vitro testing was performed on LAB isolates to determine their resistance to temperatures of 42°C, acidic pH, bile salts, hydrophobicity to the intestine, and ability to inhibit pathogenic bacteria. A promising isolate was identified using the 16S rRNA gene. Results: All LAB isolates used in this study have the potential to be used as probiotics. On the basis of the results of in vitro testing, all isolates showed resistance to temperatures of 42°C and low pH (2.5) for 3 h (79.87%–94.44%) and 6 h (76.29%– 83.39%), respectively. The survival rate at a bile salt concentration of 0.3% ranged from 73.24% to 90.39%, whereas the survival rate at a bile salt concentration of 0.5% ranged from 56.28% to 81.96%. All isolates showed the ability to attach and colonize the digestive tract with a hydrophobicity of 87.58%–91.88%. Inhibitory zones of LAB against pathogens ranged from 4.80–15.15 mm against Staphylococcus aureus, 8.85–14.50 mm against Salmonella enteritidis, and 6.75–22.25 mm against Escherichia coli. Although all isolates showed good ability as probiotics, isolate F4 showed the best probiotic ability. This isolate was identified as Lactobacillus casei strain T22 (JQ412731.1) using the 16S rRNA gene. Conclusion: All isolates in this study have the potential to be used as probiotics. However, isolate F4 has the best probiotic properties and is considered to be the most promising novel probiotic for poultry.
Cheeses are inherently microbiologically and biochemically dynamic. Numerous biotic and abiotic drivers govern the establishment and assembly of a core microbiota in cheese, which, for ...internally-ripened cheeses, having an intermediate to long period of ripening, consists of starter and non-starter lactic acid bacteria (SLAB and NSLAB). The management of this dynamic ecosystem has to consider this core as a super-organism, which results from the sums of microbial metabolisms and interactions among individual microbes.
This review focuses on all presumptive drivers, raw and pasteurized milk, farming system and house microbiota, and intrinsic and extrinsic factors during cheese manufacture and ripening, which qualitatively and mainly depending on the farm management system and cheese variety may influence the populations of SLAB and NSLAB. The interactions between these two microbial groups are described also.
The cheese ecosystem shows a variable flux of its core microbiota from milking through manufacture to ripening. Many and diverse drivers establish and assembly the lactic acid bacteria biota. If such drivers are efficient to guarantee microbial and cheese diversities, on the other hand, their control is the fundamental pre-requisite to synchronize and balance microbiological events. The methodological approaches (e.g., omics techniques and integrated system biology) have markedly improved to concretize this ambitious goal. Facing and improving the knowledge on the main drivers, the current step should focus on a unique puzzle of coexisting species/biotypes likely a super-organism, whose guide has to consider all casehardened microbial elements.
•Cheeses are microbiologically and biochemically dynamic.•Biotic and abiotic drivers govern the establishment/assembly of a core microbiota.•The core microbiota consists of starter and non-starter lactic acid bacteria.•The sums of microbial metabolisms and interactions result in a super-organism to be driven.•All presumptive drivers that influence the core microbiota are described.
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