Exopolysaccharide-producing lactic acid bacteria strains from traditional thai fermented foods: isolation, identification and exopolysaccharide characterization (original) (raw)
Related papers
Foods
Exopolysaccharides (EPSs) produced by lactic acid bacteria present a particular interest for the food industry since they can be incorporated in foods via in situ production by selected starter cultures or applied as natural additives to improve the quality of various food products. In the present study, 43 strains were isolated from different plant-based fermented foods and identified by molecular methods. The species found were distinctively specific according to the food source. Only six Lactiplantibacillus plantarum strains, all isolated from sauerkraut, showed the ability to produce exopolysaccharide (EPS). The utilization of glucose, fructose and sucrose was explored with regard to EPS and biomass accumulation by the tested strains. Sucrose was clearly the best carbon source for EPS production by most of the strains, yielding up to 211.53 mg/L by strain Lactiplantibacillus plantarum ZE2, while biomass accumulation reached the highest levels in the glucose-based culture medium....
European Food Research and Technology, 2008
A novel strain of lactic acid bacteria Pediococcus pentosaceus P 773 was isolated from spoiled beer and identified by means of 16S rDNA sequence analysis. The ability to assimilate lactose as a sole carbon source as a specific feature for this strain was detected and confirmed on dairy substrates. In the presence of sucrose containing substrates (sucrose, raffinose) this P. pentosaceus P 773 lactose-positive strain produced a complex of extracellular polysaccharides (Qp = 0.08 g/l/h) with a molecular mass about 2,000 kDa composed by glucose and fructose residues at a ratio 3:1, respectively. These exopolysaccharides were capable to stimulate the growth rate and biomass productivity of common constituent cultures of probiotic dairy starters (Bifidobacterium lactis, Lactobacillus acidophilus, Streptococcus thermophilus) as well as were assimilated as a sole carbon source by these strains. The present study confirmed the presence of lactose-positive and exopolysaccharide-producing strain of P. pentosaceus in natural environment which could be used as a starter culture to impart more functional attributes to fermented food.
Exopolysaccharide Production by Selected Lactic Acid Bacteria Isolated from Fermented Vegetables
Scientific Bulletin. Series F. Biotechnologies, 2014
Lactic acid bacteria (LAB) play a key role in the food fermentation process since they contribute to the texture, flavor, quality and conservation of the fermented products. Several LAB strains have been shown to produce exopolysaccharides (EPS), with potential applications in food industry, since they can act as natural thickeners that improve the texture of the final product, decrease syneresis and reduce the fat levels in fermented foods. In situ production of EPS by LAB to get a desired texture and mouthfeel of some fermented products is being explored, in order to replace polysaccharides from plants or animals, currently in use. Moreover, it has been suggested that some EPS produced by LAB have prebiotic activity, contributing to the promotion of human gastrointestinal health. During this study, five new EPS-producing LAB strains have been selected from 21 strains isolated from fermented vegetables. The mucoidness/ropiness of the colonies developed on MRS agar media containing ...
Journal of dairy science, 2005
The ability to produce exopolysaccharides (EPS) is widespread among lactic acid bacteria (LAB), although the physiological role of these molecules has not been clearly established yet. Some EPS confer on LAB a "ropy" character that can be detected in cultures that form long strands when extended with an inoculation loop. When EPS are produced in situ during milk fermentation they can act as natural biothickeners, giving the product a suitable consistency, improving viscosity, and reducing syneresis. In addition, some of these EPS may have beneficial effects on human health. The increasing demand by consumers of novel dairy products requires a better understanding of the effect of EPS on existing products and, at the same time, the search for new EPS-producing strains with desirable properties. The use of genetically modified organisms capable of producing high levels of EPS or newly designed biopolymers is still very limited. Therefore, exploration of the biodiversity of wild LAB strains from natural ecological environments is currently the most suitable approach to search for the desired EPS-phenotype. The screening of ropy strains and the isolation and characterization of EPS responsible for this characteristic have led to the application over the past years of a wide variety of techniques. This review summarizes the available information on methods and procedures used for research on this topic. The information provided deals with methods for screening of EPS-producing LAB, detection of the ropy phenotype, and the physicochemical and structural characterization of these molecules, including parameters related to their viscosifying properties. To our knowledge, this is the first compilation of methods available for the study of EPS produced by LAB. (
Your article is protected by copyright and all rights are held exclusively by The National Academy of Sciences, India. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Exopolysaccharides Production by Lactic Acid Bacteria
Applied Microbiology: open access, 2016
Exopolysaccharides (EPSs) are high molecular weight and biodegradable polymers. They are biosynthesized by a wide range of bacteria. Lactic acid bacteria (LAB) are also able to produce EPSs. EPSs can be classified into two groups. These are homopolysaccharides and heteropolysaccharides. Homopolysaccharides are polymers which are composed of one type of monosaccharide. Heteropolysaccharides are polymers of repeating units. They are composed of two or more types of monosaccharides. Producer microorganisms don't use the bacterial EPSs as energy sources. EPSs have been used in the production of several fermented foods such as thickeners, stabilizers, emulsifiers and gelling or water-binding agents. In addition, EPSs have some positive effects on health. These are to have antitumor effects, immune-stimulatory activity and to lower blood cholesterol. Incubation temperature and time, growth medium, acidity of growth medium and type of strain have an impact on EPSs production. In this review, EPSs production by LAB, including chemical composition, structure, biosynthesis, genetics and application of EPSs produced by LAB is discussed.
Turkish Journal of Agriculture: Food Science and Technology, 2023
Lactic acid bacteria are the substantial source for producing polysaccharides used in technological applications as thickeners and viscosifiers in the food industry. A broad variety of lactic acid bacteria species secrete structurally diverse exopolysaccharides that contribute to their surface attachment, protection against abiotic or biotic stress factors and nutrient uptake. The exopolysaccharides are produced naturally during fermentation process by living lactic acid bacteria cells and accepted as postbiotic for these metabolites having various physiological health-promoting effects. Exopolysaccharide producer lactic acid bacteria encode a great number of enzymes and regulatory proteins involved exopolysaccharide biosynthesis process. This process is a complex and occurs through presence of multiple genes. However, it is crucial the understanding of structure, composition, function, chemical, and physical properties of exopolysaccharides which vary from one type of bacteria to another via chemical analysis methods. In this review, the use of lactic acid bacteria exopolysaccharides, their structures, genetic modules and biosynthesis, and the use of exopolysaccharides derived from lactic acid bacteria in the food industry are described, discussed and focused on recent developments.
International Journal of Food Microbiology, 2007
A total of 174 lactic acid bacteria (LAB) strains isolated from dairy and cereal products were screened for the production of exopolysaccharides (EPS). Therefore, a rapid screening method was developed based on ultrafiltration and gel permeation chromatography. Furthermore, a screening through the polymerase chain reaction (PCR) was performed with primer pairs targeting different genes involved in EPS production. Nine isolates produced a homopolysaccharide of the glucan type, whereas only one strain produced a heteropolysaccharide. The production of a glucan by a strain of Lactococcus lactis and the production of a heteropolysaccharide by a strain of Lactobacillus curvatus are reported for the first time. The PCR screening revealed many positive strains. For three of the ten EPS-producing strains, no corresponding genes could be detected. Furthermore, a lot of strains possessed one or more eps genes but did not produce an EPS. Therefore, a screening on the molecular level should always be accompanied by another screening method that is able to distinguish true EPS producer strains from non-producing ones. Statistical analysis did not reveal any relationship between the type and origin of the strains, the presence or absence of a capsular polysaccharide or EPS, and the presence or absence of eps genes.
Nutrients
Lactic acid bacteria (LAB) are capable of synthesising metabolites known as exopolysaccharides (EPS) during fermentation. Traditionally, EPS plays an important role in fermented dairy products through their gelling and thickening properties, but they can also be beneficial to human health. This bioactivity has gained attention in applications for functional foods, which leads them to have prebiotic, immunomodulatory, antioxidant, anti-tumour, cholesterol-lowering and anti-obesity activity. Understanding the parameters and conditions is crucial to optimising the EPS yields from LAB for applications in the food industry. This review provides an overview of the functional food market together with the biosynthesis of EPS. Factors influencing the production of EPS as well as methods for isolation, characterisation and quantification are reviewed. Finally, the health benefits associated with EPS are discussed.