Evaluation of lactic acid bacterial strains of boza for their exopolysaccharide and enzyme production as a potential adjunct culture

In Vitro Assessment of Probiotic and Technological Properties of Lactic Acid Bacteria Isolated from Indigenously Fermented Cereal-Based Food Products

The present study concerns the isolation and characterization of potential probiotic bacteria isolated from indigenously fermented cereal-based products commonly produced by tribal people of the Aravali hills region of India and the documentation of their unexplored probiotic attributes. The isolated strains were evaluated for probiotic attributes, such as bile salt and acid tolerance, lysozyme and phenol tolerance, antagonistic and antifungal activity, cell autoaggregation, cell-surface hydrophobicity, simulated gastric and pancreatic digestion, antioxidative potential, bile salt hydrolase activity, and H2O2 production. The safety of isolates was assessed by antibiotic sensitivity, hemolytic activity, DNase activity, and biogenic amine production assays, while technological properties, such as fermenting ability, amylolytic activity, and EPS production, were also evaluated. A total of 70 LAB isolates were screened initially, and 6 strains showed good potential as probiotic candidates in in vitro assessments. The efficient strains were identified using phenotyping and biochemical characterization, which results were further confirmed and recognized at the strain level using phylogenetic analysis and 16S rDNA sequencing. The current study has shown that Lactiplantibacillus plantarum KMUDR7 isolated from “Makka ki Raab” has excellent probiotic attributes and could be a potential probiotic for product preparation. However, other strains, Lactobacillus delbrueckii subsp. bulgaricus KMUDR1 and Lacticaseibacillus rhamnosus KMUDR9, showed good properties, while KMUDR14, -17, and -20 also have comparable probiotic attributes.

Review on Non-Dairy Probiotics and Their Use in Non-Dairy Based Products

Consumer demands for foods promoting health while preventing diseases have led to development of functional foods that contain probiotic bacteria. Fermented dairy products are good substrates for probiotic delivery, but the large number of lactose intolerant people, their high fat and cholesterol content and also due to the growing vegetarianism the consumers are seeking for alternatives. Therefore, researches have been widely studied the feasibility of probiotic bacteria in non-dairy products such as fruits, vegetables, and cereals. This review describes the application of probiotic cultures in non-dairy food products.

Techno-Functional Role of Exopolysaccharides in Cereal-Based, Yogurt-Like Beverages

This review describes the technical and functional role of exopolysaccharides (EPSs) in cereal-based, yogurt-like beverages. Many microorganisms produce EPSs as a strategy for growing, adhering to solid surfaces, and surviving under adverse conditions. In several food and beverages, EPSs play technical and functional roles. Therefore, EPSs can be isolated, purified, and added to the product, or appropriate bacteria can be employed as starter cultures to produce the EPSs in situ within the matrix. The exploitation of in situ production of EPSs is of particular interest to manufacturers of cereal-base beverages aiming to mimic dairy products. In this review, traditional and innovative or experimental cereal-based beverages, and in particular, yogurt-like beverages are described with a particular focus in lactic acid bacteria (LAB’s) EPS production. The aim of this review is to present an overview of the current knowledge of exopolysaccharides produced by lactic acid bacteria, and their presence in cereal-based, yogurt-like beverages.

Isolation and characterization of an exopolysaccharide-producing Leuconostoc citreum strain from artisanal cheese

High molar mass exopolysaccharides (EPS) produced from sucrose by lactic acid bacteria (LAB) are of great interest as natural additives to use in foods, medical and pharmaceutical industry. This study aimed to identify the EPS produced by Leuconostoc citreum L3C1E7 isolated from Pico cheese and characterize the strain for technological and probiotic potential. Purified EPS was isolated from the culture of L. citreum L3C1E7 by ethanol precipitation, with a yield of 520 mg ml^-1 . The EPS-producing strain had a mucoid phenotype and average molecular weight of 5·88 × 10⁶  Da. The structural characterization of the purified EPS was determined by ¹ H, ¹³ C and two-dimensional NMR spectroscopy. EPS was composed of alternating α-(1→6)-linked and α-(1→3)-linked D-glucopyranyl units, suggesting the existence of an alternan. The strain was slow acidifying, produced diacetyl and displayed high esterase/lipase and aminopeptidase activities, which promote the desirable flavours in dairy products. Moreover, L. citreum showed moderate resistance to the adverse conditions of the gastrointestinal (GI) tract and high adhesion to GI cells. This work provides a better understanding of EPS produced by L. citreum and the potential application of EPS-producing strain in food and/or as a probiotic culture. SIGNIFICANCE AND IMPACT OF THE STUDY: Some LAB strains are known to use extracellular glycoside-hydrolase enzymes for synthesizing a diversity of exopolysaccharides (EPS) with potential application as natural additives to foods. Previous studies have identified an EPS-producing Leuconostoc citreum strain with immunomodulatory properties. This work provides a better understanding of EPS produced by this strain and the potential application of the strain in food fermentation and/or as a probiotic culture.

Production, characterization and antibacterial activity of exopolysaccharide from a newly isolated Weissella cibaria under sucrose effect

Weissella cibaria 27 (W27) is a new lactic acid bacterium which has been screened from kimchi, and is important in diary fermentation. This is first-attempt to understand the effects of sucrose and achieve the highest exopolysaccharide (EPS) productivity from W27. The metabolic compounds of lactic acid, acetic acid and ethanol are at similar levels when the cultures with glucose or lactose; except for EPS is significantly increased up to 24.8 g/L with 60 g/L of sucrose. Scanning electron microscopy (SEM) results reveal cell length changing shorter after sucrose addition. By Taguchi's approach, an L9 orthogonal array was adopted to evaluate the effects of culture were ranked according to the EPS production as temperature > time > initial pH, in which optimal conditions were at 22°C and pH 6.2 for 24 h. The major composition of EPS is dextran of α-1,6 glycosidic linkage with molecular weight of 1.2 x 10⁷ Da by nuclear magnetic resonance (NMR) and high-performance size-exclusion chromatography (HPSEC) analysis. The surface property of W27 induced by sucrose is become more hydrophobic to better inhibit bacteria. The simple cultural approach for this new dextran producing strain, W27, has potential in the food, feed, antibacterial agent, and cosmetic industry.