Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms.

Bioactive peptides are small protein fragments derived from enzymatic hydrolysis of food proteins, fermentation with proteolytic starter cultures, and gastrointestinal digestion. These peptides have positive impacts on a number of physiological functions in living beings. Lunasin, a soy-derived bioactive peptide, is one of the most promising among them. Lunasin encoded within 2S albumin (GM2S-1) gene, identified as a novel peptide extracted from soybean seed. It is composed of 43 amino acid residues with a molecular weight of 5.5 kDa. Extensive scientific studies have shown that lunasin possesses inherent antioxidative, anti-inflammatory, anticancerous properties and could also play a vital role in regulating of cholesterol biosynthesis in the body. Its high bioavailability and heat stable nature allow its potential use as dietary supplement. The present review summarizes some of the potential health and therapeutic benefits of lunasin reported hitherto.

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The study provides a comprehensive view on status of an important antioxidative system (the glutathione system) in LAB and is expected to serve as a primer for future work on mechanistic role of GSH in the group. This article is protected by copyright. All rights reserved.

With growing demands for probioitcs and bifidobacteria being prominent ones, new strains of diversified origin have the potential to be explored for commercial and functional applications and thus can be added to the existing commercially available strains of this genera.

In this work, the production of dextran was carried out in whey-supplemented media using Leuconostoc mesenteroides BA08. Different growth and nutritional parameters were optimised to maximise the dextran production. Batch production in whey-based media under optimised nutritional and growth conditions yielded a dextran concentration of 17.25 g/L. Structural analysis of the purified polymer by FT-IR, 1D 1 H and 13 C nuclear magnetic resonance methodology revealed that polymer was a linear dextran having 93% a-(1?6) linkage in the main chain. The morphology of the dried dextran and dextran-producing cells was also studied by scanning electron microscope which showed a granular and porous or weblike structure, respectively. The results obtained showed that the industrial whey supplemented with nutrients such as sucrose, yeast extract and K 2 HPO 4 can serve as an ideal growth medium for dextran production. The optimised fermentation and nutritional parameters can be further scaled up to establish the potential for the commercial production of food-grade dextran from whey as part of a novel cost-effective and environment-friendly approach.

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