Some Technological Properties of Lactic Acid Bacteria Isolated from Dahi and Datshi, Naturally Fermented Milk Products of Bhutan.

Dahi and datshi are common naturally fermented milk (NFM) products of Bhutan. Population of lactic acid bacteria (LAB) in dahi (pH 3.7) and datshi (pH 5.2) was 1.4 × 107 and 3.9 × 108 cfu/ml, respectively. Based on 16S rRNA gene sequencing isolates of LAB from dahi and datshi were identified as Enterococcus faecalis, E. faecium, Lactococcus lactis subsp. lactis. LAB strains were tested for some technological properties. All LAB strains except E. faecalis CH2:17 caused coagulation of milk at both 30°C for 48 h. Only E. faecium DH4:05 strain was resistant to pH 3. No significant difference (P > 0.05) of viable counts was observed in MRS broth with and without lysozyme. All LAB strains grew well in 0.3% bile showing their ability to tolerate bile salt. None of the LAB strains showed >70% hydrophobicity. This study, being the first of its microbiological analysis of the NFM of Bhutan, has opened up to an extent of research work that gives a new insight to the products.

Poly-γ-Glutamic Acid (PGA)-Producing Bacillus Species Isolated from Kinema, Indian Fermented Soybean Food.

Kinema, an ethnic fermented, non-salted and sticky soybean food is consumed in the eastern part of India. The stickiness is one of the best qualities of good kinema preferred by consumers, which is due to the production of poly-γ-glutamic acid (PGA). Average load of Bacillus in kinema was 10(7) cfu/g and of lactic acid bacteria was 10(3) cfu/g. Bacillus spp. were screened for PGA-production and isolates of lactic acid bacteria were also tested for degradation of PGA. Only Bacillus produced PGA, none of lactic acid bacteria produced PGA. PGA-producing Bacillus spp. were identified by phenotypic characterization and also by 16S rRNA gene sequencing as Bacillus subtilis, B. licheniformis and B. sonorensis.

Functional Properties of Microorganisms in Fermented Foods.

Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

Review: Diversity of Microorganisms in Global Fermented Foods and Beverages.

Culturalable and non-culturable microorganisms naturally ferment majority of global fermented foods and beverages. Traditional food fermentation represents an extremely valuable cultural heritage in most regions, and harbors a huge genetic potential of valuable but hitherto undiscovered strains. Holistic approaches for identification and complete profiling of both culturalable and non-culturable microorganisms in global fermented foods are of interest to food microbiologists. The application of culture-independent technique has thrown new light on the diversity of a number of hitherto unknown and non-cultural microorganisms in naturally fermented foods. Functional bacterial groups ("phylotypes") may be reflected by their mRNA expression in a particular substrate and not by mere DNA-level detection. An attempt has been made to review the microbiology of some fermented foods and alcoholic beverages of the world.

Phenotypic and genotypic identification of lactic acid bacteria isolated from ethnic fermented bamboo tender shoots of North East India.

Mesu, soidon, soibum and soijim are ethnic fermented bamboo tender shoot products prepared by the people in North East India. Microbiological analysis of mesu, soidon, soibum and soijim showed the population dominated by lactic acid bacteria (LAB) ranging up to 10(8) cfu g(-1). The phenotypic characterisation of predominant LAB isolated from the fermented bamboo shoot products was based on general morphology, physiological tests, API and Biolog systems. The genotypic characterisation of LAB was based on RAPD-PCR, rep PCR, species-specific PCR techniques, 16S rRNA gene sequencing and DNA-DNA hybridisation. Predominant functional LAB strains associated with the fermented bamboo shoot products were identified as Lactobacillus brevis, Lb. plantarum, Lb. curvatus, Pediococcus pentosaceus, Leuconostoc mesenteroides subsp. mesenteroides, Leuc. fallax, Leuc. lactis, Leuc. citreum and Enterococcus durans.

Identification of predominant lactic acid bacteria isolated from traditionally fermented vegetable products of the Eastern Himalayas.

Gundruk, sinki and khalpi are lactic-fermented vegetable products of Sikkim in India, and inziangsang is a fermented leafy vegetable product of Nagaland and Manipur in India. A total of 65 samples of gundruk (25), sinki (12), khalpi (25) and inziangsang (3) were analysed for microbial counts. The population of lactic acid bacteria (LAB) as well as aerobic mesophilic counts were at the level of 10(7) cfu g(-1). Yeasts were detected only in few samples of sinki and khalpi. No moulds were detected. In order to identify the predominating organisms, a total of 269 strains of LAB were isolated from gundruk, sinki, khalpi and inziangsang samples. The phenotypic characteristics of these strains were determined followed by genotyping using RAPD-PCR, repetitive element PCR and species-specific PCR techniques. The major representatives of the LAB involved in these fermentations were identified as Lactobacillus brevis, Lactobacillus plantarum, Pediococcus pentosaceus, Pediococcus acidilactici and Leuconostoc fallax.

Identification of yeast strains isolated from marcha in Sikkim, a microbial starter for amylolytic fermentation.

Marcha or murcha is a traditional amylolytic starter used to produce sweet-sour alcoholic drinks, commonly called jaanr in the Himalayan regions of India, Nepal, Bhutan, and Tibet (China). The aim of this study was to examine the microflora of marcha collected from Sikkim in India, focusing on yeast flora and their roles. Twenty yeast strains were isolated from six samples of marcha and identified by genetic and phenotypic methods. They were first classified into four groups (Group I, II, III, and IV) based on physiological features using an API test. Phylogenetic, morphological, and physiological characterization identified the isolates as Saccharomyces bayanus (Group I); Candida glabrata (Group II); Pichia anomala (Group III); and Saccharomycopsis fibuligera, Saccharomycopsis capsularis, and Pichia burtonii (Group IV). Among them, the Group I, II, and III strains produced ethanol. The isolates of Group IV had high amylolytic activity. Because all marcha samples tested contained both starch degraders and ethanol producers, it was hypothesized that all four groups of yeast (Group I, II, III, and IV) contribute to starch-based alcohol fermentation.