Household dahi sample with good organoleptic properties from Wayanad district of Kerala was screened for lactic acid bacteria. Gram positive cocci exhibiting potential to ferment lactose was further characterised biochemically and later identified by 16srRNA sequencing as Enterococcus faecalis. The isolate was evaluated for its physiological and probiotic properties like temperature tolerance, salt tolerance and proteolytic activity. Probiotic properties like acid tolerance, bile tolerance, adhesion potential and antimicrobial activity against clinical isolate of E. coli were evaluated. Virulence based on haemolysis in blood agar was also done. The isolate was able to survive both 4o C and 45o C as well as salt concentration of 2 to 8 per cent. This remarkably proteolytic isolate was able to survive at pH 2 and 3 for 3 h and could tolerate bile concentration of 0.3 per cent for 3 h and 0.6 per cent for 1 h. Cell surface hydrophobicity was found to be 19.6 per cent and auto aggregation 80.39 per cent. The isolate could inhibit the growth of pathogenic E.coli by producing a zone of clearance of 19mm. Antibiogram revealed resistance to Ceftriaxone, Cefotaxime, Cefazolin and Vancomycin. The isolate produced alpha haemolysis in blood agar. Study revealed that detail biochemical and molecular level characterization is required for assessing probiotic potential of lactic acid bacteria from naturally fermented products.

Aims: To determine the prevalence of Candida species in ‘thairu’, a traditional fermented milk prepared in the households of Kerala. Study Design: ‘Thairu’ samples collected randomly from the households in Wayanad, Kozhikode, Malappuram, Palakkad and Kannur districts of Kerala. This was followed by enumeration and identification of yeast using API 20CAUX Kit. Determination of pH and acidity of samples. Place and Duration of Study: Department of Dairy Microbiology, College of Dairy Science and Technology, Pookode, Wayanad, Kerala. September 2021- December 2021. Methodology: A total of 30 household ‘thairu’ samples were collected from households of Wayanad, Kozhikode, Malappuram, Palakkad and Kannur districts of Kerala in sterile bottles. The samples were serially diluted in normal saline and pour plated on to Yeast Extract Glucose Chloramphenicol Agar for isolation and enumeration. The pH was measured using pH meter by directly inserting the probe into the homogenized sample. Titratable acidity in per cent lactic acid was measured using N/10 NaOH. The isolates were identified based on the sugar fermentation pattern using API 20C AUX kit (Biomerieux, France). Results: The yeast count in the samples ranged from 5.0 to 6.7 log CFU/g with an average of 5.89±0.38 log CFU/g. Average acidity and pH of the samples were 1.92±0.34 % LA and 3.59±0.60 respectively. A total of 23 yeast isolates were identified based on morphology and carbohydrate fermentation pattern using API 20C AUX kit (Biomerieux, France). Exactly 86.95 per cent of isolates belong to Candida species. Conclusion: Observations of the study revealed the high prevalence of Candida species in traditional fermented milk ‘thairu’. Predominant Candida species were lactose fermenters, but the presence of a few species with spoilage and pathogenicity potential were also detected. The safety assessment of Candida species is essential before applying them as starter cultures for food fermentations.