Prevalence of Candida Species in ‘Thairu’ a Traditional Fermented Milk of Kerala, India

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.