Selection of potential lactic acid bacteria from fermented Sumbawa mare's milk as starter cultures

Aims: The aim of this study was to screen lactic acid bacteria (LAB) isolates from fermented Sumbawa mare's milk that meet the requirements as starter cultures, and to evaluate the effect of the selected starter culture in improving the organoleptic quality of mare's milk fermentation. Methodology and results: The LAB isolates (13 isolates) derived from naturally fermented Sumbawa mare's milk were firstly screened for acidification activity. Afterwards, the selected isolates were evaluated for the starter culture criteria such as technological properties (proteolytic test, lipolytic test, and exopolysaccharide production), food safety test (hemolytic test and antibiotic sensitivity test), antimicrobial activity test. The selected culture (SC) together with yogurt starter cultures (YC) and combination between the selected isolate and a mixture of both (MC) were used to ferment fresh mare's milk. Six LAB isolates (DB7, BC10, DC4, BC9, DC10, and BC7) were obtained from the acidification screening. Isolate BC10 was the most potential isolate as starter culture due to its ability in terms of acidification and proteolytic activity, lack of lipolytic activity, no indication of pathogenic potency, as well as able to inhibit the growth of Escherichia coli ATCC 25922. However, this isolate was resistant to antibiotics kanamycin, trimethoprim, and cinoxacin. The isolate BC10 presented 99.99% sequence similarity with respect to Lactobacillus plantarum. Conclusion, significance and impact of study: The selected starter culture (isolate BC10) was able to improve the organoleptic quality of fermented mare's milk especially aroma compared to the other starter cultures. Therefore, L. plantarum BC10 is a potential isolate to be used as starter culture for mare's milk fermentation.