Characterization of lactic acid bacteria from camel milk and their technological properties to use as a starter culture

Abstract

Proper selection and balance for starter culture is critical for the manufacture of fermented products of desirable texture and flavor. The objective of this study was to characterize lactic acid bacteria (LAB) from camel milk and elucidate their properties to use as a starter culture. Twenty-one lactic acid bacteria species were isolated from 30 samples of camel milk collected from Babile Woreda, eastern Ethiopia. Isolates were characterized phenotypically and their technological properties such as acidification, exopolysaccharide production (EPS), proteolytic and antimicrobial activities were studied following standard procedures. The results revealed that the isolated LAB strains belonged to Lactobacillus, Lactococcus, Streptococcus and Enterococcus genera. All lactic acid bacteria strains showed proteolytic activity with different degrees of clear zones. The lactic acid bacteria strains exhibited either high to low acidification activities. About 85% of the lactic acid bacterial strains had significant exopolysaccharide production (EPS). Three LAB strains showed maximum antagonistic properties against indicator organisms (Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa). It could be concluded that Lactobacillus plantarum HUM19, Lactobacillus acidophilus HUM20, and Streptococcus cremoris HUM8 had high acidifying, antimicrobial and proteolytic activities, and EPS production among all other lactic acid bacteria isolates.

Keywords: Acidifying activity; Antimicrobial activity; Exopolysaccharide production; Fermentation; Proteolytic activity; Technological properties