Isolation, identification, and potential probiotic characterization of one Lactococcus from Kefir grain

Probiotic refers to viable microorganisms that promote or support a beneficial balance of the autochthonous microbial population of the gut. In the present study, we isolated and identified one potential probiotic of Lactococcus lactis WH-C1 from Tibetan Kefir grain. We assessed its probiotic and fermentation properties. WH-C1 showed good tolerance in the condition of high bile salt concentration and acidity. Moreover, WH-C1 could remove cholesterol from the culture medium at a percentage of 31.23% during 24 h and it had high capability of exopolysaccharide production. As part of starter culture it gave the better quality yogurt with good mouth feeling and a great viscosity. The solid-phase microextraction-gas chromatography-mass spectrometry analysis showed that fermented milk had 25 kinds of flavor compounds including acids, esters, alcohols, carbonyls, diacetyl, etc. In conclusion, our results showed that WH-C1 is a very promising strain which can be used in various fields.