Evaluation of Cholesterol Degradation by an Indigenously Isolated Lactobacillus Casei With Probiotic Properties

Abstract

A strain of Lactobacillus casei isolated previously from indigenously fermented food was characterized for its ability to reduce cholesterol. The strain could remove as much as 75% cholesterol under in vitro conditions when grown in MRS media; cholesterol could be used as a carbon source but growth was extremely poor. The culture parameters viz. pH, temperature and agitation and reduction kinetics were optimized for maximal cholesterol reduction. L.casei exhibited optimum activity at temperature 26ºC and a pH value 6.0 when incubated for 72 hours at 120 rpm. The percentage reduction of cholesterol by supernatant, L. Casei exoploysaccharide and extracellular enzyme was approximately 40%, 30% and 70% respectively. Investigations into the mechanism of cholesterol revealed that cholesterol bound partially to cellular exopolysaccharides and were catalyzed by an extracellularly produced enzyme.