Isolation and Identification of Cholesterol Lowering Probiotic Bacteria from Palm Wine (Raffia mambillensis)

摘要

The purpose of this study was to isolate and identify potential lactic acid bacteria from palm raffia wine and to evaluate in vivo the effect of isolated probiotic bacteria on serum lipids and some enzymes activities in wistar albino rats. Lactic acid bacteria were isolated on MRS agar using pour plate method. The catalase negative and Gram positive isolates were selected as presumptive lactic acid bacteria. They were also assessed for invitro cholesterol assimilation from culture media, acid tolerance and bile salt tolerance. Selected isolates were biochemically characterized using the API 50 CHL BioMerieux kit. In-vivo cholesterol lowing effect was studied on hyperlipidemic induced wistar rats randomly assigned into three groups. The experiment was carried out for four weeks by oral gavages; dose level 10~(8)-10~(10) CFU/ ml. The administered volume of each dose was 1.0 ml/kg body weight/ day, after the feeding trial, the rats were dissected and blood for serum collected for lipid profile (triglyceride, total cholesterol, LDL-c, VLDL-c and HDL-c), transaminases (ALT and AST) analysis using kits. 35 colonies from palm were studied and 22 were Gram positive. Catalase negative text allowed the selection 10 of them which were studied for their acid and bile tolerance; Data from acid and bile tolerance assays showed that seven isolates were able to maintain viability at pH 2 and to grow in a medium with 0.4% of bile salts. After in vitro assessment for their cholesterol-lowering action 3 isolates were finally selected and identified using the API 50 CHL as two L. plantarum and one L. pentosus. These strains gave rise to a signi?cant reduction (P < 0.05) of the cholesterol level in MRS broth. In particular, L . pentosus strain lowered the cholesterol content by an average of 76.43%, compared to L. plantarum strains which lowered cholesterol content by an average of 51.25% for the isolate 2R30 and 55.22% for 2R36 repectively. The results showed no adverse effect on rats organs according to the enzyme activities and no sign of toxicity also. The probiotic strains (Lactobacillus pentosus) selected effectively demonstrated their effect on reduction of the levels of total cholesterol, LDL and VLDL in the rats blood serum. Data from acid and bile tolerance, in-vitro cholesterol reduction and in-vivo lipidemia assays showed that the dairy isolate L. pentosus can therefore be regarded as new probiotic for and could be used for functional food production.