Fermentation And Metabolic Characteristics Of Lactobacillus Rhamnosus Grx10 With Hypolipidemic Property

Lactobacillus rhamnosus grx10(Lactobacillus rhamnosus grx10)is isolated from camel milk.It is a safe lactic acid bacteria with good pathogenic bacteria resistance,acid resistance and bile salt resistance.Clinical studies have proved that when a certain dose of Lactobacillus rhamnosus grx10 is administered,it can improve serum triglyceride(TG),cholesterol(TC)and low-density lipoprotein(LDL)levels in patients with dyslipidemia.This article first optimizes the growth performance and fermentation performance of LRgrx10,and then analyzes the components of its fermentation products.The conclusion is as follows:LRgrx10 has good growth performance in lactose and glucose as carbon source medium.When in glucose medium,inoculation amount was 6×10~7cfu/m L and culture temperature was 37?,and LRgrx10 had the best growth state.The maximum biomass can reach 3×10~9cfu/m L,the maximum biomass can be maintained for more than 50 h.LRgrx10 sterilized milk with an inoculum of 10~8cfu/g was fermented at 37?for 13 hours after which the end acidity of the fermentation was70°T and the number of viable cells was 5×10~9cfu/g.The texture and sensory characteristics of the fermented milk were acceptable,however the fermented product had a fermented rancid smell and insufficient milk flavor.When compounded with Streptococcus thermophilus and Lactobacillus bulgaricus(2:1:1),the texture and sensory quality of fermented milk significantly improved and was close to those of ordinary fermented milk.The fermentation time was reduced from 12 h to 7 h,and the number of viable bacteria was maintained at 5×10~9cfu/g to meet the actual factory production requirements.The determination of the nitrogen distribution of the fermentation product showed that LRgrx10 has a higher degree of protein hydrolysis than Streptococcus thermophilus and Lactobacillus bulgaricus,and releases more peptides and free amino acids.In addition,the protease secreted by LRgrx10 does not have the ability to degrade whey protein,but its degradatione of casein is higher than that of Streptococcus thermophilus and Lactobacillus bulgaricus.The number of recognizable proteins in the four groups was 702.Based on GO analysis,there are 8 highly expressed differential proteins in fermented milk,including forkhead box protein and apolipoprotein,which have a significant impact on the lipid metabolism process(p<0.05).Enrichment through the KEGG metabolic pathway revealed that the five functional proteins in fermented milk are related to the PPAR lipid metabolism pathway.Therefore,LRgrx10 fermented milk regulates the lipid metabolism in the organism through the PPAR pathway.A total of824 peptides were detected in the four groups,including 66 bioactive peptides with ACE,cholesterol absorption,and DPP-IV inhibition,antibacterial,immunomodulation,and anti-cancer.LRgrx10-Y had the highest amount of bioactive peptides(19.42%).The hypolipidemic function of LRgrx10 may be due to the hypolipidemic peptides VLPVPQ and VAPFPE produced by its fermentation.1223 compounds were detected in the four groups,and it was found that the cholesterol-lowering and antibacterial effects of LRgrx10 may come from six lipid-regulating metabolites such as betaine,choline,and genistein,as well as cycloserine,benzothiazole,etc.Three compounds with antibacterial function.In addition,L-?-glyceryl phosphorylcholine,creatine and glutathione which were specifically and highly expressed in LRgrx10-Y also with anti-aging functions.