Extraction And Protein Removal Process Of Pleurotus Ostreatus Polysaccharide And Its Effect On The Growth Of Intestinal Bacteria

Pleurotus ostreatus was one type of basidiomycotina,agaricales,pleurotaceae and one of tte four kinds of edible fungi which was the most cultivation in our country at present time.The nutrition in Pleurotus ostreatus was of great variety and rich content,besides,the pleurotus ostreatus polysaccharide was one of the main components of most current research on Pleurotus ostreatus.A number of research results showed that pleurotus ostreatus polysaccharide had the function of anti-turor,antioxidant,lowering blood sugar,regulating the bodys immune,so the development of pleurotus ostreatus polysaccharide products will have good economic and social benefits,In this study,we selected pleurotus ostreatus polysaccharide as experimental materials and taken four common intestinal bacteria as the object strain to have a preliminary study on extraction and effect of pleurotus ostreatus polysaccharide in the growth of intestinal flora.The main research results were as follows:(1)By analyzing and comparing the process conditions of hot water extraction method,assisted alkaline extraction method and the mixed enzyme assisted extraction method extracting pleurotus ostreatus polysaccharide,we reached a conclusion that the mixed enzyme assisted extraction method had the best extraction effect of pleurotus ostreatus polysaccharide,its best extraction process of the mixed enzyme assisted extraction method extracting pleurotus ostreatus polysaccharide was solid-liquid ratio 1:30,pH 5,enzymolysis time 1.5h,enzymolysis temperature 50?,hot water extraction time 2.5h,enzyme mass fraction 0.5%,enzyme ratio 1:1:1,at this time,the polysaccharide yield was 15.22%.(2)We used Sevage method,hydrochloric acid-ethanol isoelectric point method and TCA method to compare the effect of pleurotus ostreatus polysaccharide dqproteinization,the experimental results showed that:best protein removal rate in pleurotus ostreatus polysaccharide was Sevage method,TCA method next;the best polysaccharide retention rate in pleurotus ostreatus polysaccharide was hydrochloric acid-ethanol isoelectric point method,TCA method next.Considering the influence of two factors comprehensively,TCA method was the best.We used the Box-Behnken test design,and then the optimal solution was obtained by response surface analysis,namely TCA concentration 5.6%,processing time 33min and processing temperature 48?,at this time,the comprehensive evaluation means was 83.96%,the protein removal rate and polysaccharides retention rate was 89.5%and 78.4%,respectively.(3)Through analyzing different concentration of pleurotus ostreatus polysaccharide on growth and acid production of common lactic acid bacteria,the results showed that 0.3 g/L concentration of pleurotus ostreatus polysaccharide had the best growth promoting effect ofLaetobacillus casei and Streptococcus thermophiles,0.2g/L had the best growth promoting effect of Lactobacillusdelbrueckii subsp.Bulgaricus,while 0.2g/L concentration of pleurotus ostreatus polysaccharide had the significant inhibition of Escherichia coli.By using high performance liquid chromatography to analyze and determinate content of 9 kinds of organic acids in fermentation broth adding pleurotus ostreatus polysaccharide,the results showed that pleurotus ostreatus polysaccharide could promote the formation of lactic acid of Lactobacillus casein Lactobacillusdelbrueckii subsp,Bulgaricus and Streptococcus thermophilus and inhibit the formation of 8 kinds of organic acid of Escherichia coli.