The Screening Of High Flocculating Starch Microbiology From Mung Bean Sour Liquid And Its Characteristics

Mung bean sour liquid was milled into pulp for a period of time,the natural fermentation of microorganisms,the formation of a pale yellow liquid.Because mung bean sour liquid is a product of natural fermentation,greatly influenced by raw materials,environmental factors such as climate change and operation method,the quality of mung bean starch produced great difference.This topic through the natural fermentation of mung bean sour liquid microbial flora for high-throughput sequencing analysis,screening a strain of highly flocculated starch.Optimization of strain culture conditions by single factor experiment and uniform experiment design.Through single factor experiment and uniform experiment design,the culture conditions of the strain was optimized.Through the response surface methodology experiment,the flocculating conditions of the strain was optimized,the best culture conditions and flocculation conditions were determined,foundation for the pure fermentation of mung bean sour liquid and the industrial production of mung bean starch were laid.1.Analysis of the natural fermentation of mung bean sour liquid microflora using metagenomic technology,determine the composition distribution of mung bean sour liquid microbe.At the phylum level,Proteobacteria accounted for the largest proportion,47%,the most abundant phylum,followed by Firmicutes and Actinobacteria.At the genus level,Acinetobacter is the most abundant genus,the proportion of which is 37.4%,followed by the genus Bifidobacterium,Lactobacillus and Aceteroides.2.Screening and identification of highly flocculated starch microorganism in the natural fermentation of mung bean sour liquid.By the method of plate separation,the flocculation rate as the index,screened two different forms of starch with high flocculating activity,LLY11 and LLY14 isolated from natural fermented mung bean sour liquid.According to its strain morphology,colony morphology,physiological and biochemical test results and 16 S rDNA sequence analysis were carried out,the bacillus was identified as Acetobacter indonesiensis and named as Acetobacter indonesiensis LLY11.The cocci LLY14 is identified as Lactococcus lactis and named as Lactococcus lactis LLY14.3.Study on the growth characteristics of high flocculation starch Acetobacter indonesiensis LLY11.The culture conditions of Acetobacter indonesiensis LLY11 were optimized by single factor test and uniform test.The best culture conditions were glucose 1%,lactose 0.05%,yeast extract 0.8%,sodium acetate 0.8%,inoculation amount 9%,pH value 6.8,and temperature 20 degrees,when the cell concentration reached the highest value.In the culture condition of cell growth curve,0~12 h for the delay period;from 12 h began to enter the logarithmic phase,the rapid growth in the number of live bacteria,and bacterial growth appeared two times,respectively,cell number reached the highest value at 24 h and 42 h.The growth of the 30~40 h cell entered the stable period and began to enter the decay period after 42 h.4.Optimization of flocculation conditions of high flocculation starch Acetobacter indonesiensis LLY11.With the flocculation rate as the index,the culture conditions of Acetobacter indonesiensis LLY11 were determined by single factor experiment and response surface methodology.The best culture conditions were inoculation amount 7.5%,age of bacteria 30 h,initial pH6.5,incubation temperature 30 degrees,culture time 36 h,casein 0.5%,glutamic acid 0.5%,and strain generation 7 times.Under this condition,the flocculation rate of LLY11 reached 70.9%.Effect of physicochemical factors on flocculation activity of A.indonesiensis LLY11 fermentation broth:(1)metal ions can inhibit the flocculation activity of A.indonesiensis LLY11 fermentation broth,and the inhibitory effect of CuSO4 is the strongest.(2)Both excessive and low pH will reduce the flocculation activity of the fermentation broth.When pH is 5.5,the flocculation activity of A.indonesiensis LLY11 is the highest.(3)The A.indonesiensis LLY11 fermentation broth is sensitive to temperature,and the flocculation activity is greatly influenced by temperature.At 25 C,the flocculation activity of A.indonesiensis LLY11 fermentation broth is the highest.(4)Lysozyme,trypsin and pepsin treated A.indonesiensis LLY11 fermentation liquid were used.The results show that the flocculating activity of three enzymes of A.indonesiensis LLY11 fermentation bacteria have different degrees of inhibition,the inhibition of trypsin and pepsin,that flocculating active substances may be a glycoprotein substance.