Study On Utilization Technology Of Elaeagnus Angustifolia Fruit Biological Fermentation

In this paper,with the goal of high-value utilization of Elaeagnus angustifolia fruit(EAF)the co-fermentation performance of glucose and fructose by microorganisms was studied with ethanol,Saccharomyces cerevisiae and Bacillus subtilis as products,so as to provide theoretical basis and technical support for the development and utilization of EAF.Based on the composition of EAF,the effects of different fermentation methods on ethanol yield were studied.At the same time,the best fermentation process of S.cerevisiae and B.subtilis was determined by single factor experiment and response surface model.The main findings of this paper are as follows:(1)Ethanol fermentation kinetics.The cofermentation of EAF was carried out by using batch fermentation,fed-batch fermentation and liquid fermentation to study the kinetics of ethanol fermentation.The results showed that the fermentation was limited by the high solid content,the addition of pectinase could effectively improve the yield of ethanol,and the fermentation of EAF extract could obtain high concentration of ethanol and save steam.(2)Fermentation and proliferation technology of S.cerevisiae.Using EAF instead of grain crops as the raw material of S.cerevisiae fermentation,using Design Expert software,based on Box-Behnken to carry out experimental design,the optimized design model of producing S.cerevisiae from EAF extract was established,and the main influencing factors on the cell yield were analyzed.The optimal culture conditions for high yield of S.cerevisiae were determined as follows: the yield of S.cerevisiae was 0.658 g/g at 30℃,p H 3.91,rotation speed 241 rpm and sugar concentration 15 g/L.The order of intensity affecting the yield of S.cerevisiae was as follows: sugar concentration > speed > p H.Under the optimal condition,fermentation of 10g/L sugar at C/N 1:1 could yield 9.81 g/L S.cerevisiae cells.(3)Optimization of culture technology of Bacillus subtilis.Based on the composition analysis of EAF,with the extract rich in glucose and fructose as the raw material,Box-Behnken experimental design method was used to analyze the main factors affecting the yield of B.subtilis based on single factor analysis.The effect of p H on the cell yield is extremely significant.Under the optimum conditions,21.1 g/L B.subtilis cells could be obtained with 40g/L sugar.