The Optimization Of Liquid Fermentation Conditions Of Morchella

The factors affecting the biomass and yield of extracellular polysaccharides of Morchella in the mode of liquid culture were optimized, and the following formula of 9.5% malt juice+40 mg/L corn flour+20 mg/L soybean flour+3 mg/L yeast powder was proven to be the optimal basal media for Morchella, and further the culture conditions were optimized as 24±1℃,140 rpm, pH 6.0 and inoculum of 10%.Under the above optimal conditions, the growth curve of Morchella was determined, and 0～48 h was of lagging period and 48-120 was of logarithmic phase. In addition, the maximum of biomass and yield of extralcellular polysaccharides were achieved at 114 h of culture with 14.11 g·L-1 and 268.9 mg·L-1, respectively.Through BIOL-5L and BIOL-50L biological fermentation tank to feed batch fermentation and fermentation, the results show that the tank after fermentation, the fermentation time reduced to 72 h, with a table of fermentation growth curve had obvious changes,0-16 hours under the experimental conditions for demurrage,16-56 hours for logarithmic phase,56 h junior period 64-72 h began to decline phase. When bacteria enter the decline phase began to decrease after bacteria, bacteria appeared autolysis phenomenon, should be put in plateau tank. Fermentation fermented liquid pH fell to 3.03, lowest in the process of fermentation, the best appropriate increase in the pH in the future. From the perspective of the result of filling material batch fermentation, ventilation 0.2-0.3 L/(L. min), stirring speed of 200-400 r/min, control of dissolved oxygen in 40%-10% for the liquid fermentation conditions of submerged fermentation more appropriate. From the perspective of the result of filling material batch fermentation, the fermentation time is extended, by batch fermentation of 72 h to 88 h of filling material fermentation, the bacteria demurrage basically the same, and the growth period, growth period of supplementary food fermentation significantly longer than batch fermentation, the stability of the plateau has been extended. From the perspective of the biological yield the overall growth rate of bacteria is also obvious growth., in turn, into the jar of BIOL-50L fermentation tank, after 50L batch fermentation fermentation bacteria biomass from BIOL-5L fermentation tank, fermentation period changed little, and stability is slightly lower, shows that the increase of tanks allow bacteria to better growth, but increased the consumption of sugar after bacteria growth makes stability of bacteria. From the perspective of the result of filling material batch fermentation, the increase of the tanks and filling material makes bacteria fermentation biomass growth to the rapid growth of the largest biomass reached 28.4 g/L, and to guarantee the stability of the bacteria also.Morchella liquid submerged fermentation conditions of experimental data the results provide a reference for industrialized production of morchella further data.