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Metarhizium anisopliae (Metarhizium anisopliae) steroidal substrates 16α , C11-α of 17α- Epoxyprogesterone (16α, 17α-epoxy-4-pregnene-3 ,20-dione) hydroxylation process , step conversion process , factors such as the content of the dilution process and mycelium cabbage . Investigated step conversion process of the medium composition, the feeding time , the dissolved material and other factors , to determine a shake flask reaction process : 28 ℃ cultured 36 ~ 38h seed inoculation amount of 10% of the inoculated two culture 22-24h (pH down to 3.6 or so) invested 20g / L concentration of substrate (0.03 % Tween- dispersed ) , the transition temperature of 30 ° C , the shaker into 72h conversion rate of up to 70% . process 10L mechanical stirred fermentor dissolved oxygen effect is not The fermentation broth viscous , conversion rate than the the shaker level dropped by nearly 20 percentage points . In order to improve the nature of dissolved oxygen, and fermentation broth dilution process . Systematic study of the dilution ratio of the dilution process , dispersing agents and defoamers , pH , metal ions, feeding mode , and other factors , on the transformed determine viable dilution process routes : a 36 to 38h of incubation at 28 ℃ seeds to the inoculation amount of 10% of the inoculated two medium, culture broth was diluted about 20 ~ 22h doubled . The total input of 1 /4 of the substrate pre-induced Add 0.4g / L MnSO4 promoting the conversion , the temperature was adjusted to 30 ° C , and inputs the remaining 3/4 of the substrate after 3H . Medium ratio of Tween-80 and 0.5 ‰ glycerol polyether same step conversion process , add the dissolved material substrate quite fermentation liquid volume of 0.5 ‰ . The process in 10L , 20L tank dissolved oxygen improvement 45h conversion rate close to 60% , conversion of the substrate concentration of 20g / L conditions , can be further enlarged and promotion . Determine the the mycelium knot ball is likely to cause a number of factors conducive to the stability of the process . Comprising: a nitrogen source and the growth factor is insufficient, the small amount of inoculation , the changes , the spores of the bacteria mass dispersion , low temperature, and pH adjustment .
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