Study On The Degradation Of The Side-chain Of Phytosterols To Produce AD/ADD

In this study, the side-chain degradation of phytosterol to produce steroid compounds-androst-4-ene-3,17-dione (4-AD) and androsta-l,4-diene-3,17-dione (ADD) by Microbial Mycobacterium SP MB 3683 was investigated. The works include:1. The Morphological Change of Mycobacterium SP MB 3683 in fermentation process and preservation of the strain activity. It was found that morphological changed from long to short and spherical with the consumption of substrate in the culture process. There were some correlation between morphological change and steroid activity: when long bacillus it has high activity, but spherical showed that has not activity.2. Preservation of strain : Because Mycobacterium SP MB 3683 gene was modified, it has specificity and high efficiency, but it was found that Mycobacterium SP MB 3683 can be preserved only 21 weeks under 0～4℃.3. The optimization of technological condition for fermentation: Scale for producing process from shake flask culture to 500 L fermentor. The factors of process was investigated.Seed fermentor condition: when pH is 8.2, it is the just time of inoculation. 10% of inoculation volume.Production fermentor: 10% of inoculation volume. Culture temperature is 31℃, DO beyond 20%. rotate speed 200-300 rpm/min culture time is 80-100 hours, when feed capacity 20% AD content 1.2%,conversion rate was 60%(g/g)and 86%(molar yield ). experiment showed that optimization oil was 16% in 500L scale.