十七碳二羧酸的发酵研究

STUDIES ON MICROBIAL PRODUCTION OF PENT ADECANE 1,15-DICARBOXYLIC ACID(DC17)FROM HEPTADECANE(nC17)

以热带假丝酵母(candida tropicalis)UP-3-24为出发菌株,经亚硝酸多次诱变,获得一株从正十七烷(nC_(17))生产十七碳二羧酸(DC_(17))的优良生产菌株 NP-260。以20%(V/V)的nC_(17)为碳源,摇瓶发酵4天,DC_(17),达80g/L以上。在16L 自动控制罐上,不另加其它生长碳源,加入总量30%(V/V)nC_(17)进行发酵试验,产酸高峰期,每升发酵液每小时能够产生1.8g 的 DC_(17)。其中产酸速率为每小时0.18%,24小时每升发酵液可增加40g 以上的 DC_(17)。发酵6天,DC_(17)高达133g/L 以上,回收残烃后,对 nC_(17)的转化率为61.8%,后处理收率为77.6%,DC_(17)的纯度为95.4%。

Mutagensis of Candida tropicallis UP-(?)-24 with sodium nitrite and selection a mutant NP-260 which yield of DC_(17) was 20% higher than parent strain UP-3-24 was obtained. On shaking flask,under optimum con- dition where the culture medium contained 20%(v/v)nC_(17),0.05%(v/v) acryli acid,inor- ganic salts and growth factors and pH was adjusted to 7.5 with 6 mol/L NaOH at 24h intervals,the amount of the product accumu- lated was more than 80g per litre of the me- dium for 4 days. On 16 litre fermenter testing,under the optimum condition where the culture contained total 30%(v/v) nC_(17),no add other carbon source for the growth,pH of the course of fermentation was maintained 7.5—7.7,at 28— 30℃,the highest level of DC_(17) production was obtained after 6 days and the amount of DC_(17) accumulated was more than 133g per li(?)re of the mudium.On optimum period of DC_(17) production,rate of DC_(17) production,and accumulated was 1.81g per litre medium per hour.After received residual nC_(17),the con- sumption rate of nC_(17),was about 61.8%.The product from nC_(17) was analysed by gas- chromatograph,the purity was 95.4%. The mutant strain NP-260 was still strong and healthy without recovery after subculture for years on malt extract-agar slant,the pro- duction of DC_(17) was also as high as usual.