采用玉米秸秆水解糖和玉米浆发酵生产丁二酸

Succinic acid fermentative production using corn straw hydrolysate and corn steep liquor

研究了以玉米秸秆水解糖为碳源,不同氮源条件下琥珀酸放线杆菌Actinobacillus succinogenesSF-9的丁二酸发酵产酸能力。结果表明玉米浆可以替代酵母膏作为丁二酸发酵的廉价氮源。厌氧摇瓶丁二酸发酵单因素试验,得到在初糖浓度50 g/L时,玉米浆的较佳用量为20 g/L。在5 L搅拌罐上,考察了不同初始玉米秸秆水解糖浓度对A.succinogenes SF-9发酵生产丁二酸的影响,结果显示高初始秸秆糖浓度对琥珀酸放线杆菌的生长有抑制作用。采用补料分批发酵,发酵60 h丁二酸的产量达到42.7g/L,丁二酸产率82.7%,生产强度0.81 g/(L·h)。丁二酸的产量和生产强度较分批发酵有明显提高。

Using corn straw hydrolysate（CSH） as a carbon source, the effects of various nitrogen sources on succinic acid production by A. succinogenes SF-9 were investigated. Results showed that corn steep liquor（CSL） could instead of yeast extract as a nitrogen source of succinic acid fermentation. The optimum amount of corn steep liquor were 20 g/L when initial sugar concentration of corn straw hydrolysate were 50 g/L in shaking flask using single-factor experiment. The effects of various initial sugar concentration of corn straw hydrolysate on succinic acid fermentation by A. succinogenes SF-9 were compared out in 5 L stirred tank bioreactor. The results indicated that the higher initial sugar concentration of corn straw hydrolysate had an inhibitory effects on cell growth. In fed-batch fermentation, 42.7 g/L succinic acid concentration and 82.7% yield were attained after 60 h incubation in a 5 L stirred tank bioreactor and productivity achieved 0.81 g/ （L·h）. It was improved apparently if compared with that of the batch fermentation.