发酵产丁二酸过程中废弃细胞的循环利用

Recycle of spent cells from anaerobic succinate fermentation

摘要:

对厌氧发酵产丁二酸后的废弃细胞进行破壁处理，考察了以细胞水解液作为有机氮源重新用于丁二酸发酵的可行性。比较了超声破碎、盐溶、酶解3种方法破碎细胞获得的水解液作为氮源发酵产丁二酸的效果，结果表明酶解制得的细胞水解液效果最佳。以总氮含量为1.11 g/L的酶解液 (相当于10 g/L酵母膏) 作为氮源发酵，丁二酸产量可达42.0 g/L，继续增大酶解液用量对耗糖、产酸能力没有显著提高。将细胞酶解液与5 g/L酵母膏联用发酵36 h后，丁二酸产量达75.5 g/L，且丁二酸生产强度为2.10 g/(L·h)，比

Abstract:

Spent cells recovered from anaerobic fermentation by Actinobacillus succinogenes were used as nitrogen source for succinic acid production. Three methods were investigated for cell wall-breaking. The results showed that enzymatic hydrolysis was more effective for higher succinic acid yield. When the enzymatic hydrolysate of spent cells was added to reach a total nitrogen concentration 1.11 g/L (equivalent to 10 g/L yeast extract), the succinic acid concentration was 42.0 g/L, but it increased slightly when enhancing the level of enzymatic hydrolysate. However, when 5 g/L yeast extract was supplemented with the enzymatic hydrolysate of spent cells, the succinic acid concentration reached 75.5 g/L after 36 hours and, the succinic acid productivity was 2.10 g/(L·h), which increased by 66.7% compared with the fermentation using 10 g/L yeast extract. Therefore, enzymatic hydrolysate of spent cells could replace 50% yeast extract in the original medium for succinic acid production.