The effect of steam pretreatment on lactic acid production from lespedeza stalks by SSF
The lespedeza stalks with steam pretreatment were fermented to lactic acid by simultaneous saccharification and fermentation (SSF) in this study. Orthogonal design methodology was used to evaluate the optimum SSF conditions that give maximum lactic acid yield. Temperature, loading of cellulase, calcium carbonate and concentration of substrate were the factors investigated. The optimum operating conditions were found to be temperature of 43 ℃, cellulase loading 30 FPU/g, calcium carbonate 3 ％ and substrate of 6 ％. The effects of different steam pretreated conditions on lactic acid yield from lespedeza stalks were compared. The results showed that lactic acid yield from lespedeza stalks with 4 min pretreatment at 1.0, 1.25, 1.5 and 2.0 Mpa were 41.8 ％, 42.5 ％, 50.6 ％ and 64.0 ％ of theoretical yield, respectively. The lactic acid yield from steam pretreated lespedeza stalks was significantly higher than that of lespedeza stalks without pretreatment (23.9 ％). It could be concluded that the lactic acid yield was remarkably improved by steam pretreatment. The productivity of lactic acid from steam pretreated lespedeza stalks was 1.68 times higher than that of untreated lespedeza stalks. Moreover, the lactic acid yield could be further promoted from 64.0 ％ to 89.4 ％ by water processing, which suggested that water processing is a promising method to remove inhibitors in broth to improve lactic acid yield.
lactic acid lespedeza stalks steam pretreatment simultaneous saccharification and fermentation
Qi Xiang Tang Yong Jian Hong-lei Li Xue Jiang Jian-xin
Department of Chemistry and Chemical Engineering, Beijing Forestry University, Beijing 100083, China
国际会议
南京
英文
59-67
2010-10-22（万方平台首次上网日期，不代表论文的发表时间）