摘要
利用环境扫描电镜观察了纸浆纤维素在同步糖化发酵(Simultaneoussaccharificationandfermentation,SSF)产酒精过程中的降解,并与单一酶解过程进行比较。在单一酶解过程中,由于纤维素酶解产物的积累,形成了对纤维素酶的反馈抑制,纸浆纤维素降解较慢。在SSF过程中,纤维素的酶解产物由于被酵母及时转化为酒精,没有形成对纤维素酶的反馈抑制,纸浆纤维的降解较快,而且过程中纤维素含量和酒精含量的变化测定结果与电镜观察结果一致,表明SSF能有效提高纤维素的酶解效率。在SSF后期,半纤维素的主要酶解产物戊糖由于不能被酵母利用而大量积累,有可能对半纤维素酶形成了反馈抑制,造成了半纤维素的降解困难。
Cellulose degradation was observed in process of simultaneous saccharification and fermentation (SSF) of wheat pulp by environmental scanning electron microscopy (ESEM) and was compared to that in single enzymatic hydrolysis process. Cellulose degraded slowly in single enzymatic hydrolysis process due to the inhibition of cellulase by accumulated enzymatic hydrolysates while it degraded fast in SSF process because the hydrolysates were immediately consumed by yeast and did not exert inhibition on cellulase. Cellulose and ethanol were assayed in SSF process in agreement with ESEM observation. SSF significantly improved enzymatic hydrolysis efficiency of cellulose. Hydrolysates of hemicellulose could not be used by yeast and accumulated in later phase of SSF, and then they had inhibition on hemicellulose degradation.
出处
《电子显微学报》
CAS
CSCD
北大核心
2003年第5期385-389,共5页
Journal of Chinese Electron Microscopy Society
基金
国家863高科技研究发展计划项目(No.2001AA514023).
