• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biotechnology Progress >Influence of enzyme loading and physical parameters on the enzymatichydrolysis of steam-pretreated softwood
【24h】

Influence of enzyme loading and physical parameters on the enzymatichydrolysis of steam-pretreated softwood

机译：酶负荷和物理参数对蒸汽预处理软木酶促水解的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Softwood is an interesting raw material for the production of fuel ethanol as a result of its high content of hexoses, and it has attracted attention especially in the Northern hemisphere. However, the enzymatic hydrolysis of softwood is not sufficiently efficient for the complete conversion of cellulose to glucose. Since an improvement in the glucose yield is of great importance for the overall economy of the process, the influence of various parameters on the cellulose conversion of steam-pretreated spruce has been investigated. The addition of beta -glucosidase up to 50 IU g(-1) cellulose to the enzymatic hydrolysis process resulted in increased cellulose conversion at a cellulase loading up to 48 FPU g(-1) cellulose. Despite very high enzyme loading (120 FPU g(-1) cellulose) only about 50% of the cellulose in steam-pretreated spruce was converted to glucose when all of the material following pretreatment was used in the hydrolysis step. The influence of temperature, residence time, and pH were investigated for washed pretreated spruce at a dry matter (DM) content of 5% and a cellulase activity of 18.5 FPU g(-1) cellulose. The optimal temperature was found to be dependent on both residence time and pH, and the maximum degree of cellulose conversion, 69.2%, was obtained at 38 degreesC and pH 4.9 for a residence time of 144 h. However, when the substrate concentration was changed from 5% to 2% DM, the cellulose conversion increased to 79.7%. An increase from 5% to 10% DM resulted, however, in a similar degree of cellulose conversion, despite a significant increase in the glucose concentration from 23 g L-1 to 45 g L-1. The deactivation of beta -glucosidase increased with increasing residence time and was more pronounced with vigorous agitation.
机译：软木由于其高含量的己糖而成为生产燃料乙醇的有趣原料，并且引起了人们的关注，特别是在北半球。然而，软木的酶促水解不足以将纤维素完全转化为葡萄糖。由于提高葡萄糖产量对于整个过程的经济性至关重要，因此，已经研究了各种参数对蒸汽预处理云杉纤维素转化率的影响。在酶水解过程中，添加高达50 IU g（-1）纤维素的β-葡萄糖苷酶会导致在纤维素酶负载高达48 FPU g（-1）纤维素的情况下提高纤维素转化率。尽管酶负荷很高（120 FPU g（-1）纤维素），但将所有预处理后的材料用于水解步骤时，蒸汽预处理的云杉中只有约50％的纤维素转化为葡萄糖。研究了洗涤后的云杉在干燥物质（DM）含量为5％且纤维素酶活性为18.5 FPU g（-1）纤维素时对温度，停留时间和pH的影响。发现最佳温度取决于停留时间和pH，并且在144℃的停留时间下，在38℃和pH 4.9下获得最大纤维素转化率69.2％。但是，当底物浓度从5％DM更改为2％DM时，纤维素转化率增加到79.7％。尽管葡萄糖浓度从23 g L-1显着增加到45 g L-1，但DM的转化率从5％提高到10％导致了相似的纤维素转化率。 β-葡糖苷酶的失活随着停留时间的增加而增加，并且在剧烈搅拌下更加明显。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号