Gao Liwei, He Xin, Guo Yingjie, Wu Zehua, Zhao Jian, Liu Guodong, Qu Yinbo
State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.
Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 11 Keyuanjingsi Road, 266101 Qingdao, China.
J Agric Food Chem. 2021 Mar 3;69(8):2539-2548. doi: 10.1021/acs.jafc.0c07659. Epub 2021 Feb 23.
Enzymatic conversion of corn fiber to fermentable sugars is beneficial to improving the economic efficiency of corn processing. In this work, the filamentous fungus was found to secrete enzymes for efficient saccharification of un-pretreated corn fiber. Separate engineering of transcriptional activators ClrB, XlnR, and AraR led to enhanced production of different sets of lignocellulolytic enzymes. Particularly, the enzymes produced by XlnR- and AraR-engineered strains showed a synergistic effect in corn fiber saccharification. Combinatorial engineering of all three activators generated a strain MCAX with 3.1- to 51.0-fold increases in lignocellulolytic enzyme production compared with the parent strain. In addition, the enzymes of strain MCAX released significantly more fermentable sugars from corn fiber than those of the parent strain at the same protein dosage. The results suggest that this strain has potential for on-site production of enzymes for corn fiber saccharification.
将玉米纤维酶解转化为可发酵糖有利于提高玉米加工的经济效益。在这项工作中，发现丝状真菌能分泌酶，用于高效糖化未预处理的玉米纤维。对转录激活因子ClrB、XlnR和AraR进行单独改造，可提高不同组木质纤维素酶的产量。特别是，经XlnR和AraR改造的菌株所产生的酶在玉米纤维糖化过程中表现出协同效应。对所有三种激活因子进行组合改造，得到了菌株MCAX，与亲本菌株相比，其木质纤维素酶产量提高了3.1至51.0倍。此外，在相同蛋白质用量下，菌株MCAX的酶从玉米纤维中释放出的可发酵糖比亲本菌株显著更多。结果表明，该菌株具有现场生产用于玉米纤维糖化的酶的潜力。
