AUTHOR=Zhong Yanan , Guo Zepan , Li Meiqun , Jia Xiaojiang , Zeng Baiquan 

TITLE=Expression of cellobiose dehydrogenase gene in Aspergillus niger C112 and its effect on lignocellulose degrading enzymes

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1330079

DOI=10.3389/fmicb.2024.1330079

ISSN=1664-302X

ABSTRACT=<p>Cellobiose dehydrogenase (CDH) is one of the cellulase auxiliary proteins, which is widely used in the field of biomass degradation. However, how to efficiently and cheaply apply it in industrial production still needs further research. <italic>Aspergillus niger</italic> C112 is a significant producer of cellulase and has a relatively complete lignocellulose degradation system, but its CDH activity was only 3.92 U. To obtain a recombinant strain of <italic>A. niger</italic> C112 with high cellulases activity, the CDH from the readily available white-rot fungus <italic>Grifola frondose</italic> had been heterologously expressed in <italic>A. niger</italic> C112, under the control of the gpdA promoter. After cultivation in the medium with alkali-pretreated poplar fiber as substrate, the enzyme activity of recombinant CDH reached 36.63 U/L. Compared with the original <italic>A. niger</italic> C112, the recombinant <italic>A. niger</italic> transformed with <italic>Grifola frondosa</italic> CDH showed stronger lignocellulase activity, the activities of cellulases, <italic>β</italic>-1, 4-glucosidase and manganese peroxidase increased by 28.57, 35.07 and 121.69%, respectively. The result showed that the expression of the <italic>gcdh</italic> gene in <italic>A. niger</italic> C112 could improve the activity of some lignocellulose degrading enzymes. This work provides a theoretical basis for the further application of <italic>gcdh</italic> gene in improving biomass conversion efficiency.</p>