Potent Fungal Chitinase for the Bioconversion of Mycelial Waste.
Liu, T., Han, H., Wang, D., Guo, X., Zhou, Y., Fukamizo, T., Yang, Q.(2020) J Agric Food Chem 68: 5384-5390
- PubMed: 32275147 
- DOI: https://doi.org/10.1021/acs.jafc.0c01342
- Primary Citation of Related Structures:  
6IGY - PubMed Abstract: 
Aspergillus niger mycelial waste is a good raw material for production of N -acetyl-d-glucosamine (GlcNAc). In this study, An ChiB, an A. niger chitinase which is upregulated during autolysis, was found to degrade A. niger mycelial waste with high efficiency. It could produce 1.45 mM (GlcNAc) 2 in 8 h from raw mycelial waste, outperforming other chitinases, including bacterial Sm ChiA, human Hs Cht, and insect Of ChtI and Of Chi-h. The crystal structure of An ChiB was determined, and residues Trp 106 and Trp 118 were found to be important for the activity of An ChiB toward mycelial waste; mutation of either Trp 106 or Trp 118 into phenylalanine or alanine resulted in dramatically decreased activity. A recombinant strain of Bacillus subtilis was constructed to extracellularly produce An ChiB, and the culture supernatant was used to treat mycelial waste. This eco-friendly strategy could produce 3.7 mM of GlcNAc from 10 g of mycelial waste in 94 h with a yield of 71.3%.
Organizational Affiliation: 
School of Bioengineering, Dalian University of Technology, Dalian 116024, China.