Potent Fungal Chitinase for the Bioconversion of Mycelial Waste.

mycelial waste is a good raw material for production of -acetyl-d-glucosamine (GlcNAc). In this study, ChiB, an chitinase which is upregulated during autolysis, was found to degrade mycelial waste with high efficiency. It could produce 1.45 mM (GlcNAc) in 8 h from raw mycelial waste, outperforming other chitinases, including bacterial ChiA, human Cht, and insect ChtI and Chi-h. The crystal structure of ChiB was determined, and residues Trp and Trp were found to be important for the activity of ChiB toward mycelial waste; mutation of either Trp or Trp into phenylalanine or alanine resulted in dramatically decreased activity. A recombinant strain of was constructed to extracellularly produce 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%.