Production of aminosugar from squid pen chitin by fungal biocatalyst

Abstract

Five species of fungi, Aspergillus fumigatus, Trichoderma viride, Trichoderma aureoviride, Trichoderma reesei and Mucor sp. were tested for production of chitinolytic enzymes. Aspergillus fumigatus was the most active fungus to be induced for production of chitinolytic enzymes. The ensemble of chitinolytic enzymes were produced from Aspergillus fumigatus with the maximum chitinolytic activity of 438 mU/mL at 40℃ in colloidal chitin minimum medium after 9 days of incubation. The enzyme preparation contained 1.70 mg protein per milliliter. The hydrolysis of β-chitin with the chitinolytic enzymes from Aspergillus fumigatus gave N-acetyl-D-glucosamine (GlcNAc) with high yields (over 70% in 1 days). The optimum ratio of enzyme to chitin was found to be 1-4 mU/mg with optimum substrate concentration at 20 mg/mL. The optimum pH range was 3-5 and the optimum temperature was 45 ℃. The hydrolysis could be carried out without any buffer that would simplify the product purification in a preparative scale.