Cloning and characterization of a chitinase from Thermobifida fusca reveals Tfu_0580 as a thermostable and acidic endochitinase

• Published in: Biotechnology reports (Amsterdam, Netherlands) Netherlands), 2018-09, Vol.19, p.e00274-e00274, Article e00274
• Main Authors: Yan, Qiang, Fong, Stephen S.
• Format: Article
• Language: English
• Subjects: Chitin; Chitinase; N-acetylchitooligosaccharides; Tfu_0580; Thermobifida fuscacloning
• ISSN: 2215-017X; 2215-017X
• DOI: 10.1016/j.btre.2018.e00274

•A Thermobifida fusca chitinase Tfu_0580 is characterized for its function.•Tfu_0580 is the first reported as a functional chitinase that can degrade colloidal chitin.•Enzymatic characterization shows Tfu_0580 as a thermostable and acidic endochitinase. Being capable of hydrolyzing chitin, chitinases have various applications such as production of N-acetylchitooligosaccharides (COSs) and N-acetylglucosamine (GlcNAc), degrading chitin as a consolidated bioprocessing, and bio-control of fungal phytopathogens. Here, a putative chitinase in Thermobifida fusca, Tfu_0580, is characterized. Tfu_0580 was purified by homogeneity with a molecular weight of 44.9 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Tfu_0580 displayed a clear activity against colloidal chitin, which is comparable to a commercial Streptomyces griseus chitinase. Enzyme activities against p-nitrophenyl β-D-N,N′,N′′-triacetylchitotriose (p-NP-(GlcNAc)3), N,N′-diacetyl-β-D-chitobioside (p-NP-(GlcNAc)2) and p-nitrophenyl N-acetyl-β-D-glucosaminide (p-NP-(GlcNAc)) showed that Tfu_0580 exhibited highest activity against p-NP-(GlcNAc)3. Further optimization of the enzyme activity conditions showed: 1) an optimum catalytic activity at pH 6.0 and 30 °C; 2) activity over broad pH (4.8–7.5) and temperature (20–55 °C); 3) stimulation of activity by the metallic ions Ca2+ and Mn2+.