Thermotolerant and protease-resistant GH5 family β-mannanase with CBM1 from Penicillium aculeatum APS1: purification and characterization

In past several years, mannanases has attracted many researchers owing to its extensive industrial applications. The search for novel mannanases with high stability still continues. Present investigation was focused on purification of extracellular beta-mannanase from Penicillium aculeatum APS1 and its characterization. APS1 mannanase was purified to homogeneity by chromatography techniques. Protein identification by MALDI-TOF MS/MS revealed that the enzyme belongs to GH family 5 and subfamily 7, and possesses CBM1. The molecular weight was found to be 40.6 kDa. The optimum temperature and pH of APS1 mannanase were 70 & DEG;C and 5.5, respectively. APS1 mannanase was found to be highly stable at 50 & DEG;C and tolerant at 55-60 ?. The enzyme was very sensitive to Mn+2, Hg+2 and Co+2 metal ions and stimulated by Zn+2. Inhibition of activity by N-bromosuccinimide suggested key role of tryptophan residues for catalytic activity. The purified enzyme was efficient in hydrolysis of locust bean gum, guar gum and konjac gum and kinetic studies revealed highest affinity towards locust bean gum (LBG). APS1 mannanase was found to be protease resistant. Looking at the properties, APS1 mannanase can be a valuable candidate for applications in bioconversion of mannan-rich substrates into value-added products and also in food and feed processing.

Automated summary

This study focused on the purification and characterization of extracellular beta-mannanase from Penicillium aculeatum APS1. The enzyme belongs to GH family 5 and subfamily 7, with a molecular weight of 40.6 kDa. It has optimum temperature and pH at 70°C and 5.5, respectively, and shows high stability at 50°C. The enzyme is sensitive to Mn+2, Hg+2, and Co+2, but stimulated by Zn+2.