Cloning and expression of the endo-1,3(4)-β-glucanase gene from Paecilomyces sp. FLH30 and characterization of the recombinant enzyme

Abstract

The cDNA encoding β-1,3(4)-glucanase, named PsBg16A, from Paecilomyces sp. FLH30 was cloned, sequenced, and over expressed in Pichia pastoris, with a yield of about 61,754 U mL⁻¹ in a 5-L fermentor. PsBg16A has an open reading frame of 951 bp encoding 316 amino acids, and the deduced amino acid sequence of PsBg16A revealed that it belongs to glycoside hydrolase family 16. The purified recombinant PsBg16A had a pH optimum at 7.0 and a temperature optimum at 70 °C, and randomly hydrolyzed barley β-glucan, lichenin, and laminarin, suggesting that it is a typical endo-1,3(4)-β-glucanase (EC 3.2.1.6) with broad substrate specificity for β-glucans.