Isolation of beta-1,3-Glucanase-Producing Microorganisms from Poria cocos Cultivation Soil via Molecular Biology

beta-1,3-Glucanase is considered as a useful enzymatic tool for beta-1,3-glucan degradation to produce (1 -> 3)-linked beta-glucan oligosaccharides with pharmacological activity properties. To validly isolate beta-1,3-glucanase-producing microorganisms, the soil of Wolfiporia extensa, considered an environment rich in beta-1,3-glucan-degrading microorganisms, was subjected to high throughput sequencing. The results demonstrated that the genera Streptomyces (1.90%) and Arthrobacter (0.78%) belonging to the order Actinomycetales (8.64%) in the phylum Actinobacteria (18.64%) were observed in soil for P. cocos cultivation (FTL1). Actinomycetes were considered as the candidates for isolation of glucan-degrading microorganisms. Out of 58 isolates, only 11 exhibited beta-1,3-glucan-degrading activity. The isolate SYBCQL belonging to the genus Kitasatospora with beta-1,3-glucan-degrading activity was found and reported for the first time and the isolate SYBC17 displayed the highest yield (1.02 U/mg) among the isolates. To check the beta-1,3-glucanase contribution to beta-1,3-glucan-degrading activity, two genes, 17-W and 17-Q, encoding beta-1,3-glucanase in SYBC17 and one gene QLK1 in SYBCQL were cloned and expressed for verification at the molecular level. Our findings collectively showed that the isolates able to secrete beta-1,3-glucanase could be obtained with the assistance of high-throughput sequencing and genes expression analysis. These methods provided technical support for isolating beta-1,3-glucanase-producing microorganisms.