One-step Purification and Characterization of Chitinolytic Enzyme produced from Paenibacillus taichungensis SH-01 using Substrate Affinity Chromatography

Abstract

This study aims to purify and characterize the chitinolytic enzyme produced from a bacterial strain Paenibacillus taichungensis SH-01, isolated as the most potent chitinolytic enzyme producer. The chitinolytic enzyme of P. taichungensis SH-01 was highly expressed in the presence of 1% colloidal chitin at 37°C and pH 5.5. Enzyme activity was simply monitored using both pNP-N-acetylglucosamine and pNP-(GlcNAc)2, during the purification. Chitinolytic enzyme designated to PtChiA (approximately 50-kDa) was partially purified by one-step purification using an affinity chitin-packed column chromatography. The optimal pH, temperature, and ionic strength of the PtChiA against colloidal chitin were determined to be 6.0, 37°C, and 25 mM, respectively. Under optimal reaction conditions, PtChiA decomposed pNP-(GlcNAc)2 very efficiently in the crude en zyme or partially purified state, but significant enzymatic activity for pNP-GlcNAc was not verified. The substrate specificity of the enzyme for other chemically and structurally similar derivatives was not significant. Additionally, the enzyme activity of PtChiA toward colloidal chitin tended to gradually increase over time. Very specifically, P. taichungensis SH-01 also showed significant chitin deacetylase activity. In conclusion, this study presents scientific significance in terms of the utilization of mi croorganisms with characteristics that enable understanding of chitin decomposition and catabolic processes using PtChiA.