Paenibacillus sp. TKU023生產胞外多醣之條件及特性分析

Abstract

In this study, an exopolysaccharide (EPS) and biosurfactant producing strain, was isolated from the soil in the northern Taiwan by using squid pen powder (SPP) as the sole carbon/nitrogen source and identified as Paenibacillus sp.. The optimal conditions for the production of the EPS were cells used to inoculate into 50 mL medium containing 0.5% squid pen powder (SPP), 0.1％ K2HPO4 and 0.05％ MgSO4．7H2O （pH 7.32）followed by culture at 37℃ for 5 days. The crude EPS (1.7631 g) was obtained from the culture supernatant by autoclave (121℃ , 20 min) and bleaching and then the crude EPS followed by deproteinization with Sevag reagent. The deproteinized EPS was hydrolyzed to oligosaccharides by enzyme and dialyzed with water. The oligosaccharides were analyzed by using nuclear magnetic resonance (NMR). The 1H and 13C NMR spectrometric results suggest that EPS hydrolyzates contained maltose as oligomeric building subunit. Additionally, Paenibacillus sp. TKU023 was cultivated with various culture volumes for 1~6 days by using squid pen powder as the sole carbon/nitrogen sources. The results indicated that the maximum DPPH free radical scavenging ability and better total phenolic contents, reducing activity, and Fe2+ chelating ability was found at the 5th day by using the medium volume of 50 mL.