产壳聚糖酶海洋Paenibacillus chitinolyticus CLT08的鉴定及酶学性质研究

目前用于制备壳寡糖的壳聚糖酶具有酶活性较低、酸稳定性较差等问题。本研究从连云港海州湾泥样中筛选产壳聚糖酶菌株，并对菌株进行鉴定、酸稳定性和酶学性质研究。结果表明，通过平板透明圈初筛和摇瓶发酵复筛，获得酸稳定性较好的壳聚糖酶产生菌株CLT08，随后利用形态学特征、生理生化测定及16S rDNA序列扩增与分析，鉴定菌CLT08为Paenibacillus chitinolyticus。菌株CLT08产壳聚糖酶最适温度为45 ℃，最适pH为4.0；Zn2+对酶有显著的激活作用，对Ba2+、Co2+、Fe2+有显著抑制作用。壳聚糖经CLT08壳聚糖酶水解后其聚合度≥6。此研究结果为该酶的进一步研究奠定了基础。

Identification and Enzymatic Properties of Chitosanase Producing Marine Paenibacillus chitinolyticus Strain CLT08

At present, chitosanase used to prepare chito-oligosaccharides has the disadvantage of low enzyme activity and poor acid stability. In this study, chitosanase-producing strain was screened from mud samples from Lianyungang Haizhou Bay, the highest chitosanase-producing strain was identified, and the acid stability and enzyme properties of the strain were studied. The screening was carried out by using the transparent zone method, and shaking flask fermentation. The chitosanase producing strain CLT08 was obtained. Then, the strain CLT08 was identified as Paenibacillus chitinolyticus with morphological characteristics, physiological and biochemical determination and 16S rDNA sequence amplification and analysis. The optimum temperature and pH for chitosanase production of strain CLT08 were 45 ℃ and pH4.0; Zn2+ had a significant activation effect on the enzyme, and Ba2+, Co2+, Fe2+ had significant effects inhibition. The degree of polymerization of chitosan was≥6 after being hydrolyzed by CLT08 chitosanase. The results of this study laid the foundation for further research on the enzyme.