Production of a Thermostable and Alkaline Chitinase by Bacillus thuringiensis subsp. kurstaki Strain HBK-51.
Production of a Thermostable and Alkaline Chitinase by Bacillus thuringiensis subsp. kurstaki Strain HBK-51.
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DOI：
10.1155/2012/135498
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Denizci AA
中科院分区：
文献类型：
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作者：
Kuzu SB;Güvenmez HK;Denizci AA
本文报道了从含几丁质的废弃物中分离鉴定出一株产几丁质酶的芽孢杆菌，并对其产酶条件进行了研究。苏云金芽胞kurstaki HBK-51是从土壤中分离出来并进行鉴定的。从B发酵液中提取几丁质酶。苏云金杆菌HBK-51菌株的最适温度为110°C，最适pH为9.0。在3小时的孵育期之后，该酶在110°C下（96%剩余活性）和在pH 9.0和12.0之间（98%剩余活性）显示出高水平的活性。考虑到这些特性，该酶被描述为超嗜热-热稳定和高碱性。在12% SDS-PAGE分析后获得了两条酶带，分子量分别为50和125 kDa。在所用的金属离子和化学物质中，Ni 2+（32%）、K+（44%）和Cu 2+（56%）提高酶活性，而EDTA（7%）、SDS（7%）、Hg 2+（11%）和乙亚胺酸乙酯（20%）降低酶活性。苏云金芽胞kurstaki HBK-51是一种重要的菌株，其可作为几丁质酶生产者用于多种生物技术应用中。
This paper reports the isolation and identification of chitinase-producing Bacillus from chitin-containing wastes, production of a thermostable and alkaline chitinasese, and enzyme characterization. Bacillus thuringiensis subsp. kurstaki HBK-51 was isolated from soil and was identified. Chitinase was obtained from supernatant of B. thuringiensis HBK-51 strain and showed its optimum activity at 110°C and at pH 9.0. Following 3 hours of incubation period, the enzyme showed a high level of activity at 110°C (96% remaining activity) and between pH 9.0 and 12.0 (98% remaining activity). Considering these characteristics, the enzyme was described as hyperthermophile-thermostable and highly alkaline. Two bands of the enzyme weighing 50 and 125 kDa were obtained following 12% SDS-PAGE analyses. Among the metal ions and chemicals used, Ni2+ (32%), K+ (44%), and Cu2+ (56%) increased the enzyme activity while EDTA (7%), SDS (7%), Hg2+ (11%), and ethyl-acetimidate (20%) decreased the activity of the enzyme. Bacillus thuringiensis subsp. kurstaki HBK-51 is an important strain which can be used in several biotechnological applications as a chitinase producer.