【摘要】 从福建地区土壤中筛选获得一株产几丁质酶菌株B120,经16S rDNA鉴定为蜡样芽孢杆菌。对菌株B120的产酶培养基进行优化,得到优化的培养基配方:乳糖3.5%,蛋白胨1.0%,细粉几丁质0.2%,K₂HPO₄0.07%,KH₂PO₄0.03%,MgSO₄0.05%,FeSO₄·H₂O 0.002%,NaCl 0.5%,初始pH 6.0。在此条件下发酵84 h酶活力可达603 U/L,比优化前（87 U/L）提高了5.93倍。对几丁质酶酶学性质的研究表明,该酶的最适反应pH 8.0,最适反应温度50℃;在30℃、pH 7.0¹0.0条件下保温1h,相对酶活力保持在74%以上,是一种中温碱性几丁质酶。更多还原

【Abstract】 A chitinase-producing strain B120 was isolated from Fujian soil and identified as Bacillus cereus by 16 S rDNA sequence analysis. The chitinase-producing media were optimized and the optimal medium formulations were ob tained and as follow : lactose 3.5%, peptone 1.0%, powdered chitin 0.2%, K₂HPO₄ 0.07%, KH₂PO₄0.03%, MgSO40.05%, FeSO₄·H₂O 0.002%, Na Cl 0.5%, pH 6.0. Fermenting under these conditions for 84 h, chitinase activity could reach 603 U/L, 5.93 times higher than before optimization（87 U/L）. Furthermore, the chitinase properties were studied. The results showed that the optimum reaction pH and temperature were 8.0 and 50 ℃, respectively. This enzyme was stable under 30 ℃ and pH 7.0-10.0, and more than 74% of relative activity was retained after incubation for 1 h. It was a kind of mesothermal and alkaline chitinases.更多还原