苏云金杆菌菌株YJ-2000生长和伴孢晶体形成的适宜培养条件

Suitable culture conditions for the growth and parasporal crystal production of Bacillus thuringiensis strain YJ-2000

苏云金杆菌菌株YJ-2000是本所选育的一个对家蚕蚁蚕无毒性,而对多种其他鳞翅目害虫表现强毒性的新菌株[3,4]。本文通过研究培养基初始pH、碳源、氮源和金属离子对苏云金杆菌菌株YJ-2000生物量和伴孢晶体产量的影响,以确定该菌生长和伴孢晶体形成的适宜培养条件。结果表明:既满足该菌生长,又能获得最高伴孢晶体产量的该菌的适宜培养条件是,培养基初始pH为6.5,碳源为麦芽糖,氮源为蛋白胨与(NH4)2SO4的混合物(比例为1∶1),培养基中Mg2+和Cu2+的浓度各为1×10-3和0.008×10-3mol/L。

The effects of the initial pH of medium, nutrition elements including carbon and nitrogen sources, the concentration of metal ions including Mg^2＋ and Cu^2＋ on the growth and parasporal crystal production of Bacillus thuringiensis strain YJ-2000, which shows no toxicity to the neonate larvae of the domestic silkworm, Bombyx mori but showed high toxicity to various important lepidopteran species, were studied to define the suitable culture conditions for this strain. The culture conditions, which are the most optimum not only for the high biomass, but also for the highest yield of the parasporal crystals of this strain, were as follow： the initial pH of the medium was 6.5, the medium carbon source was maltose, the medium nitrogen source was peptone plus （NH4）2SO4 with the ratio of 1 ： 1, the concentrations of Mg^2＋ and Cu^2＋ in the medium were 1 × 10^-3mol/L and 0.008× 10^-3mol/L, respectively.