蜡样芽孢杆菌CP-1对Cr(Ⅵ)还原效果研究

Study on Cr(Ⅵ) reduction by Bacillus cereus CP-1

为了提高蜡样芽孢杆菌CP-1菌株对Cr(Ⅵ)的还原效果,采用单因素和正交试验,通过摇瓶发酵培养,对影响蜡样芽孢杆菌CP-1菌株还原Cr(Ⅵ)的发酵培养基成分和培养条件进行了优化,并研究了最佳发酵条件下的蜡样芽孢杆菌CP-1对Cr(Ⅵ)的还原效果。结果表明,蜡样芽孢杆菌CP-1菌株还原Cr(Ⅵ)的最佳培养基组成为:1%甘露醇, 3%的大豆蛋白胨, 0.05%KCl, 0.1%CuSO4,在此基础上的最佳培养条件为:pH7.0、6%接种量、45℃培养3 d,在此条件下,Cr(Ⅵ)初始浓度为100mg·L^(-1)时,对Cr(Ⅵ)的还原率达99.75%。在Cr(Ⅵ)污染的土壤中添加蜡样芽孢杆菌CP-190d后,土壤中的Cr(Ⅵ)含量降低55.15%左右。

In order to improve the Cr(Ⅵ) reduction by Bacillus cereus CP-1, single-factor and orthogonal experiments were used to study the effects of fermentation and culture conditions on Cr(Ⅵ) reduction, and the reduction effects of B. cereus CP-1 on Cr(Ⅵ) were evaluated under the optimal fermentation conditions. The results showed that the optimal medium for the Cr(Ⅵ) reduction by B. cereus CP-1 was 1% mannitol, 3% soy peptone, 0.05% KCl and 0.1% CuSO4. The reduction rate of Cr(Ⅵ) was 99.75% based on the best culture condition of pH7, 6% inoculation amount and 45℃ for 3 d when the initial concentration of Cr(Ⅵ) was 100 mg·L^-1. Specially, the Cr(Ⅵ) content in Cr(Ⅵ)-contaminated soil was decreased 55.15%after adding B. cereus CP-1 for 90 d.