铜离子浓度对嗜酸性氧化亚铁硫杆菌生长特性和生长动力学的影响

Effect of copper ion concentration on growth activity and kinetics of Acidithiobacillus ferrooxidans

通过研究Cu^(2+)浓度对嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f)生长特性的影响,得到在不同Cu^(2+)浓度下A.f菌的生长曲线,探究不同Cu^(2+)浓度对培养液中细菌浓度、p H、亚铁浓度和氧化还原电位的影响。结果表明:A.f菌对Cu^(2+)具有一定的耐受能力;当培养液中ρ(Cu^(2+))≤0.5 g/L时,Cu^(2+)对A.f菌的生长活性影响较小;当ρ(Cu^(2+))在1.0~2.0 g/L之间变化时,A.f菌的生长活性开始受到Cu^(2+)的影响,出现明显的延迟效应,Cu^(2+)开始抑制细菌生长繁殖;当ρ(Cu^(2+))≥3.5 g/L时,A.f菌生长完全受到抑制,几乎停止生长。随着培养液中Cu^(2+)浓度的增加,A.f菌生长活性受到的抑制作用也增大。依据Monod方程推导并建立了A.f菌在不同Cu^(2+)浓度下的生长动力学方程,各动力学曲线的相关性较好,表明动力学方程能较好地描述不同Cu^(2+)浓度对氧化亚铁硫杆菌生长的影响。

The effect of initial copper ion concentration on the growth activity of Acidithiobacillus ferrooxidans was investigated, and the bacterial growth curves, bacteria concentration, pH, ferrous concentration and oxidation-reduction potential in the culture solution were obtained at different Cu^2＋ concentrations. The results show that to some extent Acidithiobacillus ferrooxidans is tolerant to copper ion. When cultured in 9K medium containing ρ（Cu^2＋）≤0.5 g/L, little effect on the growth and activity of Acidithiobacillus ferrooxidans is brought to copper ion. When ρ（Cu^2＋） is 1.0-2.0 g/L, the growth and activity of Acidithiobacillus ferrooxidans are obviously influenced by copper ion and appear delayed effects, and then copper iron begins to inhibit the bacterial growth. When the concentration of copper ion is over 3.5 g/L, the inhibiting effect on activity of Acidithiobacillus ferrooxidans is completely inhibited, bacteria almost stops growing. With the increase of Cu^2＋ concentration in the culture medium, the inhibiting effect on growth activity of Acidithiobacillus ferrooxidans increases. Based on the model of Monod function, the growth kinetics equation of Acidithiobacillus ferrooxidans at different copper iron concentration is built up. The correlation of kinetic curve is better, which shows that the kinetics equation can well describe the growth of Acidithiobacillus ferrooxidans at different initial copper iron concentrations.