(1. 北京科技大學(xué) 土木與環(huán)境工程學(xué)院, 北京 100083；
2. 中國科學(xué)院 過程工程研究所生化工程國家重點(diǎn)實(shí)驗(yàn)室，北京 100190)
摘 要: 在氧化亞鐵硫桿菌(T. f)培養(yǎng)過程中其他營養(yǎng)物質(zhì)足量的情況下，通過考察不同初始Mg2+濃度對氧化亞鐵硫桿菌(T. f)生長活性的影響，得到在不同Mg2+濃度下細(xì)菌的生長曲線。結(jié)果表明：T. f對Mg2+具有一定的耐受能力；當(dāng)培養(yǎng)基中ρ(Mg2+)≤10 g/L時，Mg2+對細(xì)菌生長活性影響很小；其ρ(Mg2+)為15 g/L時，Mg2+開始產(chǎn)生延遲效應(yīng)，抑制細(xì)菌生長；ρ(Mg2+)為20 g/L時，細(xì)菌生長完全受到抑制。同時利用基于存在非競爭性抑制的Monod方程，建立了T. f在高M(jìn)g2+濃度下的生長動力學(xué)方程模型，確定在不同條件下細(xì)菌生長動力學(xué)參數(shù)，包括最大比生長速率μmax、Monod常數(shù)Km及鎂離子抑制常數(shù)KI。利用correl系數(shù)工具分析細(xì)菌比生長速率的實(shí)驗(yàn)值和模擬值之間的相關(guān)系數(shù)為 0.973，表明該動力學(xué)方程能較好地描述Mg2+濃度對氧化亞鐵硫桿菌生長的影響。
關(guān)鍵字: 氧化亞鐵硫桿菌；生長動力學(xué)；非競爭性抑制；比生長速率
（1. School of Civil and Environmental Engineering, University of Science and Technology Beijing,
Beijing 100083, China;
2. State Key Laboratory of Biochemical Engineering, Institute of Process Engineering,
Chinese Academy of Sciences, Beijing 100190, China）
Abstract:When the other nutrients were sufficient in the culture of Thiobacillus ferrooxidans, the impact of the different initial Mg2+ concentration on the activity of the growth of Thiobacillus ferrooxidans was studied, and the bacterial growth curves were obtained at different magnesium ion concentrations. The results of the experiment show that Thiobacillus ferrooxidans is tolerant to Mg2+ some extent. No bad effect on the growth and activity of Thiobacillus ferrooxidans by Mg2+ is brought when cultured in 9K medium containing ρ(Mg2+)≤10 g/L. The growth and activity of Thiobacillus ferrooxidans are obviously influenced by Mg2+ when ρ(Mg2+) is 15 g/L. When the concentration of Mg2+ is around 20 g/L, the growth and activity of Thiobacillus ferrooxidans are completely inhibited. Simultaneously the kinetic model for the growth of Thiobacillus ferrooxidans at high magnesium ion concentrations is deduced on the basis of the non-competitive inhibition of the Monod equation. The values of kinetic parameters (i.e. maximum growth rate μmax, Monod constant Km and magnesium ion inhibition constant KI) under different initial experiment conditions are determined. The correlation coefficient between the simulated and experiment specific growth rates is 0.973, which shows that the kinetics equation can well describe the effect of magnesium ion concentration on the growth of Thiobacillus ferrooxidans.
Key words: Thiobacillus ferrooxidans; growth kinetics; non-competitive inhibition; specific growth rate
