外源镧对土壤微生物碳源利用的影响

Effects of exogenous lanthanum on carbon utilization of soil microorganisms

摘要: 用¹⁴ C标记葡萄糖法研究了外源镧对土壤微生物碳源利用的影响。结果表明 :外源镧在低浓度下可增强土壤微生物利用碳源进行呼吸作用 ,而高浓度下则产生显著抑制作用 ,最大抑制率为 3 3 %。土壤微生物呼吸产生的¹⁴ CO₂ 主要是培养初期释放的 ,培养 14d后¹⁴CO₂ 释放已非常少。外源镧可增强土壤微生物利用碳源合成自身的生物量 ,最大增幅为 2 5 %。

Abstract: Effects of exogenous lanthanum (La) on carbon utilization of soil microorganisms were studied by means of ¹⁴C-labeled glucose.Results show that low concentration of exogenous lanthanum increased carbon utilization of soil microorganisms in respiration.But when the concentration of exogenous lanthanum was high,the carbon utilization was inhibited by 33% to the maximum. Most of the ¹⁴CO ₂ generated was the product of respiration of soil microorganisms during the initial period of the incubation and the production of ¹⁴CO ₂ was very limited after D14.The supply of exogenous La improved carbon utilization of soil microorganisms in respiration, thus increasing the microbial biomass of the microorganisms per se by 25% to the maximum.