土壤样品长期保存对微生物群落代谢活性和功能类群的影响

Effects of long-term soil storage on the metabolic activity and functional groups of soil microbial community

【目的】评估土壤长期保存(4个月)对土壤微生物群落代谢活性的影响。【方法】采用Biolog?Eco PlateTM生态板研究4°C风干保存和-20°C低温冻存的农田土壤和森林土壤中微生物群落的碳源利用模式。【结果】与新鲜土壤样品相比,长期保存的土壤样品的微生物群落对碳源的利用能力大大降低,其多样性、均匀度和Simpson指数均降低;风干保存和低温冻存两者对土壤微生物的碳源利用的影响没有显著差异;除风干保存的土壤样品中利用多聚物类的微生物类群的代谢活性外,两种保存方法显著降低微生物群落的代谢活性,降低幅度为54.5%–99.8%。【结论】长期保存土壤可能会导致对微生物群落信息的低估,土壤微生物代谢活性研究的最佳样品为新鲜土壤。

[Objective] The aim of this study is to assess the effects of long-term（4 months） soil storage on the metabolic activity of soil microbial community. [Methods] Biolog Eco PlateTM was used to test carbon source utilization patterns of the microbial communities in the arable and forest soils stored at 4 ℃ after air drying or at-20 ℃ with field moisture, respectively. [Results] Compared with the fresh soil samples, the abilities of carbon source utilization of microbial communities in the stored soils were greatly reduced, with the microbial diversity index, evenness and Simpson index decreased as well. There was no significant difference in the influence on the abilities of carbon source utilization of microbial community between air dried samples and frozen samples. Two storage methods significantly decreased the metabolic activity of microbial community except for the metabolic activity of polymer-utilizing microbial group in air dried soil samples, with the reduction of 54.5%-99.8%. [Conclusion] Long-term storage of soil samples may lead to underestimation of the information about soil microbial community, and fresh soils are the best samples for exploring soil microbial metabolic activity.