基于流式细胞特性的LNA和HNA细菌相关性研究

Correlation of LNA and HNA bacteria based on flow cytometric characteristics

采用流式细胞技术分析了7种不同陆地环境介质中LNA和HNA细菌的浓度变化及流式细胞特性特征.结果显示,在水体和土壤等环境中都存在LNA和HNA细菌的分类,其中,土壤环境中LNA细菌浓度（107~108cells/g数量级）高于水环境中浓度（105~106cells/m L数量级）,但其相对比重（29.80%~33.94%）低于水环境（除地下水外,21.60%）中LNA细菌（42.25%~65.92%）,主成分分析（PCA）显示水体和土壤环境介质中LNA和HNA流式细胞参数具有明显差异;相关分析表明,LNA与HNA细菌的流式细胞参数（绿色荧光信号FL1和侧向散色信号SSC）之间具有显著相关性（FL1：R2=0.711,P〈0.01,SSC：R2=0.762,P〈0.01）,在不同生态系统中SSC变异大于FL1变异.结果表明,LNA和HNA细菌之间既不是各自对应的某一特殊生理阶段细菌,也不是两个完全相互独立的细菌群体,而是具有特殊共变关系的细菌.

In the present study, bacterial concentration and FCM characteristics of LNA and HNA were analyzed in seven different terrestrial environments. Results showed clear separation between LNA and HNA bacteria in both aquatic and soil environments. The LNA abundance in soil（107~108cells/g） was higher than that of freshwater（105~106cells/m L） while the proportion of LNA in soil（29.80%~33.94%） was lower than that of freshwater（42.25%~65.92%）, but not underground water（21.60%）. Principal component analysis（PCA） indicated that the flow cytometric characteristics of LNA and HNA had distinct differences between freshwater and soil. Correlation analysis further revealed that both green fluorescence（FL1） and side scatter（SSC） signals between LNA and HNA bacteria had a significant correlation（FL1：R2=0.711, P〈0.01; SSC：R2=0.762, P〈0.01）, i.e. co-variation between LNA and HNA. The variance of SSC was higher than that of FL1 in different ecosystems. The results demonstrated that LNA and HNA bacteria were neither physiologically related nor completely independent communities, but rather have a close co-variation.