土壤微生物群落结构分析中磷脂脂肪酸法和温和碱性甲酯化法的比较及定量优化

Comparison of phospholipid fatty acid method and mild alkaline methylesterefication method in characterizing soil microbial communities and quantitative optimization

分别用磷脂脂肪酸法(PLFA)和温和碱性甲酯化法(EL)对同一土壤样品脂肪酸(FAs)进行提取,结果表明,EL法提取到更多种类的短链和长链FAs,且总FAs含量是PLFA法的3倍;两种方法提取的细菌、真菌和放线菌的相对含量存在显著差异.此外,在定量计算时,基于"内标对比法"与"直接计算法"计算值之间的差异得到校正系数珔K,用于定量值的校正.经检验,借助校正系数可使定量结果更准确.

In the present study, fatty acids （ FAs ） were extracted from soil samples by bothphospholipid fatty acid （ PLFA） method and mild alkaline methylesterefication （ EL） method. More kinds of both short and long chain FAs, and 2-fold higher total FAs content were extracted by EL method than by PLFA method. Relative content of bacteria, fungi and actinomycetesshowed significantly different between the two methods （ P〈0. 05 ） . When quantitating FAs, a correction factor K was defined based on the variance between quantitation values that calculated by “internal standard correlation method” and “direct calculation method”, then was used to correct values that calculated by “direct calculation method”. The results showed thatcorrection values were more accurate than values calculated by “direct calculation method”.