With the same steps of extraction and methanolysis, the variety of PLFA measured by GC-MS is 18 while that by MIDI is 40, so we conclude that MIDI is better than GC-MS.

• 提取及甲基化等提取步骤完全相同，但是用GC-MS测定得到的PLFA共18种，而用MIDI测定得到的PLFA高达40种，采用MIDI方法检测较好。