The quantitative description of microbial community is one of the difficult tasks for microbial ecologist. Conventional cultivation techniques cannot be used to fully characterize most soil microorganisms in respect that most of species cannot be cultured. Using phospholipid fatty acids (PLFA) profiles to characterize microbial communities can overcome the limitation of traditional techniques, because it doesn't require the removal and the culture of the microbes. The membrane phospholipids exist in all l...