Application of Biomarker PLFA to Groundwater Microbial Ecology Study and the Problems

As a young technology used in groundwater microbial ecology, PLFA technology overcomes several shortcomings of traditional culture-based approaches and has a number of advantages. However, there are still a few of problems to be solved when PLFA technology is applied. Although the groundwater microbial biomass can be estimated from total PLFA by a conversion factor, both the difference of communities and physical changes of environment are potential erroneous sources, which can be reduced by combination of PLFA and traditional technology and employing a proper conversion factor. In some cases, certain PLFA ratio can also indicate the physiological status of microbes under some environmental stresses. In describing groundwater communities and their changes by certain PLFA biomarkers, PLFA pattern and PLFA fingerprint technology, PLFA overlap among different species, background lipids and changes of environmental factors are the main factors influencing the reliability of results. However, with the aid of mathematical statistics and other technologies including nucleic-acid technology and tracer technology, PLFA technology is expected to picture the groundwater ecology and physiology clearly, which can provide theoretical guidance for bioremediation of contaminated groundwater.