The
vast majority of microbes have not yet been isolated, identified or
characterized. This is largely due to a lack of knowledge of how these
organisms survive and grow in natural habitats.
A bacterium is often part of a complex community or ecosystem with co-dependence
on other members. So it is understandable why traditional culturing techniques
fail to accurately reflect the large microbial diversity in an environmental
sample. The advent of culture-independent techniques has transformed the field
of microbiology and soil microbial ecology in particular. PCR-based techniques
such as DGGE, T-RFLP allow the classification of microorganisms based on
particular genetic markers such as 16S rRNA and the profiling of complex
microbial communities on the basis of sequence diversity.
