Although we recognize the short-comings of traditional culture techniques in isolating most of the microorganisms
in nature, we certainly need these isolates for a better understanding of their physiology and role in the cycling of
chemical elements. Molecular tools can be helpful in monitoring enrichment cultures and in facilitating the
successful isolation of ecologically relevant bacterial populations. PCR-DGGE/TGGE is well suited for this
purpose, because it allows the rapid and simultaneous analysis of mixed cultures grown under different conditions
together with the environmental samples from which the inocula for these cultures were taken [34-361.
Recently, Smalla etal. [37’] used DGGE and TGGE analysis to determine the bacterial populations contributing to
BIOLOG substrate utilization patterns. Two microbial
communities were tested, one from the