DNA-based, culture-independent strategies for evaluating microbial communities in food-associated ecosystems

Culture-independent molecular techniques are now available to study microbi al ecosystems. They are opening interesting perspectives to problems relate d to composition and population dynamics of microbial communities in variou s environmental niches (e.g., soil, water) and foods. In fermented food pro ducts, estimates of true microbial diversity is often difficult chiefly on account of the inability to cultivate most of the viable bacteria. The incr easing knowledge of gene sequences and the concomitant development of new c ulture-independent molecular techniques are providing new and effective too ls to compare the diversity of microbial communities and to monitor populat ion dynamics in minimally disturbed samples. In this review, recent advance s in these techniques are reported. Possible applications to food-associate d microbial ecosystems are emphasised. (C) 2001 Elsevier Science B.V. All r ights reserved.