To date, around 700 species of yeast have been described, but this represents only a fraction of yeast diversity on this planet. For ascomycetes in general, the numbers of undescribed genera and species have been calculated at 62,000 and 669,000, respectively. At the current rate of new yeast species descriptions each year, it would take yeast biologists several hundred years to document all new species thought to exist in numerous habitats (Hawksworth and Mouchacca, 1994). Even with conventional selective media isolation approaches, Lachance (1990) has noted that it is highly likely that a considerable portion of the yeast community is being ignored. It is important for yeast biologists not only to appreciate the immerse untapped yeast diversity but also to develop ways of characterizing and preserving remaining species, especially those of biotechnological potential. Several molecular biological approaches are now assisting in the detection of yeasts in the environment, and together with input from yeast physiological studies, this will provide means to preserve and exploit yeast diversity (Roberts and Wildman, 1995).
In this study, we conducted a survey on yeast communities associated with the digestive tracts of honeybees collected in Thailand to demonstrate the distribution of sugar tolerant yeasts as well as to see whether there is a specific relationship between the yeasts and their insect hosts.