Abstract:
Microorganisms in the intestinal tracts of termites play a crucial role in the nutritional physiology of
termites. The bacterial diversity in the fungus-cultivating Macrotermes michaelseni was examined using
both molecular and culture dependent methods. Total DNA was extracted from the gut of the termite
and 16S rRNA genes were amplified using bacterial specific primers. Representatives from forty-one
(41) RFLP patterns from a total of one hundred and two (102) clones were sequenced. Most of the
clones were affiliated with 3 main groups of the domain Bacteria: Cytophaga-Flexibacter-Bacteriodes
(73), Proteobacteria (13), and the low G+C content Gram-positive bacteria (9). Two RFLPs related to
planctomycetes, but deeper branching than known members of the phylum, were detected. In addition,
1 and 2 RFLPs represented the spirochetes and TM7-OP11 groups, respectively. In studies using
culture dependent techniques, most of the isolates obtained belonged to the Gram-positive bacteria
with a high G+C content. However, only one of the clones represented Gram-positive bacteria with High
G+C content. These results show a high bacterial diversity in the intestinal microbiota of M.
michaelseni, which continues to escape cultivation. As is the case in other termites many of the clones
represent previously uncultured bacteria. The fact that most of the clones clustered with clones from
Macrotermes gilvus provides further support for the hypothesis that microorganisms in intestinal tracts
of termites have co-evolved with their hosts.
