Termites (Dictyoptera, Isoptera) comprise of approx. 2800 species, roughly divided into socalled lower and higher termites with maximum diversity found in tropical and sub-tropical regions, close to the equator, while fewer species live at higher altitudes. Lower termites harbor a dense and diverse population of prokaryotes and flagellated protists (single-cell eukaryotes) in their gut. Higher termites comprise only one apical family (Termitidae) but more than three-quarters of all termite species. While they also harbor a dense and diverse array of prokaryotes, higher termites typically lack flagellated protists. Cellulose digestion in termites depends upon mutualastic interaction with a variety of symbionts present in gut of termites. These microorganisms play a crucial role in the nutritional physiology of termites. Diverse microorganisms inhabit the intestinal tracts of all termite groups at a high density of 106–107 cells per μl of gut volume. The ability of Isopteras to digest complex molecules is mostly attributed to the action of these intestinal microbes. Comprehensive study of bacterial diversity in termites showed that microbes from all known domains, i.e., Bacteria, Archaea, and Eucarya were represented in gut symbionts of termites which include many cultured and uncultured species. The midgut contains a purely prokaryotic microbiota, whereas the hindgut is colonized by prokaryotes and special single-celled eukaryotes. As a result of the microbial activities, high concentrations of fermentation products accumulate in this system The enlarged hindgut, also known as paunch, is the “hotspot” of the microbial activity. In the hindgut, the symbiotic microbiota polymerizes cellulose and hemicellulose, which are further fermented to short-chain fatty acids; to be used as the main energy source by the host termite. Apart from their importance in the nutrition of the termites, the microorganisms in the termite may also include novel species with potential for exploitation in biotechnology. They may have large industrial applications as they are potentially good resource of functional genes which can be exploited using classical enrichment culture technique and recent metagenomic approach. Recent researches have shown that termites and its symbionts have not only cellulolytic or lignin decomposition activity but also aromatic hydrocarbons degradation. These functions would be useful for biomass utilization, environmental remediation, and fine-chemicals production.