Isolation and Identification of Cellulolytic Bacteria Symbiont from Various Termites on Different Nest Type in Bukit Baka Bukit Raya National Park, West Kalimantan, Indonesia

The microbial symbiotic community in the digestive tract of termites is reportedly influenced by the taxonomy and feeding habit of the host. Both factors are strongly correlated with the nest type. This study aimed to isolate the cellulolytic bacteria from termite’s digestive tract on different nest types and characterize and identify the potential isolates. The research methods included termite sampling conducted in Bukit Baka Bukit Raya National Park (BBBRNP), Melawi, West Kalimantan, isolation of cellulolytic bacteria from termites’ gut, endoglucanase activity test, biochemical characterization, and DNA analysis based on the amplification of 16S rRNA gene. Thirty isolates from 6 different species of termites on three different nest types were successfully isolated. Sixteen potential endoglucanase bacterial isolates were tested in terms of their endoglucanase activity. The cellulolytic index measured from those isolates ranged from 1.162 - 4.894. Three isolates (MRH.13.S, MRH.13.AF, and MRH.13.O2) with the highest cellulolytic index on each nest type were identified. The analysis of 16S rRNA gene using BLAST (Basic Local Alignment Search Tool for Nucleotides) revealed that isolate MRH.13.S had the closest relationship with Bacillus tequilensis (99 % homology). Based on biochemical characterization, MRH.13.AF and MRH.13.O2 isolates were related to Bacillus spp. HIGHLIGHTS Potential cellulolytic bacteria from termite intestinal tract from different nests (i.e., soil, wood, and arboreal) were isolated and compared Termites were obtained from a lowland dipterocarp primary forest ecosystem in Bukit Baka Bukit Raya National Park, West Kalimantan Province, Indonesia Termite species collected were Termes comis, Dicuspiditermes garthwaitei, Synhamitermes quadriceps, Havilanditermes proatripennis, Bulbitermes borneensis, and Bulbitermes parapusillus Potential cellulolytic bacteria acquired were closely related with Bacillus tequilensis and Bacillus spp GRAPHICAL ABSTRACT