Molecular Characterization and Cellulolytic Activities of Bacterial Isolates from the Hindgut of Wood-feeding Termites Amitermes evuncifer Silvestri

Abstract

Aims: To characterize the bacterial microbiota of the wood-eating termite Amitermes evuncifer Silvestri using the 16S rRNA molecular analysis and to determine the cellulolytic capability of the isolates. Study Design: The study was designed to assess the different types of cultivable bacteria present in the gut of A. evuncifer. The cellulolytic potential of the bacterial isolates was also determined. Place and Duration of Study: Department of Microbiology, Ekiti State University Ado Ekiti, Nigeria, between January 2017 and February 2018. Methodology: Gut microbiota of twenty wood-feeding worker termites Amitermes evuncifer were characterized using phenotypic methods and 16SrRNA molecular analysis. The bacterial isolates were also analyzed for cellulase production. Results: The molecular analysis revealed that the isolates belonged to the Bacteria domain and phyla Pseudomonas, Bacillus, Achromobacter and Lysinibacillus. All the bacterial isolates exhibited both exoglucanase (FPase) and endoglucanase (CMCase) activities. Three of the isolates: Bacillus cereus ATCC 14579, Bacillus mycoides ATCC 6462 and Pseudomonas aeruginosa ATCC 10145 exhibited the highest endoglucanase activity of 6.38 μmol min−1mg−1, 5.96 μmol min−1mg−1 and 4.89 μmol min−1mg−1 respectively. Meanwhile Pseudomonas aeruginosa ATCC 10145 showed the highest exoglucanase activity (1.47 μmol min−1mg−1) followed by Bacillus cereus ATCC 14579 (1.14 μmol min−1mg−1) and Pseudomonas aeruginosa DSM 50071 (1.10 μmol min−1mg−1). Conclusion: Diversity of cellulolytic bacterial isolates was found in the hindgut of A. evuncifer. Further work needs to be carried out to determine the properties of the cellulase produced by bacterial community and the possible application of the isolates and their extracellular enzymes in biodegradation and treatment of agricultural wastes to alleviate pollution.