Isolation, molecular identification, and characterization of cellulolytic microbes from the gut of grasshopper Eyprepocnemis alacris alacris (Serv. 1838)

Cellulose from agricultural waste is one of the abundant biopolymers on earth. The accumulated cellulosic biomass in a terrestrial ecosystem is renewable to value-added bioproducts and maintaining the carbon cycle. Insect gut is an abundant reservoir of unexplored microbiota. Many life forms are associated with insect’s gut of which bacteria were predominant and have necessary dependability within the digestion of lignocelluloses. During the study, cellulase producing microbes had been differentiated from Eyprepocnemis alacris alacris (Serv. 1838). Microbes are segregated from the whole gut suspension of twenty adult insects, and its cellulolytic activity is checked using the congo-red method. Results suggested that among the 106 strains, two strains showed significant and high potential hydrolyzing zones on agar plates. Morphological tests revealed that the basic functional units of the two strains were rod in arrangement along with gram-positive in nature. The molecular characterization revealed that the two strains were Klebsiella pneumoniae and Enterobacter xiangfangensis. SDS-PAGE and zymogram analysis also showed clear bands and zones with different protein sizes. The reducing sugars of the samples were confirmed through the HPLC analysis. FT-IR analysis revealed the presence of functional groups. The extracellular cellulase production was done by a submerged fermentation process, and K. pneumoniae showed a better yield when compared to E. xiangfangensis. As a result, this study provided further information about the diversity of aerobic bacteria in the insect gut capable of hydrolyzing cellulose. To our knowledge, this is the first report on K. pneumoniae and E. xiangfangensis for the hydrolysis of cellulase producing bacteria from E. alacris alacris.