Preliminary Screening of Cellulase Producing Bacteria Isolated from the Gut of African Palm Weevil Larvae

Insects of the taxonomic order Coleoptera are recognized for considerable cellulolytic activity in their digestive tract. However, the cellulolytic activity of the gut microbiome of the African palm weevil (Rhynchoporus phoenicis), has not been reported. Thus, this study aimed at isolating cellulose degrading bacteria from the gut of the insect’s larva and assessingtheir cellulolytic activities. The larva of the insect was dissected and inoculated in carboxymethylcellulose-Congo red (CMC-CR) agar medium and incubated at room temperature (28±2) for 14 days. Isolate with the highest cellulolytic index was identified as Pseudomonas luteola. The isolate was used in the fermentation study for the production of enzyme in Erlenmeyer flasks for 12 days. Glucose production and enzyme activities were measured every two days. A total of 25 pure colonies of bacteria were isolated from the sample, among which 9 were found to hydrolyze CMC. The isolate produced glucose ranging in concentration from 0.101 - 0.320 mg/ml. The enzyme activities of crude enzyme extracts ranged from 0.028 – 0.200 UI/ml. This study therefore highlights the prospect of bacteria from the gut of R. phoenicis larvae as important sources of cellulase production for potential industrial and environmental applications.