EVALUATION OF CELLULOLYTIC ACTIVITY OF BLACK SOLDIER FLY [Hermetia illucens (Linnaeus)] LARVAE FED DIFFERENT COMBINATIONS OF RICE BRAN AND MARKET VEGETABLE WASTE FROM LOS BAÑOS, LAGUNA, PHILIPPINES

Abstract

Utilization of black soldier fly (BSF) larvae as biological decomposers shows potential in developing market vegetable waste (MW) management strategies alongside the production of natural fertilizers and animal feeds. BSF larvae’s ability to degrade lignocellulosic materials remains elusive due to various factors such as their digestive enzymes’ capacity and the rearing substrate composition. This study evaluated the cellulolytic activity and growth rate of BSF larvae fed different combinations of rice bran (RB) and MW. BSF larvae were reared up to 5th instar using an in-house standard procedure. The cellulolytic activity was assayed on larvae crude extract, the growth rate was estimated via larvae weight monitoring, and protein content was analyzed using the Kjeldahl method and Bradford assay. Results showed that BSF larvae fed with 25:75 %RB:%MW yielded the highest cellulolytic activity while those fed with 50:50 %RB:%MW had the fastest growth rate. Cellulolytic activity was found to increase with larvae soluble protein content, but neither did correlate with growth rate. Protein content of rearing substrate correlated positively with that of the larvae and negatively with total days of rearing, indicating that protein levels of substrates may affect the rearing duration and protein content of BSF larvae intended for fertilizer and animal feed use.