Reducing sugar-producing bacteria from guts of Tenebrio Molitor Linnaeus (yellow mealworm) for lignocellulosic waste minimization

Abstract

The guts of Tenebrio Molitor Linnaeus (yellow mealworm) were used as inocula to isolate reducing sugar-producing bacteria during bioconversion of lignocellulose to reducing sugars in this study. Three carbon sources, i.e., carboxymethyl cellulose (CMC), filter paper (FP), and lignocellulosic waste (LIG), were specifically selected; and two types of culturing media (M1 and M2) were used. After 6 months of sequential cultivation, lignocellulose (i.e., polysaccharides) degradation of enrichments M1-CMC (47.5%), M1-FP (73.3%), M1-LIG (70.4%), M2-CMC (55.7%), M2-FP (73.1%) and M2-LIG (71.7%) was achieved, respectively, with incubation for 48 h. Furthermore, seven bacterial strains were successfully isolated corresponding to most of the major bands detected by denaturing gradient gel electrophoresis analysis. The maximum reducing sugars yield by the combination of Agromyces sp. C42 and Stenotrophomonas sp. A10b was 56.7 mg g·LIG-1 of 48 h, which is approximate 2-5 times higher than the original enrichments and individual microbial strains. These findings suggest that bioconversion by microorganisms from mealworm guts has great application potential for lignocellulose hydrolysis.