This study investigated chitin production from both Before Oil Extraction (BOE) and After Oil Extraction (AOE) types of mealworms (Tenebrio molitor) larvae, using the proteolytic and lipolytic enzyme-producing bacterium Bacillus subtilis EG1. The AOE type of mealworm meal yielded approximately 43? 49% oil. After 6 d of incubation with B. subtilis EG1, the dry weight yields of the BOE and AOE types of mealworm were 12.4% and 18.7%, respectively. Furthermore, the soluble peptide contents of BOE and AOE media containing B. subtilis EG1 increased to 2.23 μmol/mL and 2.58 μmol/mL, respectively, after 3 d of incubation. Additionally, B. subtilis EG1 exhibited peak protease activity, with values reaching 689.6 unit/mg P in the BOE medium after 4 d and 351.2 unit/mg P in the AOE medium after 7 d. The protease isozymes of B. subtilis EG1 were expressed as P1, P2, P3, P4, P5, and P6 in the BOE medium and as P1, P2, P5, P6, and P7 in the AOE medium. Moreover, the AOE medium provided more favorable conditions for both lipase activity and lipase expression.