Novel Nematocidal Compounds from Shrimp Shell Wastes Valorized by Bacillus velezensis RB.EK7 against Black Pepper Nematodes

Among various organic wastes, shrimp shell powder (SSP) was the most suitable carbon/nitrogen source for producing antinematode compounds (ANCs) via Bacillus veleznesis RB.EK7 fermentation. The fermentation process enhancement of activity investigated. B. produced highest in medium containing 0.8% SSP with an initial pH 6.5–7.0, and performed at 35–37 °C a saking speed 150 rpm 72 h. Targeting ANCs were purified from fermented culture broth identified as thymine (1) hexahydropyrrolo [1,2-a]pyrazine-1,4-dione (2) based on nuclear magnetic resonance (NMR) mass spectra analysis compared to those reported compounds. Notably, first time, these found novel ANCs. Thymine demonstrated potential nematicidal effect near 100% mortality second-stage juvenile (J2) nematodes anti-egg hatching effects 70.1%, while showed moderate activities 64.2% J2 57.9%. docking study coupled experimental enzyme inhibition results indicated that potent may be possibly due targeting acetylcholinesterase. data this suggest can potentially reused eco-friendly production management black pepper nematodes.