This study examined enrichment of biogas slurry vermicompost with Azotobacter chroococcum and Bacillus megaterium, inoculum levels, timing, and microbial survival. Viable populations decreased over storage (0-180 days) across treatments, with total microbial populations highest during initial phases and declining uniformly, indicating similar population maintenance for both inoculants. © 2012 Asian Network for Scientific Information. © 2012 Elsevier B.V., All rights reserved.