Operating conditions
(batch vs. continuous feed) does not influence E. coli survival. The
number of E. coli drop below the legal limit of 103 CFU/g dry
weights within 18–21 days, in both continuous or batch systems
with a rich microbial community and varying earthworm abundance,
whereas the absence of earthworms or a reduction in the
indigenous microbial community lead to longer E. coli survival
(23–51 days). Our results also suggest that certain nutrients (i.e.
sugar abundance, but not labile C) play an indirect role in E. coli
survival, perhaps via antagonistic microbial populations rather
than a direct effect on the indicator organism itself. Our study suggest
that vermicomposting is a promising method in the sanitation
of organic waste, which would allow producing proteins and lipids
for animal feed. While the E. coli inactivation observed in the
current study is promising, further studies on a more diverse array
of pathogens are required.