Highlighting earthworm contribution in uplifting biochemical response for organic matter decomposition during vermifiltration processing sewage sludge: Insights from proteomics.

A vermifilter (VF) was steadily operated to explore the mechanism of lower microbial biomass and higher enzymatic activities due to the presence of earthworms, with a conventional biofilter (BF) as a control. The analysis of 2-DE indicated that 432 spots and 488 spots were clearly detected in the VF and BF biofilm. Furthermore, MALDI-TOF/TOF MS revealed that six differential up-regulated proteins, namely Aldehyde Dehydrogenase, Molecular chaperone GroEL, ATP synthase subunit alpha, Flagellin, Chaperone protein HtpG and ATP synthase subunit beta, changed progressively. Based on Gene Ontology annotation, these differential proteins mainly performed 71.38% ATP binding and 16.23% response to stress functions. Taken the VF process performance merits into considerations, it was addressed that earthworm activities biochemically strengthened energy releasing of the microbial metabolism in an uncoupled manner.