Epigenetic regulations enhance adaptability and valorization efficiency in Eisenia fetida and Eudrilus eugeniae during vermicomposting of textile sludge: Insights on repair mechanisms of metal-induced genetic damage and oxidative stress

Genotoxicity-based assessments of vermitechnology for textile-sludge valorization have rarely been attempted. Therefore, waste sanitization and epigenetic stress-regulation efficiency of Eisenia fetida and Eudrilus eugeniae were evaluated in silk (DSPS) and cotton (CPWS) processing sludge-based vermibeds. Vermicomposting resulted in greater C, N, and P recovery than composting. Earthworm population reduced by 6-50% in DSPS/CPWS, while it significantly increased in cow dung (CD) mixed DSPS/CPWS. The Cr, Cd, Pb, and Zn accumulation efficiency of earthworms was higher in DSPS-based feedstocks than CPWS. However, metal-rich sludge elevated oxidative stress, causing greater inhibition of cell viability and DNA damage in Eudrilus than in Eisenia. Although histoarchitecture of chloragogenous tissues was perturbed, earthworms combatted metal-induced lipid peroxidation via the activation of catalase, superoxide-dismutase, and reduced-glutathione. Correlation statistics revealed that genetic integrity in earthworms was restored through DNA-methyltransferase activity, especially in DSPS/ CPWS + CD vermibeds. Overall, Eisenia was a healthier choice than Eudrilus for sustainable valorization of textile-sludge.

Automated summary

The study evaluated the waste sanitization and epigenetic stress-regulation efficiency of Eisenia fetida and Eudrilus eugeniae in silk and cotton processing sludge-based vermibeds. Vermicomposting was more effective in recovering C, N, and P compared to composting. Earthworm populations decreased in DSPS/CPWS but increased in cow dung mixed DSPS/CPWS, with higher metal accumulation efficiency in DSPS-based feedstocks. Metal-rich sludge caused oxidative stress, resulting in greater inhibition of cell viability and DNA damage in Eudrilus than in Eisenia.