Dynamics of microbiological parameters, enzymatic activities and worm biomass production during vermicomposting of effluent treatment plant sludge of bakery industry

This paper reports the changes in microbial parameters and enzymatic activities during vermicomposting of effluent treatment plant sludge (ETPS) of bakery industry spiked with cow dung (CD) by Eisenia fetida. Six vermibins containing different ratios of ETPS and CD were maintained under controlled laboratory conditions for 15 weeks. Total bacterial and total fungal count increased upto 7th week and declined afterward in all the bins. Maximum bacterial and fungal count was 31.6 CFU x 10(6) g(-1) and 31 CFU x 10(4) g(-1) in 7th week. Maximum dehydrogenase activity was 1921 mu g TPF g(-1) h(-1) in 9th week in 100 % CD containing vermibin, whereas maximum urease activity was 1208 mu g NH4-N g(-1) h(-1) in 3rd week in 100 % CD containing vermibin. The enzyme activity and microbial counts were lesser in ETPS containing vermibins than control (100 % CD). The growth and fecundity of the worms in different vermibins were also investigated. The results showed that initially biomass and fecundity of the worms increased but decreased at the later stages due to non-availability of the palatable feed. This showed that quality and palatability of food directly affect biological parameters of the system.