Gupta, R.K.Shweta2021-08-042021-08-042020-06https://krishikosh.egranth.ac.in/handle/1/5810171438Earthworms are most easily obtained and one of the largest component of the soil biota and these organisms are very suitable for estimating disturbance to soil ecosystems. The worms have the ability to increase the availability of nutrients to plants due to the presence and activity of micro flora in their gut. Many activities of human beings such as waste disposal and land treatment etc. have led to increase in amount of metals in soil ecosystems. These metals not only kill target species, but prove harmful to non-target organisms like earthworms and due to this reason; the present study was carried out to investigate the effect of heavy metals on biomolecules and antioxidative enzymes of earthwormE. fetida. The maximum reduction in biomolecules i.e. 17.80% in crude protein, 33.37% in total tissue carbohydrate and 37.59% in crude lipid was seen in earthworms treated with Cu + Sn (0.05 +0.05 ppm). There was a significant increase in the activity of antioxidative enzymes i.e. SOD, 23.65% and 31.77% and POD 44.44% and 28.57% in worms exposed to Cu (1.00 ppm) and Cu+Sn (0.05+0.05 ppm), respectively. Thus the study proves that copper is toxic to earthworms as compared to tin.The maximum ethanol production i.e. 5.30% was observed with 0.50% earthworm cast as compare to control in which no cast was used and ethanol production was found to be 0.83%. After the observation it can be concluded that earthworm cast, is also a rich source of nitrogen and phosphorous, may be considered as alternative of chemical fertilizers like urea and disodium hydrogen phosphate, required for the growth of yeast during fermentation.EnglishThesis