The role of Eudrillus eugenia in the degradation of paper cup waste and the morphological, physiological and histological changes in the organism

Abstract

Earthworms play an important role in the monitoring of environmental pollution. Hence when exposed to pollution (or) stress condition, physical and deleterious changes are reported to be set in the metabolism of the exposed organism. Karthika et al. (2014) reported that earthworms degrade the paper cup wastes by separating the plastic lining material coated inside the paper cup during the process of vermicomposting. During the degradation process, the organisms take in the plastic resulting in toxicity of the organism (Karthika et al. 2014). Hence attempt was carried out to observe the physiological and morphological modification in the earth worm during the degradation of paper cup wastes. Fortunately there were some abnormal changes noted in the morphology and physiology of earthworm during the initial, middle and final stages of vermicomposting process In the present study, the morphological changes (length, weight) and physiological changes including the antioxidative enzymes (CAT, SOD, GST, GPX), DNA damage and tissue damage occurred during the degradation were investigated in earthworms. However, the overall antioxidant activity was normal during the 1st week of process, later there was increase in its activity during the 12th week and at the 19th week of the process, a drastic reduction in the antioxidant enzyme was noted. However the enzyme activities were observed to be normal in the control. Meanwhile the DNA damage to the earthworm was observed by comet assay where the high level of DNA damage was noted in test animal compared to control. Also the histological examination of the earthworm shows the changes in the external barrier of the tissues of the test animal when compared to the control. The results demonstrate that the earthworm employed for the degradation of paper cup waste undergoes oxidative stress, DNA damage and also tissue damage. However the earthworms have the capable of regaining its metabolic activity when inoculated into the new substrate.