Effect of Metal Contamination and Pesticides on the Cellulase-producing Microbes Present in the Gut of Perionyx Excavatus

Abstract

Cellulase-producing microorganisms were isolated and identified as Micrococcus luteus, Bacillus megaterium and Enterobacter cloacae among the bacteria and P. boydii, Streptomyces sp. and Candida sp. among the fungal isolates from the gut of Perionyx excavatus. They were then subjected to two different doses of metal Zinc ((Dose I- 60mg/Kg and Dose II- 120 mg/Kg.) and two doses of two commonly used pesticides (Pendimethalin and Pretilachlor). It has been observed that out of the six cellulase-producing microbes, the higher dose of the metal was proved to be detrimental for three of them. Bacillus megaterium, that was found to be producing a sufficient amount of the enzyme, was absent even when it has been exposed to the lower dose of the metal. Also, the fungal isolates showed a decrease in number when exposed to higher dose of the contaminants. But the cellulase- producing bacterial isolates like Micrococcus luteus and Enterobacter cloacae were not at all affected by the presence of either metal or the pesticides. The experiment throws light on the microbe-earthworm relationship and effect of toxins and metals on the commercially- important microbes present in the soil and earthworm’s gut. The isolates that were present even at the higher doses of the metal and pesticides would be very promising for the production of large amount of the enzyme cellulase.