ENZYME CHARACTERIZATION, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF PROTEASE FROM CHICKPEA(Cicerarietinum L.) SEED AND LEAF EXTRACTS

Abstract

Chickpea proteins are appreciated due to their high biological values, well balanced amino acid content and low content of anti-nutritional factors. The present study was undertaken to investigate enzyme Characterization, antioxidant and antimicrobial activities of protease extract from chickpea (Cicerarietinum L.). The chickpea seed and leaf samples collected from farmer’s field were used for protease enzyme extraction. The protein concentration was determined by Lowry method. Protease activity was assayed by using casein as a substrate. Optimization of the enzyme activity was made based on pH and temperature. The antioxidant activity was tested based on hydrogen peroxide, and DPPH free radical scavenging activities. The antimicrobial experiment was conducted based on disc diffusion and broth dilution methods. The result of crude protein extracts and protease activity has demonstrated that significantly the highest protein concentration (74.53%) and protease activity (22. 20U/ml) in seed supernatant solution. The effect pH on protease activity demonstrated the optimum pH for the protease extract was > pH6. The effect of temperature on protease activity demonstrated that the optimum temperature for protease activity was around 40oC. Significantly the highest free radical scavenging activity of diphenyl-1-picrylhydrazyl DPPH (40.65%) and HPSA (57.95%) were recorded for seed supernatant enzyme extract. The highest concentration of the enzyme extract (30µg/ml) presented the strongest antibacterial activity with maximum zone of inhibition (22.35mm) recorded for leaf supernatant enzyme extract against S. aureus (gram positive) indicating that S. aureus is more susceptible to the enzyme extract than E.coli (negative control). The highest dose of the enzyme extract (30µg/ml) revealed maximum antifungal activity with the highest zone of inhibition (18.25mm) was recorded for leaf supernatant against C. albicans showing that C. albicans was more susceptible to the enzyme extract than A. nigerwhereas the weakest antifungal activity with minimum zone of inhibition (12.25mm), with the highest concentration of the extract, was recorded for seed pellet enzyme extract against A. niger. The enzyme extracts from leaf and seed supernatants have presented the strongest antibacterial activity with minimum inhibitory concentration MIC (1.5µg/ml) and corresponding minimum bactericidal concentration MBC (2.5µg/ml) against S. aureus .On the other hand, the strongest antifungal activity with MIC (1.5µg/ml) and corresponding minimum fungicidal concentration MFC (2µg/ml) was recorded for leaf supernatant against C. albicans whereas no effect antifungal activity was recorded for seed and leaf pellet against A. niger indicating that the pellet enzyme extract didn’t exhibit effective antifungal potential.