Comparative activity of polyphenol oxidase produced In vivo by Aspergillus niger and Aspergillus flavus, seed-borne storage molds of rice (Oryzae sativa L)

Abstract

The ability to produce polyphenol oxidase in vivo by Aspergillus niger and Aspergillus flavus seed-borne storage molds of rice (Oryzae sativa> L.) was investigated. Also, was the effect of temperature and pH on the activity of the above enzyme secreted by each of the above seed-borne storage molds of rice. The result of the assay for in vivo production of polyphenol oxidase by Aspergillus niger and Aspergillus flavus, showed that the activity of PPO secreted by A. niger was 0.029ΔA/min, while that from A. flavus was 0.035ΔA/min at 25°C. The activity of the enzyme secreted by A. niger and A. flavus was optimum at temperature of 25°C and 30°C respectively, while it was least 50°C for the two molds. The activity of the enzyme secreted by A. niger was optimum at pH 7, while it was at pH 7 and 8 for that secreted by A. flavus. The activity of the enzyme secreted by the two mold was least at pH2.

Keywords: enzyme, activity, infection, disease, storage



Plant Products Research Journal Vol. 9 2005: 11-13