Journal of Pure and Applied MicrobiologyVol. 6 No. 1

Antifungal Potential of Papaya Lipoxygenase Metabolites against Phytophthora palmivora

B. Sujatha and P. Uma Maheswari Devi*

Department of Applied Microbiology, Sri Padmavati Mahila Visvavidyalayam (Women’s University), Tirupati - 517 502, India.

Received on 20 May 2011 and accepted on 04 July 2011

 

ABSTRACT

Partially purified lipoxygenase (LOX) protein from papaya seedlings was incubated with linoleic acid and a-linolenic acid and the resulting hydroperoxides were monitored by high performance liquid chromatography. Invitro characterization of the LOX enzyme activity showed that it possesses both 9- and 13-LOX specificity, with a predominance for the 13-LOX function. The relative ratio of 13-hydroperoxy fatty acids to 9- hydroperoxy fatty acids was found to be 8:2. The hydroperoxy fatty acids were screened for their antifungal activity against phytophthora palmivora, the causative agent of phytophthora blight in papaya. The 13-hydroperoxides showed pronounced antifungal activity by inhibiting both the germination of sporangia as well as the growth of the mycelium.

Keywords : Lipoxygenase, 13-HPODE, Phytophthora palmivora, Antifungal activity.