Study of yeast flora of fruits  and their  in vitro screening for antagonistic property against Penicillium digitatum

Swapan Kr. Ghosh; Tumpa Santra; Amit Chakravarty

Volume : IV, Issue : VII, July - 2015

Study of yeast flora of fruits and their in vitro screening for antagonistic property against Penicillium digitatum

Swapan Kr. Ghosh, Tumpa Santra, Amit Chakravarty

Abstract :

Hundred fifty(150) samples of different types of fruits(thirty samples of each fruit of Orange, Green grape, Fig, Dried date and Apple) were collected from different markets of ( N) 24 Parganas of West Bengal in sterile biodegradable polyethylene bags. These were ought to laboratory and the isolation of different yeasts were done from the washing of the fruit samples by using dilution plating method on MA medium. From these samples 480 yeast colonies were isolated.These isolates of yeasts were identified by conventional morphological, microscopical and biochemical testing methods. These colonies comprise of 13genera and 20 species of yeasts. Maximum number of four species were found in both Candida and Rhodotorula. The percent of occurrence of each species was calculated.All yeast species isolated were screened by dual culture plate method for their antagonistic property against Penicillium digitatum, causal pathogen of Penicillium rot of Citrus. Out of 20 species of yeasts, 15 species are antagonistic to Penicillium digitatum.Candida guilliermondii gave maximum percent of radial inhibition of growth ( 75.50 PIRG)followed by Candida famata(70.56 PIRG),Rhodotorula mucilaginosa( 68.21 PIRG),and Debaryomyces hansenii(58.00 PIRG).Therefore, these fruits are good habitats of various yeast species and the antagonistic yeasts can be applied as biological control agents against post harvest Penicillium rot disease of Citrus.