Biodegradation of gossypol by the white oyster mushroom, Pleurotus florida, during culturing on rice straw growth substrate, supplemented with cottonseed powder.

Rajarathnam, S. and Shashirekha, M. N. and Zakia, Bano. (2001) Biodegradation of gossypol by the white oyster mushroom, Pleurotus florida, during culturing on rice straw growth substrate, supplemented with cottonseed powder. World Journal of Microbiology and Biotechnology, 17 (3). pp. 221-227.

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Abstract

The capacity of the white oyster mushroom, Pleurotus florida to biodegrade gossypol was studied, when grown on rice straw supplemented with cottonseed powder. The mushroom fruiting bodies did not contain any residues of gossypol at concentrations of cottonseed powder 0.15–0.60% nitrogen contents of rice straw at the end of mycelial ramification. However, the cottonseed supplementation (at 0.30% N level itself) caused a doubling in the mushroom yield and its protein content, per unit weight straw substrate. The mushroom mycelium when grown on synthetic medium in liquid cultures was able to biodegrade gossypol. A pre-incubation period of 5 days before the addition of gossypol into the culture medium, an inoculum load 10 mg and an incubation period of 10 days at 25 °C caused the biodegradation of 100 g gossypol. Increased concentrations of gossypol required increased duration and increased inoculum levels to effect biodegradation. However, the effect was more pronounced with an increase in inoculum density. The fungal monoculture when grown in rice straw (powder) (5%) + glucose (1%) liquid culture medium, showed an increase in hexosamine content and laccase activity that produced an increased degradation of gossypol over an incubation period from 5 to 25 days. Enzymic extracts of the mycelial monoculture raised on the chopped rice straw substrate when incubated with 100 g of gossypol demonstrated its biodegradability; the increase in enzyme concentration showed enhanced gossypol degradation. This study adds to the world list of organic compounds that Pleurotus is able to biodegrade, and explains the cause of non-yellowing of the white oyster mushroom (P. florida) fruiting bodies, during culture on rice straw with supplementation of cottonseed powder for enhancing the mushroom yields.

Item Type:	Article
Uncontrolled Keywords:	biodegradation, gossypol, liquid culturing, oyster mushroom, pleurotus florida
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 04 Microbiology > 04 Fungi
Divisions:	Fruit and Vegetable Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	19 Jul 2011 04:05
Last Modified:	28 Dec 2011 09:43
URI:	http://ir.cftri.res.in/id/eprint/3181

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