6+ January - February 2015
Reduction of Gossypol and Increase in Crude Protein Level of
Cottonseed Cake using Mixed Culture Fermentation
Asim Shaikh, A. A. Kathe and V. Mageshwaran*
Central Institute for Research on Cotton Technology, Matunga (E), Mumbai-400019, India
*Corresponding author: firstname.lastname@example.org
Cottonseed is a good source of high quality meal and edible oil. However it contains a toxic polyphenolic
compound called gossypol, an anti-nutritious factor that limits the use of cottonseed cake (CSK) in non-ruminants feed.
The aim of this paper was to study the effect of seven selected microbial strains and their combination on free gossypol
(FG) and total gossypol (TG) detoxification, reduction in fibre content and also to evaluate the crude protein (CP)
improvement during solid state fermentation of CSK. Initially, CSK contained 20.6% CP, 37.8% crude fibre, 0.28% FG
and 2.37% TG. The microbial strains used were Saccharomyces cerevisiae, Pleurotus flabellatus MTCC 1799,
Candida tropicalis, S. cerevisiae MTCC 6933, Monascus purpureus MTCC 1090, Pleurotus sajor-caju MTCC 1806
and Aspergillus oryzae MTCC 3782. The cultures were individually and in combinations inoculated in sterile CSK and
incubated for 48hrs at 30 oC, after incubation, the level of FG and TG, crude fibre and CP were determined. The results
showed that individually, C. tropicalis could reduce FG by 82.1% and M. purpureus MTCC 1090 could reduce TG by
59%. The significant gossypol detoxification was observed in culture combinations P. sajor-caju MTCC 1799 and S.
cerevisiae MTCC 6933 (FG, 91.6% and TG, 65%) followed by C. tropicalis and S. cerevisiae (FG, 75% and TG,
67.7%). The combination ofP. sajor-caju MTCC 1799 and S. cerevisiae MTCC 6933 showed 6.5% CP improvement
and 10.8% fibre reduction while C. tropicalis and S. cerevisiae exhibited excellent CP improvement (9.3%) and fibre
reduction (11.3%). The study revealed that the mixed culture fermentation of CSK was more effective than single strain
fermentation, which not only had higher gossypol reduction but also improved CP and decreased crude fibre contents.
Keywords : Cottonseed Cake, Detoxification, Fungi, Gossypol, Solid state fermentation