Bioconversion of water hyacinth lignocellulose into feed supplement by lignocellulolytic streptomyces. – C. A Etok and S. P. Antai
The bio-conversion of Eichhornia crassipes (MART) (water hyacinth) into feed supplement by some Streptomyces species isolated from compost dump in Calabar was investigated. The proximate composition analysis revealed 14% crude protein, 16.8% crude fibre, 7% crude fat, 8% ash content and 54.2% carbohydrate. After fermentation for fourteen days, all the components decreased in composition except crude protein which increased from 14 to 21%. The toxicants were hydrocyanic acid (0.70mg), total and soluble oxalate (2.12mg, 1.21mg), phytic acid (0.274 mg) and tannins (0.038mg), per kg. All the toxicants showed a decrease in composition after fermentation. Of the four Streptomyces species studied for their ability to degrade water hyacinth lignocellulose, two, GS3 and S22 had the highest lignocelulolytic activity. GS3 and S22 produced a lignin loss of 20% and 27% respectively, carbohydrate loss of 52% and 55%, lignocellulose weight loss of 47% and 48%, crude protein production of 15% and 14%, APPL production of 0.20 gram and 0.180 gram respectively. A consortium of these two isolates was used for fermentation of water hyacinth lignocellulose into protein feed supplement. A 20% level supplementation gave weight increases and an apparent digestibility of 87.23 in rats fed with the diets. The present study demonstrates the high potentials of Streptomyces in converting lignocellulose waste into useful products.