Effect of solid state fermentation on nutrient composition of selected feed

Solid-state cultivation of the fungusAspergillus niger and the bacterium Bacillus coagulans was carried out to enrich thenutritional value of plant ingredients like soybean meal, mixed ingredients and wheat bran to use as aquafeed ingredients.Fermentation of soybean meal (FSBM) usingB. coagulans for 48 h resulted in significant (p<0.05) increase in the crudeprotein content (@ 3 to 7%) with concurrent decrease in nitrogen free extract (NFE) (11 to 16 %). Among the essentialamino acids, valine (7%), isoleucine (2%), leucine (2%), lysine (93%) and tryptophan (42%) showed substantial increases inFSBM after 48 h. Solid state fermentation (SSF) of ingredient mix usingA. niger NCIM 616 resulted in initial reduction ofcrude protein content during the first 48 h followed by significant (p<0.05) increase of 4 to 14% during the course offermentation. The crude fat content showed a 35% increase in 96 h. Nitrogen free extract though increased marginally (4%)at 48 h showed significant reduction (17%) at 96 h. A marginal increase in arginine, valine and methionine levels were alsoobserved in the fermented ingredient mix (FIM). Solid state fermentation of wheat bran usingA. niger S14 (a mangroveisolate) had resulted in substantial increase in crude protein level (57 to 66%) as compared to that of raw wheat bran. Thecarbohydrate content in wheat bran showed substantial reduction (75 to 39%) during the course of fermentation. Essentialamino acids like, histidine, threonine, valine, isoleucine and lysine showed increase during SSF. The results of the presentstudy show thatB. coagulans and the selected strains of A. niger can be used for nutritional enrichment of plant ingredientsfor further use in aquafeed formulations.