Exploitation of agro industrial wastes as immobilization carrier for solid-state fermentation

Ten agro industrial wastes were assessed for their suitability as fungus immobilization carrier for solid-state fermentation (SSF). The wastes included creosote bush leaves (Larrea tridentara), variegated Caribbean agave (Agave lechuguilia), lemon peel (Citrus aurantifolia), orange peel (Citrus sinensis), apple pomace (Malus domestica), pistachio shell (Pistacia vera), wheat bran (Triticum spp.), coconut husk (Cocos nucifera), pecan nutshell (Carya illinoinensis), and bean residues (Phaseolus vulgaris). All of them were physical-chemically and microbiologically characterized. Physical-chemical tests consisted in the determination of the critical humidity point and the water absorption index; while the microbiological tests were based on the evaluation of Aspergillus niger Aa-20 growth rate in such materials. The study pointed out that coconut husk, apple pomace, lemon and orange peels were the materials of greater potential for use as immobilization carrier in SSF, since they have high water absorption capacity, and allowed good microorganism growth rate. This result is of significant interest due to the low cost and abundant availability of such wastes. (c) 2009 Elsevier B.V. All rights reserved.