Pengaruh Lama Penyimpanan terhadap Kualitas Inokulum Aspergillus niger dan Neurospora sitophila untuk Hidrolisis Tongkol Jagung

Abstract

Production of Aspergillus niger and Neurospora sitophila inoculums prepared from cassava bagasse (solid waste from tapioca industry) enriched with rice bran powder, defatted peanut, and tofu solid waste substrates, were investigated the storage time effects to the spore viabilities. The mixed substrates were formulated to C/N ratio of 5, then fermented in solid-state cultivation systems (3 days for A. niger; 4 days for N. sitophila). Each dried inoculum was wrapped in polyethylene plastics and kept on room temperature (25–30°C) for 8 weeks, and evaluated the qualities weekly for spore viability and moisture content. Each inoculum with high viability was applied in the fermentation of corncob to prove the cellulolytic hydrolysis capability, that fermented in solid-state cultivation system for 9 days. Generally, storage of inoculum caused the reduction (from 100% to 91.84% for A. niger; from 100% to 82.73% for N. sitophila) of spore viability even the moisture content increased during the storage (from 6.82% to 10.04% for A. niger; from 4,16% to 7,63% for N. sitophila). The results showed that inoculum of A. niger produced from cassava bagasse and defatted peanut; and N. sitophila produced from cassava bagasse and rice bran powder could maintain the spore viabilities after 2 months storage (from 86 x 107 spore/g to 36 x 107 spore/g for A. niger; from 83 x 107 spore/g to 18 x 107 spore/g for N.sitophila). After the application of inoculum in corncob hydrolisis, it showed that crude fiber was reduced (from 68.13% to 55.82% by using A. niger inoculum; from 69.05% to 51.03% by using N. sitophila inoculum) as the effect of cellulolytic breakdown to produce oligosaccharides (DP 3.26–3.29 by using A. niger inoculum; DP 2.60–2.65 by using N. sitophila inoculum).