OPTIMASI PROSES BIOKONVERSI BIM SORGUM DENGAN KAPANG Rhizopus oligosporus UNTUK BAHAN PAKAN UNGGAS

Abstract

The aim of this research was to determine the changes of nutrient composition of fermented sorghum seed for bird feed. Materials used in this research were ground sorghum seed, Rhizopus ohgoporus and chemical agents. Tools used in this research were a sterilized fermentation room, plastic, a steamer, pH sticks, and a thermometer. The experiment was arranged in a two thctor factorial design based on a completely randomized design. The first factor was the levels of Rhizopus (0.2%, 0.4% and 0.6%) and the second factor was the length of fermentation (0, 1, 2 and 3 days). Data were analyzed by analysis of variance and the differences among the means were determined by using Duncan's Multiple Range Test. The results showed that steam on plastic wraps appeared after 20, 14 and 14 hours of fermentation for 0.2%, 0.4% and 0.6% Rhizopus respectively. Micellium growth at treatment of 0.2% Rhizopus (T I ) was less than that of treatments of 0.4% and 0.6% Rhizopus (T2 and T3). At the second day of fermentation, all treatments (TI, T2 and T3) resulted in similar maximal growth of Rhizopus. Optimum pH (4.2 to 5.5) for Rhizopus growth was achieved at the first and second days of fermentation. Both the levels of Rhizopus (0.2%, 0.4% and 0.6%) and the length of fermentation (0, 1, 2 and 3 days) and interaction between the two factors highly significantly affected crude protein content of fermented sorghum seed (p<0.0 I ). The levels of Rhizopus of 0.2%, 0.4% and 0,6% resulted in protein contenl of 16.64, 19.75 and 19.16% respectively. The levels of Rhizopus (0.2%, 0.4% and 0.6%) did not affect tannin content but the length of fermentation (0, I, 2 and 3 days) highly significantly affected tannin content. The interaction effect between the two factors existed in decreasing tannin content. Treatment of 0.2% Rhizopus (TI) resulted in the lowest tannin content (1.75%) and followed by treatments of 0.4% (.2) and 0.6% Rhizopus (T3) with tannin content of I .91 and 2.02% respectively. It can he concluded that the best treatment was level of Rhizopus of 0.4% with length of fermentation of 2 days (T2W2) giving the lowest tannin content (1.43%) and the highest protein content (20.84%).