THE QUALITY OF FERMENTED CASSAVA TUBER SKIN AS HERBIVOROUS FISH FEED
Yuli Andriani, Sukaya Sastrawibawa, Ratu Safitri, Abun Abun
This research aims was to determine the quality improvement in the nutritional value of cassava (Manihot esculenta Crantz) tuber skin waste through the fermentation process by cellulolytic microbial consortium of Aspergillus tamari, Bacillus megaterium and Bacillus mycoides. The usefulness of this research is to improve the quality of the nutritional value of cassava tuber skin waste that can be used as herbivorous fish feed material. The research was conducted in the Laboratory of Microbiology, Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran. The experiment was conducted with experimental methods, while the data were analyzed using the T test. Fermentation was carried out for 7 days by the method of solid substrate. The parameters measured included 1) content of crude protein, crude fat, water, ash and energy using proximate analysis, 2) levels of cyanide acid (HCN) using AOAC method, 3) content of lignin, cellulose and hemicelluloses using van Soest analysis, and 4) content of glucose and starch using Luff Schoorls methods. The results showed that the enzymatic activity of microbial consortia of A. tamari, B. megaterium and B. mycoides in the fermentation process improved the quality of the nutritional value of cassava tuber skin. There was an increase in crude protein content, energy and glucose content from 4.63%, 3510 kkal and 7.36 ppm to 10.91%, 4015 kkal and 10.59 ppm at fermentation with 5% of microbial consortium. Meanwhile, the enzymatic process of the microbes decreased the content of crude fat, water, ash, HCN, starch, lignin, cellulose, and hemicelluloses. The HCN content of cassava tuber skin waste significantly declined from 265.142 mg/kg to 5.49 mg/kg. This fermentation product in turn has a better biological value to be used as feed materials for herbivorous fishes.
Key words: cassava tuber skin, fermentation, cellulolytic fungi and bacteria, nutrition value quality, herbivorous fishes