Judul: Pengaruh Lama Penyimpanan terhadap Kualitas Inokulum Aspergillus niger dan Neurospora sitophila untuk Hidrolisis Tongkol Jagung
Abstrak: 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).
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Judul: Kajian Hidrolisis Tongkol Jagung oleh Kapang Selulolitik Menggunakan Kultivasi Media Padat untuk Produksi Pakan
Abstrak: Corn (Zea mays L.) is one of the main food crops in the world. Most of corn use as raw material for food and non-food industries. But these applications are limited to the corn kernel, and other parts of corn plant were not utilized yet. Among the available agricultural products, corncob is an abundant lignocellulosic raw materials and potential sources for feed in Indonesia. Corncob utilization for feed has been conducted for years, although it is limited as fiber source. High amount of lignocellulosic compound affects low digestibility of corncob. Biological process can be used to improve the nutritional value corncob, which can impact to the feed availability during the dry season. The objective of this research was to improve the nutrition value of corncob through fungal cellulolytic hydrolysis by using solid-state cultivation. Trichoderma viride and Rhizopus oryzae were used as fungal cellulolytic microorganisms which were cultivated in different bed thickness (2 and 4 cm) and mixing treatment (intermittent mixing every 3 days, and no mixing). Inocula were prepared from 7 days-old of fungi slant and grown on rice bran flour for 10 days. The process was conducted for 15 days, and the cultures were monitored every 3 days. The changes on chemical composition (moisture, fiber, protein, reducing sugar, and total sugar), pH value, and loss weight of the substrate. In the final cultivation, the products were analyzed as in vitro digestibility, the changes of fiber structure by using microscopic examination. T. viride caused low moisture content (10%) remained on the substrate in the end of cultivation; while in inverse fact was to R. oryzae (91%). Cellulolytic enzymes acts on corncob accumulated the total and reducing sugar content, and produced cello-oligosaccharides which functioned as prebiotic for ruminant animal. In vitro digestibility of the products from both fungal, bed thickness and mixing treatments also showed insignificantly effects. Since it was very long cultivation process caused the available nutritional value were re-used for fungal metabolism.
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Judul: Formulasi Hamiltonian untuk Menggambarkan Gerak Gelombang Soliter Dimensi Tiga di Permukaan Laut
Abstrak: Gelombang permukaan adalah gelombang yang terjadi perbedaan rapat massa antara air dan udara. Salah satu gelombang permukaan yang ditinjau adalah gelombang soliter. Formulasi gelombang soliter dilakukan dengan menggunakan formulasi Hamiltonian.
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