Judul: Study of microencapsulated bioinsecticide from Bacillus thuringiensis
Abstrak: Bacillus thuringiensis is one of well known bioinsecticide resources. Bioinsecticide is utilized in organic farming for the replacement of chemical insecticide. Weaknesses of B. thuringiensis toxin are easily disrupted by ultra violet from sunlight and easily washed by rain. The purposes of this research were to produce microencapsulated B. thuringiensis and to produce microencapsulated formula for the protection of toxin active ingredient from the environmental factor. The experimental result showed maltodextrin can be used as an encapsulation material for bioinsecticide using spray drying process. Lactose could not be used as an microencapsulation agent in spray dryin process, especially for areas with high humidity levels due to its low Tg ( Temperature of glass transition) characteristic. Increase ratio in concentration of encapsulation material increased the number of spores contained but gave lower product toxicity. Result showed that 5% maltodextrin concentration produce highest level product of toxicity, but because of poor quality of encapsulation material formed, the product showed high level of degradation after drying process. Rainfall simulation test showed that product encapsulated by maltodextrin gave increase persistence against rain wash on leaf but it could not protect active ingredient deterioration caused by sunlight.
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Judul: Proses Produksi Bioinsektisida Bacillus thuringiensis Isolat Lokal Menggunakan Limbah Agroindustri pada Kultivasi Media Padat.
Abstrak: Due to increased awareness of the need for safe insecticide, currently the use of bioinsecticide is increasingly in demand by farmers who want to produce vegetables and fruits safe for consumption. Also, it is used in the control of mosquito larvae that can be vectors of several dangerous diseases. The use of safe insecticides is needed, so as not to pollute the soil, water and other living creatures. The advantages of using microbial bioinsecticide are safe, environmentally friendly, specific to certain insect pests, not harmful to pets, do not result in residues on crops and soil. The purpose of this research was to develop the production process of bioinsecticide (Bacillus thuringiensis) using local isolates with starter and cultivation media of agroindustrial by products, using solid state cultivation, in order to obtain bioinsecticide that is cheap and easy to produce. The purpose of each stage are to obtained isolate characteristics suitable with the solid state cultivation and suitable with climatic environment in Indonesia, development of starter from agroindustrial waste, design the condition of solid state cultivation production process using agroindustrial waste, and for evaluation and analysis of efficacy in the target insects. The stages of research began from isolate isolation from Attacus atlas and Bombyx mori caterpillar carrions. Isolates further obtained were then characterized and identified to obtain B. thuringiensis, from both isolates obtained, it was then selected one of the most suitable for solid state cultivation. The next stage was the selection of starter medium from agroindustrial waste, followed by a bioinsecticide production using the mixed media of sago lees and iles-iles lees by solid state cultivation. Bioinsecticide produced was characterized by amino acid content protein profiles and toxicity ability against A. aegepty larvae dan C. pavonana larvae. B. thuringiensis producing endotoxins that served as a bioinsecticide active ingredient could be isolated from A. atlas and B. mori caterpillar carrions from Bogor, Indonesia. The isolate characteristics of A. atlas caterpillar are the bacteria belonging to Gram-positive, having flagella, punctiform shaped colonies, slimy, white, rod-shaped vegetative cells with a length of approximately 1700 nm and a width of about 830 nm. The protein crystals yielded are spherical, with a diameter of 470-770 nm, and diameter of spore of 550-750 nm. The isolate characteristics of B. mori caterpillar are, belonging to Gram-positive bacteria, motile, circular, white and slimy, long and round vegetative cells with a length approximately of 3900-9500 nm and a width approximately of 830 nm. The protein crystals yielded are spherical, bipyramid and cuboid with a size of 300-700 nm, and diameter of spore of 500-750 nm. Philogenetic tree reconstruction showed that both isolates are in the same cluster with B. thuringiensis. Of two selected isolates, for bioinsecticide production by solid state cultivation is isolates from A. atlas. Selection of isolate is based on the nature of higher motility characteristic, cell growth, the number of spores produced and their toxicity against the test insects. Starter media is selected based on the growth parameters of B. thuringiensisin tofu whey media, tofu whey plus urea, coconut water, and nutrient broth. It is obtained the
Keyword: Bioinsecticide, solid-state cultivation, B. thuringiensis, solid waste sago, solid waste iles-iles

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular