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: Bioinsecticides Production by Bacillus thuringiensis Using Agroindustrial By Product in Solid Fermentation
Abstrak: Bacillus thuringiensis is one of well-known bioinsectiside resources, and utilized in organic farming for the replacement of chemical insecticide. Substrate composition affect the bioinsecticides production. In fermentation process, microorganisms require water, carbon, nitrogen, and minerals for the growth. Substrate composition also affect the characteristics of bioinsecticides products, especially in growth, toxicity, and potential products. Agroindustrial by product contains the necessary complex nutrients components as a substrate for the growth of microorganisms. This research aimed to assess the ability of Bacillus thuringiensis using substrate combination of carbon source (onggok, pulp of coffee, starch fractions of iles-iles, and sago’s waste) and nitrogen source (tofu’s waste, peanut meal, palm kernel cake, and corn hominy) in bioinsecticides production using solid media cultivation. The main parameters to select the carbon and nitrogen sources are LC50 value and potential bioinsecticides products. The research consisted of three stages, there were substrates characterization, microorganisms characterization, and bioinsecticides production. Substrates characterization was conducted to analyze proximates content and physical characteristics such as aw, bulk density, and water holding capacity. Microorganisms that was used consisted of three strains, there were Bacillus thuringiensis subsp. aizawai, Bacillus thuringiensis subsp. berliner dan Bacillus thuringiensis subsp. israelensis. Microorganisms characteristics includes the ability of cellulolytic, amylolytic, and ability of the cell production. Bioinsecticides production stages was divided into three stages, there were influence of carbon source substrates, and nitrogen source substrates for bioinsecticides production, and the influence of bioinsecticides production using carbon and nitrogen sources that were selected on a scale of 2 kg. Carbon source substrates have main component contents like carbohydrate (50.7 – 65.9 %), total simple sugars (23.5 – 30.5 %), crude fiber (11.3 – 31.4 %), and protein (0.5 – 11.5 %). Nitrogen source substrates have carbohydrate (25.1 – 59.4 %), total simple sugars (10.5 – 25.1 %), crude fiber (6.5 – 37.4 %), and high protein (7.1 – 24.9 %). Nitrogen source substrates has a higher protein content than the carbon source substrates. The results showed that all strains of Bacillus thuringiensis that were determined has the ability to produce cellulase and amylase enzymes so they can use all substrates as a carbon and nitrogen sources in solid media cultivation. Pulp of coffee has an advantage because it contains simple sugars higher than other substrates so in the carbon source substrate selection, cultivation using pulp of coffee as a substrate for Bacillus thuringiensis subsp. berliner and Bacillus thuringiensis subsp. israelensis can produce the highest potential product. Cultivation of Bacillus thuringiensis subsp. berliner using pulp of coffee as a substrate can produce the highest toxicity with LC50 value of 0.07 μg/ml and potency of 11429 IU/mg, while cultivation of Bacillus thuringiensis subsp. israelensis using pulp of coffee as a substrate can produce the highest toxicity with LC50 value of 0.05 μg/ml and potency of 16000 IU/mg. Bacillus thuringiensis subsp. aizawai has high amylolytic capability thus in the carbon source selection, cultivation of Bacillus thuringiensis subsp. aizawai can produce the highest toxicity with LC50 value of 0.09 μg/ml and potency of 8889 IU/mg. Suitable substrates for the cultivation of Bacillus thuringiensis subsp. aizawai is
Keyword: bioinsecticide, Bacillus thuringiensis, toxixity, solid media cultivation

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