Judul: Formulasi Produk dan Penurunan Mutu selama Penyimpanan Bioinsektisida Bacillus Thuringiensis subsp. aizawai dari Limbah Industri Tahu
Abstrak: Bioinsecticide can kill insects and disease vector. Bioinsecticide developed from bacteria, virus, mushroom, and protozoa. Bacteria that often used to produce bioinsecticide is “Bacillus thuringiensis”. Bacillus thuringiensis subsp. aizawai (Bta) as one of the Bacillus thuringiensis (Bt) species produces crystal protein called delta endotoxin (δ-endotoxin). As other Bt crystal protein, this crystal is specifically toxic to larvae Lepidoptera and Dipteral ordo. One of advantage bioinsecticide Bta is savety for our environment. Therefore, in this research produce bioinsecticide Bta from waste of industrial tofu as raw material standard. This research was to obtain the best product formulations Bta, reduction quality Bta, and to asses the level of toxicity Bta during storage. Media formulation using tofu waste and tofu waste water, with a ratio of 20: 80 and the starter added 10 (% v /v). In this research, product formulation using lactose as filler. The highest viable spore count (VSC) is the product formulation of freeze lactose (1.45 x 108 spora/mg), whereas the lowest VSC is the product formulation of freeze without lactose (9.25 x 107 spora/mg). After storage one month, the highest VSC is product formulation of freeze lactose was storaged on temperature 5 oC (9 x 106 spora/mg), whereas the lowest VSC is the product formulation of freeze without lactose was storaged on temperature 35 oC (1.5 x 106 spora/mg. The level toxicity (LC50) product formulation of freeze lactose and freeze without lactose are 0.25 mg/l. Value of LC50 from all of the treatment higher than value of LC50 Bactospeine (0.05 mg/l). During storage one month, value of LC50 and potential product bioinsecticide Bta go down continually.
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Judul: Produksi Bioinsektisida Dari Bacillus thuringiensis subsp. aizawai Menggunakan Limbah Industri Tahu Sebagai Substrat.
Abstrak: This research was to obtain the best media formulation oftions for bioinsectisides production using Bacillus thuringiensis subsp. aizawai and to asses the level of toxicity against larvae Crocidolomia binotalis (cabbage worms). Media formulation oftions using tofu waste and tofu waste water, with a ratio of 20: 80, 30: 70, and 40: 60 and the amount of starters added 10, 15, and 20 (% v /v). Observations done at 0, 30, and 48 hours of the cultivation time which include pH, total residual sugar, the total plate count, and the viable spore count. Toxicity tests were conducted by bioassay using larvae Crocidolomia binotalis (cabbage worms). The analysis of raw materials obtained on the carbon content of tofu waste and tofu waste water at 5.64% (wb) and 0.27% (wb), while the nitrogen content of 0.42% (wb) and 0.02% (wb). During the cultivation, the pH in the cultivation liquid was increased while total sugars is decreased. The pH values during cultivation was ranging from 7.27 to 8.21. Efficient use of substrate for cultivation 30 hours ranged from 13.14% (C2) to 33.61% (A3) and for cultivation 48 hours ranged from 31.73% (C3) to 41.91% (B3). The highest total plate count in this research is media formulation of B3 (2.14 x 108 cells/ml) with cultivation time during the 48 hours, whereas the lowest total plate count in this research is media formulation of A3 (1 x 107 cells/ml) with cultivation time during the 48 hours. The highest amount of viable spore count in this research is the media formulation of B2 (2.95 x 107 spores/ml) with cultivation time during the 48 hours, whereas the lowest viable spore count in this research is the media formulation of A1 (1.25 x 106 spores/mL) with cultivation time during the 48 hours. Cultivation during 30 hours using media formula A1 produces crystal protein in high toxicity to Croccidolomia binotalis larva. This is indicated by the highest toxicity level from bioassay test which shown by medium formulae of A1, which was 1,34 mg/L, and the lowest toxicity level was shown by media formulae of C3, which was 174,16 mg/L. Whereas cultivation during 48 hours using media formulation of A2 produces crystal protein in high toxicity to Croccidolomia binotalis larva. This is indicated by the highest toxicity level from bioassay test which shown by medium formulae of A1, which was 7,44 mg/L, and the lowest toxicity level was shown by media formulae of C3, which was 45636,00 mg/L. In the control (distilled water + prostiker) who were not given fluids bioinsectiside products not found of C. binotalis larva is dead, while in the commercial product (Bactospeine) toxicity was obtained at 0.05 mg / L with potential products 16 000 UI / mg.
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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