Judul: Uji Efektivitas Bakteri Pemicu Tumbuh Tanaman Penyusun Pupuk Hayati Provibio.
Abstrak: The use of biofertilizers is expected to improve soil health, stimulate plant growth and increase crop production. In connection with the utilization of microbial biofertilizers, quality testing needs to be done periodically to maintain the quality of biofertilizers. This study aims to evaluate the effective of plant growth promoting bacteria at Provibio biofertilizer. The stages of this research are strains testing of plant growth promoting bacteria which includes purification, testing the potency of bacteria, pathogenicity test, antagonism test, characterization and identification, the calculation of the total population for each strain of bacteria in mixed cultures. The results show that plant growth promoting bacteria inoculan real in increase plant growth, but does not significant effect in increasing root length, wet weight and dry weight of plant compared to controls. ICBB 6099 isolate potentially pathogenic to humans or animals. ICBB 6088 shown antagonistic characteristic on ICBB 6099 isolate when combined in vitro. ICBB 6099 isolate has similar characteristics to the genus Listeria. Whereas ICBB 8767 isolate which has similar characteristics to the genus Phenylobacterium and Aeromicrobium. ICBB 8767 has highest density of populations in the mixed cultures.
Keyword: effectivity test, pathogenicity, identification, plant growth promoting bacteria, antagonism

Judul: Uji Efektivitas Mikrob Anti Hama, Anti Bau dan Dekomposer yang terkandung dalam Pupuk Hayati “Provibio”
Abstrak: Biofertilizer quality tests should be done to analyze the content, the benefits and the risks to meet the biofertilizer quality standards. The study was conducted by testing the effectivity of microbe against pest, odor reducer and decomposer, its pathogenicity for animal and hypersensitivity for plant, antagonism among microbes and identification of the microbes. Biofertilizer of "Provibio" contained 9 isolates, but 1 isolate of ICBB 7125 which was suspected as Microbacterium lacticum could not be cultured. The results showed that isolate of ICBB 6095 possess inclination can mortality increase of grayak caterpillar (Spodoptera litura), isolate of ICBB 8808 can reduce feces odor of chicken which was tested by organoleptic method, isolate of ICBB 8810 and ICBB 9182 possess inclination can hasten straw composting. ICBB 6099 and ICBB 6095 showed pathogen (α-hemolysis) for animals, meanwhile ICBB 6099 was antagonistic against ICBB 6088. Based on the morphological and biochemical studies, the isolate of ICBB 6099 was identified as Listeria sp., ICBB 6088 as Azospirillum sp., ICBB 9098 as Azotobacter sp., ICBB 9251 as Bradyrhizobium sp., ICBB 9065 as Bacillus thuringiensis and ICBB 8810 as Bacillus sp. In addition, isolate of ICBB 6099 had been identified as Lactobacillus sp. most probably the stock culture of isolate was contaminated of the Listeria sp. Two of the member of “Provibio” community are fungi i.e. the ICBB 9182 that was identified as fungi belongs to class of Basidiomycetes and ICBB 8808 that was identified as Saccharomyces sp.
Keyword: biofertilizer, pathogen, identification, effectivity

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