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: Biofertilizer Consortium Formulation and Its Application on Corn Plants
Abstrak: Pupuk hayati merupakan pupuk yang mengandung mikrob hidup yang dapat membantu penyediaan unsur hara yang dibutuhkan untuk pertumbuhan dan perkembangan tanaman. Penelitian ini bertujuan menguji formula pupuk hayati yang berisi konsorsium bakteri non-aktinomiset, cendawan, dan aktinomiset terpilih dengan bahan pembawa cair, berdasarkan kestabilan viabilitas sel mikrob, dan aplikasinya pada tanaman jagung. Uji efektivitas terhadap tanaman jagung dilakukan di rumah kaca menggunakan rancangan acak kelompok satu faktor antara kombinasi dosis pupuk N, P, K dan pupuk hayati dengan tiga ulangan. Isolat yang digunakan yaitu Bacillus thuringiensis SAHA 12.12, Lactobacillus plantarum IN05, Rhizobium sp. R1KG, Sacharomyces cerevisiae L1, Streptomyces sp. A4J, dan Trichoderma sp. T2J yang dikonsorsiumkan dengan bahan pembawa cair. Formula pupuk hayati disimpan selama 8 minggu dan dilakukan uji viabilitas setiap satu bulan selama penyimpanan. Hasil uji menunjukkan viabilitas mikrob menurun setelah disimpan selama delapan minggu dan penurunan paling tinggi pada Streptomyces sp. Aplikasi formula konsorsium pupuk hayati memberikan pengaruh nyata terhadap panjang akar, diameter batang, bobot kering tajuk, bobot tongkol berkelobot, dan bobot biji tongkol. Pemberian formulasi konsorsium hayati kombinasi perlakuan P1M2 (kombinasi 50% pupuk N, P, K dan 100% formulasi pupuk hayati) dapat mengurangi penggunaan N, P, K sebanyak 50% dari dosis rekomendasi., Biofertilizer is a fertilizer that contains live microbes that help the plants to obtain nutrients needed for growth and development. This study aimed to observe the effectiveness of a biofertilizer formula containing a consortium of selected bacteria, fungi, and actinomycetes with liquid carrier materials to maize based on the stability of microbial cell viability and its application. The experiment was conducted in a greenhouse using a randomized block design with one-factor which consisted of a combination of N, P, and K fertilizers and biological fertilizers with three replications. The isolates used in thus experiment were Bacillus thuringiensis SAHA 12.12, Lactobacillus plantarum IN05, Rhizobium sp. R1KG, Saccharomyces cerevisiae L1, Streptomyces sp. A4J, and Trichoderma sp. T2J which were combined as a consortium with liquid carrier material. The formula was stored during 8 weeks, and every weeks was analyzed to observed its viability. The results showed that microbial viability decreased after being stored for eight weeks and the highest decrease was shown by Streptomyces sp. The biofertilizer consortium formula applied to corn significantly influenced the growth and production, including root length, stem diameter, crown dry weight, husk cobs, and cob seed weight. Biological consortium formulations PIM2 can reduce N, P, and K application up to 50% of the recommended dose.
Keyword: actinomycetes, Bacillus, biofertilizer, corn, viability

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