Judul: Isolasi dan Identifikasi Bakteri Manolitik Laut dari Pulau Pari
Abstrak: Indonesia's tropical marine biodiversity of microorganisms have high potential and commercial value. This study focused on the isolation and identification of potential microbes which produce mannanase enzyme to hydrolyze mannan and eventually produce manno-oligosaccharides. Sampling was conducted in Pari island at Jakarta Bay area, the screening and observation of mannanase enzyme activity from those marine biodiversity have been conducted. The research succeed to collect 20 bacteria that could produce mannanase enzyme, three of them have the most high activity from qualitative analysis based on mannolytic index using congo red method for Pari 3, 4 dan 5 such as 4,33, 2,40, dan 2,60. Further quantitative analysis for these bacteria were conducted such as activity of mannanase using dinitrosalicylic acid method and resulted the highest activity is Pari 3 with 2,474 U/mL and Pari 4 with 1,193 U/mL both in the second day of fermentation, whereas Pari 5 with 1,087 U/mL in the third day of fermentation. Analysis 16S rRNA gene were showed that Pari 3, 4, and 5 are domain Bacteria, filum Firmicutes, class Bacilli, ordo Bacillaceae and genus Bacillus. For the spesific identification are using phylogenetic tree and concluded that Pari 3 has similar sequence 91.1% with Bacillus safensis and 92% Bacillus pumilus, from the both result showed the genetic relationship which is less than 97% in similarity therefore it was suggested that the bacteria Pari 3 is a new strain and can be further investigated. Whereas The results of Pari 4 identification has similar sequence 94.1% with Bacillus anthacis and 92.2% with the Bacillus cereus in the genetic relationship. The results of Pari 5 identification has similar sequence 97.1% with Bacillus anthracis and 95.2% with the Bacillus cereus in the genetic relationship.
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Judul: Isolasi dan Pencirian Bakteri Mananolitik Pendegradasi Bungkil Inti Sawit
Abstrak: Mannanase is an enzyme which can be utilized in food and feed sector. This research is aimed to isolate and characterize the mannanase producing soil bacteria from palm plantations in Cikasungka, Bogor, and to know the ability of manannase in hydrolyzing palm kernel cake (PKC) substrate become to manno-oligosaccharide (MOS). There were 8 isolates isolated from the soil of Cikasungka Plantation, Bogor. Three isolates were choosen with the highest mannanolytic index to be further characterized. Isolate 5 produced the highest mannanase activity at 18 h of incubation (0.039 U/mL) and 54 h (0.051 U/mL). Isolate 6 produced the highest mannanase activity at 30 h of incubation (0.041 U/mL) and 66 h (0.058 U/mL). Isolate 7 produced the highest mannanase activity at 24 h of incubation (0.041 U/mL). The specific activity of isolate 5, 6 and 7 had value 2-3 times higher than their own enzymatic activity. One selected isolate, isolate 6 had optimum activity in pH 5.5 at 30 °C and pH 7 at 40 °C. The enzyme stability of isolate 6 were decreasing at the both pH and temperature optimum. The polimerization degree of isolate 6 in pH 5.5 at 30 °C had value of 4.0-4.1 and 6.9-7.5 in pH 7 at 40 °C. Isolate 6 posseses high degree of polimerization in MOS production, it is potentially used as cattle prebiotic.
Keyword: mannanase, mannanolytic, manno-oligosaccharide, palm kernel cake, polimerization degree

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