Judul: Optimasi Aktivitas Selulase Ekstraseluler dari Isolat Bakteri RF-10
Abstrak: Cellulase is one of the enzymes used in many industrial applications. High enzyme price is the major problems faced in enzyme based industrial. One of the solution to decrease the enzyme price is to explore the potential microbe as producers of cellulase. This study aimed to determine the optimum incubation time for cellulase production of the RF-10 bacterial isolates and optimized optimum temperature and pH of cellulase. Cellulase activity of RF-10 bacterial isolate qualitatively was measured by Congo Red 0.1% staining method and quantitatively by 3.5-dinitrosalicylic acid method. The results showed that RF-10 produced cellulase based on clear zone formation and extracellular enzymes was obtained 1.625. The maximum cellulases production in CMC medium reached at the 42 hours with the activity 10.712 x 10-6 U/mL. Optimization of enzyme activity showed that the optimum temperature at 50 °C and optimum pH at 6.5. In addition, the enzyme has actively working in the range of pH 5.5-7.5.
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Judul: Pemurnian dan Karakterisasi Enzim Selulase dari Bakteri yang Diisolasi dari Limbah Rumput Laut
Abstrak: Seaweedwasteis a sourceof bacteria thatcanproduce cellulaseenzyme. PMP0126yisolateis one collection isolateof the Research and Development Center for Marine and Fisheries Product Proecessing and Biotechnology Agency for Marine and Fisheries Research and Development Ministry of Marine Affairs and Fisheries obtainedfromseaweed wastefrom Pameungpeukarea, Garut, West Java. The aims this research were to purify, characterize the cellulase enzyme, and identify the bacteria producing the enzyme using 16S-rRNA. PMP 0126yisolatewasa Gram-negativeshortrodshape bacteria. Based on thesequencingof the 16S-rRNA genfrom 1282base pairPMP0126y isolate had96%similaritywith Chryseobacteriumindologenesstrain McR-1. Theisolate had 1.9 cellulolytic index onCarboxymethyl Cellulose(CMC) agar medium. The highestcellulaseactivityobtained onthe thirdday offermentation timewith acellulaseactivityof0.108U/mLandspecificactivityof0.120U/mg. Initialpurificationof cellulasebyultrafiltrationproducedactivityof0.112U/mL. Purificationthe enzyme byanionexchange chromatographyproducedthe highestpeak of proteininthefraction no. 48withcellulaseactivityof0.154U/mLat 37.3mMNaCl.Optimumactivity ofthe cellulaseenzymeafterultrafiltrationwaspH 5and300C,while optimumactivity ofthe cellulaseenzymebyanionexchange chromatographywaspH 5and400C. At 300C, the enzymeremainedstableup to4hourincubation.Theactivity ofthe cellulasewasincreasedbyaddition ofCaCl2ions by 53%anddecreased bythe additionof ZnCl2 ions by 78%. Thecellulase showed the highest activity i.e. 0.149U/mL using treated seaweed wasteGlacilariasp. as substrate. Using SDS-PAGE and zimogram analysis, the molecular weight of the cellulase was estimated to be 39 kDa, 30 kDa, and 14 kDa.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf