Judul: Characterization of Cellulase from Marine Fungi RS6A and Its Application for Hydrolysis of Kappaphycus alvarezii
Abstrak: Hidrolisis secara enzimatis diketahui memiliki keunggulan diantaranya yaitu secara spesifik menghasilkan oligosakarida, ramah lingkungan dan tidak berpotensi meninggalkan residu toksik. Kapang RS6A dimanfaatkan dalam proses hidrolisis rumput laut K. alvarezii sebagai penghasil enzim selulase untuk memisahkan komponen lignoselulosa dan oligosakarida. Penelitian ini bertujuan menentukan pengaruh perbedaan waktu inkubasi dan konsentrasi CMC terhadap aktivitas selulase, menentukan waktu inkubasi dan konsentrasi CMC terbaik untuk produksi enzim selulase dan menentukan waktu hidrolisis rumput laut K. alvarezii menggunakan enzim selulase dari isolat kapang RS6A. Analisis data aktivitas selulase yang digunakan dalam penelitian ini adalah rancangan acak lengkap faktorial dua faktor. Konsentrasi sumber karbon dan waktu inkubasi yang menghasilkan aktivitas selulase optimum yaitu CMC 2% dan inkubasi enam hari. Ekstrak kasar selulase memiliki aktivitas selulase optimum sebesar 0,071±0,001 U/mL, aktivitas endoglukanase sebesar 0,197±0,035 U/mL, dan aktivitas spesifik selulase sebesar 0,088±0,009 U/mg. Hidrolisis selama 3 jam menghasilkan persentase hidrolisis selulosa sebesar 73% dan persentase hidrolisis lignin sebesar 4,8%., Enzymatic hydrolysis potentially offers many advantages, such as specific hydrolysis resulting in the production of target oligosaccharides, environmentally friendly and without produce toxic residual molecules. Fungi RS6A was applied in the hydrolysis of algae K. alvarezii as a cellulase enzyme producer to separated lignocellulose and oligosaccharide. The objectives of this research were to determine the effect of differences in incubation time and concentration of CMC on cellulase activity, determine the best incubation time and concentration of CMC for cellulase enzyme production and determine the hydrolysis time of K. Alvarezii. Data analysis of cellulase used in this research was completely randomized factorial design with two factors. The incubation time for 6 days and treatment of 2% CMC showed the highest cellulase activity of 0.071±0.001 U/mL, the highest endoglucanase activity of 0.197±0.035 U/mL and the highest specific cellulase activity of 0.088±0.009 U/mg. Hydrolysis for 3 hours showed cellulose hydrolysis degree of 73% and lignin hydrolysis degree was 4.8%.
Keyword: cellulase, hydrolysis, marine fung

Judul: Karakterisasi Enzim Selulase dan Aplikasinya pada Substrat Limbah Pertanian
Abstrak: Cellulose is the most abundant plant cell walls. Lignocellulolytic are consist of cellulose, hemicelluloses and lignin. Degradation of cellulose involves a complex interplay between different cellulolytic enzymes. Among others, it has been widely accepted that three types of cellulases including endoglucanases, exoglucanases and β-glucosidases act synergistically to convert cellulose to glucose. This study was aimed to characterized cellulase enzyme which produced by cellulolytic bacteria from soil and applied it on agricultural waste such as rice straw, corn cob and banana peel. Qualitative analysis have done on 9 isolates cellulolytic bacteria to know the highest cellulolytic index by using congo red 0.1%. From 9 isolates, 1 isolate have IS 1.75. Quantitative analysis showed isolate 6-2 has the highest cellulase activity of 0.005U/ml. Highest activity of cellulase enzyme from isolate 6-2 resulted on bufer pH 7 and 40oC. Cellulase activity of isolate 6-2 was stable for 75 minutes. Isolate 6-2 has relatively low cellulase activities in CMC as it has small enzyme activity in degrading substrates of agriculture waste. The cellulose enzyme activity on ricestraw resulted 0.007U/ml, corncob resulted 0.008U/ml, and bananapeel resulted 0.013U/ml. Isolate 6-2, gram positive bacteria can degrade cellulose by using cellulase enzyme. On the application cellulase enzyme activity on bananapeel was higher than the others.
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Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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