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Abstrak :
ABSTRAK
Senyawa UK-3A telah diketahui merupakan senyawa aktif untuk anti kanker dan anti jamur. Senyawa UK-3A telah diisolasi sebagai komponen minor dari miselium Streptomyces sp. 512-02 dan mempunyai gugus aktif hidroksil, amida, dan dilakton cincin sembilan yang terbukti aktif menghambat pertumbuhan bakteri dan sel kanker. Untuk mensintesis senyawa tersebut membutuhkan proses sintesis yang rumit dan waktu yang cukup lama. Pada Penelitian ini disintesis senyawa analog UK-3A yaitu 6-hidroksi-N-oktilnikotinamida dan 3-hidroksi–N-oktilpikolinamida berdasarkan modifikasi gugus aktif senyawa UK-3A. Modifikasi gugus aktif dalam senyawa UK-3A dimungkinkan untuk mendapatkan senyawa analog yang mempunyai bioaktivitas yang sama atau lebih aktif dari senyawa UK-3A induk dan dengn reaksi yang sederhana. Kedua senyawa hasil sintesis tersebut diidentifikasi menggunakan KLT, FTIR, 1H-NMR, dan 13C-NMR. Hasil uji bioaktivitas metode Brine Shrimp Lethality Test (BSLT) terhadap kedua senyawa diperoleh nilai LC50 sebesar 41,14 dan 80,16 μg/mL.

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ABSTRACT
Compound UK-3A is a known active compound for anti-cancer and anti-fungal. UK-3A compound was isolated as a minor component of the mycelium of Streptomyces sp. 512-02 and has active function groups are hydroxyl, amide, and dilactone nine rings were shown to actively inhibit the growth of bacteria and cancer cells. To synthesize these compound require complicated synthesis process and longer periods of time. In this study synthesized compound UK-3A analogue that is 6-hydroxy-N-octylnicotinamide and 3-hydroxy-N-octylpicolinamide modifications based active group of compounds UK-3A. Modification of active groups in the compound UK-3A analogue is possible to obtain compounds that have the same bioactivity or more active than the parent compound UK-3A and simple with less reaction. Both compounds synthesized were identified by TLC, FTIR, 1H-NMR, and 13C-NMR. Test results of brine shrimp lethality bioactivity test method (BSLT) of the two compounds obtained LC50 values of 41,14 and 80,16 mg/mL.

Abstrak :
UK-3A adalah senyawa antibiotika untuk anti kanker dan anti jamur. UK-3A telah diisolasi sebagai komponen minor dari miselium Streptomyces sp. 512-02 dan mempunyai gugus aktif hidroksil, amida, dan dilakton cincin sembilan yang terbukti aktif menghambat pertumbuhan bakteri dan sel kanker. Untuk mensintesis senyawa tersebut membutuhkan proses sintesis yang rumit dan waktu yang cukup lama. Telah disintesis senyawa antibiotik baru, yaitu analog UK-3A berdasarkan modifikasi gugus aktif senyawa UK-3A. Modifikasi gugus aktif dalam senyawa UK-3A dimungkinkan untuk mendapatkan senyawa analog yang mempunyai bioaktivitas yang sama atau lebih aktif dari senyawa UK-3A induk. Senyawa analog pada penelitian ini adalah 3-hidroksi-N-oktilpikolinamida [S1], 2-hidroksi-N-fenil-benzamida [S2], 3-hidroksi-N-fenilpikolinamida [S3], dan 2-hidroksi-N-oktilbenzamida [S4] yang diperoleh melalui reaksi amidasi asam karboksilat dengan amina primer. Keempat senyawa tersebut diharapkan dapat dikembangkan untuk mendapatkan senyawa antibiotik baru dengan rendemen hasil yang tinggi, rute reaksi yang lebih sederhana, dan mempunyai bioaktivitas dalam menghambat pertumbuhan sel kanker terutama leukemia. Senyawa-senyawa hasil sintesis tersebut diidentifikasi menggunakan UV, FT-IR, 1H-NMR, dan 13C-NMR. Hasil uji bioaktivitas secara in vitro terhadap sel kanker Murine leukemia P-388 memperlihatkan kemampuan penghambatan terhadap pertumbuhan sel kanker yang lebih tinggi dibandingkan dengan senyawa UK-3A yaitu IC50 [S1]= 13,2; [S2]=7,75; [S3] =18,5; dan [S4]= 7,5 µg/mL, sementara IC50 UK-3A adalah 38 µg/mL.

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The Synthesis UK-3A analogs i.e 3-hydroxy-N-octylpicolinamide [S1], 2-hydroxy-N-phenyl-benzamide [S2], 3-hydroxy-N-phenylpicolinamide [S3], and 2-hydroxy-N-octylbenzamide [S4] were obtained by modification of UK-3A. UK-3A was isolated from the Streptomyces sp. 512-02 mycelium and has been elucidated as a nine membered ring dilactone derivative possessing hydroxyl (OH) and amide (CONH) moieties . The compound shows ability to inhibit bacterial and cancer cell growth. The analogs were synthesized by amidation of carboxylate. The structure of products were confirmed by 1H- and 13C-NMR, FT-IR, and also UV spectrophotometer. The result of bioassay showed that their compound inhibits the growth of cancer cell Murine leukemia P-388. That's higher compared to that of UK-3A with IC50 are 13,2 µg/mL for [S1], 7,75 for [S2], 18,5 for [S3], and 7,5 for [S4], respectively. Whereas IC50 for UK-3A is 38 µg/mL.

Abstrak :
ABSTRAK
Malaria masih menjadi salah satu masalah di dunia. Salah satu tantangan dalam eliminasi malaria adalah timbulnya resistensi obat antimalaria. Terjadinya resistensi telah mendorong usaha untuk penemuan kandidat obat antimalaria. Beberapa studi yang dilakukan memperlihatkan adanya aktivitas antimalaria dari produk fermentasi Streptomyces sp. Streptomyces sp. menghasilkan beberapa metabolit sekunder yang diantaranya memilki aktivitas antimalaria yaitu prodigiosin. Penelitian ini bertujuan untuk mengetahui efektivitas produk fermentasi Streptomyces sp. sebagai antimalaria, mekanisme kerja hambatannya dan sifat toksisitasnya terhadap sel HepG2. Penelitian ini merupakan penelitian eksperimental dengan teknik in vitro, menggunakan galur parasit Plasmodium falciparum 3D7 drug sensitive . Penelitian dilakukan untuk mengetahui potensi produk fermentasi Streptomyces sp. sebagai antimalaria dengan melakukan uji IC50, dan mekanisme kerja dengan Transmission Electron Microscopy TEM . Dilakukan pula uji toksisitas produk fermentasi Streptomyces sp. pada sel HepG2. Produk fermentasi Streptomyces sp. memiliki aktivitas sebagai antimalaria dengan nilai IC50 sebesar 0,001 ?g/mL, sedangkan kontrol kuinidin yang digunakan memiliki nilai IC50 sebesar 0,054 ?g/mL dan prodigiosin 0,022 ?g/mL. Hasil pengamatan dengan TEM menunjukkan tidak terbentuknya hemozoin. Produk fermentasi Streptomyces sp. bersifat tidak toksik terhadap sel hati HepG2 dengan nilai CC50 1380 ?g/mL. Produk fermentasi Streptomyces sp. memiliki potensi sebagai antimalaria dan tidak memiliki efek toksik terhadap sel HepG2

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ABSTRACT
Malaria remains one of the problem in the world. One of the challenge in malaria elimination is the emergence of antimalarial drug resistance. The occurance of drug resistance has been encouraging efforts to find antimalarial drugs candidate. Some studies showed that there was antimalarial activity from Streptomyces sp. fermentation. Streptomyces sp. produced some secondary metabolite, which include prodigiosin who had antimalarial activity. This research aim to know the activity of Streptomyces sp. fermentation product as antimalarial, worked mechanism and toxicity on HepG2 cell. This research was experimental research with in vitro technique using Plasmodium falciparum 3D7 drug sensitive parasite. The research was done to know potency of Streptomyces sp. fermentation product as antimalarial by IC50 test, and worked mechanism by Transmission Electron Microscopy TEM . Toxicity tests was also done on HepG2 cell. Streptomyces sp. fermentation product has activity as antimalarial with IC50 value 0,001 g mL, quinidine control has IC50 value 0,054 g mL and prodigiosin 0,022 g mL. Observation with TEM showed no formation of hemozoin. Streptomyces sp. fermentation product was not toxic for HepG2 sel with CC50 value 1380 g mL. Streptomyces sp. fermentation product has a potency as antimalarial and not toxic for HepG2 cell.

Abstrak :
Isolat Actinomycetes BCy diisolasi dari lamun Cymodocea rotundata di Prapat Agung, Bali Barat dan telah diidentifikasi menggunakan gen 16S rRNA menunjukkan kemiripan 99,00 dengan Streptomyces sp. Isolat tersebut difermentasi dalam Production Medium 4 PM4 , diinkubasi selama 1 dan 2 minggu. Medium difiltrasi dengan etil asetat lalu biomassa dikeringkan. Hasil biomassa kering minggu 1 dan 2 1,68 g, 2,79 g . Ekstrak kasar minggu 1 68,30 mg lebih tinggi dibandingkan minggu 2 62,35 mg . Metode uji antimikroba menggunakan Kirby-Bauer. Hasil uji menunjukkan ekstrak kasar senyawa antimikroba tidak mampu menghambat Escherichia coli NBRC 3301, namun mampu menghambat Staphylococcus aureus NBRC100910 pada konsentrasi 5 mg/mL dan apabila konsentrasi ditingkatkan menjadi 15 mg/mL maka mampu menghambat Candida albicans UICC Y-29 dan Staphylococcus aureus NBRC100910. ......Isolate Actinomycetes BCy was isolated from seagrass Cymodocea rotundata in Prapat Agung, Bali Barat and was identified using 16S rRNA gene showing similarities 99,00 with Streptomyces sp. The isolates were fermented in Production Medium 4 PM4 , incubated for 1 and 2 weeks. Medium was filtered with ethyl acetate then the biomass was dried. Total dried biomass during the 1st and 2nd weeks were 1,68 g and 2,79 g respectively. The crude extract of the 1st week 68,30 mg was higher than 2nd week 62,35 mg. Antimicrobial test was done using the Kirby Bauer method. The results show that crude extract can not inhibit Escherichia coli NBRC 3301, but inhibit Staphylococcus aureus NBRC100910 in 5 mg mL and if the concentration was added into 15 mg mL, it can inhibits Candida albicans UICC Y 29 and Staphylococcus aureus NBRC100910.

Abstrak :
Kolesterol terkandung di banyak bahan makanan. Kolesterol yang terkandung dalam bahan makanan diekstraksi menggunakan pelarut organik. Pembentukan produk oksidasi kolesterol dalam proses makanan dan kesehatan melibatkan reaksi kimia dan biokimia, reaksi oksidasi kolesterol ini dapat dikendalikan dalam trend oksidasi. Reaksi oksidasi kolesterol melibatkan enzim sebagai katalisator, yaitu enzim kolesterol oksidase. Bakteri yang digunakan untuk menghasilkan enzim kolesterol oksidase adalah Streptomyces sp. Reaksi oksidasi dilakukan dengan oksidasi langsung dari metode substrat. Penelitian sebelumnya jarang menggunakan bahan makanan sebagai substrat dan hanya digunakan kolesterol murni komersial. Pada penelitian ini substrat yang digunakan adalah kolesterol murni dan ekstrak kolesterol kasar dari bahan pangan. Penelitian ini bertujuan untuk mengekstrak kolesterol dari bahan makanan, memperoleh enzim oksidase kolesterol dari Streptomyces sp., Mengoksidasi ekstrak kolesterol kasar, dan membandingkannya dengan kolesterol murni komersial. Dalam penelitian ini akan dilakukan berbagai variabel bebas yaitu konsentrasi enzim (0,5; 1; 2 mg / mL), jenis substrat (kolesterol murni dan ekstrak kolesterol kasar) dan waktu reaksi (5, 30,60,120 dan 180 menit) . Uji oksidasi dilakukan pada parameter konstan tertentu dengan menghitung hasil menggunakan HPLC. Hasil ekstraksi kolesterol diperoleh konsentrasi kolesterol tertinggi dari kuning telur dengan konsentrasi 1,94 mg/mL, hati ayam (0,93 mg/mL), daging sapi (0,25 mg/mL) dan daging ayam (0,23 mg/mL)). Enzim oksidase kolesterol dengan konsentrasi 2 mg/mL dapat mengoksidasi ekstrak kasar kolesterol dari kuning telur, hati ayam dan daging ayam hingga terdegradasi 20%, sedangkan ekstrak kolesterol kasar dari daging sapi mengalami degradasi sebesar 10%. ......Cholesterol is contained in many food ingredients. Cholesterol contained in food ingredients is extracted using organic solvents. The formation of cholesterol oxidation products in food and health processes involves chemical and biochemical reactions, these cholesterol oxidation reactions can be controlled in an oxidation trend. Cholesterol oxidation reaction involves an enzyme as a catalyst, namely the cholesterol oxidase enzyme. The bacteria used to produce cholesterol oxidase enzymes are Streptomyces sp. The oxidation reaction is carried out by direct oxidation of the substrate method. Previous studies rarely used food ingredients as a substrate and only used commercially pure cholesterol. In this study, the substrate used was pure cholesterol and crude cholesterol extract from food ingredients. This study aims to extract cholesterol from food ingredients, obtain cholesterol oxidase enzymes from Streptomyces sp., Oxidize crude cholesterol extracts, and compare it with commercial pure cholesterol. In this research, various independent variables will be carried out, namely enzyme concentration (0.5; 1; 2 mg/mL), type of substrate (pure cholesterol and crude cholesterol extract) and reaction time (5, 30,60,120 and 180 minutes). The oxidation test is carried out at certain constant parameters by calculating the results using HPLC. Cholesterol extraction results obtained the highest cholesterol concentration from egg yolk with a concentration of 1.94 mg/mL, chicken liver (0.93 mg/mL), beef (0.25 mg/mL) and chicken meat (0.23 mg/mL). Cholesterol oxidase enzyme with a concentration of 2 mg/mL can oxidize the crude cholesterol extract from egg yolk, chicken liver and chicken meat to 20% degradation, while crude cholesterol extract from beef is degraded by 10%.

Abstrak :
Tobacco stalk (TS), which is one type of lignocellulosic material, has a xylan content of up to 21.9%. Lignocellulose can be used to produce xylooligosaccharides (XOs). XOs are dietary fibers that have prebiotic activity. This study aimed to produce XOs from tobacco stalk xylan using xylanase from Streptomyces sp. BO 3.2. After the TS was delignified, the xylan was extracted using the alkali method. The delignification process, which used 1% natrium hypoclorite (NaOCl), decreased the lignins from 32.93% to 18.15%. Xylan extraction was conducted using 10% natrium hydoroxide (NaOH); this extraction produced xylan of 15.53% (w/w). The xylanase produced by Streptomyces sp. BO 3.2 on a 0.5% TS medium had 5.92 U/mL of activity, with the optimum condition occurring at pH 5.5 and a temperature of 60 °C. The xylanase was stable, at temperature 4 °C and 30 °C for 120 hours. The xylanase Streptomyces sp. BO 3.2 was capable of hydrolyzing 2% TS xylan and 2% beechwood xylan during the first, third, sixth, and twelfth hours of incubation time; it also produced XOs with degrees of polymerization (DP) of 2.18 and 2.15, respectively. A Thin layer chomatography (TLC) analysis indicated that the hydrolysis products were XOs with the absence of xylose, glucose, and arabinose.

Produksi Xilooligosakarida dari Tangkai Tembakau Menggunakan Streptomyces sp. BO 3.2. Tangkai tembakau merupakan salah satu limbah lignoselulosa yang memiliki kandungan xilan sebesar 21,9%. Lignoselulosa dapat digunakan sebagai bahan baku untuk produksi xilooligosakarida. Xilooligosakarida (XOs) merupakan oligosakarida yang merupakan dietary fiber yang memiliki aktivitas prebiotik. Penelitian ini bertujuan untuk produksi xilooligosakarida dari xilan tangkai tembakau secara enzimatik menggunakan xilanase Streptomyces sp. BO 3,2. Xilan tangkai tembakau diekstraksi secara alkali. Deliginifikasi dilakukan dengan mengunakan natrium hipokorit (NaOCl) 1% mampu menurunkan kandungan lignin dari 32,93% menjadi 18,15%. Ekstraksi xilan tangkai tembakau dengan menggunakan natrium hidroksida (NaOH) 10% mampu mengasilkan rendemen kandungan xilan sebesar 15,53 %. Produksi xilanase Streptomyces sp. BO 3,2 pada media xilan tangkai tembakau 0,5% memiliki aktivitas sebesar 5,92 U/mL dengan kondisi optimum pada pH 5,5 dan suhu 60 °C. Xilanase Streptomyces sp. BO 3,2 stabil pada suhu 4 °C dan 30 °C selama 120 jam. Xilanase Streptomyces sp. BO 3.2 (4.40 U/mL) mampu menghidrolisis xilan tangkai tembaku 2% dan xilan beechwood 2% pada waktu inkubasi 1, 3, 5, dan 12 jam dan mampu menghasilkan xilooligosakarida dengan derajat polimerasi masing-masing 2,18 dan 2,15. Analisis Thin layer chromatography (TLC) menunjukkan produk hidrolisis berupa xilooligosakarida tanpa adanya xilosa, glukosa, dan arabinosa.

Abstrak :
Pembentukan produk oksidasi kolesterol pada proses pangan maupun kesehatan melibatkan reaksi kimia dan biokimia, reaksi oksidasi kolesterol ini dapat dikontrol melalui model kinetika pada tren oksidasi. Penggunaan model kinetika menjadi salah satu aspek penting dalam memprediksi kadar kolesterol hasil oksidasi. Reaksi oksidasi kolesterol melibatkan enzim sebagai katalisator, yaitu enzim kolesterol oksidase. Bakteri yang digunakan sebagai penghasil enzim kolesterol oksidase yaitu Streptomyces sp. Enzim kolesterol oksidase diproduksi dengan menggunakan metode fermentasi submerged. Untuk meningkatkan efektifitas enzim kolesterol oksidase dalam oksidasi kolesterol, maka dibutuhkan matriks pendukung. Enzim kolesterol oksidase diimobilisasi dengan material magnetit silikon dioksida. Material magnetit silikon dioksida disintesis melalui metode hidrotermal dengan proses pelapisan silika pada partikel magnetit. Reaksi oksidasi dilakukan dengan metode oksidasi secara langsung terhadap substrat. Penelitian ini bertujuan untuk memperoleh enzim kolesterol oksidase dari Streptomyces sp., mengimobilisasi enzim terhadap material magnetit silikon dioksida, estimasi konstanta laju reaksi oksidasi kolesterol, serta membandingkannya dengan enzim bebas dan enzim terimobilisasi. Enzim yang telah diproduksi memiliki aktivitas sebesar 5,12 U/mL. Enzim yang telah diproduksi digunakan untuk imobilisasi dan reaksi oksidasi. Variabel bebas yang digunakan dalam penelitian ini yaitu konsentrasi enzim (5;10;20 mg/mL), konsentrasi substrat (1,64;3,23;6,46 mM) dan bentuk enzim (ekstrak kasar enzim kolesterol oksidase dan enzim kolesterol oksidase terimobilisasi). Hasil karakterisasi FTIR dari material magnetit menunjukkan gugus fungsi M-O di bilangan gelombang 559,88; 598,91 dan 680,1 cm-1 gugus Si-O di bilangan gelombang 1615,78 dan 1761,65 cm-1. Hasil uji oksidasi dengan menggunakan HPLC diperoleh konsentrasi substrat secara optimal dioksidasi oleh enzim terimobilisasi dengan konsentrasi 20 mg/mL serta konsentrasi kolesterol awal 1,94 mM dengan hasil akhir sebesar 0,49 mM, sedangkan enzim kolesterol oksidase bebas mengoksidasi kolesterol dengan hasil akhir sebesar 1,459 mM. ......The formation of products related to reactions and chemical reactions, these reactions can be carried out through the kinetics model on the oxidation trend. The use of kinetics is an important aspect in achieving oxidation cholesterol levels. A catalyst of cholesterol oxidation reaction is a cholesterol oxidase enzyme. The bacteria that used as a producer of cholesterol oxidase enzyme is Streptomyces sp. Cholesterol oxidase enzymes are produced using submerged fermentation methods. To increase the effectiveness of cholesterol enzymes in cholesterol oxidation, a support matrix is needed. The cholesterol oxidase enzyme is immobilized with magnetite silicon dioxide. Magnetite silicon dioxide material is synthesized by using hydrothermal method with silica coating process. The oxidation reaction is carried out by the oxidation method directly against the substrate. The aims of this study are to produce the enzymes from Streptomyces sp., immobilize enzymes to magnetite silicon dioxide, obtaining the rate of oxidation reactions, and comparing data between free enzyme and immobilized enzyme. The produced enzyme activity was 5,12 U/mL, this enzyme is used for immobilization and oxidation reaction. In this study, the independent variables are enzyme concentration (5;10;20 mg/mL), substrate concentration (1,94; 3,23;6,46) and enzyme forms (crude extract cholesterol oxidase enzyme and immobilized enzyme). The FTIR characterization of materials have shown that metal oxide functional groups appeared at wavenumber of 559,88; 598,91 dan 680,1 cm-1- and Si-O groups at wavenumber of 1615,78 dan 1761,65 cm-1. The oxidation test by HPLC showed that the substrate concentration optimizely oxidized by immobilized enzyme with the initial concentration 20 mg/mL and substrate concentration 1,94 mM with final oxidation concentration was 1,94 mM, meanwhile the free enyme with same concentration showed 1,459 mM at final concentration.

Abstrak :
Actinomycetes BCy berhasil diisolasi dari lamun Cymodocea rotundata, Pantai Prapat Agung Bali Barat, Indonesia. Identifikasi dengan 16S rRNA menunjukkan isolat termasuk marga Streptomyces. Penelitian bertujuan untuk mengkaji potensi aktivitas antimikroba Streptomyces sp. BCy yang ditumbuhkan pada medium Bushnell-Haas BH dengan penambahan glukosa 0,1 dan yeast extract 0,05 . Isolat diinokulasikan ke dalam 400 mL medium BH Broth lalu diinkubasi pada suhu 30oC selama 1 dan 2 minggu secara statis. Percobaan dilakukan sebanyak dua batch. Medium difiltrasi dan biomassa diukur. Filtrat diekstraksi dengan etil asetat 1:1, v/v lalu ekstrak kasar ditimbang. Ekstrak disuspensikan dengan DMSO dan akuades 1:6, v/v untuk uji antimikroba dengan metode Kirby Bauer pada konsentrasi 5 dan 15 mg/mL. Mikroba uji yang digunakan adalah Escherichia coli NBRC 3301, Staphylococcus aureus NBRC 100910, dan Candida albicans UICC Y-29. Biomassa kering meningkat dari minggu kesatu 469,9 mg ke minggu kedua 667,2 mg . Namun, berat ekstrak kasar menurun dari minggu kesatu 24,7 mg ke minggu kedua 17,05 mg . Aktivitas antimikroba dari ekstrak kasar hanya mampu menghambat Staphylococcus aureus NBRC 100910 serta ukuran zona bening meningkat pada konsentrasi 15 mg/mL. ......Actinomycetes BCy has been isolated from seagrass Cymodocea rotundata, Prapat Agung Coastal Bali Barat, Indonesia. Identification by 16S rRNA showed that isolate belongs to genus Streptomyces. The objective of this study is to analyze antimicrobial potential of Streptomyces sp. BCy which was grown in Bushnell Haas BH medium added with 0.1 glucose and 0.05 yeast extract. The isolate was inoculated into 400 mL BH Broth then incubated at 30oC for 1 and 2 weeks using static fermentation. The experiment was carried out in two batches. Medium was filtered and dry weight of biomass was measured. Filtrate was extracted using ethyl acetate 1 1, v v and also measured for dry weight. The dried crude extract was resuspended in DMSO and aquades 1 6, v v and used for antimicrobial testing using Kirby Bauer method in 5 and 15 mg mL. The target microbes are Escherichia coli NBRC 3301, Staphylococcus aureus NBRC 100910, and Candida albicans UICC Y 29. Biomass increased from first 469.9 mg to second week 667.2 mg. However, crude extract decreased from first 24.7 mg to second week 17.05 mg. The antimicrobial activity of crude extract was able to inhibit Staphylococcus aureus NBRC 100910 and also had larger clear zone in 15 mg mL.

Abstrak :
Enzim kolesterol oksidase adalah enzim oksidoreduktase yang mampu mendegradasi kolesterol. Pada percobaan ini, dilakukan produksi enzim kolesterol oksidase oleh Streptomyces sp. melalui fermentasi submerged lalu dilakukan investigasi terhadap aktivitas dan kemampuan katalisis enzim kolesterol oksidase. Pada percobaan, substrat dan enzim divariasikan pada berbagai konsentrasi, yaitu 0,15, 0,075, dan 0,0375 U/mL dan 1,25, 2,5, dan 5 mg/mL. Perbandingan konstanta laju reaksi antara ekstrak kasar enzim dan enzim komersial diperoleh dari hasil penelitian. Perbandingan konstanta laju reaksi enzimatis oleh faktor yang mempengaruhi, diantaranya imobilisasi enzim dan suhu inkubasi enzim, dengan data yang diperoleh dari literatur. Enzim dan substrat mengalami reaksi oksidasi pada waktu inkubasi 5, 30, 65, 120, dan 240, lalu konsentrasi kolesterol residu pada sampel dilakukan plotting dengan waktu inkubasi, dan konstanta laju reaksi diperoleh melalui permodelan reaksi orde 1 dengan pendekatan integrasi numerik Euler. Aktivitas ekstrak kasar enzim yaitu 1,69 U/mL dengan konstanta laju reaksi yaitu 0,01/menit untuk ekstrak kasar enzim dan 0,014/menit untuk enzim komersial. Selanjutnya, diperoleh faktor yang mempengaruhi konstanta laju reaksi oksidasi kolesterol secara enzimatik oleh enzim kolesterol oksidase, yaitu konsentrasi enzim, jenis enzim, imobilisasi, dan suhu inkubasi. Reaksi oksidasi kolesterol oleh enzim kolesterol oksidase dari Streptomyces sp. mengikuti reaksi orde 1. ...... Cholesterol oxidase well known as oxidoreductase enzyme which able to degrade the cholesterol. Here, we produced cholesterol oxidase from Streptomyces sp. by submerged fermentation and investigate the activity and cholesterol oxidation kinetics of cholesterol oxidase. The enzyme and substrate are diluted in various concentration, 0.15, 0.075, 0.0375 U mL and 1.25, 2.5, 5 mg mL, respectively. Further step was comparing crude enzyme and commercial enzyme from Streptomyces sp. by oxidation constant rate of reaction. The enzyme and substrate were through the oxidation reaction, and the amount of cholesterol residue in the sample are determined by HPLC. In this work, we also compared the oxidation constant rate of reaction of previous experiment from literature with affecting factors, such as immobilization and incubating temperature. The cholesterol residue in the sample are plotted by time reaction and the rate constant is obtained by first order rate reaction using Euler integration method. The crude enzyme activity is 1.69 U mL and the reaction constant are 0.01 U mL and 0.014 for crude extract and commercial enzyme, respectively. Furthermore, several factors affecting constant rate of enzymatic oxidation of cholesterol were enzyme concentration, enzyme type, immobilization, and incubating temperature. Cholesterol oxidation by Streptomyces sp. cholesterol oxidase was follow the first order reaction.

Abstrak :
The objective of this study is to know effectiveness of various antagonist microorganism (Streptomyces sp., Bacillus subtilis, Pseudomonas fluorescens and Trichoderma sp.) for controlling leaf spot that caused by Phaeotrichocornis crotalariae on seedling of Acacia Crassicarpa. This study wwas caried out in two phases, they are in vitro antagonistic test and in vivo antagonistic test In Vitro antagonistic test was carried out according to multiple test method, a part of filterpaper 0,5 cm in diameter was dipped on to suspension of each microorganism that would be tested and then dried to be put in to a petridish that contain P.crotalariae 0,5 cm in diameter was dipped on to suspension of each microorganism that would be tested and then dried to be put in to a petridish that contain P. crotalariae 0,5 cm in diameter at PDA medium. Obeservation was carried out to know inhibiting capacity of antagonist microorganism. In the mean time, in vivo antagonistic test was carried out with spraying a suspension of each microorganism to seedling of A. crassicarpa and inoculate pathogen fungi. Observation was carried out according to multiple test method, a part of filterpaper 0,5 cm in diameter was dipped on to suspension of each microorganism that would be tested and then dried to be put in to a petridish that contain P.crotalariae 0,5 cm in diameter at PDA medium. Observaton was carried out to know inhibiting capacity of antagonist microorganism. In the mean time, in vivo antagonistic test was carried out with spraying a suspension of each microorganism to seedling of A. crassicarpa and inoculate pathogen fungi. Observation was carried out to know pathogen incubation periode, disease intensity and disease percentage. Result of in vitro antagonistic test showed that isolates of Streptomyces sp., B. subtilis, P.fluorescens and Trichoderma sp able to inhibit pathogen growth with capacity inhibiting 43.07%, 44.03%, 32.03% dan 53.23% by successively. In the mean time, in vivo antagonistic test showed that each of the microorganism antagonist able to lenghten incubation periode of control treatment is 4.1 days. Treatment of each application of the antagonist microorganism unable to depress disease intensity and disease percentage of P.crotalariae on seedling of A.crassicarpa.