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Introduksi Gen Penyandi AHL-Laktonase (aiiA) Bacillus cereus INT1c ke dalam Agrobacterium tumefaciens AGL 1.
No full textBakteri menggunakan mekanisme quorum sensing (QS) dalam berkoordinasi untuk melakukan suatu proses tertentu melalui perantara molekul sinyal asil homoserin lakton (AHL). Bakteri fitopatogen umumnya menggunakan mekanisme QS untuk mengekspresikan gen virulen pada saat menginfeksi tanaman. Penghambatan ekspresi gen virulen tersebut dapat dilakukan dengan mendegradasi senyawa AHL menggunakan AHL-laktonase. AHL-laktonase merupakan kelompok enzim yang berfungsi untuk menghidrolisis cincin lakton pada molekul AHL. Enzim ini umumnya ditemukan pada kelompok Bacillus spp. dan disandikan oleh gen aiiA. Penelitian ini bertujuan mengintroduksi gen penyandi AHL-Laktonase (aiiA) dari isolat Bacillus cereus INT1c dalam E.coli DH5α transforman ke dalam Agrobacterium tumefaciens AGL 1. Gen aiiA dari isolat Bacillus cereus INT1c dalam E.coli DH5α rekombinan berhasil diintroduksikan ke dalam sel A. tumefaciens AGL 1 melalui plasmid vektor pCambia 2300. Pemotongan plasmid rekombinan dengan menggunakan enzim Nco I dan Bgl II menunjukkan adanya fragmen DNA berukuran 8743 pb (pCambia 2300) dan 800 pb (gen aiiA) pada gel agarosa 1.0%. Hasil ini membuktikan bahwa plasmid rekombinan berhasil diintroduksikan dan telah diperbanyak di dalam sel A. tumefaciens AGL 1 transforman
Efektivitas Bakteri Metanotrof dan Ochrobactrum anthropi sebagai Pupuk Hayati dan Pereduksi Emisi Gas CH4 serta N2O di Sawah Anorganik.
No full textGlobal warming is the increasing of earth's surface temperature which can occurred due to agricultural activities. Agricultural activities contribute to the global warming as sources of CH4 and N2O emissions. Application of methanotrophic bacteria, Ochrobactrum anthropi, Azotobacter and Azospirillum combination could reduce the emission of CH4 and N2O. In addition, these bacteria can fix nitrogen (N2) to enhance the plant growth. The purpose of this study was to determine the effectiveness of methanotrophic bacteria, Ochrobactrum anthropi, Azotobacter and Azospirillum combination as biofertilizer and emission reducer of CH4 and N2O in the inorganic paddy fields. This experiment was arranged by treating 100% dosage of inorganic fertilizer as positive control, 25% dosage of inorganic fertilizer and 25% dosage of inorganic fertilizer mixed by biofertilizer. The observations were made on the growth parameters and the rate of gas fluxes. The combination of bacterial isolates could increase rice growth, grain yield productivity and they also could reduce CH4 and N2O emission
Karakterisasi Bakteri Isolat Bacillus sp. NTT 3a dan Bacillus sp. NTT 3e.
No full textQuorum sensing (QS) is a bacterial communication mechanism controled by bacterial population and mediated by autoinducer (AI) molecule. AI molecule of Gram-negative bacteria generally is Acyl Homoserine Lactone (AHL). Acyl Homoserine Lactone Lactonase (AHL-lactonase) enzyme encoded by aiiA gene is an enzyme that can hydrolyze the lactone ring so that inhibiting QS process. This study aimed to characterize the AHL-Lactonase producing bacteria i.e. Bacillus sp. NTT 3a dan Bacillus sp. NTT 3e. the characterization is based on colony morphology, characteristics of growth in NB medium (growth curve, specific growth rate and generation time), and activity of AHL-lactonase. AHL-lactonase activity was observed using bioindicator Chromobacterium violaceum. Colonies of Bacillus sp. NTT 3a and Bacillus sp. NTT 3e are round, have a convex elevation and slippery ledges. The colony color of Bacillus sp. NTT 3a is white, while Bacillus sp. NTT 3e is beige. The maximum specific growth rate of Bacillus sp. NTT 3a and Bacillus sp. NTT 3e was 0,005 minute-1 and 0,0042 minute-1 respectively. The highest activity of AHL-lactonase in both of bacterial culture reached the age of 42 hours (stationary phase). Protein content of Bacillus sp. NTT 3a (0,539 mg/ml) lower than Bacillus sp. NTT 3e (0,578 mg/ml) at the 48 hours. However, the activity of AHL-lactonase in Bacillus sp. NTT 3a is higher than Bacillus sp. NTT 3
Growth of Transgenic and Non-transgenic Jala Ipam Potato Inoculated by Endophytic Bacteria Micrococcus endophyticus G053
No full textTanaman kentang kultivar Jala Ipam transgenik JCL2 dan JCL3 mengekspresikan gen LYZ-C secara konstitutif di dalam sitosol sehingga resisten terhadap bakteri patogen, yaitu Ralstonia solanacearum dan Pectobacterium carotovorum subsp. carotovorum. Gen LYZ-C menyandi lisozim yang merusak dinding sel bakteri dengan cara memotong ikatan β-1,4 di antara N-asetil-D-muramat dengan N-asetil-D-glukosamin pada peptidoglikan sehingga dapat mengakibatkan lisisnya sel bakteri. Bakteri endofit Micrococcus endophyticus G053 dapat meningkatkan pertumbuhan tanaman kentang. Penelitian ini bertujuan untuk mengetahui pertumbuhan plantlet kentang kultivar Jala Ipam transgenik yang mengandung gen LYZ-C dan non-transgenik yang diinokulasi dengan bakteri endofit M. endophyticus G053 secara in vitro. Plantlet kentang kultivar Jala Ipam non-transgenik, JCL2, dan JCL3 yang diinokulasi dengan bakteri endofit M. endophyticus G053 secara in vitro, tidak menunjukkan perbedaan nyata dalam pertumbuhan tinggi batang, jumlah buku, panjang akar, dan jumlah akar. Reisolasi bakteri dari plantlet yang telah diinokulasi sebelumnya dengan M. endophyticus G053 dan dari hasil subkultur plantlet tersebut menunjukkan bahwa M. endophyticus G053 tidak mengalami kematian di plantlet transgenik. Hasil ini mengindikasikan bahwa gen LYZ-C yang terdapat di dalam tanaman kentang kultivar Jala Ipam transgenik JCL2 dan JCL3 yang diekspresikan secara konstitutif di dalam sitosol tidak mempengaruhi pertumbuhan dan perkembangan bakteri endofit M. endophyticus G053. Kata kunci: jumlah akar, jumlah buku, lisozim, panjang akar, tinggi batangThe transgenic potato cultivar Jala Ipam JCL2 and JCL3 expressed the LYZ-C gene constitutively in the cytosol so that it was resistant to pathogenic bacteria Ralstonia solanacearum and Pectobacterium carotovorum subsp. carotovorum. The LYZ-C gene encodes the lysozyme that damages cell walls of the bacteria by cutting the β-1,4 bonds between N-acetyl-D-muramate and N-acetyl-D-glucosamine of peptidoglycan resulting in bacterial cells lysis. Endophytic bacteria Micrococcus endophyticus G053 increases the growth of potato plants. This study aims to determine the growth of transgenic potato cv Jala Ipam plantlets containing the LYZ-C genes and non-transgenic one which were inoculated with endophytic bacteria Micrococcus endophyticus G053 in vitro. Non-transgenic Jala Ipam, JCL2, and JCL3 inoculated with endophytic bacteria M. endophyticus G053 in vitro, did not show significant differences in the growth of stem height, number of nodes, root length, and number of roots. The re-isolation of bacteria from the plantlets previously inoculated with M. endophyticus G053 and the results of the plantlet subcultures showed that M. endophyticus G053 did not die in the transgenic plantlets. These results indicated that the LYZ-C gene contained in the transgenic potato cultivar Jala Ipam, i.e. JCL2 and JCL3 which was expressed constitutively in the cytosol did not affect the growth and development of endophytic bacteria M. endophyticus G053. Keywords: lysozyme, number of nodes, number of roots, root length, stem heightProyek Penelitian Terapan yang berjudul “Pengembangan Kentang Untuk Industri Keripik dan Kentang Sayur” atas nama Prof. Dr. Ir. Suharsono, DEA
Aktivitas Quorum Quenching Ahl-Laktonase Bacillus Sp. Ntt3a Dan Bacillus Cereus Int1c Terhadap Pseudomonas Syringae
No full textProses penghambatan Quorum Sensing (QS) dapat dilakukan melalui suatu proses yang disebut Quorum Quenching. Salah satu mekanisme QQ adalah adalah dengan cara degradasi enzimatis untuk mencegah akumulasi senyawa sinyal QS “Asil Homoserin Lakton (AHL)” sehingga gen-gen yang ekspresinya dikendalikan oleh mekanisme QS tidak dapat diekspresikan. Beberapa gen yang ekspresinya dikontrol oleh mekanisme QS diantaranya adalah gen penyandi faktor-faktor virulensi bakteri, sintesis antibiotik, dan beberapa enzim hidrolitik. AHL-laktonase merupakan salah satu enzim QQ yang menghidrolisis cincin lakton pada senyawa AHL. Penelitian ini bertujuan untuk menguji aktivitas AHL-laktonase Bacillus sp. NTT3a dan B. cereus INT1c serta menguji potensinya sebagai agens biokontrol terhadap P. syringae. Penelitian ini terdiri dari beberapa percobaan yaitu pembuatan kurva pertumbuhan kedua kultur Bacillus, penentuan aktivitas AHL-laktonase terhadap C. violaceum sebagai bioindikator, produksi dan pemekatan AHL-laktonase menggunakan pengendapan amonium sulfat, uji penghambatan swarming motility terhadap P. syringae, bioesei penghambatan patogenisitas P. syringae pada buncis, dan penghitungan populasi P. syringae pada buncis yang busuk menggunakan metode cawan hitung. Pengamatan terhadap pertumbuhan kultur kedua Bacillus tersebut menunjukkan fase lag pada periode 1 jam pertama, dilanjutkan dengan fase log pada periode 2-3 jam setelah inkubasi. Fase stasioner tercapai setelah 15 jam inkubasi. Penentuan aktivitas AHL-laktonase dilakukan dengan cara mengukur zona QQ yang terbentuk disekitar kertas cakram yang mengandung supernatan kultur atau enzim pekat. Hasil pengujian menunjukkan bahwa kedua Bacillus tersebut menghasilkan AHL-laktonase ekstrasel dan intrasel. Pemekatan enzim kasar menggunakan amonium sulfat pada persen saturasi 70% menghasilkan konsentrasi protein tertinggi. Nilai Indeks zona QQ tertinggi diperoleh dari enzim kasar pekat Bacillus sp. NTT3a yang diendapkan pada 60% saturasi amonium sulfat, sedangkan hasil pemekatan enzim kasar B. cereus INT1c tidak menyebabkan terbentuknya zona QQ. Nilai indeks QQ enzim kasar Bacillus sp. NTT3a hasil pemekatan 1.16 kali lebih tinggi dibandingkan supernatannya. Uji aktivitas enzim kasar pekat Bacillus sp. NTT3a hasil pengendapan menggunakan amonium sulfat pada 60% saturasi menghasilkan Indeks zona QQ tertinggi, sedangkan hasil pemekatan enzim kasar B. cereus INT1c tidak ada yang menghasilkan zona QQ. Nilai Index Quorum Quenching (IQQ) enzim kasar Bacillus sp. NTT3a yang telah dipekatkan meningkat 1.16 kali lebih tinggi dibandingkan dengan supernatannya.
Aktivitas Quorum Quenching kedua Bacillus menghambat swarming motility P. syringae dan menurunkan pertumbuhan koloni fitopatogen ini. Swarming motility P. syringae pada cawan kontrol mencapai 12.25 mm, sedangkan pada agar cawan agar yang telah diinokulasi Bacillus sp. NTT3a dan B. cereus INT1c P. syringae berturut-turut hanya 3.0 mm dan 3.3 mm. Aplikasi kedua Bacillus tersebut juga dapat mereduksi gejala busuk pada buncis yang
disebabkan oleh P. syringae. Rata-rata panjang gejala busuk pada buncis kontrol positif mencapai 6.4 cm sedangkan gejala busuk pada buncis yang telah disemprot Bacillus sp. NTT3a dan B. cereus INT1c terlebih dahulu berturut-turut hanya 4.55 dan 3.92 cm. Data populasi P. syringae menunjukkan adanya penurunan. Penurunan populasi ini diduga disebabkan leh adanya kompetisi nutrisi antara P. syringae dengan kedua Bacillus pada kondisi percobaan yang dilakukan. Hasil penelitian ini menunjukkan bahwa kedua Bacillus penghasil AHL-laktonase tersebut berpotensi untuk dikembangkan sebagai agen hayati untuk mengendalikan penyakit yang disebabkan oleh Pseudomonas syringae pada buncis
Karakterisasi gen nifD bakteri metanotrof asal sawah
Get PDFMethanotrophic bacteria are methane oxidizing bacteria. Some methanotrophs able of fix nitrogen using nitrogenase enzyme. Nitrogenase is composed of two multisubunit metallo protein. Component I contains the active site to nitrogen reduction, encoded by the nifD and nifK genes. Methanotrophic isolates of BGM 3 and BGM 9 had high ammonium accumulation cultured in Nitrate Mineral Salts (NMS) free nitrogen medium. nifD gene fragmens from BGM 3 and BGM 9 were amplified and sequenced. Sequences analyzed using bioinformatics tools such as Blast-N, Blast-X, Expasy Translate Tools, Conserved Domain (CDD) and Scan PROSITE. Phylogenetic construction made using MEGA 4 software. Sequence analysis showed that the nifD sequences of BGM 3 and BGM 9 most closely related to nifD fragmen of Xanthobacter autotropicus PY2. The Identity values of nifD sequences was 92% and 91% respectively. nifD genes from these isolates encode FeMo protein, which was 4Fe4S and 2Fe2S clusters. The nifD gene of BGM 3 and BGM 9 suspected to have same ancestor with the nifD gene of Xanthobacter autotropicus PY2 and Bradyhizobium japonicum USDA 110
Penentuan pH dan suhu optimum aktivitas kitinase Bacillus cereus I.5 dan pengujian kitinase dalam mendegradasi eksoskeleton kutu bertepung putih (Ferrisia virgata Cockerell)
Get PDFBacillus cereus I.5 is one of chitinolytic bacteria isolated from chilli rhizosphere. The chitinase could be apply as a biocontrol of plant pest. One method to precipitate enzyme by using ammonium sulphate. It could increase specific activity enzyme. This research was conducted to determine optimum pH and temperature of chitinase activity of Bacillus cereus I.5 and tested its ability to degrade chitin exoskeleton of Ferrisia virgata Cockerell, one of Jatropha’s pest. Enzyme activity was obtained at the 10% ammonium sulphate saturation level, which is 20 times higher compared to crude enzyme. Specific enzyme activity increased from 0,039 U/mg of crude extract to 0,778 U/mg after ammonium sulphate precipitation. Chitinase of B. cereus i.5 showed highest activity at pH 7,0 and 55 °C although the enzyme also showed its activity at pH 5,0-9,0 and temperature 26-≤55 oC. Application of crude chitinase and the enzyme after ammonium sulphate precipitation on degrading of chitin Ferrisia virgata showed it worked better if incubated firstly at its optimum temperature
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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