Judul: Perbandingan insensitas matahari dan kualitas sinarnya pada musim hujan dan musim kemarau di pondok betung jakarta
Abstrak: Penelitian ini merupakan analisis terhadap data sekunder dari hasil pengamatan salah satu komponen cuaca, yaitu radiasi matahari yang terdiri dari pengukuran intensitas radiasi global, intensitas radiasi baur, intensitas radiasi pantul, lama penyinaran dan pengukuran kualitas sinar dengan menggunakan filter pada pengukuran intensitas radiasi global. Pengukuran ini dilakukan di Stasiun Klimatologi Pondok Betung Jakarta, yang terletak pada posisi 06° 16' Lintang Selatan dan 106° 45' dengan ketinggian 26. m dari permukaan laut, selama empat tahun dari tahun 1982 sampai tahun 1985. Tujuan dari penelitian ini adalah untuk mengetahui : (1). Perbedaan tingkat penerimaan radiasi matahari yang mencapai permukaan bumi pada musim hujan dan musim kemarau. (2). Perbedaan komposisi penyusun radiasi global (radiasi baur dan radiasi langsung) di setiap musim.. (3). Kualitas sinar matahari, terbatas pada spektrum cahaya sesuai dengan filter yang digunakan, untuk musim yang berbeda. (4). Fluktuasi penerimaan radiasi secara umum dari rata- rata musiman dari tahun ke tahun. ..dst
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Judul: Pengaruh atmosfer pada musim hujan dan musim kemarau terhadap penyiraman pancaran surya di desa Cikarawang
Abstrak: Energi surya adalah sumber utama dari energi atmos- fer. Penyebarannya di seluruh permukaan bumi pengendali dari cuaca dan iklim. Energi surya merupakan merupakan penyebab pokok dari semua perubahan dan gerak di dalam atmosfer. 4 Keterbatasan energi surya di daerah tropik sering juga menjadi kendala dalam produksi padi, khususnya yang ditanam pada musim hujan. Produksi padi, jagung, kacang- kacangan dan sorgum semakin meningkat dengan meningkatnya kerapatan limpahan pancaran surya. Suatu penelitian telah dilakukan untuk mengetahui perbedaan (penyirnaan) pancaran tingkat pancaran baur, tingkat pancaran surya oleh atmosfer dan surya yang mencapai permukaan bumi hujan dan musim kemarau. attenuasi komposisi pada musim Penelitian ini menggunakan data sekunder dari data penelitian Dr. Ir. M. Blantran de Rozari, pada bulan Juli 1987 sampai Pebruari 1988, di Desa Cikarawang Sindangbarang Kabupaten Bogor. Kecamatan ...
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Judul: Extracellular Expression of thermostable Geobacillus stearothermophilus T1.2RQ Lipase for Biodiesel Production
Abstrak: The extracellular expression of enzymes in an excellent secretion host such as Bacillus subtilis is a useful strategy for making enzymes of industrial significance more affordable by lowering the cost of its downstream processing. Lipases are a category of hydrolases that catalyze the hydrolysis of triglycerides to glycerol and free fatty acids. Also, lipases catalyze the hydrolysis and transesterification of other esters as well as the synthesis of esters. They can perform very specific biotransformation reactions and are widely used in food, organic synthesis, detergents, cosmetic, and pharmaceutical industries. Geobacillus stearothermophilus T1.2RQ lipase is an industrially-desired thermostable lipolytic enzyme with an excellent hydrolytic and transesterification activity. This study aimed to express T1.2RQ lipase, in B. subtilis WB800 and ensure its secretion into the extracellular medium. Three signal peptides (AmyQ, Epr, LipA) and two promoters (Pgrac01 and Pgrac100) were used in the secretory-expression of T1.2RQ lipase, based on five constructed expression vectors constructed by restriction cloning and PCR mutagenesis. Sangers sequencing was used to verify constructs to ensure they are in the correct reading frame. Recombinants vectors, pHT43 (plasmid control), pHT43-T1.2RQ, pHT43- T1.2RQ_AmyQ, pHT43-T1.2RQ_Epr, and pHT43-T1.2RQ_LipA, were transformed by electroporation into Bacillus subtilis WB800. The electroporation was successful with the optimum condition of 2500V, 200 ohms, 25µF, and 5milliseconds. Recombinant B. subtilis pHT43 (negative control) and pHT43-T1.2RQlip + signal peptides were streaked on the lipidic agar, LA+TBN. All four recombinants, including the negative control (B. subtilis WB800-pHT43), produced clear zones on the TBN agar plate after overnight incubation (fig 2), indicating the presence of a lipolytic enzyme in all of the recombinant B. subtilis cells. pHT43-T1.2RQlip + signal peptides (AmyQ, Epr, and LipA) have clear zones with significantly higher diameters than B. subtilis WB800-pHT43 (negative control). This phenomenon suggests that the recombinant thermostable lipase T1.2RQ introduced into these cells was successfully expressed, thereby increasing the lipolytic capability of its host cells T1.2RQ lipase was expressed in 50ml terrific broth medium (TB) and the expression induced with 1mM IPTG. Lipase activity assay using p-nitrophenyl esters showed that all three signal peptides directed the secretion of T1.2RQ lipase into the extracellular medium. Signal peptide, LipA, resulted in the highest extracellular activity of 5.6 U/mL, which corresponds to a 6-fold increase over the parent B. subtilis WB800 strain. Meanwhile, signal peptides, AmyQ and Epr produced 4.2 U/mL and 3.4 U/mL activity respectively. SDS-Zymogram analysis confirmed that T1.2RQ lipase was correctly processed and secreted in its original size of 44 kDa. An attempt to further increase lipase expression level by promoter optimization showed that, contrary to expectation, promoter Pgrac100 exhibited similar expression levels as the original Pgrac01. Nevertheless, the demonstration of the successful secretion of T1.2RQ lipase in this work confirms the latter as a promising approach for the industrial production of the enzyme
Keyword: Bacillus subtilis, Expression, Extracellular, Heterologous, Lipase, Thermostable