Judul: Analisa hubungan curah hujan daerah aliran sungai dan debit sungai bengawan Solo dengan beberapa metode
Abstrak: Waduk atau bendung yang merupakan bagian dari suatu sistem irigasi sangatlah penting artinya untuk memantapkan aliran air, baik dengan cara pengaturan persediaan air yang berubah-ubah, maupun dengan cara memenuhi tuntutan kebutuhan dari konsumen yang sering berubah-ubah. Jumlah air yang dapat ditampung oleh suatu waduk tergantung pada jumlah curah hujan yang jatuh pada DAS waduk tersebut, sehingga perubahan jumlah curah hujan yang jatuh di DAS dari suatu waduk akan mempengaruhi jumlah air yang dapat disa- lurkan oleh waduk tersebut keluar. Tujuan dari Masalah Khusus ini adalah untuk mengetahui hubungan antara curah hujan area bulanan dengan Debit Sungai Bengawan Solo sebagai debit aliran rata-rata per bulan yang masuk (Q) ke dalam waduk Wonogiri. Metode-metode yang digunakan untuk Analisa Hubungan Curah Hujan Area Bulanan DAS Wonogiri dengan Debit Sungai Bengawan Solo rata-rata bulanan adalah: (1) metode Parabola, (2) metode Linier, (3) metode Eksponen- sial dan (4) metode Korelasi. ...
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Judul: Analisis Tren Jangka Panjang Curah Hujan dan Debit Daerah Aliran Sungai Bengawan Solo
Abstrak: Bengawan Solo Watershed is classified as one of the most degraded watershed in Indonesia. The Watershed usually was utilized as water resource for irrigation, transportation and industry. The problems in the Bengawan Solo Watershed is deforestation, illegal logging and land conversion. This research aimed to find out trend of rainfall and streamflow in Bengawan Solo Watershed for period of 1980-2010. Twelve rainfall stations in the Watershed were chosen for rainfall trend analysis and calculating rainfall area. The trend analysis was divided into two parts that is before and after reformation era (year at 1998). Trend analysis was performed using Mann-Kendall test at 95% confidence interval (α= 5%). Research result showed that before reformation era we found there were no significantly trend for rainfall and annual streamflow. However, after reformation era we found that there was a significantly negative trend for rainfall at most stations, but significantly positive trend for average annual streamflow. Coefficient of runoff in Bengawan Solo Watershed range 0,4-0,81 and did not occur a significantly trend for this research.
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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