Judul: Aktivitas oksidasi amonium dan reduksi Nitrat Alcaligenes sp. Isolat SDTT5 dan KDTST3 asal tambak udang menggunakan berbagai sumber karbon
Abstrak: Water quality is one problem found in shrimp culture caused by increasing of ammonium and nitrite concentration. This problem correlates with a~mulation of uneaten feed and shrimp waste products. Both ammonium and dhUte are toxic to shrimp. Recently, addition of bacteria as bioremidiation agent to;:shrimp ponds can remedy water quality. SDTT5 and KDTST3 isolate are ni:trate reducing bacteria isolated from shrimp ponds using denitrification media ~h acetate as carbon source in anaerob condition. Based on mollecular analysis 0~1 6S-rRNA sequences the isolate was 99% closely related to Alcaligenes sp. TIDs study was to investigate ammonium oxidation and nitrate reduction activities bis DTT5 and KDTST3 isolates on different carbon sources. This expriment was c<j.ducted used different media i.e. heterotroph and autotroph nitrification media, ami ammonium oxidation and nitrate reduction media. The incubation was held u~er either aerob or anaerob conditions. The results shows that SDTT5 and Kf>TST3 isolates were able to oxidize ammonium heterotrophycally with acetate, s~cinate, glucose and glycerol as carbon sources and autothrophically with cibonate as carbon source. The highest activity of ammonium oxidation by St>TT5 and KDTST3 was found in succinate and acetate as carbon sources. S~TT5 isolate was able to oxidize ammonium and reduce nitrate either aerobically or anaerobically with different carbon sources. Under anaerob c.gndition SDTT5 isolate was able to oxidize ammonium and reduce nitrate with a~tate, succinate, glucose and glycerol as carbon sources but SDTT5 isolate can not oxidize ammonium and reduce nitrate aerobically with glycerol as carbon source Meanwhile, KDTST3 isolate was only able to oxidize ammonium aerobically with acetate, succinate, and glucose as carbon sources, and reduced nitrate with glycerol as carbon source.
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Judul: Aktivitas oksidasi amonium dan reduksi nitrat Pseudomanas stutzeri ASLT2 pada sumber karbon yang berbeda
Abstrak: Isolat ASLT2 merupakan bakteri pengoksidasi amonium yang diisolasi dari perairan tambak udang. Berdasarkan analisis molekuler 16S rRNA, isolat ini memiliki kemiripan sebesar 99 % dengan bakteri pereduksi nitrat P. stutzeri. Hasil pengamatan menunjukkan bahwa isolat ASLT2 dapat mengoksidasi amonium pada kondisi autotrof dengan karbonat sebagai sumber karbon dan kondisi heterotrof dengan asetat, suksinat, glukosa, dan gliserol sebagai sumber C. Konsentrasi amonium menurun hinggá tujuh hari inkubasi pada semua perlakuan sumber C. Penurunan konsentrasi amonium yang terjadi disebabkan penggunaan amonium sebagai sumber nitrogen dan sumber energi melalui proses nitrifikasi. Isolat ini memiliki aktivitas oksidasi amonium paling tinggi pada medium dengan menggunakan suksinat sebagai sumber C. Isolat ASLT2 dapat mereduksi nitrat pada kondisi aerob dan anaerob dengan asetat, suksinat, glukosa dan gliserol sebagai sumber C. Aktivitas reduksi nitrat secara aerob paling tinggi terjadi pada medium dengan menggunakan glukosa sebagai sumber C dan secara anaerob aktivitas paling tinggi terjadi pada medium dengan menggunakan suksinat sebagai sumber C. Perbedaan aktivitas reduksi nitrat pada masing-masing perlakuan sumber C disebabkan oleh perbedaan banyaknya elektron yang dihasilkan dari proses oksidasi sumber C yang berbeda.
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Judul: Fungsi Interpolasi untuk Tabel Mortalita
Abstrak: Every human has a risk of death. Insurance is a way to minimize the risk. People who join the insurance have an obligation to pay a premium. One of the parameters to calculate the premium price is the table of mortality. The purpose of this paper is to model the table of mortality with the interpolation method and analyze the difference of premium price between endowment insurance with term insurance. We use the method of linear, quadratic, and more than two degree spline interpolation. The best interpolation method for the mortality table is a linear spline interpolation because the error of calculate is relative small.
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