Judul: Methane oxidation activity of methanotrophic bacteria from ricefields under different consentration of oxygen
Abstrak: Methane-oxidizing bacteria (methanotrophs) have ability to oxidize methane to carbon dioxide via methanol, formaldehyde, and format in aerobic condition. Methanotrophic bacteria are normally abundant where methane is present. In aerobic environment, methanotrophic bacteria oxidize methane to provide carbon and energy for their growth. Methanotrophic bacteria have an unique enzyme known as methane mono oxygenase (MMO) catalizing reaction of CH4 and O2 to methanol. Three selected isolates from rice fields in Bogor and Sukabumi were tested the growth and methane oxidation activity under different concentration of oxygen (02) using Nitrat Medium Salts (NMS) medium. Methane oxidation rate ofBGM 9 isolate at 0%,10%, 20% and 50% air saturation was 129182.06 mol/day, 138185.16 mol/day, 137484.32 mol/day, 167015,88 mol/day respectively. In contl:ast, high rates of Methane oxidation were performed by BGM 2 and SKM 14 isolates at air saturation of 10% and 20%. However the activity was decreased at 50% air saturation.
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Judul: Growth and Methane Oxidation Activity of Methanotrophic Bacteria in Different Media
Abstrak: Methanotrophs are bacteria that can utilize methane or C1 compounds as their sole carbon and energy source. Previous study resulted that BGM 1, BGM 3, BGM 9, and SKM 14 isolates could oxidized CH4. Objective of this research was to formulate medium composition for production of methanotrophic bacteria. The substances that we used as carbon sources were methanol, mollase. And a nitrate was as a nitrogen source. Specific growth rate of bacteria in methanol and nitrate was different for each isolate. The best carbon and nitrogen sources of medium for bacterial growth was methanol 2% and nitrate 1 g/L. Methane oxidation rate of BGM 1, BGM 3, BGM 9, and SKM 14 isolates was 0.01, 0.04, 0.03, and 0.03 mol/ml culture/day respectively. The highest activity of methane oxidation was perfomed by BGM 3 isolate, and the highest ammonium accumulation was perfomed by BGM 9 isolate. The bacterial cells produced by medium of combination methanol 2% and nitrate 1 g/L were tested in soil of a rice field in laboratorium scale. The result showed that methane concentration was decreased in twelveth days of incubation. The methane reduction activity of the isolates during incubation of 8 to 12 days was 88.5%, 85.1%, 47.8%, and 66.4% for BGM 1, BGM 3, BGM 9, and SKM 14 isolates respectively.
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Judul: berjudul Pelabelan Prima pada Graf Gurita (On) dengan Penambahan Simpul Duplikasi.
Abstrak: Setiap graf gurita adalah graf prima sedemikian sehingga pelabelan simpul pada graf gurita merupakan pelabelan simpul pada graf prima. Suatu Graf ( ( ) ( )) dapat dikatakan memiliki pelabelan simpul pada graf prima jika graf tersebut memenuhi fungsi bijektif ( ) { } dan untuk setiap sisi ( ( ) ( )) . Dalam karya ilmiah ini, akan ditunjukkan bahwa graf gurita memiliki pelabelan prima dan merumuskan graf gurita duplikasi dengan penambahan simpul dari simpul graf kipas ( ) graf gurita ( ), graf bintang ( ) graf gurita ( ), dan simpul utama pada graf gurita ( ) adalah graf prima dengan
Keyword: graf gurita, graf prima, pelabelan prima, penambahan simpul