Methane Oxidation and Nitrous Oxide (N2O) Reduction Activity on Combination Culture of Methanotrophic Bacteria and Ochrobactrum anthropi

Abstract

Methane Oxidation and Nitrous Oxide (N2O) Reduction Activity on Combination Culture of Methanotrophic Bacteria and Ochrobactrum anthropi. Under supervision of IMAN RUSMANA and ALINA AKHDIYA. Rice fields are one source of methane (CH4) and nitrous oxide (N2O) emission. Methanotrophic bacteria and denitrifying bacteria possesing high methane oxidation and N2O reduction activity are very important for controlling CH4 and N2O emission from rice fields. This research was conducted to test the activity of methane oxidation and N2O reduction from four methanotrophic bacteria (BGM 1, BGM 5, BGM 9, and SKM 14 isolates) and two Ochrobactrum anthropi isolates (BL 1 and BL 2 isolates). Six combination were inoculated into Nitrate Mineral Salt (NMS) media mixed with denitrification media, then the activity of methane oxidation, N2O reduction, accumulation of ammonium, nitrite, and nitrate was analyzed. Combination culture E of BGM 1, SKM 14, BL 1, and BL 2 isolates had the highest CH4 oxidation (2,9 x 10-8 ìM/cell/day), N2O reduction activities (0,15 x 10-9 ìM/cell/day), and accumulation of ammonium (19,3 x 10-8 ìM/cell/day) than the other combination cultures. Combination culture of BGM 1, SKM 14, and BL 1 isolates had the highest accumulation of nitrate (17,6 ìM) and combination culture of BGM 5, BGM 9, BL 1, and BL 2 isolates had the highest accumulation of nitrite (10,9 ìM).

Lahan sawah merupakan salah satu sumber emisi metan (CH4) dan dinitrogen oksida (N2O). Bakteri metanotrof dan bakteri denitrifikasi yang memiliki aktivitas tinggi dalam oksidasi metan dan reduksi N2O berperan sangat penting untuk mengendalikan emisi CH4 dan N2O dari lahan sawah. Penelitian ini dilakukan untuk menguji aktivitas oksidasi metan dan reduksi N2O dari empat bakteri metanotrof (BGM 1, BGM 5, BGM 9, dan SKM 14) dan dua isolat Ochrobactrum anthropi (BL 1 dan BL 2). Sebanyak enam kombinasi diinokulasikan ke dalam campuran media Nitrate Mineral Salt (NMS) dan media denitrifikasi, kemudian diuji aktivitas oksidasi metan, reduksi N2O, akumulasi amonium, nitrit, dan nitrat. Kultur kombinasi isolat BGM 1, SKM 14, BL 1, dan BL 2 memiliki aktivitas oksidasi CH4 (2,9 x 10-8 ìM/sel/hari), reduksi N2O (0,15 x 10-9 ìM/sel/hari), dan akumulasi amonium (19,3 x 10-8 ìM/sel/hari) tertinggi dibandingkan kultur kombinasi lainnya. Kultur kombinasi isolat BGM 1, SKM 14, dan BL 1 memiliki akumulasi nitrat tertinggi (17,6 ìM) dan kultur kombinasi isolat BGM 5, BGM 9, BL 1, dan BL 2 memiliki akumulasi nitrit tertinggi (10,9 ìM).