Aktivitas fiksasi nitrogen dan oksidasi metan kultur campuran bakteri metanotrof pada lumpur sawah

Abstract

Metanotroph bacteria are methane oxidizing bacteria. Besides, type II and type X of methanotrophic bacteria were also able to fix nitrogen using nitrogenase enzyme. This reasearch was conducted to test the activity of nitrogen fixation and methane oxidation of five isolates of methanotropic bacteria i.e. BGM 1, BGM 3, BGM 5, BGM 9, and SKM 14 which combined with one another. Seven combinations (SKM 14/BGM 1; SKM 14/BGM 3; SKM 14/BGM 5; SKM 14/BGM 9; BGM 9/BGM 1; BGM 9/BGM 3; BGM 9/BGM 5) were cultured and inoculated into NMS medium mixed with slurry of mud, then the activity of methane oxidation, nitrogen fixation and nitrogenase enzyme activity was tested. The highest accumulation of ammonium in the mud sterile treatment (35.489 μM) was higher than that of in non-sterile mud treatment (26.617 μM). Formulation 6 (BGM 9/BGM 3) in sterile mud treatment and formulation 4 (SKM 14/BGM 9) in non-sterile mud treatment has the highest nitrogenase enzyme activity, it was 5,16 mmol/h/ml culture and 75,85 mmol/h/ml culture respectively. Formulation 1 (SKM 14/BGM 1) and formulation 2 (SKM 14/BGM3) had the higest activity of methane oxidation in sterile and non sterile mud treatment i.e. 17428 and 16759 ppm /ml culture /day respectively.