Keragaman Komunitas Bakteri Pemfiksasi Nitrogen pada Tanah Sawah di Sukabumi

Abstract

Dinitrogenase is an important enzyme in nitrogen fixation. The enzyme has 2 sub unit proteins, Fe Protein and MoFe protein, each encoded by nifH and nifD. DGGE is one of metagenomic analysis technique that can represent the abundance of specieses in environment, based on melting behavior of amplicones in linearly increasing denaturant in polyacrylamide gel. The aim of this research was to assay diversity of nitrogen fixing-bacteria on rice field. The soil samples of rice field treated with inorganic fertilizer NPK 15:15:15 250 kg/ha (100% dosage) (K), biofertilizer and NPK 62.5 kg/ha (25% dosage) (C), and NPK only 62.5 kg/ha (25% dosage) without biofertilizer application (TC), were extracted for DNA. Those DNA were amplified using primer-GC, hence, analyzed using DGGE. The nifH gene had high variability more than nifD gene. It was expected that there were at least 7 kinds of nifH gene in sample C, 5 in sample TC, and 1 in sample K. High genetic variability of nifH genes was caused evolutionary line. In the other hand, nifD genes tended to be conserved.