DIVERSITY OF NITROGEN FIXING BACTERIA WITH ORGANIC FERTILIZER APPLICATIONS IN PADDY SOIL
Hadija1Tutik Kuswinanti2 Muh. Jayadi2, Siti Halima Larekeng2

1Agricultural Science, Postgraduate School, Hasanuddin University, Makassar, 90245, Indonesia.
2Metagenomic Microbial Research group, Faculty Agricultural Science, Hasanuddin University, Makassar, 90245, Indonesia.

Abstract

KNitrogen-fixing bacteria are free livings bacteria and play a role in providing nitrogen in the soil. The high organic matter content allows soil microbial activity to recycle organic matter which is essential for life such as the nitrogen cycle. This study aims to isolate and characterize nitrogen-fixing bacteria in paddy soil using organic fertilization applications. This research was conducted in the Village of Salassae Bulukumba, South Sulawesi, the Microbiology Laboratory of the Soil Science Department. This research method is descriptive research. This study succeeded in obtaining 10 isolates. The character of the bacterial colonies showed a high enough diversity among the selected isolates from the hole of the colony. The highest ability to fix nitrogen was obtained in isolates. L.P, where the highest nitrogen-fixing ability was 0.26%, where the selected isolate would then be continued for molecular identification. The results of 16S rRNA gene sequencing were carried out to determine taxonomic strains, L.P isolates could be identified with certainty with 99% similarity as Bacillus subtilis subsp. subtilis str. 168.

Keywords: Diversity, Nitrogen-fixing Bacteria, Bacillus subtilis, Paddy Soil

Topic: Biodiversity and Climate Change