Potential of Methanotroph bacteria as non-symbiotic nitrogen fixation in rice paddy fields in Morowali regency

Nitrogen makes up about 78% of all the gases in the atmosphere. Although it is very abundant in the atmosphere, nitrogen cannot be used directly by plants. The aims of this study were to isolate, characterize and identify the morphology and physiology of methanotrophic bacteria, calculate the total population of methanotrophic bacteria and analyze the chemical properties of paddy rice soil in Morowali Regency. Results Based on the gram reaction test, 11 isolates were gram negative, 11 isolates were catalase positive, 11 isolates were capable of nitrogen fixation, five isolates were yellowish white, five isolates were white, one isolate was yellow, six isolates had a convex elevation, and five isolates had a flat elevation. Based on the identification results, the Witaponda sub-district produced five isolates, three isolates from Bumiraya, two isolates from Bungku Barat and one isolate from Bungku Tengah District. Based on the results of the calculation of the number of bacteria found in Witaponda subdistrict as much as 54.05x10 6 Cfu/mL Bumiraya as much as 40.21x10 6 Cfu/mL, Bungku Barat as much as 12.06x10 6 Cfu/mL, Bungku Tengah as much as 11.65x10 6 Cfu/mL. The results of the analysis of soil chemical properties showed that pH, CEC, organic C, P205, K were classified as low in both irrigated and rainfed rice fields.