Strategy On Promoting Microbial Growth Of Methanothrophic Bacteria To Enhance Paddy Productivity While Reducing Methane Emission For Climate Adaptation

Food security of Indonesia is problematic due for four reasons: land shortage, lacking of irrigation infrastructure, climate anomaly, and fertilizer and pesticide availability. Soil microorganism in general could offer an alternative solution for increasing crop productivity as well as maintaining ecosystem services. We particularly interested in methane oxidizing community in soil rhizosphere of rice which responsible for methane oxidation and their unique physiological properties, such as nitrogen fixation and trichloroethylene degradation. The challenge of this approach is how to stimulate the growth and activities of methanothrophic bacteria since obligate methanothroph are mostly slow growing Proteobacteria. The new concept is exploring facultative methanothrop bacteria that are able to use other carbon sources than methane that are widely available in soil. We isolated methanothroph bacteria from paddy root which are able to oxidize methane and use several carbon sources include degrading tricholoroethylene. These bacteria also harbor particulate methane monooxygenase and methanol dehydrogenase. Most of the isolated methanothrop are aerobic bacteria, therefore aerobic rice cultivation system will beneficial for oxidizing methane, but under aerobic condition, soluble phosphate could be limiting factor for P-availability, therefore augmentation of phosphate solubilizing microorganism would be necessary. Regional initiative of aerobic rice cultivation is already adopted in Asian countries. Further research on plant nutrient behavior under aerobic-anaerobic regime and microorganisms involve are important issue on optimizing sustainable rice cultivation for climate adaptation. Badan Penelitian dan Pengembangan Pertanian Kementerian Pertanian IAARD Press. 2016