This study aimed to isolate and characterize a novel bacterium with iron-reducing and nitrogen-fixing capabilities from rice paddy soil，with potential applications in green，low-nitrogen rice production.A strain ZLJ24 was isolated from paddy soil through a series of screening processes，including cultivation on nitrogen-free medium，ferric citrate medium，LB agar medium.Morphological observations，16S rRNA gene sequencing，and nifH gene amplification were employed for identification，revealing strain ZLJ24 to be a member of the genus Klebsiella pneumoniae，a Gram-negative bacillus，and it was positive for the nifH gene，which is associated with biological nitrogen fixation.The efficiency of iron reduction by strain ZLJ24 under anaerobic conditions was found to be 90.24% after 72 hours of cultivation.Its nitrogenase activity in a nitrogen-free medium was 89.28 nmol-C2H4/(min·mg protein).Intriguingly，the addition of low concentrations of glucose significantly enhanced the nitrogenase activity，reaching a maximum of 19460.76 nmol-C2H4/(h·mg protein).These results demonstrated that strain ZLJ24 could possesse both robust iron reduction and nitrogen fixation capabilities，with glucose acting as a potent stimulant for its nitrogenase activity.This study contributed a promising strategy for developing a green，low-nitrogen rice production system based on biological nitrogen fixation，and offered a novel approach to sustainable agriculture.