This study investigated the role of the Zymomonas mobilis recA gene in conferring stress resistance when expressed in Escherichia coli. The recA gene was cloned and expressed in E. coli BL21(DE3), producing a 39 kDa polypeptide. The results of comparative analyses demonstrated that the recombinant strain significantly enhanced survival rates under various stress conditions. In oxidative stress tests, the recombinant E. coli pET-22b(+)-recA exhibited superior survival at 3 mM and 5 mM H₂O₂ concentrations. Heat stress experiments at 50 °C and 55 °C revealed increased survival for the recombinant strain. Under ethanol stress, particularly at 20% (v/v), E. coli pET-22b(+)-recA displayed higher viability than controls. UV-C exposure tests further highlighted the protective effect of recA expression, with the recombinant strain maintaining viability after 60 min of exposure, while control strains showed no survival. These results indicate that the Z. mobilis recA gene product enhances resistance to oxidative, heat, ethanol, and UV-C stresses when expressed in E. coli. This study elucidates the broad stress-protective functions of the RecA protein across bacterial species and suggests potential applications in developing stress-tolerant bacterial strains for biotechnological purposes.