Demand for sustainable infrastructure has spurred the development of innovations, including bacterial self-healing concrete, which repairs cracks using Microbially Induced Calcite Precipi￾tation (MICP). Examining the material’s self-repair relative to bacterial concentrations (0 %, 1 %, 2.5 %), and strains (Bacillus Megaterium and Bacillus Sphaericus), performance was tested at 24◦C and sub-zero temperatures (-16 ± 2 ◦C and − 24 ◦C). Energy-dispersive spectroscopy, scanning electron microscopy, and X-ray diffraction were among the tests used; ultrasonic, compressive, and flexural testing were also employed. With compressive strength growing by 40.24 % after 28 days at normal temperature, Bacillus Megaterium (BM) showed notably better mechanical stability and crack-healing efficiency than Bacillus Sphaericus (BS) at sub-zero tem￾peratures. At 0◦C with a 2.5 % concentration, both strains attained 100 % crack healing. At low temperatures, BM raised compressive strength by 23.52 % while BS showed a drop. Whereas BS’s modest 4.8 % gain at − 16◦C, BM’s cold tolerance produced a strength rise of 54.87 % at 0◦C.