Autogenous healing material remains a type of exclusive material with the structural capacity to repair mechanical wear and tear over time. Environmentally sustainable autogenous healing materials with lower carbon content are in peak demand across the globe. The investigation was carried out on the immobilization of Bacillus bacteria (megaterium, subtilis) which made a novel bacterium for self-healing concrete. The pH values and temperature are maintained at 4, 7, 10, and 25 °C to 34 °C upon bacterial cultivation, respectively. Clay pellets were used to immobilize the most prominent and positive-sustaining bacteria at 32 °C. The clay pellets are well-shaped and dried to develop efficiency better than wet clay pellets. Those immobilized bacteria in clay pellets are diversified into the concrete and the results are compared to concrete with immobilized bacteria in silica gel. The strength parameters are assessed through compression, tension, and flexure tests as well as water absorption test. Sorptivity analysis ensures the durability of concrete. The crack healing efficiency of potential bacteria is finally found and satisfying. The characterization of clay pellets and bacterial concrete ensures the precipitation produced by the novel bacterium under a favorable methodology. The bacterial concrete integrated with clay pellets with 10⁵ cells/mg^-1 produces promising results in all the scales, pre-and post-cracking. Decisively, the catalyst quickly reacted efficiently and prevented the crack from spreading further.

Keywords: Microbial, Bacterial concrete, Bacillus, Clay pellets, Element mapping.