The current technologies used for reducing CO₂ emission are not sufficient to sequestrate the high amount of CO₂ in atmospheric. This research rolls up a new direction of CO₂ sequestration process in bio-foamed concrete bricks (B-FCB) using Bacillus tequilensis 401 as an acceleration factor of natural carbonation. The strain of B. tequilensis 401 was isolated from cement kiln dust (CKD) and adapted to B-FCB environment. It produces carbon anhydrase (CA) and urease enzymes to accelerate sequestration process of CO₂. The sequestration of CO₂ into B-FCB was optimised based on; concrete density (D), B. tequilensis 401 concentration (B), temperature (T), and CO₂ percentage (CO₂). Two methods were used in design of experiments (DOE) by Minitab 18 included; 2^k factorial design and Response Surface Methodology (RSM) analysis. The results reveal that the factors exhibited significant effects on sequestration process. The optimal carbonation depth of B-FCB was 12.2 mm under the following conditions: 20 % of CO₂, 3 × 10⁵ cell/mL of B, 40 °C of T, and 1300 kg/m³ of D at 28 days. B. tequilensis 401 in B-FCB increased carbonation depth by 30 % compared to FCB at 28 days. The increase in carbonation depth resulted in increased formation of calcium carbonate (CaCO₃) in B-FCB compared to FCB, which is confirmed by microstructure analysis using SEX, EDX, and XRD.