Engineered microbial SDC-cheater system. (A) The SDC strain underwent programmed cell death when exposed to antibiotic stress (blue lightning). This self-destruction released public goods (dots), such as the antibiotic-degrading enzyme BlaM, which mitigated the antibiotic stress. The cheater strain (red strain) underwent cell lysis without providing BlaM. (B–C) Experiments and simulations of the growth dynamics of engineered SDCs and cheaters in the homogeneous group (B) and heterogeneous group with an initial SDC ratio of 0.5 (C), with 0.4 mg/ml 6-APA added at time 0. The error bar represented the standard deviation of three biological replicates.