Model of the B. subtilis survival strategies of in competition with P. chlororaphis and S. Typhimurium. During interaction with P. chlororaphis on LB agar, B. subtilis responds to Tse1-T6SS-mediated envelope disturbance by upregulating sporulation via SigW, KinA, and KinB. Under nutrient-depleted conditions in 1/20 TSB, B. subtilis sporulates in response to starvation. However, co-cultivation with S. Typhimurium impairs sporulation. This effect is mediated by the T6SS of S. Typhimurium, which in an unknown manner activates the SigB-dependent general stress response, resulting in formation of fewer but higher quality spores. Created in BioRender. Podnar, E. (2025) https://BioRender.com/x41m214.