Though Spo0A is the key regulator for sporulation in Firmicutes, it regulates numerous other processes in various bacteria. In the non-pathogenic B. subtilis, for instance, the protein also affects competence development, biofilm formation, the production of and resistance to antimicrobial compounds, chromosome dynamics and aspects of phage biology [10, [14] [15] [16] . Importantly, several of these processes are indirectly regulated, through the Spo0A-dependent repression of abrB. Additionally, transcription of abrB responds already to low levels of Spo0A,P [43] . As a result these effects are detectable in late-exponential and early stationary phase, as some Spo0A is present throughout growth in B. subtilis cells.