FIG 2.

Congenic mutants exhibiting resistance to biofilm inhibition by d-amino acids. Spontaneous mutants (columns a and c) and their reconstituted counterparts (columns b and d) were spotted on solid MSgg medium alone or solid MSgg medium containing 10 μM d-Tyr. The reconstituted spontaneous mutants are as follows: ppaC^A145V, tyrS riboswitch (tyrS^−38C>T), tyrS^A202V, trnD-Phe^35A>T, and hrcA^−8A>G. The parental strain of the spontaneous mutants (3610, which is mutant for dtd) and a dtd⁺ strain (SLH31) are included as a negative control and positive control, respectively. Images were taken after 72 h of incubation at 30°C.