Fig. 3

Acid resistance of strain 367 and strain 367ΔgadR in buffer (pH 2.5) with 10 mM MSG (+) or without MSG (−). a Diagram of acid challenge for strain 367 and strain 367ΔgadR. Red arrows, the start point of acid challenge; green dotted line, buffer (pH 7.0); Red line, buffer (pH 2.5). b Viable cell number of strain 367 and strain 367ΔgadR after acid challenge. c GABA production of strain 367 and strain 367ΔgadR after acid challenge. d Survival of strain 367 and strain 367ΔgadR after acid challenge. The images represent serial dilutions of the cultures in tenfold steps