Factors affecting production of the group A streptococcus bacteriocin SA-FF22

Factors influencing the production of streptococcin A-FF22 (SA-FF22) in liquid media were examined. Despite good growth of the producer strain, no SA-FF22 was detected during incubation at 40 degrees C, at pH 7, in Brain Heart Infusion Broth or in Mg(2+)-supplemented media. Optimal SA-FF22 production occurred at 32 degrees C, at pH 6.7, in cultures in Tryptic Soy Broth supplemented with glucose 2.25% and yeast extract 1%. Under these conditions SA-FF22 remained cell-associated but could be extracted with acid.