PRODUCTION OF COMPETENCE-PROVOKING FACTOR AND DEVELOPMENT OF COMPETENCE OF A TRANSFORMABLE STREPTOCOCCUS IN SERUM-FREE MEDIA

Abstract

Production of competence-provoking factor and transformation of a group H streptococcus were achieved in the absence of serum or albumin in media sterilized by filtration through Millipore filters.No significant transformation was found when the medium was heated more than 40–50 minutes at 115°−117 °C. This suggests that the medium contained a heat-labile factor necessary for transformation. The factor was found in yeast extract, one of the ingredients of the medium.Addition of serum to heated medium allowed production of the competence-provoking factor and of transformation. Serum albumin, claimed to be an adequate substitute for serum, was less active in this respect. It is concluded that serum contains, in addition to albumin, another factor enhancing transformation.