A Comparison of Streptococcal Competence Factors Produced by Strain CHALLIS in Chemically Defined and Complex Media

Abstract

SUMMARY: A comparison was made between streptococcal competence factors (CF) elaborated by strain CHALLIS in a chemically defined medium and in a complex medium (defined medium containing neopeptone and horse serum). The CF preparations acted similarly in that: (i) both CFs maximally activated the normally non-transformable streptococcal strain WICKY to the competent state when the WICKY cells were incubated for 40 to 100 min. in phase 2; (ii) both CF preparations had to react with WICKY cells for about 20 min. before the cells would take up deoxyribonucleic acid (DNA); (iii) the rates of DNA uptake in WICKY populations were identical when either CF preparation was used; (iv) both CFs activated different concentrations of WICKY cells so that a fixed proportion of the total population transformed to dihydro-streptomycin resistance; and (v) upon dilution both CF preparations behaved as if they contained more than a single component.