RT Journal Article SR Electronic(1) A1 Dobrzanski, W. T. A1 Osowiecki, H.YR 1967 T1 Isolation and Some Properties of the Competence Factor from Group H Streptococcus Strain challis JF Microbiology, VO 48 IS 2 SP 299 OP 304 DO https://doi.org/10.1099/00221287-48-2-299 PB Microbiology Society, SN 1465-2080, AB SUMMARY: In several bacterial species the occurrence of competence in transformation is strictly related to the production of a competence factor (c.f.). In the present work this factor was isolated from the cell surface of Streptococcus group H strain challis by the centrifugation of competent bacteria at pH 2.0, followed by thermal shock. Streptococci of strain wicky adsorb c.f. isolated from the challis organisms because supernatant fluids containing c.f. lose their activity after having been in contact with organisms. It was possible to ‘tear off’ again from such organisms of strain wicky the c.f. they had adsorbed. The re-isolated c.f. was still active in the transformation systems used. Some biochemical properties of the c.f. from strain challis are described. The factor was relatively heat resistant and sensitive to proteolytic enzymes. Streptococcal c.f. or a fragment of it seems to be a protein or polypeptide of fairly low molecular weight. This streptococcal c.f. is probably different from the pneumococcal c.f., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-48-2-299