GENETIC TRANSFER OF THE ABILITY TO GROW AT 55 C IN BACILLUS SUBTILIS.

McDonald, William C. (U.S. Army Chemical Corps, Fort Detrick, Frederick, Md.) and Thomas S. Matney. Genetic transfer of the ability to grow at 55 C in Bacillus subtilis. J. Bacteriol. 85:218-220. 1962.-Two strains of Bacillus subtilis, 168 and P1, were found to grow at 55 C (55(+)) on complete media; strain 168S(r) failed to grow at temperatures above 50 C (55(-)). When 168S(r) bacteria were grown in the presence of deoxyribonucleic acid extracted from 168, the ability to grow at 55 C was transformed at a frequency of 10(-4). An incubation period of 3 to 4 hr at 37 C was necessary for phenotypic expression of the 55(+) character. Only 10 to 20% of the 55(+) transformants retained the high-level streptomycin resistance (S(r)) of the recipient, indicating close linkage between the S(s) and 55(+) loci.