Abstract
Bacitlus sphaericus ts-Dl290 was characterized comparatively with the wild type strain 1593 by themeasurements of the biosynthesis of total DNA, RNA and protein on the temperature-shift culturesat permissive temperature of $30^{\circ}C$ and at nonpermissive temperature of $42^{\circ}C$. The growth patterns of the wild type strain and ts-Dl290 were similar at $30^{\circ}C$, but at 4Z C the mutant almost did not grow (temperature-sensitivity). When the growth temperatures of both stains were shifted-up from $30^{\circ}C$ to $42^{\circ}C$ after a 4 hour culture, their growths were normal, but when shifted-down from $42^{\circ}C$ to $30^{\circ}C$ after a 4 h culture, the mutant did not grow. When shifted up from $30^{\circ}C$ to $42^{\circ}C$ after a 4 hculture, the DNA syntheses of the two strains were at a normal rate for 1 h, but after 1 h the biosynthesesdecreased. The rate of DNA synthesis of the wild type strain at the nonpermissive temperature was about 93%, and that of the mutant was about 50% of the ratio of the wild type strain, and the RNA synthesis of the wild type strain was maintained for 3 h, and that of the mutant for 2 h. Thereafter the RNA synthesis decreased, and the synthesis of proteins in the both strains were similarlykept high for 8 h. The reversibility of the DNA synthesis of the mutant at $42^{\circ}C$ was lessened whenthe culture times were increased.re times were increased.
B.sphaericus ts-D1290의 특성을 정상균주 (B.sphaericus 1593)와 비교하기 위하여 방사성 동위원소를 이용하여 DNA, RNA 그리고 단백질 생합성량을 허용온도와 비허용온도에서 측정하고, 온도의 영향을 조사하였다. 1. ts-D1290 돌연변이주를 $30^{\circ}C$에서 배양하였을 때는 정상균주와 유사한 증식을 보였으나, 제한 온도인 $42^{\circ}C$에서는 거의 증식을 하지 않았다. 2. 온도를 $30^{\circ}C$에서 $42^{\circ}C$로 상승하여 배양하였을 때는 두 균주 모두 정상적인 높은 증식률을 보였으며, 온도를 $42^{\circ}C$에서 4시간 배양 후 $30^{\circ}C$ 하강하여 배양하였을 때는 정상균주는 정상적인 증식을 하였으나, ts-D1290 돌연변이주는 거의 증식을 하지 않았다.
