Antimutagenic effect of Ge-132 on #betta#-ray-induced mutations in Escherichia coli B/r WP2 trp-

The effect of carboxyethylgermanium sesquioxide (Ge-132) over a concentration range of 0-30μg/ml on #betta#-irradiated cells of Escherichia coli B/r WP2 trp (dose range 0-10 kR) has been examined. The mutation frequency (Trp- → Trp+) in absence of Ge-132 was approximately 1.1 x 10-6, whereas it became about 5.4 x 10-8 with soft agar supplementing 30 μg/ml of the metal compound. When similar experiments were made with unirradiated bacteria, the Ge-132 had little effect on the survival as well as on the mutability, indicating that Ge-132 itself is not a mutagen. (U.K.)