THE MUTAGENIC ACTION OF FORMALDEHYDE ON BACTERIA

Abstract

highly mutagenic for Drosophila when administered with its food. Auerbach (1949), however, observed negative results when Drosophila was exposed to formaldehyde vapor and concluded that formaldehyde acts indirectly through chemical changes brought about in food constituents. Dickey, Cleland, and Lotz (1949) found formaldehyde and a mixture of formaldehyde and hydrogen peroxide mutagenic for Neurospora crassa. This paper will report investigations on the mutagenic effect of formaldehyde on bacteria. MATERIALS AND METHODS The mutation principally studied was that of Pseudomonas fluorescens, strain A3.7, wild type, I-, to a mutant, I +, which can use, as the sole source of car-bon for growth, itaconic acid (methylene succinic acid), a substance not used by the parent strain. Experiments were also conducted on the mutation of Escherichia coli, strain B, to resistance to phage Ti. Cultures of E. coli and phage Ti were obtained