The nutritional requirements of Acetobacter melanogenum and related species.

During the course of some physiological studies with Acetobacter melanogenum it became necessary to investigate the nutritional requirements of several isolates in considerable detail. Grey and Tatum (1944) already had described a minimal medium for growth of one isolate of this species. However, since only one isolate was studied and the nutritional observations were made more or less incidental to the main investigation of the effect of X-rays on this species, it was thought desirable to confirm and, if possible, to expand their observations. The discrepancies in our knowledge of physiology and nutrition as related to taxonomy and nomenclature are particularly evident among the group of acetic acid bacteria which oxidize ethanol only to the stage of acetic acid and are popularly known as "underoxidizers". Therefore, a culture of A. oxydans was used as a second representative of this group to be compared with the cultures of A. melanogenum in order to determine whether the nutritional requirements differed significantly from those of A. suboxydans. The nutritional requirements of this latter species, a well known member of the group causing partial oxidation of ethanol, have been investigated in detail (see Lampen, Underkofler, and Peterson, 1942; Landy and Dicken, 1942; Underkofler, Bantz, and Peterson, 1943; Landy and Streightoff, 1943; Sarett and Cheldelin, 1945; Cheldelin and Bennett, 1945; and Stokes and Lsen, 1945). The nutritional requirements of A. melanogenum and A. oxydans also were compared with those of a representative culture of A. rancens, one of the species capable of causing complete oxidation ("overoxidation") of ethanol (8ee Visser't Hooft, 1925; Vaughn, 1942). It was