The response of certain Acetobacter species to the lactone moiety of pantothenic acid.

Underkofler et al. (1943) first demonstrated that pantothenic acid is an essential requirement for Acetobacter suboxydans, ATCC 621, and that this organism responds to pantolactone in a pantothenate deficient medium. j5-Alanine, however, is not able to replace pantothenic acid. Subsequently, Sarett and Cheldelin (1945) described the assay of pantolactone using the same strain of A. suboxydans. In this study it was shown that pantolactone possessed only 20 to 25 per cent of the activity of pantoic acid, prepared by the alkaline hydrolysis of the lactone. Very recently, reports on the vitamin requirements of Acetobacter species other than A. suboxydans have been published (Foda and Vaughn, 1953; Rao and Stokes, 1953; Hall et al., 1953; Rainbow and Mitson, 1953) which permit the conclusion that pantothenic acid is either essential or stimulatory to several species of this genus. The purpose of the present investigation was to study the response of a selection of pantothenate requiring Acetobacter to pantolactone.