A Neutral (?) Strain of Mucor sphaerosporus from Missouri

Abstract

In the caves of the Ranken estate in Missouri, where the atmosphere is moist and the temperature approximately 160 C., was found a segment of a twig matted with a growth of mycelial threads, white in a mass, and hyaline when single. The appearance of the latter was that of many fine root hairs. When transferred to agar substrates, numerous sporangia, sporangioles, oidia, and chlamydospores developed, with no evidence of zygospores. The characteristics and description were similar to those given by Lendner ('08) for Mucor sphaerosporus Hagem 1908. This fungus has been reported chiefly from Europe, and in this country by Waksman ('16) and Gilman and Abbott ('27), as isolations from soil. As far as the author could determine, this is the first report of the above organism from Missouri. A culture sent to Dr. A. F. Blakeslee at the Carnegie Institution of Washington, Department of Genetics, was tested with strains of presumably the same species, one being a minus isolated by Waksman in 1915, and another a plus strain probably from the Centralstelle, of unknown origin. No zygospores were produced. An attempt was made to obtain imperfect hybridization by treating this strain with some of the strong testers in the above laboratory, but no sexual reaction resulted. Growth on various media produced changes in the amount of mycelium, size and number of sporangia, sporangioles, hyphae, oidia and chlamydospores, and in chromogenesis. Thanks are due Dr. Blakeslee and Miss Satina of the Carnegie Institution of Washington for their interest and assistance.