Production of aflatoxins by strains of the Aspergillus flavus group maintained in ATCC

A total of 169 strains of the Aspergillus reference cultures in the Aspergillus flavus group maintained in the American Type Culture Collection (ATCC) were studied for their aflatoxin-producing abilities in rice, peanut and semisynthetic medium, utilizing high pressure liquid chromatography. Fifty-nine of the strains examined were positive for aflatoxin formation. No strains of the food fungi A. oryzae or A. sojae produced detectable levels of aflatoxins, while 33-85% of the strains of A. flavus and A. parasiticus were toxigenic.

Biochemical variation of Cryptococcus neoformans

Ninety-seven strains of Cryptococcus neoformans and C. bacillisporus were examined for 44 biochemical characters and the results were analyzed numerically. One phenon emerged at the 86% level of similarity when strains were clustered according to their M-similarity values. All strains grew in ten carbon sources (D-glucose, D-galactose, arbutin, maltose, sucrose, D-melezitose, D-xylose, D-mannitol, D-glucitol, and meso-inositol), and also grew at 37 degrees C and produced urease and phenoloxidase. None of them grew in melibiose, lactose, nor valine, and none reduced nitrate to nitrite. Comparison of selected biochemical characters, creatinine utilization, and serotypes of 49 aberrant strains is presented. Forty-eight of the 97 strains produced the Filobasidiella state either alone or when paired with a strain of compatible mating-type. Filobasidiella neoformans serotypes A and D were interfertile with compatible mating-types of F. bacillispora serotypes B and C. The 44 biochemical characters and 4 serotypes did not predict barriers to mating competence. The present study further substantiates that Filobasidiella neoformans and F. bacillispora are one species.

Serologic grouping and sexual compatibility of airborne Cryptococcus neoformans

Through the use of Anderson air samples, 214 isolates of Cryptococcus neoformans were cultured from the air in a vacant tower in a large complex of buildings in Oklahoma City. The tower contained hundreds of pigeons, a massive amount of droppings, nests with eggs and young, dying and dead pigeons. All isolates were serotype A-D and self-sterile for the production of basidiospores. Among these 193 were of the "alpha" mating type, producing basidiospores when paired with "alpha" mating type. No isolates of "alpha" mating type were found. The findings imply that the infectious particles of C. neoformans in nature are relatively small, nonencapsulated yeast cells and not basidiospores.

Conservation of reference strains of Fusarium in pure culture

More than 300 reference strains representing 60 species and varieties of Fusarium cultures named according to different taxonomic systems are currently maintained at the American Type Culture Collection (ATCC). They have been preserved by freeze-drying and by freezing and subsequent storage in liquid nitrogen (-196 degrees C) to insure their viability without contamination, variation, mutation, or deterioration. The materials and procedures used at the ATCC for the acquisition, accessioning, cataloguing, preservation and distribution are described. Longevity storage data for the strains available for distribution are presented and discussed.

Reproducibility of vitamin assays with mutants of Neurospora crassa maintained by freeze-drying

Three mutant strains (ATCC 9277, ATCC 9278, ATCC 9683) of Neurospora crassa requiring choline, inositol, and p-aminobenzoic acid respectively for normal growth were deposited at the ATCC by G.W. Beadle 30 years ago and were preserved at various time intervals by freeze-drying. Each preservation batch yielded cultures that, when used for biological assays, exhibited the same biochemical properties as they originally possessed. The freeze-drying technique is shown to be applicable to preserving biological properties of sporulating fungi for bioassay over prolonged periods of time.

Effect of carbon source on conidiogenesis in Fonsecaea dermatitidis, agent of chromomycosis

Hormiscium dermatitidis Kano is a well known etiological agent of cutaneous and generalized chromomycosis. However, the generic designation of this fungus has long been a much debated question. The results of the present study of the type culture ATCC 28869 indicate that the fungus is polymorphic, producing a Phialophora state in media containing glucose or maltose and a Cladosporium state in media containing galactose or melibiose. Morphologically and developmentally this chromomycotic agent is closely related to Fonsecaea pedrosoi (Brumpt) Negroni and should be classified as Fonsecaes dermatitidis (Kano) Carrion.

Preservation of living fungi pathogenic for man and animals

The paper describes the materials and procedures presently used at the American Type Culture Collection (ATCC) for the long-term preservation of living fungi pathogenic for man and animals by freeze-drying and by freezing and subsequent storage in liquid nitrogen. Longevity storage data for the strains available for distribution is presented.