RESUMO
Two hormones, tremerogens A-9291-I and A-9291-II, that induce conjugation tube formation in a-type cells of Tremella brasiliensis were isolated from the culture filtrate of A-type cells. Both hormones are peptides and they have similar amino acid compositions. The N-terminal amino acids of these peptides are aspartic acid or asparagine.
Assuntos
Basidiomycota/análise , Proteínas Fúngicas/isolamento & purificação , Hormônios Peptídicos , Reguladores de Crescimento de Plantas/isolamento & purificação , Aminoácidos/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de MassasRESUMO
Trimorphomyces Bandoni and Oberw. gen. nov. (Tremellaceae) includes a single species, T. papilionaceus Bandoni and Oberw. sp. nov., which parasitizes Arthrinium sphaerospermum Fckl. The sporocarps are mainly or entirely conidial at first; conidia and basidia are mixed in mature basidiocarps. The basidia are cruciately-septate, stalked. Basidiospores germinate by repetition or by budding to form a haploid yeast phase. Blastic conidia are formed successively; terminal pairs develop synchronously and conjugate before release. The conidia are H-shaped and dikaryotic. The dikaryotic conidia germinate by forming paired buds and a dikaryotic yeast phase is initiated. Dikaryotic yeast cells are produced in the same manner as the parental conidia and are released as H-shaped, conjugated pairs. In the presence of Arthrinium sphaerospermum hyphae, dikaryotic conidia or dikaryotic yeast cells germinate by hyphal and haustorial formation.
RESUMO
Description is provided of a new heterobasidiomycetous genus, Cystofilobasidium, based on Rhodosporidium capitatum. The genus is characterized by teliospores which give rise to filobasidiaceous basidia, sessile primary basidiospores which remain attached to the basidium, and a yeast phase developing from buds produced by the primary spores. Two species formerly placed in Rhodosporidium are transferred to Cystofilobasidium; these are C. bisporidiis (Fell, Hunter and Tallman) Oberw. and Bandoni comb, nov., and C. capitatum (Fell, Hunter and Tallman) Oberw. and Bandoni, comb. nov.
RESUMO
A survey of North, Central, and South American composites, and of certain polyacetylenic compounds occurring in them, confirmed that the ultraviolet-mediated antibiotic activity against Candida albicans can be ascribed to the presence of particular polyacetylenes and their thiophene derivatives. Leaves, stems, roots, and achenes were assayed separately. An attempt was made to relate the phototoxic activity of specific compounds to their chemical structures. Most composites tested were not phototoxic against Candida, but many were antibiotic. The antibiotic activity also appears to be caused by polyacetylenes. Of 65 sequiterpene lactones assayed, only a few were found to be antibiotic, and only one, glaucolide G, was phototoxic.
Assuntos
Alcinos/farmacologia , Antibacterianos , Candida albicans/efeitos dos fármacos , Plantas Medicinais , Raios Ultravioleta , Alcinos/efeitos da radiação , América , Fenômenos Químicos , Química , Fotoquímica , Sesquiterpenos/farmacologia , Especificidade da EspécieRESUMO
Aqueous films on terrestrial litter are inhabited by numerous microorganisms; the surfaces of such films are covered by monolayer-forming substances. The spreading pressure of the latter can result in transport of floating and submerged organisms to adjacent water films with clean surfaces. The clean surfaces, produced by rain or possibly dew, permit rapid vertical and horizontal dispersal of microorganisms onto newly fallen leaves and other plant materials.