RESUMO
Three new asexual yeast species were isolated from various floricolous insects. Candida cleridarum sp. nov. was the dominant species in clerid beetles collected in flowers of various cacti in Arizona and Southern California. The sequence of the D1D2 domains of the large-subunit rDNA showed that it is a sister species to Candida fragi (0.9% base difference), a yeast isolated once from fermenting strawberries. Candida tilneyi sp. nov. and Candida powellii sp. nov. were recovered from bees and from nitidulid beetles in flowers of two species of morning glory (Ipomoea) in north-western Costa Rica. C. tilneyi sp. nov. is most closely related to Candida geochares, but differs in the D1D2 sequence by 4.7% base substitutions. C. powellii sp. nov. is a relative of Candida batistae and Candida floricola, showing sequence differences of 5.9 and 6.9%, respectively. In all cases, the new species are phenotypically similar to their nearest relatives, but are sufficiently different to allow conventional identification. The type strains are C. cleridarum strain UWO(PS) 99-101.1T ( = CBS 8793T), C. tilneyi strain UWO(PS) 99-325.1T ( = CBS 8794T) and C. powellii strain UWO(PS) 99-325.3T ( = CBS 8795T).
Assuntos
Candida/classificação , Insetos/microbiologia , Filogenia , Animais , Asteraceae/parasitologia , Candida/genética , Candida/isolamento & purificação , Besouros/microbiologia , Costa Rica , DNA Ribossômico/genética , Ecossistema , Fermentação , Frutas/microbiologia , Dados de Sequência Molecular , Caules de Planta/parasitologiaRESUMO
Two new haplontic heterothallic species of Metschnikowia were isolated from floricolous insects and flowers. Metschnikowia lochheadii was recovered from insects found in various flowers on the Hawaiian Islands of Kauai and Maui, and from Conotelus sp. (Coleoptera: Nitidulidae) in northwestern Guanacaste Province, Costa Rica. The morphology, physiology, and sexual cycle are typical of the large-spored Metschnikowia species, and the partial ribosomal DNA large subunit (D1D2) sequences suggest that the new species is most closely related to Candida ipomoeae. Metschnikowia lochheadii is nearly indistinguishable from its ascogenous relatives and conjugates freely with Metschnikowia continentalis, forming sterile asci. It also exhibits asymmetric mating with Metschnikowia hawaiiensis. Metschnikowia drosophilae was found in morning glory (Ipomoea sp.) flowers and associated Drosophila bromeliae on Grand Cayman Island. Its nutritional profile is atypical of the genus, being the only species that does not utilize sucrose or maltose as carbon sources, and one of the few that does not utilize melezitose. D1D2 sequences show that Metschnikowia drosophilae is a sister species to Candida torresii, to which it bears considerable similarity in nutritional profile. The type cultures are: Metschnikowia lochheadii, strains UWO(PS)00-133.2 = CBS 8807 (h+, holotype) UWO(PS)99-661.1 = CBS 8808 (h-, isotype); and Metschnikowia drosophilae, strains UWO(PS)83-1135.3 = CBS 8809 (h+, holotype) and UWO(PS)83-1143.1 = CBS 8810 (h-, isotype).
Assuntos
Insetos/microbiologia , Plantas/microbiologia , Leveduras/classificação , Animais , Costa Rica , Genoma Fúngico , Havaí , Dados de Sequência Molecular , Filogenia , Leveduras/genéticaRESUMO
We report on the yeast community associated with sap fluxes of Maclura tinctoria, family Moraceae, in the dry forest of the Area de Conservación Guanacaste, Costa Rica. Eleven samples yielded seven hitherto undescribed ascomycetous yeasts in the genera Candida and Myxozyma. We describe the two most abundant as new species. Candida galis utilizes very few carbon compounds limited to some alcohols and acids. Analysis of rDNA sequences suggests that it occupies a basal position with respect to the Pichia anomala clade, with no obvious sister species. Candida ortonii is also restricted in nutritional breadth, and growth is generally very slow. It is a sister species to Candida nemodendra. The type cultures are: C. galis, strain UWO(PS)00-159.2=CBS 8842; and C. ortonii, strain UWO(PS)00-159.3=CBS 8843.
Assuntos
Candida/classificação , Candida/genética , Ecossistema , Maclura/microbiologia , Estruturas Vegetais/microbiologia , Candida/isolamento & purificação , Costa Rica , DNA Fúngico/análise , DNA Ribossômico/análise , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Saccharomycetales/classificação , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNARESUMO
The seed predator,Caryedes brasiliensis [Bruchidae] generates appreciable ammonia in its dietary use and detoxification ofL-canavanine and its catabolic product,L-canaline.L-Canavanine is a toxic allelochemical ofDioclea megacarpa seeds, the food of the developing larvae. Bruchid beetle larvae rely upon glutamic acid dehydrogenase and glutamine synthetase to use ammonia for glutamic acid synthesis from 2-oxoglutaric acid and conversion of the former to glutamine. These reactions provide the larvae with a means for metabolically eliminating ammonia. Proline serves as a carbon skeleton source for glutamic acid formation.
RESUMO
Larvae of the bruchid beetle,Caryedes brasiliensis (Bruchidae) have the ability to avoid significant incorporation ofL-canavanine, the guanidinooxy structural analog ofL-arginine, into de novo synthesized proteins. This ability is related to a highly discriminatory protein-synthesizing system which exhibits marked ability to avoid processing an array of nonprotein amino acids structurally related to arginine.
RESUMO
Larvae of the bruchid beetle Caryedes brasiliensis (Bruchidae) develop entirely within the seed of the neotropical legume Dioclea megacarpa. The seed contains an appreciable concentration of L-canavanine, a potent antimetabolite and structural analog of L-arginine. This bruchid beetle uses the nitrogen stored in this toxic allelochemical as an effective dietary nitrogen source for amino acid biosynthesis.