A new and effective approach to boron removal by using novel boron-specific fungi isolated from boron mining wastewater.

Boron-resistant fungi were isolated from the wastewater of a boron mine in Turkey. Boron removal efficiencies of Penicillium crustosum and Rhodotorula mucilaginosa were detected in different media compositions. Minimal Salt Medium (MSM) and two different waste media containing molasses (WM-1) or whey + molasses (WM-2) were tested to make this process cost effective when scaled up. Both isolates achieved high boron removal yields at the highest boron concentrations tested in MSM and WM-1. The maximum boron removal yield by P. crustosum was 45.68% at 33.95 mg l(-1) initial boron concentration in MSM, and was 38.97% at 42.76 mg l(-1) boron for R. mucilaginosa, which seemed to offer an economically feasible method of removing boron from the effluents.

[Assessment of the MSP-PCR technique for the molecular characterization of Rhodotorula mucilaginosa isolates from northwestern Patagonia]. / Evaluación de la técnica de MSP-PCR para la caracterización molecular de aislamientos de Rhodotorula mucilaginosa provenientes de la Patagonia noroccidental.

The rapid identification of environmental or clinical yeast isolates is important for biodiversity studies and the detection of probable pathogens. Rhodotorula mucilaginosa is a ubiquitous and pigmented yeast capable of infecting immunocompromised patients. In this study, we evaluated the Micro/mini satellite-primed PCR (MSP-PCR) fingerprinting method for the characterization and identification of R. mucilaginosa isolates from natural environments in northwestern Patagonia. There were selected 110 putative R. mucilaginosa isolates from 200 environmental pigmented yeast isolates on the basis of phenotypic criteria. (GTG)5, (GAC)5 and M13 primers were initially evaluated in representative R. mucilaginosa isolates. (GTG)5 allowed a good grouping of these isolates and, at the same time, a good differentiation among closely related species, and thus was selected for subsequent studies. R. mucilaginosa isolates (87%) presented similar (> 60%) MSP-PCR profiles to those of the reference strain CBS 316T. The MSP-PCR technique was effective, both, for the characterization and identification of a large number of R. mucilaginosa environmental isolates as well as for the detection of polymorphisms within the species.

Evaluación de la técnica de MSP-PCR para la caracterización molecular de aislamientos de Rhodotorula mucilaginosa provenientes de la Patagonia noroccidental / Assessment of the MSP-PCR technique for the molecular characterization of Rhodotorula mucilaginosa isolates from northwestern Patagonia

La identificación rápida de levaduras de origen ambiental o clínico es de importancia para el estudio de la biodiversidad de estos microorganismos y para la detección de posibles patógenos. Rhodotorula mucilaginosa es una levadura ubicua y pigmentada, capaz de producir infecciones en pacientes inmunocomprometidos. En este trabajo se evaluó la utilidad de la técnica de fingerprinting conocida como MSP-PCR (Micro/Minisatellite-Primed PCR) en la caracterización e identificación de aislamientos ambientales de R. mucilaginosa provenientes de la Patagonia noroccidental. Sobre la base de sus caracteres fenotípicos, de un total de 200 levaduras pigmentadas se seleccionaron 110 aislamientos que presuntamente corresponderían a la especie R. mucilaginosa. Se evaluaron los iniciadores (GTG)5, (GAC)5 y M13 en aislamientos representativos, y se seleccionó el iniciador (GTG)5 por ser el que permitió una mejor agrupación de los aislamientos pertenecientes a R. mucilaginosa y una mejor diferenciación de éstos con los de especies filogenéticamente próximas. Utilizando dicho iniciador, el 87% de los aislamientos de R. mucilaginosa presentó un perfil de MSP-PCR similar (> 60%) al de la cepa de referencia CBS 316T de R. mucilaginosa. La técnica de MSP-PCR resultó efectiva, tanto para caracterizar e identificar un número elevado de aislamientos ambientales de R. mucilaginosa como para detectar polimorfismos en la especie.

The rapid identification of environmental or clinical yeast isolates is important for biodiversity studies and the detection of probable pathogens. Rhodotorula mucilaginosa is a ubiquitous and pigmented yeast capable of infecting immunocompromised patients. In this study, we evaluated the Micro/mini satellite-primed PCR (MSP-PCR) fingerprinting method for the characterization and identification of R. mucilaginosa isolates from natural environments in northwestern Patagonia. There were selected 110 putative R. mucilaginosa isolates from 200 environmental pigmented yeast isolates on the basis of phenotypic criteria. (GTG)5, (GAC)5 and M13 primers were initially evaluated in representative R. mucilaginosa isolates. (GTG)5 allowed a good grouping of these isolates and, at the same time, a good differentiation among closely related species, and thus was selected for subsequent studies. R. mucilaginosa isolates (87%) presented similar (> 60%) MSP-PCR profiles to those of the reference strain CBS 316T. The MSP-PCR technique was effective, both, for the characterization and identification of a large number of R. mucilaginosa environmental isolates as well as for the detection of polymorphisms within the species.

Evaluation of two commercialized systems for the rapid identification of medically important yeasts.

A total of 77 recent clinical isolates of Candida albicans and other medically important yeasts were identified by two different commercial tests, Rapidec albicans (API-bioMérieux) and Fongiscreen 4H (Sanofi Diagnostics Pasteur), and conventional mycological methods. The strains were from 13 different species of yeasts and consisted of strains of 36 C. albicans, three of Candida famata, nine of Candida (Torulopsis) glabrata, five of Candida guilliermondii, two of Candida kefyr, three of Candida krusei, one of Candida lusitaniae, four of Cryptococcus neoformans, five of Candida parapsilosis, six of Candida tropicalis, one of Candida viswanathii, one of Rhodotorula rubra and one of Saccharomyces cerevisiae. According to the reactivity profiles of the isolates, identification was always correct with Fongiscreen 4H and was correct in 97.3% of the strains with Rapidec albicans. The latter test did not identify two C. albicans isolates that were correctly identified by Fongiscreen 4H. Both methods (97.3% correlation) were very useful for identification of C. albicans achieving the aim of their manufacturers. Additionally, Fongiscreen 4H was very useful for the identification of three other species of yeasts: C. glabrata, C. tropicalis and Cr. neoformans. The results of our study indicate that the accuracy of Rapidec albicans and Fongiscreen 4H is similar to that of the conventional methods used in this study for the identification of C. albicans. The same is true of Fongiscreen 4H in the identification of C. glabrata, C. tropicalis and Cr. neoformans. Both tests could be rapid and easy-to-perform tools in the clinical microbiology laboratory, but differences in cost must be taken into account.