Biosynthesis of chemical compounds by Candida albicans and Candida glabrata / Biosíntesis de compuestos químicos por Candida albicans y Candida glabrata

Background: In the last three decades the species of Candida have been of great interest due to the high mortality rates that they cause in immunocompromised and hospitalized patients. These species are opportunistic pathogens and they have inhabited other environments long before colonizing human cells. Among these environments we find wastewater from mines, and water from aquifers and soils that contain high concentrations of precious metals as well as toxic and base metals. Aims: The aim of this study was to assess whether Candida albicans and Candida glabrata are able to maintain homeostasis in the presence of zinc, copper, cobalt or silver. Methods: To achieve the objective, each of the Candida species was exposed to every single metal individually in a salt solution. Subsequently the treated cells were lysed to evaluate the compounds formed by means of Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDS). Results: When analyzing the compounds that both C. albicans and C. glabrata formed in the presence of each of the metals, we found that they had synthesized silver sulfide (Ag2S), cobalt sulfate (CoSO4), zinc phosphate (Zn3(PO4)2), or copper oxide (CuO). Conclusions: Our results indicate that both C. albicans and C. glabrata have enzymatic and non-enzymatic mechanisms that allow them to achieve homeostasis in a different specific manner for each of the single metals to which they were exposed. To our knowledge, this is the first work reporting that C. albicans and C. glabrata can reduce different metals, with the subsequent formation of sulfides, sulfates, phosphates and oxides. This ability, developed over time by these Candida species, is probably a kind of biochemical mechanism in order to survive and colonize many different environments, from water or soil to humans. For this reason, C. albicans and C. glabrata make up an excellent model of study, both from a medical and biotechnical point of view

Antecedentes: Las especies de Candida han cobrado gran interés en las últimas tres décadas debido a los altos índices de mortalidad que ocasionan en pacientes inmunodeficientes y hospitalizados. Estas especies son consideradas patógenas oportunistas y existen otros medios ambientes que estas levaduras han habitado mucho antes de haber colonizado al ser humano: aguas residuales de minas, agua de mantos acuíferos y suelos que contienen altas concentraciones de metales preciosos, metales tóxicos y metales comunes. Objetivos: El objetivo del presente trabajo fue evaluar si Candida albicans y Candida glabrata eran capaces de mantener la homeostasis en presencia de los elementos químicos cinc, cobre, cobalto y plata. Métodos: Para lograr el objetivo, las dos levaduras fueron expuestas a cada uno de los metales elegidos de manera independiente, y posteriormente las células tratadas fueron lisadas para permitir la evaluación por medio de microscopía electrónica de barrido con espectrometría de dispersión de energía de rayos X (SEM-EDS) del compuesto formado. Resultados: Al analizar los compuestos que tanto C. albicans como C. glabrata formaron en presencia de cada metal, se encontró que habían sintetizado sulfuro de plata (Ag2S), sulfato de cobalto (CoSO4), fosfato de cinc (Zn3(PO4)2), u óxido de cobre (CuO). Conclusiones: Nuestros resultados indican que tanto C. albicans como C. glabrata poseen mecanismos enzimáticos y no enzimáticos que les permiten alcanzar una homeostasis de manera específica para cada metal al que son expuestas. A nuestro entendimiento este es el primer trabajo que documenta que C. albicans y C. glabrata pueden reducir distintos metales, con la subsecuente formación de sulfuros, sulfatos, fosfatos y óxidos. Esta habilidad que pudieron desarrollar a lo largo del tiempo estas especies de Candida para poder sobrevivir y colonizar medios ambientes tan diferentes, que van desde el agua o los suelos hasta el ser humano, las convierte en un excelente modelo de estudio, tanto desde el punto de vista médico como biotecnológico

Biosynthesis of chemical compounds by Candida albicans and Candida glabrata.

BACKGROUND: In the last three decades the species of Candida have been of great interest due to the high mortality rates that they cause in immunocompromised and hospitalized patients. These species are opportunistic pathogens and they have inhabited other environments long before colonizing human cells. Among these environments we find wastewater from mines, and water from aquifers and soils that contain high concentrations of precious metals as well as toxic and base metals. AIMS: The aim of this study was to assess whether Candida albicans and Candida glabrata are able to maintain homeostasis in the presence of zinc, copper, cobalt or silver. METHODS: To achieve the objective, each of the Candida species was exposed to every single metal individually in a salt solution. Subsequently the treated cells were lysed to evaluate the compounds formed by means of Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDS). RESULTS: When analyzing the compounds that both C. albicans and C. glabrata formed in the presence of each of the metals, we found that they had synthesized silver sulfide (Ag2S), cobalt sulfate (CoSO4), zinc phosphate (Zn3(PO4)2), or copper oxide (CuO). CONCLUSIONS: Our results indicate that both C. albicans and C. glabrata have enzymatic and non-enzymatic mechanisms that allow them to achieve homeostasis in a different specific manner for each of the single metals to which they were exposed. To our knowledge, this is the first work reporting that C. albicans and C. glabrata can reduce different metals, with the subsequent formation of sulfides, sulfates, phosphates and oxides. This ability, developed over time by these Candida species, is probably a kind of biochemical mechanism in order to survive and colonize many different environments, from water or soil to humans. For this reason, C. albicans and C. glabrata make up an excellent model of study, both from a medical and biotechnical point of view.

Biosynthesis of micro- and nanocrystals of Pb (II), Hg (II) and Cd (II) sulfides in four Candida species: a comparative study of in vivo and in vitro approaches.

Nature produces biominerals (biogenic minerals) that are synthesized as complex structures, in terms of their physicochemical properties. These biominerals are composed of minerals and biological macromolecules. They are produced by living organisms and are usually formed through a combination of chemical, biochemical and biophysical processes. Microorganisms like Candida in the presence of heavy metals can biomineralize those metals to form microcrystals (MCs) and nanocrystals (NCs). In this work, MCs and NCs of PbS, HgS or HgCl2 as well as CdS are synthesized both in vitro (gels) and in vivo by four Candida species. Our in vivo results show that, in the presence of Pb2+ , Candida cells are able to replicate and form extracellular PbS MCs, whereas in the presence of Hg2+ and Cd2+ , they did synthesize intercellular MCs from HgS or HgCl2 and CdS NCs respectively. The MCs and NCs biologically obtained in Candida were compared with those PbS, HgS and CdS crystals synthetically obtained in vitro through the gel method (grown either in agarose or in sodium metasilicate hydrogels). This is, to our knowledge, the first time that the biosynthesis of the various MCs and NCs (presented in several species of Candida) has been reported. This biosynthesis is differentially regulated in each of these pathogens, which allows them to adapt and survive in different physiological and environmental habitats.