| Autor: |
Moreira D; Unité d'Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud/Paris-Saclay, AgroParisTech, 91400 Orsay, France., Tavera R; Facultad de Ciencias, Universidad Nacional Autónoma de México, CDMX, Mexico., Benzerara K; Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, Sorbonne Universités-UPMC Univ Paris 06, CNRS UMR 7590, MNHN, IRD UMR 206, Paris, France., Skouri-Panet F; Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, Sorbonne Universités-UPMC Univ Paris 06, CNRS UMR 7590, MNHN, IRD UMR 206, Paris, France., Couradeau E; Present address: School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.; Facultad de Ciencias, Universidad Nacional Autónoma de México, CDMX, Mexico.; Unité d'Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud/Paris-Saclay, AgroParisTech, 91400 Orsay, France., Gérard E; Géobiosphère Actuelle et Primitive, Institut de Physique du Globe de Paris, CNRS UMR 7154, Université Paris Diderot, Sorbonne Paris Cité, Paris, France., Fonta CL; Nestlé Research Center, Minerals and Imaging Group, P.O Box 44, Ch-1000 Lausanne 26, VD, Switzerland., Novelo E; Facultad de Ciencias, Universidad Nacional Autónoma de México, CDMX, Mexico., Zivanovic Y; Institut de Génétique et Microbiologie, CNRS UMR 8621, Université Paris-Sud/Paris-Saclay, 91405 Orsay, France., López-García P; Nestlé Research Center, Minerals and Imaging Group, P.O Box 44, Ch-1000 Lausanne 26, VD, Switzerland. |
| Abstrakt: |
A unicellular cyanobacterium, strain Alchichica-D10, was isolated from microbialites of the alkaline Lake Alchichica, Mexico. The cells were short rods (3.9±0.6 µm in length and 1.1±0.1 µm in width) forming biofilms of intense emerald green colour. They exhibited red autofluorescence under UV light excitation. UV-visible absorption spectra revealed that they contain chlorophyll a and phycocyanin, and electron microscopy showed the presence of thylakoids. The strain grew within a temperature range of 15-30 °C. Genomic DNA G+C content was 52.2 mol%. The most remarkable feature of this species was its granular cytoplasm, due to the presence of numerous intracellular spherical granules (16-26 per cell) with an average diameter of 270 nm. These granules, easily visible under scanning electron microscopy, were composed of amorphous carbonate containing Ca, Mg, Ba and Sr. A multi-gene phylogeny based on the analysis of 59 conserved protein markers supported robustly that this strain occupies a deep position in the cyanobacterial tree. Based on its phenotypic characters and phylogenetic position, strain Alchichica-D10 is considered to represent a new genus and novel species of cyanobacteria for which the name Gloeomargarita lithophora gen. nov., sp. nov. is proposed. The type strain is Alchichica-D10 (Culture Collection of Algae and Protozoa CCAP strain 1437/1; Collections de Cyanobactéries et Microalgues Vivantes of the Museum National d'Histoire Naturelle in Paris strain PMC 919.15). Furthermore, a new family, Gloeomargaritaceae, and a new order, Gloeoemargaritales, are proposed to accommodate this species under the International Code of Nomenclature for algae, fungi and plants. |
