title: Alkaline phosphatases in microbialites and bacterioplankton from Alchichica soda lake, Mexico.
abstract: Dissolved organic phosphorus utilization by different members of natural communities has been closely linked to microbial alkaline phosphatases whose affiliation and diversity is largely unknown. Here we assessed genetic diversity of bacterial alkaline phosphatases phoX and phoD, using highly diverse microbial consortia (microbialites and bacterioplankton) as study models. These microbial consortia are found in an oligo-mesotrophic soda lake with a particular geochemistry, exhibiting a low calcium concentration and a high Mg : Ca ratio relative to seawater. In spite of the relative low calcium concentration in the studied system, our results highlight the diversity of calcium-based metallophosphatases phoX and phoD-like in heterotrophic bacteria of microbialites and bacterioplankton, where phoX was the most abundant alkaline phosphatase found. phoX and phoD-like phylotypes were more numerous in microbialites than in bacterioplankton. A larger potential community for DOP utilization in microbialites was consistent with the TN : TP ratio, suggesting P limitation within these assemblages. A cross-system comparison indicated that diversity of phoX in Lake Alchichica was similar to that of other aquatic systems with a naturally contrasting ionic composition and trophic state, although no phylotypes were shared among systems.
authors.affiliation: Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Coyoacán, Mexico; Laboratorio de Ecología Bacteriana, Instituto de Ecología, Universidad Nacional Autónoma de México, Coyoacán, Mexico.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Valdespino-Castillo
authors.forename: Rocio J
authors.initials: RJ
authors.lastname: Alcántara-Hernández
authors.forename: Javier
authors.initials: J
authors.lastname: Alcocer
authors.forename: Martín
authors.initials: M
authors.lastname: Merino-Ibarra
authors.forename: Miroslav
authors.initials: M
authors.lastname: Macek
authors.forename: Luisa I
authors.initials: LI
authors.lastname: Falcón
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D014644:Genetic Variation; D060106:Lakes / Q000737:chemistry* / Q000382:microbiology*; D008800:Mexico; D008969:Molecular Sequence Data; D010758:Phosphorus / Q000378:metabolism*; D010802:Phylogeny; D054712:Salinity
chemical_list: D010758:Phosphorus; D000469:Alkaline Phosphatase
keywords: dissolved organic phosphorus utilization; extracellular enzymes; low calcium environment; microbial functional diversity