Phylotype Dynamics of Bacterial P Utilization Genes in Microbialites and Bacterioplankton of a Monomictic Endorheic Lake

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• 作者：Patricia M. Valdespino-Castillo ; Rocío J. Alcántara-Hernández…
• 关键词：Extracellular enzymes ; DOP utilization ; Phytase ; P turnover ; Phylotype seasonality ; Microbial functional diversity
• 刊名：Microbial Ecology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：73
• 期：2
• 页码：296-309
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Microbiology; Ecology; Microbial Ecology; Geoecology/Natural Processes; Nature Conservation; Water Quality/Water Pollution;
• 出版者：Springer US
• ISSN：1432-184X
• 卷排序：73

文摘

Microbes can modulate ecosystem function since they harbor a vast genetic potential for biogeochemical cycling. The spatial and temporal dynamics of this genetic diversity should be acknowledged to establish a link between ecosystem function and community structure. In this study, we analyzed the genetic diversity of bacterial phosphorus utilization genes in two microbial assemblages, microbialites and bacterioplankton of Lake Alchichica, a semiclosed (i.e., endorheic) system with marked seasonality that varies in nutrient conditions, temperature, dissolved oxygen, and water column stability. We focused on dissolved organic phosphorus (DOP) utilization gene dynamics during contrasting mixing and stratification periods. Bacterial alkaline phosphatases (phoX and phoD) and alkaline beta-propeller phytases (bpp) were surveyed. DOP utilization genes showed different dynamics evidenced by a marked change within an intra-annual period and a differential circadian pattern of expression. Although Lake Alchichica is a semiclosed system, this dynamic turnover of phylotypes (from lake circulation to stratification) points to a different potential of DOP utilization by the microbial communities within periods. DOP utilization gene dynamics was different among genetic markers and among assemblages (microbialite vs. bacterioplankton). As estimated by the system’s P mass balance, P inputs and outputs were similar in magnitude (difference was <10 %). A theoretical estimation of water column P monoesters was used to calculate the potential P fraction that can be remineralized on an annual basis. Overall, bacterial groups including Proteobacteria (Alpha and Gamma) and Bacteroidetes seem to be key participants in DOP utilization responses.