Volume 17, Issue 10 p. 4133-4142
Research article

Seasonality in molecular and cytometric diversity of marine bacterioplankton: the re-shuffling of bacterial taxa by vertical mixing

Francisca C. García

Corresponding Author

Francisca C. García

Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, 33212 Gijón/Xixón, Spain

For correspondence. E-mail [email protected]; Tel. (+34) 985308672; Fax (+34) 985326277. E-mail [email protected]; Tel. (+34) 985308672; Fax (+34) 985326277.Search for more papers by this author
Laura Alonso-Sáez

Laura Alonso-Sáez

Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, 33212 Gijón/Xixón, Spain

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Xosé Anxelu G. Morán

Xosé Anxelu G. Morán

Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, 33212 Gijón/Xixón, Spain

Red Sea Research Center, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, 23955-6500 Thuwal, Saudi Arabia

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Ángel López-Urrutia

Corresponding Author

Ángel López-Urrutia

Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, 33212 Gijón/Xixón, Spain

For correspondence. E-mail [email protected]; Tel. (+34) 985308672; Fax (+34) 985326277. E-mail [email protected]; Tel. (+34) 985308672; Fax (+34) 985326277.Search for more papers by this author
First published: 17 July 2015
Citations: 21

Summary

The ‘cytometric diversity’ of phytoplankton communities has been studied based on single-cell properties, but the applicability of this method to characterize bacterioplankton has been unexplored. Here, we analysed seasonal changes in cytometric diversity of marine bacterioplankton along a decadal time-series at three coastal stations in the Southern Bay of Biscay. Shannon–Weaver diversity estimates and Bray–Curtis similarities obtained by cytometric and molecular (16S rRNA tag sequencing) methods were significantly correlated in samples from a 3.5 year monthly time-series. Both methods showed a consistent cyclical pattern in the diversity of surface bacterial communities with maximal values in winter. The analysis of the highly resolved flow cytometry time-series across the vertical profile showed that water column mixing was a key factor explaining the seasonal changes in bacterial composition and the winter increase in bacterial diversity in coastal surface waters. Due to its low cost and short processing time as compared with genetic methods, the cytometric diversity approach represents a useful complementary tool in the macroecology of aquatic microbes.