Effect of turbulence and viruses on prokaryotic cell size, production and diversity

Mg Weinbauer,A Malits

doi:10.3354/ame01274

Abstract

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 54:243-254 (2009) - DOI: https://doi.org/10.3354/ame01274 Effect of turbulence and viruses on prokaryotic cell size, production and diversity Andrea Malits, Markus G. Weinbauer* Microbial Ecology & Biogeochemistry Group, Université Pierre et Marie Curie-Paris 6, Laboratoire d’Océanographie de Villefranche, 06230 Villefranche-sur-Mer, France; CNRS, Laboratoire d’Océanographie de Villefranche, 06230 Villefranche-sur-Mer, France *Email: wein@obs-vlfr.fr ABSTRACT: A factorial design was used to assess the roles of turbulence and viral infection in prokaryotic production and diversity in a spring phytoplankton bloom experiment in the Bay of Villefranche, France. Several consistent trends were observed in 2 experiments: (1) turbulence stimulated prokaryotic production, (2) prokaryotic cell length increased in experimental turbulence and virus treatments, and (3) organic micro-aggregates with attached prokaryotes formed only in the turbulence treatments and seemed to be reduced in the presence of viruses. We conclude that turbulence likely influenced prokaryotes indirectly by affecting micro-aggregate formation and nutrient availability. Turbulence and viruses had only small influences on the number of bacterial and archaeal bands detected by 16S rRNA gene denaturing gradient gel electrophoresis. However, taking into account presence versus absence of specific bands and their intensities, we detected strong effects in the experiments. We not only detected a negative effect of viruses, but also found that some bands increased in intensity in the presence of active viruses, e.g. one of 3 phylotypes affiliated with the Rhodobacteriaceae. In both experiments, several consistent patterns were found: (1) a phylotype affiliated with Roseobacter was negatively affected (in terms of band intensity) by viruses and turbulence, (2) the relative band intensity of a Rhodobacter increased in the turbulence treatments, and (3) a phylotype related to Oceanospirillum was detected only in the turbulence treatment. We suggest that turbulence and viruses play a significant and previously neglected role in shaping prokaryotic diversity, aggregation and production. KEY WORDS: Virus infection · Prokaryotic activity · Morphology · Roseobacter · Oceanospirillum Full text in pdf format PreviousNextCite this article as: Malits A, Weinbauer MG (2009) Effect of turbulence and viruses on prokaryotic cell size, production and diversity. Aquat Microb Ecol 54:243-254. https://doi.org/10.3354/ame01274Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 54, No. 3. Online publication date: March 02, 2009 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2009 Inter-Research.

Highlights

Prokaryotic viruses play an important role in aquatic food web processes through top-down control of the microbial community, thereby influencing biogeochemical cycles in the sea (Wommack & Colwell 2000, Weinbauer 2004)
Estimates indicate that virus infection can be as important as protistan grazing for total bacterial mortality (Fuhrman & Noble 1995)
The model by Wilhelm & Suttle (1999) suggests that through viral lysis, up to 26% of photosynthetically produced organic carbon is directed to the dissolved organic carbon (DOC) pool

Summary

Introduction

Prokaryotic viruses play an important role in aquatic food web processes through top-down control of the microbial community, thereby influencing biogeochemical cycles in the sea (Wommack & Colwell 2000, Weinbauer 2004). Estimates indicate that virus infection can be as important as protistan grazing for total bacterial mortality (Fuhrman & Noble 1995). A broad range of lysis to grazing ratios has been reported from different depths and locations, suggesting that the contribution of lysis to overall bacterioplankton mortality will depend greatly on environmental conditions and host community structure (Wommack & Colwell 2000). The persistence and decay of free viruses are controlled by biotic factors, such as extracellular enzymes, and abiotic factors, such as solar radiation and adsorption onto particles (Suttle & Chen 1992, Noble & Fuhrman 1997). Any process that brings host and virus together is important for the fate

Methods

Results

Conclusion