Role of Marine Microbes in Carbon and Nutrient Cycles

1. Microbes in the sea. Defining the subject of study in marine microbiology. 2. The role of microbes in the cycles of nutrients and carbon. A historical view. 2.1 The abundance of pelagic microbes. How many are there ? 2.2 The growth and production of bacteria 2.3 The control of bacterial abundance 2.4 The rediscovery of planktonic viruses 2.5 The concept of the Microbial Food Web 3. The end of the black box approach to the study of the ecology of plankton microbes. 3.1 Heterogeneity in the ecological roles of microbes 3.2 Heterogeneity in the activity of the different microbes 3.3 Heterogeneity in the phylogeny of the different microbes 3.4 From phylogenetic probing (“who is there ?”) to molecular probing (“Who is doing what?”) 4. Evolving perceptions on the role of microorganisms in the organic matter fluxes in planktonic food webs. 4.1 The Pomeroy’s still-changing paradigm 4.2 Sources of C for bacterial use 4.3 Bacterial use of “old” or allochthonous organic carbon 4.4 Bacterial respiration, and bacterial nutrient deficiency 4.5 Newer paradigms on the role of bacteria in the ocean and their relationships to phytoand zooplankton 5. Evolving perceptions on the role of microorganisms in the inorganic nutrient fluxes. 5.1 Microbe cell structure and nutrient cycling 5.2 Nutrient-recycling mechanisms 5.3 Dual role of bacteria as nutrient-scavengers or releasers. 5.4 Microbes and plankton microestructure 6. Conclusions Acknowledgements Glossary Bibliography Biographical Sketch