Interactions between viruses and bacteria

Posted on June 26, 2010


Viruses are a major source of mortality for aquatic organisms, and their attacks on bacteria and plankton release nutrients which are recycled through the microbial and plant-based food chains.  Although suspended organic and inorganic particles in rivers and lakes are known to support rich microbial communities, there have been few studies on the interactions between suspended particles, viruses and bacteria.  Experiments with water taken from theDanubeRivershowed that abundances of both viruses and bacteria were higher on organic particles (leaf litter and visible suspended aggregates) than inorganic particles (mineral sediment).  They were also higher on particles that were aged in water rather than fresh, presumably because aging allowed a biofilm to develop on the particle surface.  Bacterial production in the water was reduced when counts of planktonic viruses were high, but it increased when attached viruses were abundant, possibly because the adhesion of viruses to particles prevented them from infecting bacteria in the water, and/or because attacks by attached viruses released nutrients from particle cells.  In summary, attached bacteria were strongly affected by particle quality, while bacteria in the plankton were more affected by viral abundance.

References:

Kernegger, L., Zweimuller, I. & Peduzzi, P.   2009.  Effects of suspended matter quality and virus abundance on microbial parameters: experimental evidence from a large European river.  Aquatic Microbial Ecology 57, 161–173.

Weinbauer, M.G., Bettarel, Y., Cattaneo, R., Luef, B., Maier, C., Motegi, C., Peduzzi, P. & Mari, X.  2009.  Viral ecology of organic and inorganic particles in aquatic systems: avenues for further research.  Aquatic Microbial Ecology 57, 321-341.

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Posted in: microbial, plankton