Algal-bacterial interactions at a distance

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• Francois Peaudecerf (University of Cambridge)
• Thursday 05 March 2015, 12:00-13:00
• TCM Seminar room, 530 Mott building.

If you have a question about this talk, please contact Salvatore Tesoro.

Microbial interactions are often predicated on metabolism: e.g. auxotrophs depend on nutrients made by other microbes. Many algae are vitamin auxotrophs, with several known species requiring exogenous vitamin B12 [1]. This vitamin must be obtained from bacteria, as only they can synthesise it. Laboratory experiments have demonstrated mutualistic interactions between bacteria and B12 -dependent algae. Populations of the bacterium Mesorhizobium loti (B12 producer, carbon requirer) and the green alga Lobomonas rostrata (B12 requirer, carbon producer) in co-culture stabilise to an algae/bacteria ratio of 1/30, independent of initial inoculum ratio [2].

Here we consider the interactions between microbial populations separated in space. Experiments on hard agarose indicate that mutualistic interactions exist at a distance. We present a mathematical model capturing the essence of these experiments: growing populations of algae and bacteria coupled by a diffusive channel. Solutions to the model reveal rich dynamics. We will discuss these and speculate on the ecological significance of our findings for understanding environmental biofilms and microbial mats.

[1] Croft, M. T. et al. Nature 483:90–93 (2005) [2] Kazamia, E. et al. Environ. Microbiol. 14, 1466 (2012)

This talk is part of the Biological and Statistical Physics discussion group (BSDG) series.

This talk is included in these lists:

• Biological and Statistical Physics discussion group (BSDG)
• Cambridge Infectious Diseases
• Combined TCM Seminars and TCM blackboard seminar listing
• PMRFPS's
• TCM Seminar room, 530 Mott building

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