Figure 3. Variation in acetate concentration in the co-culture of P. aestuarii and G. sulfurreducens in the presence and absence of light.

(a) Switching the co-culture from a dark to an illuminated condition stimulated acetate consumption by the co-culture. (b) Switching from an illuminated to a dark condition stopped the photosynthesis of P. aestuarii, and therefore terminated acetate consumption by the co-culture. (c) Cell density (OD₆₀₀) of the co-culture of P. aestuarii and G. sulfurreducens in the presence and absence of light. The error bars represent the s.e.m. of replicated experiments (n=3).