Fig 1. Source of nitrogen is expected to influence the metabolic interactions between C. acetobutylicum and W. succinogenes.
A shows the expected interactions between C. acetobutylicum and W. succinogenes in the presence of NH4+ and NO3-. B shows the interactions in the presence of only NH4+, C in the presence of only NO3- and D shows the expected interactions in the presence of only N2. Although we expect certain interactions in the co-culture during the various environmental conditions, we do not know at what rate the metabolites are exchanged.