model vs media exchange reaction fluxes

[jmol0917]

Hi All!

Not sure if I missed this from somewhere in the documentation but I am wondering how are the values in solution.fluxes calculated.

For example, in a 3-member community EX_ddca(e) flux is -0.95 for one strain and NaN for the other two, but EX_ddca_m is -0.43 in the same solution.

Does individual growth rate/biomass has anything to do with this?

Not sure if this is relevant but growth rate for the strain that consumes the metabolite is 3.8 and the other two get to 7.8 and 23.7. Community growth is 7.43.

Thanks!!

[cdiener]

Hi, internal fluxes like EX_ddca(e) are given per 1 gDW of the respective taxon, but external fluxes are given per 1 gDW of the total biomass/abundance. In your case, because only one taxon is consuming ddca those are related by EX_ddca_m = a_i * EX_ddca(e)_i where a_i is the relative abundance of the strain (which seems to be around 0.45 in your case). Basically 1gDW of strain one would consume 0.95 mmol/h of ddca but 1gDW of the microbial consortia only include 0.45 gDW of strain 1 so the total consumption is 0.45 gDW[i]/gDS[total] * -0.95 mmol/(h * gDW[i]) = -0.43 mmol/(h * gDW[total]).

[jmol0917]

Thanks for clarifying @cdiener. Really appreciate the ongoing support and improvement of MICOM.