Hi everyone, I have been using GWB to model populations of microbes cycling sulfur in sediments. I am interested in including a population of fermentative microbes that degrade cellulose and provide the acetate that is used as an electron donor in reduction reactions (like sulfate reduction). I understand that GWB has some functionality for specifying custom rate laws (such as for microbial respiration) but I am unsure as to how to include a new chemical species, because the GWB database does not currently contain cellulose. Also, will it be a problem that the production of acetate will be governed by a custom rate law and the consumption of acetate will be governed by the normal GWB functions for microbial respiration for the populations I have included. Thanks very much! Regards, Tim Bush