In order to minimize possible test variation and to supply
the adapted inoculums for batch experiments, three
anaerobic master culture reactors (MCR, 5 L each) were
operated at 25, 30 and 35 C, respectively. These MCRs
were initiated with digested swine manure from a mesophilic
anaerobic digester as a seed inoculum, and then
operated on a semi-continuous basis with raw swine manure
for four weeks until a steady state reached. A steady
state was assumed when the daily biogas yield, pH and
COD values were shown to be constant. After confidence
in the steady state of MCRs had been obtained, the
enriched inoculums were transferred into batch reactors
under anaerobic conditions.