Mixed fermentative/hydrolytic bacteria were enriched on lignocellulose substrates in minimal medium
under semi-anaerobic mesophilic conditions in the presence or absence of natural zeolite as growth supporter
to ultimately bioaugment non-adapted sludge and thereby enhance the overall anaerobic digestion
(AD) of recalcitrant plant material. Desired enzyme activities, i.e. xylanases and cellulase were
monitored during subsequent cultivation cycles. Furthermore, enriched microbial communities were
characterized by 16S rRNA-based 454-Pyrosequencing, revealing Firmicutes, Bacteriodetes,
Proteobacteria and Spirochaetes to be the predominant bacterial groups in cultures derived from anaerobic
sludge and raw crop material, i.e. maple green cut and wheat straw as well. Enriched populations relevant
for biopolymer hydrolysis were then compared in biological methane potential tests to demonstrate positive
effects on the biogasification of renewable plant substrate material. A significant impact on methane
productivity was observed with adapted mixed cultures when used in combination with clinoptilolite to
augment and supplement non-adapted bioreactor sludge