Improvement of biogas production by bioaugmentation.

Biogas production technologies commonly involve the use of natural anaerobic consortia of microbes. The objective of this study was to elucidate the importance of hydrogen in this complex microbial food chain. Novel laboratory biogas reactor prototypes were designed and constructed.

Changes in the Archaea microbial community when the biogas fermenters are fed with protein-rich substrates.

Terminal restriction fragment length polymorphism (T-RFLP) was applied to study the changes in the composition of the methanogens of biogas-producing microbial communities on adaptation to protein-rich monosubstrates such as casein and blood. Specially developed laboratory scale (5-L) continuously stirred tank reactors have been developed and used in these experiments. Sequencing of the appropriate T-RF fragments selected from a methanogen-specific (mcrA gene-based) library revealed that the methanogens responded to the unconventional substrates by changing the community structure.

Exploitation of the extremely thermophilic Caldicellulosiruptor saccharolyticus in hydrogen and biogas production from biomasses.

Caldicellulosiruptor saccharolyticus has attracted considerable attention by virtue of its ability to degrade various polysaccharide, oligosaccharide and monosaccharide substrates at temperatures above 70 degrees C, while its ability to convert various sugars to hydrogen has led to C. saccharolyticus being selected for the fermentative production of hydrogen. In this study, the utilization of a pure cellulosic substrate and mixed biomasses of plant origin was investigated.