Because Size does matter: F420 tail length in methanogenesis

Cofactors are indispensable in many enzymatically catalyzed processes. In biogas processes, the coenzyme F420 is involved in methanogenesis and inevitable for methane generation. This remarkable cofactor is found in methanogenic Archaea but also in other Prokaryotes and is equipped with a polyglutamic-tail that varies in length. Although this process is well studied in methanogens, little is known about of F420tail-length expression. Latest research elucidated the genes involved in the formation of F420-n. However, in situ analyses of methanogenic organisms regarding F420 tail-length are largely missing. Hence, this project is a microbiologically orientated approach to systematically investigate the cofactor tail length in methanogenic pure-, then co- and subsequently mixed cultures to finally understand how F420 tail length is connected to the performance of anaerobic digestion systems. In the course of this project the role of F420 tail length in methanogenic pure and mixed culture systems will be elucidated: 1. The systematic analyses of cofactor tail length in various meso- and thermophilic, acetoclastic, hydrogeno- and methylotrophic methanogenic pure cultures as a function of growth phase, electron donors as well as incubation temperature will lead to a better understanding of the expression of F420 tail length in pure cultures and provide the basis for further analyses. 2. Applying RNA based analyses intends to gain an insight into the regulation of F420 tail length expression in methanogenic pure cultures with regard to different environmental conditions. 3. F420 tail length profiles from methanogenic mixed cultures in large scale digestion systems will be used to link F420 to varying environmental conditions.