Identification of the bacterial actors of the anaerobic plant biomass delignification

The anaerobic plant biomass delignification was questioned till recently despite being a key process for plant cell wall degradation in anaerobic biotopes where plant debris accumulate, the carbon mineralization being the limiting step of the Carbon cycle. Besides no actors were identified till now and no data were available on this processus performed by anaerobic cellulolytic bacteria or even on its existence Using RNAseq, we here report the idenfication of secreted (including cellulosomal) enzymes, especially SGNH hydrolase family members known to be esterases but never described to act on lignin. We also propose based on our genetic, biochemical and bioinformatic approaches, a new role for the SGNHs in the remodeling of lignin to favor the access to polysaccharides by plant polysaccharides degrading proteins, function that could be useful for the design of biotechnological applications. Overall design: RNA-seq profiling of R. cellulolyticum grown on more or less lignified substrates at the mid and end of the exponential growth phases