Genome sequence and description of the anaerobic lignin-degrading bacterium Tolumonas lignolytica sp nov.

Tolumonas lignolytica BRL6-1(T) sp. nov. is the type strain of T. lignolytica sp. nov., a proposed novel species of the Tolumonas genus. This strain was isolated from tropical rainforest soils based on its ability to utilize lignin as a sole carbon source. Cells of Tolumonas lignolytica BRL6-1(T) are mesophilic, non-spore forming, Gram-negative rods that are oxidase and catalase negative. The genome for this isolate was sequenced and returned in seven unique contigs totaling 3.6Mbp, enabling the characterization of several putative pathways for lignin breakdown. Particularly, we found an extracellular peroxidase involved in lignin depolymerization, as well as several enzymes involved in beta-aryl ether bond cleavage, which is the most abundant linkage between lignin monomers. We also found genes for enzymes involved in ferulic acid metabolism, which is a common product of lignin breakdown. By characterizing pathways and enzymes employed in the bacterial breakdown of lignin in anaerobic environments, this work should assist in the efficient engineering of biofuel production from lignocellulosic material.