Degradation of lignin by bacteria

Abstract

Bacteria are involved in the degradation and modification of lignin in nature. Many strains are able to metabolize lignin-related compounds and some of them also mineralize and solubilize polymeric lignin. Cleavage of the different types of linkages in lignin, oxidations, demethylations and aromatic ring cleavages are catalyzed by bacterial enzymes. Lignin-degrading bacteria or their enzymes could find novel applications in biotechnology for the modification of the lignin biopolymer. Most of the recent progress in understanding the mechanism of bacterial lignin degradation has been obtained from work with Pseudomonas species and with the Gram-positive actinomycetes. From both groups of organisms, key enzymes of the degradation of lignin substructures have been identified recently and recombinant DNA techniques have been successfully applied to elucidate the structure and regulation of the corresponding genes.