Isolation of bacterial strains able to metabolize lignin and lignin related compounds

The valorization of lignocellulosic biomass opens novel possibilities in production of biogas. Bacteria presenting ligninolytic potential could be source of novel enzymes for controlled lignin depolymerization. In this study, the identification of five soil bacteria exhibiting degradation activity on kraft lignin, aromatic dyes and lignin derivates were presented. By 16S rRNA gene sequencing, the isolates were identified as Serratia sp. JHT01, Serratia liquefacien PT01, Pseudomonas chlororaphis PT02, Stenotrophomonas sp. PT03 and Mesorhizobium sp. PT04. The Mesorhizobium sp. PT04 was isolated from under water environment. All isolates showed significant growth on water-extractive-free lignin. Synthetic aromatic dyes were used to assess the presence of oxidative enzymes. Pseudomonas chlororaphis PT02 presented high potential in degradation of aromatic monomers and biphenyl. Mesorhizobium sp. PT04 being a facultative anaerobic strain, its degradation of lignin polymer might be executed by specific sets of enzymes. Novel lignin degradation bacterial consortium may be prepared by using these isolates for delignification of the lignocellulosic biomass.