Isolation, characterization, and selection of lignin-degrading bacteria from a microbial consortium and environmental samples.

Abstract

Because of the current alarming problems involving the use of petroleum derivatives for the production of various essential products for today's society, the search for renewable and sustainable raw material sources has been gaining strong prominence in scientific efforts. Lignin, the second most renewable biopolymer on the planet, has remarkable biological potential for the production of various basic chemicals, with special emphasis on biofuels and bioplastics. However, certain characteristics of the molecular structure of lignin itself, such as its heterogeneous macromolecule, are still obstacles to the full utilization of this compound, as they hinder both the degradation and the exploitation of this biopolymer. The present study proposes the isolation, characterization, and sequencing of lignin-degrading bacteria from environmental samples and a consortium of microorganisms. To achieve the desired results, the samples will be grown in selective mineral salt media enriched with kraft lignin, glucose, and trace elements, aiming to isolate and purify the bacteria of interest. Evaluations of enzymatic activity will be conducted for the enzymes laccase, lignin peroxidase, and manganese peroxidase and the characterization of the isolate obtained will be performed by sequencing of the 16S rRNA gene. Thus, the present proposal may identify a new lignin-degrading bacterial strain.