Identification and Characterization of Ligninolytic Enzyme by Serratia marcescens HY-5 isolated from the Gut of Insect

A lignin degradation bacteria, symbiotic bacteria was isolated from the gut of Sympetrum depressiusculum and tested for its lignin degrading activity using lignin model compounds and related aromatic compounds. The strain was identified as Serratia marcescens HY-5 based on the 165 rDNA, cellular fatty acid composition, biochemical and physiological characteristics. S. marcescens showed 40-50% lignin degrading activity in the media that contained vaillin, guaiacol and dealkaline lignin. S. marcescens showed three ligninase activities [Jaccase, lignin peroxidase(LiP) and Manganase peroxidase(MnP)]. Addition of dealkaline lignin to the basal media increased about 6fold of laccase activity. Vanillic acid or vanillin increase 1.3fold of MnP activity and p-coumaric acid increased 12fold of LiP activity which added to the basal medium.