Lignin degradation by Comamonas serinivorans C35

Abstract:

[Objective] The aim of this study was to study the degradation of lignin by Comamonas serinivorans C35. [Methods] Comamonas serinivorans C35 growth was measured. Chemical oxygen demand (COD) reduction was investigated. Lignin degradation and decolorization rates were conducted. In addition, secretion of ligninolytic enzymes were investigated by using lignin mineral salt medium. The changes in lignin structural appearance and the chemical bonds of it before and after degradation were assessed by scanning electron microscope (SEM) and fourier transform infrared spectroscopy techniques (FTIR), respectively. [Results] The ability of Comamonas serinivorans C35 in the presence of lignin as a sole carbon source with 44.4% reduction in COD value after 7 days of incubation. The degradation and decolorization removal reached 43.57% and 42.26%, respectively. It was shown that the maximal enzyme activities of lignin peroxidase, manganese peroxidase and laccase of the studied isolate recorded 648.4, 177.8 and 70.1 U/L, respectively throughout the incubation course. SEM revealed the depolymerization of lignin into smaller pieces and FTIR confirmed the benzene ring structure, C–O–C and C=O bonds of lignin were broken down. [Conclusion] The results of this study indicate that Comamonas serinivorans C35 potentiates its ability not only to utilize lignin as a sole carbon source but also its applicable value in lignin bioconversion.