| Title | Degradation and polymerization of monolignols by Abortiporus biennis, and induction of its degradation with a reducing agent |
|---|---|
| Author | Chang-Young Hong1, Se-Yeong Park1, Seon-Hong Kim1, Su-Yeon Lee2, Won-Sil Choi3, and In-Gyu Choi1,4,5* |
| Address | 1Department of Forest Sciences, Seoul National University, Seoul 08826, Republic of Korea, 2Division of Wood Chemistry & Microbiology, Department of Forest Products, National Institute of Forest Science , Seoul 02455, Republic of Korea, 3National Instrumentation Center for Environmental Management, Seoul National University, Seoul 08826, Republic of Korea, 4Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea, 5Green Eco Engineering, Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea |
| Bibliography | Journal of Microbiology, 54(10),675-685, 2016, |
| DOI | 10.1007/s12275-016-6158-9 |
| Key Words | degradation, polymerization, monolignols, Abortiporus biennis, white rot basidiomycetes, reducing agent |
| Abstract | This study was carried out to better understand the characteristic modification mechanisms of monolignols by enzyme system of Abortiporus biennis and to induce the degradation of monolignols. Degradation and polymerization of monolignols were simultaneously induced by A. biennis. Whole cells of A. biennis degraded coniferyl alcohol to vanillin and coniferyl aldehyde, and degraded sinapyl alcohol to 2,6-dimethoxybenzene- 1,4-diol, with the production of dimers. The molecular weight of monolignols treated with A. biennis increased drastically. The activities of lignin degrading enzymes were monitored for 24 h to determine whether there was any correlation between monolignol biomodification and ligninolytic enzymes. We concluded that complex enzyme systems were involved in the degradation and polymerization of monolignols. To degrade monolignols, ascorbic acid was added to the culture medium as a reducing agent. In the presence of ascorbic acid, the molecular weight was less increased in the case of coniferyl alcohol, while that of sinapyl alcohol was similar to that of the control. Furthermore, the addition of ascorbic acid led to the production of various degraded compounds: syringaldehyde and acid compounds. Accordingly, these results demonstrated that ascorbic acid prevented the rapid polymerization of monolignols, thus stabilizing radicals generated by enzymes of A. biennis. Thereafter, A. biennis catalyzed the oxidation of stable monolignols. As a result, ascorbic acid facilitated predominantly monolignols degradation by A. biennis through the stabilization of radicals. These findings showed outstanding ability of A. biennis to modify the lignin compounds rapidly and usefully. |