Structural Analysis of Milled Wood Lignins Isolated From Aspen Wood (Populus tremuloides L.) Biotreated by Ceriporiopsis subvermispora

Ceriporiopsis subvermispora 처리에 의한 아스펜 목재 리그닌의 구조 변화

  • Choi, Joon-Weon (Division Wood Chemistry & Microbiology, Korea Forest Research Institute) ;
  • Moon, Sung-Hee (College of Life & Environmental Science, Korea University) ;
  • Ahn, Sye-Hee (Division Life & Environmental Resources, Daegu University) ;
  • Choi, Don-Ha (Division Wood Chemistry & Microbiology, Korea Forest Research Institute) ;
  • Paik, Ki-Hyun (College of Life & Environmental Science, Korea University)
  • 최준원 (국립산림과학원 화학미생물과) ;
  • 문성희 (고려대학교 생명환경과학대학) ;
  • 안세희 (대구대학교 생명환경학부) ;
  • 최돈하 (국립산림과학원 화학미생물과) ;
  • 백기현 (고려대학교 생명환경과학대학)
  • Received : 2005.07.18
  • Accepted : 2005.09.08
  • Published : 2005.11.25

Abstract

Aspen wood (Populus tremuloides, L.) was biotreated with Ceriporiopsis subvermispora for 1, 2, 4, and 6 weeks to observe the physical/chemical modification of wood components. Milled wood lignins (MWLs) isolated from each decayed wood were analyzed by gel permeation chromatography (GPC) and nitrobenzene oxidation (NBO). As fungal treatment was progressed, lignin contents continuously decreased up to 20% after 6-week treatment. The lignin polymer could be fragmented to low-molecular phenolics, which make an enhancement of alkali solubility. Holocellulose contents were not affected severely during the period of fungal treatment, only reduction of 5~6% compared to the control. Xylose contents were decreased gradually from 23.4% to 18% after 6 weeks, whereas alpha-cellulose remained almost unchanged. Gel permeation chromatography (GPC) indicates that molecular weight of lignin undergoes a slight decrement for 4 weeks of fungal treatment. Nitrobenzene oxidation revealed that total yield of NBO products of lignins were lowered ca 20% after fungal treatment. Sum of syringaldehyde and syringic acid are remarkably decreased. However, increment of sum of vanillin and vanillic acid was surprisingly observed. These results work as indirect evidence that a specific lignolytic reaction, maybe selective demethoxylaytion of S-lignin, can occur during fungal treatment of aspen wood by C. subvermispora.

아스펜 목재(Populus tremuloides, L.)를 Ceriporiopsis subvermispora로 1, 2, 4, 6주 동안 부후 처리한 후, 목재의 화학적 성상변화를 관찰하였으며, 부후목재로부터 리그닌(MWL)을 단리하여 Gel permeation chromatography (GPC) 분석과 nitrobenzene oxidation (NBO)을 실시하였다. 부후가 진행되면서 목재내 리그닌의 함량은 계속 감소하여 6주 후에는 미처리재와 비교하여 20%까지 감소하였다. 리그닌은 균주처리에 의하여 저분자화되어 알칼리에 쉽게 용출되는 것으로 예측된다. 부후목재의 전섬유소(Holocellulose) 함량은 미처리재와 비교하여 5~6% 정도 감소하였다. 부후 과정 동안 $\alpha$-셀룰로스의 함량은 커다란 변화가 관찰되지 않았으나, xylose의 함량은 대조구의 23.4%에서 6주후에는 18%까지 감소하였다. 아스펜 목재의 리그닌 분자량은 균주처리에 의해서 점차 감소되었다가 부후 6주 이후에는 안정화 단계에 접어드는 경향을 보였다. 단리한 리그닌의 NBO 분석 결과, NBO 분해산물의 수율은 대조구와 비교하여 6주처리 후에는 20% 가량 감소되었다. 특히, 부후 목재 리그닌에서 S-타입 유도체(syringaldehyde+syringic aicd)의 감소량이 두드러졌다. G-타입 유도체(vanillin+vanillic acid)의 수율은 부후가 진행되면서 약 20% 가량 증가되었는데, 이는 부후과정에서 리그닌 분해 효소에 의한 S-리그닌의 탈메톡실화 반응이 진행되었음을 암시한다. 결론적으로, C. subvermispora는 부후 과정동안 G-리그닌보다 S-리그닌을 더욱 선택적으로 분해하는 경향을 나타내었다.

Keywords

References

  1. Bjorkman, A. 1956. Studies on finely divided wood. I. Extraction of lignin with neutral solvents. Sven. Papperstidn. 59: 477-485
  2. Blanchette, R. A., E. W. Krueger, J. E. Haight, M. Akhtar, and D. E. Akin. 1997. Cell wall alteration in loblolly pine wood decayed by the white-rot fungus, Ceriporiopsis subvermispora. Journal of biotechnology 53: 203-213 https://doi.org/10.1016/S0168-1656(97)01674-X
  3. Boudet, A. M. 1998. A new view of lignification. Trends in plant sciences. 3:67-71 https://doi.org/10.1016/S1360-1385(97)01176-X
  4. Breen, A and F. L. Singleton. 1999. Fungi in lignocellulose breakdown and biopulping. Curr. Opin. Biotechnol 10: 252-258 https://doi.org/10.1016/S0958-1669(99)80044-5
  5. Browning, B. 1967. Methods of wood chemistry. New Yark. Wiley
  6. Daine, S., M. Orlandi, G. Bestetti, C. Wiik, and G. Elegir. 2002. Degradation of ${\beta}$-5 lignin model dimers by Ceripariopsis subvermispora. Enzyme Microb. Technol. 30: 499-505 https://doi.org/10.1016/S0141-0229(01)00524-5
  7. Dence, C. W. 1992. The determination of lignin, In S. Y. Lin and C. W. Dence (ed.), Methods of lignin chemistry. Springer-Verlag, Heidelberg. 33-61
  8. Ferraz, A., A. M. Cordova, and A. Machuca. 2003. Wood biodegradation and enzyme production by Ceriporiopsis subvermispora during solid-state fermentation of Eucalyptus grandis. Enzyme and Microbial Technol. 32: 59-65 https://doi.org/10.1016/S0141-0229(02)00267-3
  9. Guerra, A., R. Mendonca, and A. Ferraz. 2002. Characterization of the Residual Lignins in Biodegraded by Ceriporiopsis subvermispora by Using in situ CuO Oxidation and DFRC Methods. Holzfarschung 56: 157-160 https://doi.org/10.1515/HF.2002.026
  10. Guerra, A., R. Mendonca, and A. Ferraz. 2003. Molecular weight distribution of wood components extracted from Pinus taeda biotreated by Ceriporiopsis subvermispora. Enzyme and Microbial Technol. 33: 12-18 https://doi.org/10.1016/S0141-0229(03)00099-1
  11. Hammel, K. E., M. Tien, B. Kalyanaraman, and T. K. Kirk. 1985. Mechanism of oxidative C-C cleavage of a lignin model dimmers by ligninase. J. Biol. Chem. 260: 8348-8353
  12. Iiyama, K. and T. B. T. Lam. 1990. Lignin in wheat nodes. Part I: The reactivities of lignin units during alkaline nitrobenzene oxidation. Journal of Sci. Food Agric. 51: 481-491 https://doi.org/10.1002/jsfa.2740510405
  13. Jensen, K. A., W. Bao, S. Kawai, E. Srebotnik, and K. E. Hammel. 1996. Manganese dependent cleavage of nonphenolic lignin structures by Ceriporiopsis subvermispora in the absence of lignin peroxidase. Appl. Environ. Microbiol. 62: 3679-3686
  14. Kirk, T. K., M. Tien, P. J. Kersten, M. D. Mozuch, and B. Kalyanaraman. 1986. Ligninase of Phanerochaete chrysosporium. Mechanism of its degradation of the non-phenolic arylglycerol ${\beta}$-aryl ether substructure of lignin. Biochem. J. 236: 279-287
  15. Srebotnik, E., K. A. Jensen, Jr., and K. E. Hammel. 1994. Fungal degradation of recalcitrant nonphenolic lignin structures without lignin peroxidase. Proc. Natl. Acad. Sci. USA. 91: 12794-12797
  16. Srebotnik, E., K. A. Jensen, Jr., S. Kawai, and K. E. Hammel. 1997. Evidence that Ceriporiopsis subvermisporadegrades nonphenolic lignin structures by a one electron oxidation mechanism. Appl. Environ. Microbiol. 63: 4435-4440
  17. Umezawa, T. and T. Higuchi. 1987. Mechanism of aromatic ring cleavage of ${\beta}$-O-4 lignin substructure models by lignin peroxidase. FEBS Lett. 218: 255-260 https://doi.org/10.1016/0014-5793(87)81057-8