Lignins microbial degradability

Cleavage of Carbon—Carbon Bonds. Under appropriate conditions, the propanoid side chain in lignin maybe mptured to form three-, two-, or one-carbon fragments. This carbon—carbon fragmentation occurs in a variety of laboratory treatments and technical processes such as in bleaching of chemical pulps with CI2, CIO2, and O2, in microbial degradation (15), and in photooxidation (16). 

Odier, E. Lignin Enzymic and Microbial Degradation INRA, 1987. 

Shimada, M. Hattori, T. Umezawa, T. Higuchi, T. Okamoto, T. Proc. Inti. Symp. on Lignin Enzymic and Microbial Degradation Paris, France, April 23-24, 1987 p. 151. 

Odier, E., Ed. In Lignin Enzymic and Microbial Degradation INRA Symposia, Vol. 40, Paris 1987 INRA Publications. 

Kirk, T. K. Farrell, R. L. (1987). Enzymatic combustion the microbial degradation of lignin. Annual Reviews in Microbiology, 41, 465-505. 

There are also structural differences between humic substances or UDOM collected from rivers and oceans (Table I). Humic substances and UDOM from rivers are enriched in aromatic components compared with their counterparts from the ocean. Terrestrial vegetation is relatively rich in aromatic components, such as lignins and tannins, and this is reflected in the greater aromatic nature of DOM in rivers. These biopolymers are relatively resistant to microbial degradation and are important components of river DOM. Humic substances and UDOM from the ocean are enriched in carbohydrates compared with their counterparts from rivers. This is consistent with observations of higher C-normalized yields of neutral sugars in bulk DOM from the ocean compared with rivers (Table I). 

Martin, J. R, and Haider, K. (1980). Microbial degradation and stabilization of 14C-labeled lignins, phenols, and phenolic polymers in relation to soil humus formation In Lignin Biodegradation Microbiology Chemistry and Potential Applications, Vol. II. Kent-Kirk, T., Higuchi, T., and Chang, H., eds., CRC Press, Boca Raton, FL, pp. 77-100. 

Burdon542 has surveyed the current hypotheses for the structure of humic substances and has concluded that the various products from chemical degradations and NMR data are all consistent with their being mixtures of plant and microbial materials and their microbial degradation products. The examination of soil carbohydrates, proteins, lipids, and aromatics supported this view the presence of colour, fluorescence, ESR signals, mellitic acid, and other features do not contradict it. Regarding the Maillard reaction, some free monosaccharides and the necessary amino species are present in soil, so it may proceed, but only to a small extent it is not a major process. However, in marine environments, the relative abundance of carbohydrates and proteins makes them more probable precursors of humic substances than lignin or polyphenols. 

Ruiz-Duenas FJ, Martmez AT (2009) Microbial degradation of lignin How a bulky recalcitrant polymer is efficiently recycled in nature and how we can take advantage of this. Microb Biotechnol 2 164—177... 

Kirk TK, Farrell RL (1987) Enzymatic combustion The microbial degradation of lignin. Annu Rev Microbiol 41 465-505... 

Jeffries T. W. (1994) Biodegradation of lignin and hemi-ceUuloses. In Biochemistry of Microbial Degradation (ed. C. Ratledge). Kluwer Academic, pp. 233-277. 

Colberg P. J. (1988) Anaerobic microbial degradation of cellulose, lignin, oligonols and monomeric bgnin derivatives. In Biology of Anaerobic Microorganisms (ed. A. J. G. Zehnder). Wiley, New York, pp. 333-372. 

Colberg P. J. and Young L. Y. (1982) Microbial degradation of lignin-derived compounds under anaerobic conditions. Care J. Microbiol. 28, 886-889. 

TK Kirk, RL Farrell. Enzymatic Combustion The microbial degradation of lignin. Ann Rev Microbiol 41 465-515, 1987. 

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