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For example, laccases play a role in the formation of lignin by promoting the oxidative coupling of monolignols, a family of naturally occurring phenols. [ 1 ] [ 2 ] Other laccases, such as those produced by the fungus Pleurotus ostreatus , play a role in the degradation of lignin, and can therefore be classed as lignin-modifying enzymes . [ 3 ]
Lignin is found to be degraded by enzyme lignin peroxidases produced by some fungi like Phanerochaete chrysosporium. The mechanism by which lignin peroxidase (LiP) interacts with the lignin polymer involves veratrole alcohol , which is a secondary metabolite of white rot fungi that acts as a cofactor for the enzyme.
Lignin-modifying enzymes benefit industry as they can break down lignin; a common waste product of the paper and pulp industry. These enzymes have been used in the refinement of poplar as lignin inhibits the enzymatic hydrolysis of treated poplar and Lignin-modifying enzymes can efficiently degrade the lignin thus fixing this problem. [4 ...
Production of lignin-peroxidase and manganese-peroxidase is the hallmark of basidiomycetes and is often used to assess basidiomycete activity, especially in biotechnology applications. [38] Most white-rot species also produce laccase, a copper-containing enzyme that degrades polymeric lignin and humic substances.
The conventional method for lignin quantitation in the pulp industry is the Klason lignin and acid-soluble lignin test, which is standardized procedures. The cellulose is digested thermally in the presence of acid. The residue is termed Klason lignin. Acid-soluble lignin (ASL) is quantified by the intensity of its Ultraviolet spectroscopy.
Lignin, comprising a major fraction of biomass, is sometimes classified according to the guaiacyl component. Pyrolysis of lignin from gymnosperms gives more guaiacol, resulting from removal of the propenyl group of coniferyl alcohol. These lignins are said to have a high guaiacyl (or G) content.
The black liquor is an aqueous suspension of lignin residues, hemicellulose, and the inorganic chemicals used in the process. The black liquor comprises 15% solids by weight of which two thirds are organic chemicals and the remainder are inorganic. [3] Normally the organics in black liquor are 40-45% soaps, [4] 35-45% lignin and 10-15% other ...
[1] [2] [3] Streptomyces viridosporus produces sistomycine and lignin peroxidase. [ 3 ] [ 4 ] [ 5 ] Streptomyces viridosporus can degrade lignin and humic acids . [ 6 ] [ 7 ] Streptomyces viridosporus also produces moenomycin A , a component of bambermycin .