Genetics and chemistry of lignin degradation by Streptomyces

Technical Report · Wed Jan 01 04:00:00 EST 1992

DOI:https://doi.org/10.2172/6643947· OSTI ID:6643947

Crawford, D L

Our research goal was to define the involvement of lignin peroxidases and other extracellular enzymes in lignin degradation by Streptomyces. We examined the biochemistry and genetics of lignin degrading enzyme production by several strains of Streptomyces. The lignin peroxidase ALiP-P3 of S. viridosporus was characterized kinetically and its activity optimized for oxidation of 2,4-dichlorophenol and vanillyl-acetone. Sensitive spectrophotometric assays were developed for monitoring oxidation of these substrates. ALiP-P3 reaction chemistry was examined using both spectrophotometric assays and gas chromatography/mass spectroscopy. Results showed that the enzyme oxidizes phenolic lignin substructure models in strong preference to nonphenolic ones. The peroxidase was also shown to depolymerize native lignin. We also cloned the ALip-P3 gene S. lividans in plasmid vector pIJ702. The cloned gene was partially sequenced, We also immunologically characterized the lignin peroxidase of S. viridosporus T7A and showed it to be structurally related to peroxidases produced by other lignin-solubilizing Streptomyces, but not the the H8 lignin peroxidase of P. chrysosporium. Studies with peroxidase deficient mutants of strain T7A showed that lignin peroxidases of S. viridosporus are directly involved in the solubilization of lignin. Additional research showed that other enzymes are also probably involved in lignin solubilization, possibly including extracellular esterases.

• Research Organization: Idaho Univ., Moscow, ID (United States). Dept. of Bacteriology and Biochemistry
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG07-86ER13586
• OSTI ID: 6643947
• Report Number(s): DOE/ER/13586-T2; ON: DE93011726
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090900* -- Biomass Fuels-- Processing-- (1990-)
550200 -- Biochemistry
550500 -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIODEGRADATION
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
DOCUMENT TYPES
ENZYMES
LIGNIN
MICROORGANISMS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PEROXIDASES
POLYSACCHARIDES
PROGRESS REPORT
PROTEINS
SACCHARIDES
SPECIES DIVERSITY
STREPTOMYCES