Phanerochaete mutants with enhanced ligninolytic activity

Conference · Tue Jun 01 04:00:00 EDT 1993

OSTI ID:10162002

Kakar, S N; Perez, A; Gonzales, J

In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organopollutants in soils and aqueous media. Although some of the organic compounds are degraded under nonligninolytic conditions, most are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient starvation (e.g., nitrogen limitation). The fungus and its enzymes can thus provide alternative technologies for bioremediation, biopulping, biobleaching, and other industrial applications. The efficiency and effectiveness of the fungus can be enhanced by increasing production and secretion of the important enzymes in large quantities and as primary metabolites under enriched conditions. One way this can be achieved is through isolation of mutants that are deregulated or are hyperproducers or supersecretors of key enzymes under enriched conditions. Through ultraviolet-light and gamma-rays mutagenesis we have isolated a variety of mutants, some of which produce key enzymes of the ligninolytic system under high-nitrogen growth conditions. One of the mutants produced 272 units (U) of lignin peroxidases enzyme activity per liter after nine days under high nitrogen. The mutant and the parent strains produced up to 54 U/L and 62 U/L, respectively, of the enzyme activity under low-nitrogen growth conditions during this period. In some experiments the mutant showed 281 U/L of enzyme activity under high nitrogen after 17 days.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10162002
• Report Number(s): ANL/ER/CP--78177; CONF-930552--1; ON: DE93015147
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090900
COBALT 60
ENZYMATIC HYDROLYSIS
ENZYME ACTIVITY
ENZYME INDUCTION
GAMMA RADIATION
GROWTH
LIGNIN
PEROXIDASES
PHANEROCHAETE
PROCESSING
RADIATION INDUCED MUTANTS
ULTRAVIOLET RADIATION