Publisher Summary This chapter discusses the role of free radicals and catalytic metal ions in human disease. The importance of transition metal ions in mediating oxidant damage naturally leads to the question as to what forms of such ions might be available to catalyze radical reactions in vivo . The chapter discusses the metabolism of transition metals, such as iron and copper. It also discusses the chelation therapy that is an approach to site-specific antioxidant protection. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. A wide range of techniques is available to measure the rate of this process, but none is applicable to all circumstances. The two most popular are the measurement of diene conjugation and the thiobarbituric acid (TBA) test, but they are both subject to pitfalls, especially when applied to human samples. The chapter also discusses the essential principles of the peroxidation process. When discussing lipid peroxidation, it is essential to use clear terminology for the sequence of events involved; an imprecise use of terms such as initiation has caused considerable confusion in the literature. In a completely peroxide-free lipid system, first chain initiation of a peroxidation sequence in a membrane or polyunsaturated fatty acid refers to the attack of any species that has sufficient reactivity to abstract a hydrogen atom from a methylene group.

Role of free radicals and catalytic metal ions in human disease: an overview.

Biomass is an important feedstock for the renewable production of fuels, chemicals, and energy. As of 2005, over 3% of the total energy consumption in the United States was supplied by biomass, and it recently surpassed hydroelectric energy as the largest domestic source of renewable energy. Similarly, the European Union received 66.1% of its renewable energy from biomass, which thus surpassed the total combined contribution from hydropower, wind power, geothermal energy, and solar power. In addition to energy, the production of chemicals from biomass is also essential; indeed, the only renewable source of liquid transportation fuels is currently obtained from biomass.

The Catalytic Valorization of Lignin for the Production of Renewable Chemicals

Publisher Summary Several procedures have been described for growing Phanerochaete chrysosporiurn for ligninase production. These procedures differ somewhat in the medium formulation and types of growth vessels: (1) shallow stationary cultures, (2) agitated liquid cultures, and (3) rotating biological contactors (RBCs; disk fermenters). The recently developed use of agitated culture for production of ligninase permits easier “scale up.” Although ligninase can be produced in agitated flask cultures, the reliable use of stirred tank fermenters awaits further development, which is ongoing in several laboratories. This chapter describes the production of ligninase in shallow stationary cultures and in agitated cultures. Shallow stationary cultures (10 ml) are grown in rubber-stoppered, 125-ml Edenmyer flasks at 39 ° under 100% oxygen. The stationary cultures give somewhat more reliable and reproducible results than the agitated cultures.

Lignin peroxidase of Phanerochaete chrysosporium

https://febs.onlinelibrary.wiley.com/doi/epdf/10.1016/0014-5793%2890%2980298-W

Oxidation of non-phenolic substrates. An expanded role for laccase in lignin biodegradation.

White-rot fungi and their enzymes for the treatment of industrial dye effluents.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/0014-5793%2884%2980327-0

Separation and characterization of two extracelluar H2O2-dependent oxidases from ligninolytic cultures of Phanerochaete chrysosporium

An extracellular H2O2-requiring enzyme preparation involved in lignin biodegradation by the white rot basidiomycete Phanerochaete chrysosporium.

Purification and characterization of an extracellular H2O2-requiring diarylpropane oxygenase from the white rot basidiomycete, Phanerochaete chrysosporium☆

Masaaki Kuwahara

Papers

Separation and characterization of two extracelluar H2O2-dependent oxidases from ligninolytic cultures of Phanerochaete chrysosporium

An extracellular H2O2-requiring enzyme preparation involved in lignin biodegradation by the white rot basidiomycete Phanerochaete chrysosporium.

Purification and characterization of an extracellular H2O2-requiring diarylpropane oxygenase from the white rot basidiomycete, Phanerochaete chrysosporium☆