Reduction of Disulfide Bonds by Streptomyces pactum during Growth on Chicken Feathers

For disintegration of chicken feathers by Streptomyces pactum, keratinolytic proteinases and extracellular reduction of disulfide bonds were necessary. Conditions for disulfide reduction were examined with oxidized glutathione as model substrate. The reduction of glutathione depended on the presence of metabolically active cells. The mycelium also reduced tetrazolium dyes and cystine.</jats:p

Manganese-Mediated Lignin Degradation by Pleurotus pulmonarius

Pleurotus pulmonarius produced the strongest degradation of lignin during solid-state fermentation of [(sup14)C]lignin wheat straw with different fungi. A manganese-oxidizing peroxidase seemed to be involved in lignin attack, since the addition of Mn(sup2+) to the culture increased lignin mineralization by ca. 125%. This enzyme was purified and characterized from both solid-state fermentation and liquid cultures.</jats:p