The initial reactions in anaerobic degradation of phenol to CO, have been studied in vitro with a denitrifying Pseudomonas strain grown with phenol and nitrate in the absence of molecular oxygen. Phenol has been proposed to be carboxylated to 4-hydroxybenzoate [(1987) Arch. Microbial. 148,213-2171. CHydroxybenzoate was activated to 4-hydroxybenzoyl-CoA by a coenzyme A ligase. Cell extracts also catalyzed the reductive dehydroxylation of Chydroxybenzoyl-CoA to benzoyl-CoA with reduced benzyl viologen as electron donor. This enzyme, benzoyl-CoA:(acceptor) Coxidoreductase (hydroxylating) (EC 1.3.99.-), has not been reported before. The data suggest that phenol and 4-hydroxybenzoate are anaerobically metabolized by this strain via benzoyl-CoA. Anaerobic degradation; Aromatic compound; Phenol; Hydroxybenzoyl-CoA, 4-; Benzoyl-CoA:(acceptor) Coxidoreductase (hydroxylsting); (Pseudomonas) 2.2. Preparation of cell extracts Cell extracts were prepared anaerobically in 50 mM potassium phosphate buffer (pH 7), 2 mM MgCl2, 1 mM DTE by French press treatment and 100000 x g centrifugation (supernatant) [9].

Paper 3/02087H

An in 2016 published DECHEMA guideline concerning process engineering characterization and a new Escherichia coli model process were utilized for the qualification of two geometrically similar stirred stainless steel bioreactors (30 L and 100 L working volume). The achieved results demonstrate that performing an additional biological model process is a valuable complement to the process engineering characterization. Optical densities of 27 (100 L) and 39 (30 L) were reached in the batch cultivation process.

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