Production and characterization of polygalacturonase fromGeotrichum candidum

An extracellular polygalacturonase (EC 3.2.1.15) fromGeotrichum candidum ATCC 34614 grown onsauerkraut brine was produced and characterized. Polygalacturonic acid markedly increased the enzyme yield in the brine. The fungus produced the highest activity (290 U/l) in brine with 0.3% (w/v) polygalacturonic acid. The pH and temperature optima of the enzymes were 4.5 to 5.0 and 30°C, respectively. It was stable from pH 4.0 to 5.8 and at 30°C but lost its activity at higher temperatures. The K_m and V_max values for polygalacturonic acid were 4.2 mg/ml and 0.19mm galacturonic acid/min, respectively. The enzyme was not substrate inhibited.