Rapid purification of extracellular tannase using polyethylene glycol-tannic acid complex

This paper reports on a rapid procedure for partial purification of extracellular tannase using a combination of tannic acid and PEG-6000. A pH-dependent protein precipitation nias obtained within 30 min. Monitoring the primary precipitation curve of the culture filtrate at varying pH, a second step was designed that yielded an approximately eight-fold increase in the enzyme purification. This procedure is of importance as no temperature and pH monitoring is required and a very fast precipitation is obtained without any alteration in the enzymatic properties of the precipitant.