OVERPRODUCTION AND PURIFICATION OF AN AGARASE OF BACTERIAL ORIGIN

The agarase gene from Streptomyces coelicolor has been cloned in the n on-producer bacterium Streptomyces lividans under the control of its o wn set of promoters and under the control of a heterologous promoter t hat is functional only during exponential growth. The best level of ov erproduction was obtained when the strain containing the natural gene was cultivated in fed batch with mannitol as carbon source. The protei n, with a relative molecular mass of 32 kDa, has been purified followi ng an affinity purification method. Contaminating activities seem to b e absent from the purified enzyme preparation that can be used to puri fy DNA from agarose gels. (C) 1997 Elsevier Science B.V.