beta-Lactamase and beta-lactam antibiotics resistance in acinetobacter anitratum (syn: A. calcoaceticus).

The cephalosporin beta-lactamase (cephalosporinase) produced by Acinetobacter was studied. The enzyme was partially purified by means of column chromatography and its properties were investigated. The enzyme was induced by benzylpenicillin, 6-aminopenicillanic acid and cephaloridine. Its molecular weight is 30,000 its optimal temperature 40C, and its optimal pH 7.25 similar to 7.50. Substrate specificity studies using various cephalosporins and penicillins, showed that the enzyme functioned as a cephalosporinase rather than penicillinase.