Distinctive electrophoretic patterns of Esterases from Levinea malonatica, Levinea amalonatica and Citrobacter

Esterases of 42 strains of Levinea malonatica, Levinea amalonatica and Citrobacter were analysed by horizontal slab electrophoresis in polyacrylamide-agarosegel using several synthetic substrates. On the basis of esterase zymograms a distinctive pattern was established for each of the three species. Levinea malonatica was characterized by two major bands: one hydrolysing acetate esters but not butyrate esters; and the other hydrolysing alpha-naphthyl acetate and reacting weakly with alpha-naphthyl butyrate and beta-naphthyl acetate. Levinea amalonatica showed one prominent band that hydrolysed alpha-naphthyl esters and reacter weakly with beta-naphthyl esters. Citrobacter strains showed one major band that hydrolysed alpha-naphthyl esters and appeared slightly more towards beta-naphthyl esters than that of L. amalonatica. Considerable variations in electrophoretic mobility were observed among Citrobacter strains. Levinea amalonatica was less variable. In addition, one minor anodal band reacting with beta-naphthyl acetate was observed in both L. malonatica and Citrobacter. The relative molecular sizes of the major esterase bands were determined by disc electrophoresis with gels of different acrylamide concentrations. The molecular size of the major band of Citrobacter appeared to be smaller than that of the corresponding esterase band of L. amalonatica.