Isolation, purification, and properties of a second bacteriolytic enzyme from Hartmannella glebae

The crude extract of a soil amoeba, Hartmannella glebae grown in the presence of both Aerobacter aerogenes and Alcaligenes faecalis was subjected to acetone fractionation and chromatography on DEAE-cellulose. Two bacteriolytic enzymes were obtained. No further work was done on the first enzyme as it is probably the same enzyme which was reported earlier when amoebas were grown on A. aerogenes only. The second enzyme is produced only when A. faecalis was used as an additional source of nutrition. It was further purified by gel filtration on a Bio-Gel A column. Even though a purification of 30.9% with a total recovery of 380% was obtained with the second enzyme after DEAE-cellulose column chromatography, 87.5%, of the lytic activity was lost after gel filtration. As a result, it showed a 12-fold purification with a final recovery of 47%. Digestion of the cell walls of Micrococcus lysodeikticus resulted in the rapid solubilization of walls accompanied by the liberation of reducing groups, acetylamino sugars, and free amino groups. The enzyme is suspected to be a glycosidase i.e., endo-β-N-acetylmuramidase or endo-β-N-acetylglucosaminidase.