Back to Contents

FREE FULL TEXT PDF

SCREENING AND PARTIAL CHARACTERIZATION OF HEMOLYSINS FROM BACILLUS SP.: STRAIN S128 & S144 ARE HEMOLYSIN B (HBL) PRODUCERS

SAMINA NAZ MUKRY, AQEEL AHMAD AND SHAKEEL AHMED KHAN*

Abstract: The potential of 130 different strains of the genus Bacillus for hemolysin production and their effects against erythrocytes from different sources was examined. Complete hemolytic units (CHU) of three randomly selected strains of B. cereus group viz. S128, S140(c) and S144 were determined at different temperatures and pH. The highest CHU in yeast extract-tryptone (YT) broth was found at pH 5 & 7 for S140(c); pH 7 and 9 for S144 and S128, respectively. Hemolysins from the strains S128 and S140(c) remained stable at 50°C for 30 min, while hemolysin from strain S144 completely lost its activity at this temperature. However, no hemolytic activity was noted at 60°C in any of the test strains. Strains S128 and S144 showed discontinuous pattern of hemolysis which is an indication of hemolysin BL (HBL) producers.

Department of Microbiology, University of Karachi, Karachi-75270, Pakistan.