Autoradiographic and immunofluorescent studies of cytological changes induced inBacillus cereus by chloramphenicol

Autoradiographic and fluorescent antibody techniques were used to study the formation of protrusions on the cell periphery ofBacillus cereus. The cells were grown in a synthetic medium containing chloramphenicol and H³-labelleddl-alanine, and examined at time intervals for cytological changes. One or more protrusions were detected on approximately 4% of the cell population. Active cell-wall synthesis was found to take place in these cells except at the periphery of the protrusions. On this basis it is suggested that the protrusions are not abnormal growing points but represent osmotically fragile zones where cell-wall synthesis has not taken place.The study was supported by a grant from the National Research Council of Canada.