The effect of alcohols on the synthesis of lipase, lecithinase and other enzymes by Bacillus cereus

MECHANISM OF ACTION OF THE TOXIN OF BACILLUS ANTHRACIS II. : Alkaline Phosphatasemia Produced by Culture Filtrates of Various Bacilli

Slein, Milton W. (Fort Detrick, Frederick, Md.) and Gerald F. Logan, Jr. Mechanism of action of the toxin of Bacillus anthracis. II. Alkaline phosphatasemia produced by culture filtrates of various bacilli. J. Bacteriol. 83:359-369. 1962.-A factor which produces hyperphosphatasemia after intravenous injection into animals has been found in culture filtrates of several bacilli. The factor appears not to be lecithinase, although it has been found only in culture filtrates of microorganisms, such as Bacillus cereus variants and B. thuringiensis, which are known to produce lecithinase. The factor has been shown to be different from the protective antigen fraction of the toxin of B. anthracis. The phosphatasemic response can be prevented by mixing the factor with antiserum before injection. Immunological tests indicate that the centers of ossification may be a principal source of the excess alkaline phosphatase which is liberated into the bloodstream. However, moderate changes in bone alkaline phosphatase activity levels, brought about by the development of scurvy in guinea pigs or by treatment of scorbutic guinea pigs with ascorbic acid, did not seem to affect the phosphatasemic response of the animals. Marked release of alkaline phosphatase occurs when slices of rabbit epiphyseal bone or kidney cortex, or suspensions of leukocytes, are incubated with small amounts of the phosphatasemia factor.

Stimulation of lipase production during bacterial growth on alkanes

Acinetobacter lwoffi strain O(16), a facultative psychrophile, can grow on crude oil, hexadecane, octadecane, and most alkanes when tested at 20 but not at 30 degrees C. Growth occurred on a few alkanes at 30 degrees C but after a longer lag than at 20 degrees C. Cells grown on alkanes as sole carbon sources had high levels of cell-bound lipase. In contrast, previous work has shown that those grown on complex medium produced cell-free lipase and those grown on defined medium without alkanes produced little or no lipase. Low concentrations of the detergent Triton X-100 caused the liberation of most of the lipase activity of alkane-grown cells and increased total lipase activity. When ethanol and hexadecane were both present in a mineral medium, diauxic growth occurred; until the ethanol was completely used up, hexadecane was not utilized, and the lipase activity was very low. When growth on hexadecane began, lipase activity increased, reaching a level 50- to 100-fold higher than that of cells growing on ethanol. A similar pattern of lipase formation and hexadecane utilization was observed with Pseudomonas aeruginosa. Whenever A. lwoffi and other bacteria degraded alkanes they exhibited substantial lipase activity. Not all bacteria that produced lipase, however, could attack alkanes. Bacteria that could not produce lipase did not attack alkanes. The results suggest that a correlation may exist between lipase formation and alkane utilization.

Lethal toxin of Bacillus cereus. I. Relationships and nature of toxin, hemolysin, and phospholipase

Bacillus cereus phospholipase was characterized as a phospholipase C by the analysis of lecithin degradation products by thin-layer and paper chromatography. Methanol in the growth menstruum inhibited completely the synthesis of phospholipase C, whereas the synthesis of lethal toxin and hemolysin were only partially inhibited. Dialysis of preformed B. cereus products against ethyl alcohol and methanol did not inactivate hemolytic, phospholipase C, or lethal activity. The hemolytic and lethal activities of culture filtrates were completely abolished by trypsin, but phospholipase C activity was resistant to inactivation. Lethal and phospholipase C properties of culture filtrates were resistant to inactivation at 45 C, whereas the hemolytic activity was completely destroyed. Lethal, hemolytic, and phospholipase C activities appeared simultaneously in a complex growth menstruum, but the kinetics of synthesis were different in all cases. Resolution of B. cereus filtrates on columns of Sephadex showed that the phospholipase C, hemolysin, and lethal toxin are distinct proteins. Evidence is also presented which suggests a correlation between the synthesis of B. cereus toxin and the period of transition from vegetative growth to sporulation. The activity of each B. cereus product was cation-independent, as opposed to cation-dependency of the phospholipase C and lethal activities of Clostridium perfringens alpha-toxin. Immunological cross-reactivity between the B. cereus products and C. perfringens alpha-toxin was not apparent; indeed, they were shown to be antigenically distinct.