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.     

Decomposition of cellulose in soils

1. Cellulose decomposition in forest and orchard soils was investigated by studying the breakdown of boiled and washed cellophane in the soils and in vitro. Decomposition occurred from quick to slow in the order: orchard on clay soil, forest on clay soil, forest on sandy loam, and in the latter in the order: calcareous mull, acid mull and mor. 2. In the different forest soils which were investigated the rate of decomposition was parallel to their water capacity. It slowed down considerably when the water content of the soil decreased, especially after the wilting point was reached. 3. Of the fungi isolated from these soils, those from orchard soil — 5% to 50%Fusarium spp. — were among the fastest decomposers of cellulose. This agrees with, and may explain the high rate of decomposition in orchard soil. 4. Decomposition in pure culture is quicker than in soil. As filtersterilized soil extract checked the decomposition in pure culture, but heat-sterilized soil extract did not, an extractable but heat-sensitive substance may be one retarding factor.     

On the formation of adipocere from fats

Summary The formation of adipocere is a process occurring under virtually anaerobic conditions in which human fat is converted into a complex of saturated fatty acids by a great variety of bacterial species occurring in and on the decomposing body.