SCANNING ELECTRON MICROSCOPIC STRUCTURE OF THE BACILLUS ORGANISMS ISOLATED FROM SOIL

Soil has been defined as the region on the earth's crest where geology and biology meet. From a functional view point the soil may be consider as the land surface on the earth which provides substratum for plant and animal life. The genous bacillus consists of aerobic bacilli forming heat resistance spores they are gram positive but tend to be decolourised on gram staining. A scanning electron microscope ( SEM) is a type of electron microscope that produces images of the sample by scanning with a focused beam of electron. easily so that it is gram variable or may be gram negative. the soil is collected from the mountain regions of south india, the primary screening and secondary screening were done and isolated organism is subjected to morphological and biochemical studies. Colonies where fixed in formalin vapour for a period of 24hr. After fixing the outer edge of the colonies were marked with dissecting needle. The agar was removed. The colonies were then coated with gold –palladium alloy to a thickness of 500A 0 by means of vacuum evaporation. Then the colonies were viewed using scanning electron microscopy. After that the chamber was evacuated to 10(-5) torr the specimens were scanned using electron beam the electrons liberated from the surface of the specimen were detected using a scintillation photo multiplier system. The resulting image was formed on a cathode ray tube. Photo graphs were taken with the Polaroid camera. At 3000x a small rode shaped, non- uniform distribution of organism were seen. At 5000x the rods were more elongated and the arrangement of colonies were non uniform. At 10,000x the colonies showed a length of 1.46micrometer and 1.64 micrometer and the width of the colonies were found to be 630.1 nanometre and 752.9 nanometre and irregularly arranged colonies. At 20,000x the rods were found to be more elongated. Scanning electron microscope can be used to view the organism isolated from the soil. The examination depends on the concentration of cells in the soil. This limits the use of sem technique in soils with more than 10-7 organisms per gram of the soil. Keywords: Soil, Bacillus organisms, Scanning electron microscopy.