ABSTRACT
Bacteria are the most important group of microorganisms in the environment. The environmental approach led to the development of large-scale environmental systems to reduce human exposure to disease-producing bacteria. Many bacteria metabolize organic matter to create new cell protoplasm. It is recognized that there are three basic shapes of bacteria: spheres, rods and spirals. In 1884 a Danish bacteriologist, Christian Gram, found that it was possible to use stains to divide bacteria into “positive” and “negative” groups, depending upon their reactions with his stains. Energy generated at the cell membrane causes the flagella to move and propel the bacteria through the liquid environment. Bacteria were grown in media that contained excess nutrients. Many different hydrolytic enzymes exist on the surface of bacteria to break complex organic compounds into simple organic compounds for complete metabolism. Sulfate reducing bacteria can metabolize short chain organic acids.
