Bacteria are group of microorganisms all of which lack a distinct nuclear membrane (and hence are considered more primitive than animal and plant cells) and of most which have a cell wall of unique composition. Most bacteria are unicellular; the cells maybe spherical (coccu), rod-shaped (bacillus), spiral (spirillum), comma-shaped (vibrio) or corkscrew-shaped (spierocheate). Generally, they range in size between 0.5 and 5um. (Elizabeth and Martin, 2003).

Food is any substance that people or animal eat or drink or that plants absorb to maintain life and growth. Food is any substance consumed for nutritional support for the body; it is usually of plant and animal origin. (Ezeronye, 2007). Food consists of chemical compounds which heterophilic living thing consume in order to carry out metabolic processes. They are also substances which when introduced to the digestive system under normal circumstances contribute to the growth, repair and production of energy. (Ezeronye, 2007). Foods are classified into six essential nutrients known as protein, carbohydrate, vitamin, mineral, fat and oil, and water.