Microbiological Analysis


Microbiology is the study of microorganisms, which are unicellular and cluster forming entities not visible to the naked eye as individual organisms. The study of microorganisms has become important, especially in foods, due to their ability to cause food spoilage and bring about pathogenic reactions in humans and animals. Controlling the microbial activities contribute to high hygienic standards in food preventing the spread of food borne illnesses especially those spread through food and water.

Vast developments in the area of food microbiology have resulted in standardization of test methods and practices in the testing laboratories. The current emphasis in ensuring microbiological safety requires use of accredited laboratories, ensuring reliability of test results for global acceptance. The related titles in this document describe the basic requirements in establishing a microbiology testing laboratory.

A Microbiology laboratory deals with the qualitative and quantitative estimations of Micro organisms of interest in a given situation. The interest may arise due to the need to assure the quality of products, the safety in handling and consuming them, probable spoilage a product may undergo and to recognize effective functioning of microorganisms employed in processing (fermenting) food.

The products examined microbiologically may be water (potable and for other uses), foods & feeds, and non-food items and other Industrial products. The tests performed in a microbiology testing laboratory are mostly to examine the following parameters or microorganisms, but are not limited to what is given below.

Escherichia coli Coliform Total Plate Count Sulphite Reducing Anaerobes
Pseudomonas Aeruginosa Aerobic Microbial Count Faecal Streptococci Staphylococcus Aureus
Salmonella Shigella Vibrio cholera Yeast and Moulds
Total Bacterial Count Bacillus Cereus Incubation test Clostridium Perfringens

The testing may extend to the following microorganisms on specific situations where the products are known to be vulnerable or exposed to reservoirs of pathogenic microorganisms such as Clostridium botulinum ,Clostridium perfringens, Vibrio cholera, Vibrio parahaemolyticus, Shigella

In a given situation the need for examination of the microorganisms are judged based on the intrinsic and extrinsic characteristics of the foods, that permit preferential growth of certain microorganisms, processing the food were subjected to, and the historical evidence of exposure to reservoirs of microorganisms. In all microbiological tests culture techniques are used in combination with examination of biochemical color reactions to identify and confirm the presence of microorganisms.