Anaerobic microorganisms require special weather conditions for their development. Most of these mirkoorganisms do not require oxygen in the environment for their development. However, a small part of them use a certain amount of oxygen. Anaerobic bacteria are found in the normal bacterial flora of humans and animals.

Although they are very important in terms of hygiene of foodstuffs, anaerobic bacteria have not been emphasized until now and mostly aerobic microorganisms have been studied. However, especially in recent years, anaerobic bacteria have become better known and the importance given to them has increased.

Among anaerobic bacteria, clostridium species are important for food microbiology. While the structures, reactions and natural behavior of anaerobic microorganisms show significant changes, they all have in common that they need an anaerobic environment for their development and growth.

Anaerobic bacteria are generally classified as: anaerobic gram-negative bacilli, anaerobic gram-negative cocci, anaerobic gram-positive bacilli, and anaerobic gram-positive cocci. Within each group there are different types of bacteria.

Environmental conditions affect the presence and activity of bacteria in an environment. Oxygen, temperature, acidity (pH value), humidity and pressure are effective in the development of bacteria. The most important factor in the growth of bacteria is oxygen. Bacteria are divided into four groups according to their needs for oxygen. Aerops must be in an oxygenated environment (eg acetic acid bacteria) to multiply and thrive. Anaerobes do not proliferate in an oxygen environment (for example, bacteria of the genus Clostridium). Facultative anaerobes can grow and develop in an oxygenated or non-oxygenated environment (such as lactic acid bacteria). Microaerophils can reproduce in the presence of very little oxygen.

In advanced laboratories, analyzes are carried out for the determination of anaerobic bacteria number within the framework of microbiological analyzes. During these studies, the relevant legal regulations and the standards issued by domestic and foreign organizations are complied with.