Microbial physiology is a broad ranging subject covering the study of the cell structure, function, growth and metabolism of single cell organisms. Major applications of the subject include medicine, agriculture and food sciences.
Microbes are organisms that are microscopic, too small to be seen by the naked eye. They live everywhere in our environment where there is liquid water. From deep within the Earth to high in the atmosphere, from acid hot springs where nothing else can survive to the very rock that makes up the surface of our planet, microbes are ubiquitous.
These organisms come from all biological realms. Bacteria, protozoa, fungi, animals and plants can all be microbial. Also, while most microbes are single cell organisms, some can be found in colonies and all microbial animals are multi-cellular.
In medicine, microbial physiology is an important component of pathology and immunology. In pathology the study of how microbes cause disease, how they're transmitted and the biochemical functions that release toxins into the body are major fields of study. Immunology studies how the body fights off disease. The microbial application of immunology involves how microbes cause the body to create an immune response and how to apply that knowledge to prevent illness.
Agricultural application of microbial physiology similarly covers a wide range of areas. The study of microbes in soil primarily involves their action in decomposition of organic material. Some microbes, however, fix nitrogen into the soil providing nutrients for plant growth. Plant pathology is also important to agriculture. How microbes affect the health and growth of plants is the key to this study.
Fermentation and spoilage are primary applications of microbial physiology in food sciences. Different aspects of the same processes, fermentation is the study of the beneficial aspects of microbial action while spoilage is concerned with the harmful ones. Fermentation of grains and sugars into alcohol is important to the production of beer, wine and spirits. Fermentation by yeast is key to baking and the fermentation of dairy products by molds and bacteria gives us different varieties of cheeses and yogurts. Fermentation with the wrong kinds of microbes, or in the wrong conditions, results in spoilage of food.
Recent studies and applications of microbial physiology have lead to advances in many other areas. Bio-engineered bacteria can now produce insulin and many other useful proteins, hormones and drugs. The application of the fermentation process to energy production is key to bio-fuels. And algae are being developed that may be able to convert carbon dioxide and sunlight directly into useful fuels.
The wide range of application of microbial physiology makes it an important area of study. With ever-greater needs to understand the processes of our planet and apply biological technologies it will be a growing subject for a very long time.