Requirements of Micro-Organisms for Growth

Micro-organisms, or microbes, are microscopic entities that include bacteria, fungi, protozoans and viruses, that can only be seen through a microscope.
All micro-organisms require certain basic elements for growth: oxygen (except for anaerobic microbes), carbon, hydrogen, nitrogen, and other elements like sulphur and phosphorus.
Temperature is a crucial factor in microbial growth. Most of them thrive in a range between 20-40 degrees Celsius, known as mesophiles. However, some, known as thermophiles, can survive in extremely high temperatures, while others, called psychrophiles, can grow in cold conditions.
Specific pH levels are required for microbial growth. Most bacteria grow best in a neutral pH environment (around pH 7), while fungi prefer slightly acidic conditions.
Nutrients are required for microbial growth. The most important nutrients are carbon and nitrogen. Carbon is used for energy and as a building block for cellular structures, while nitrogen is essential for the production of proteins and nucleic acids.
Water is absolutely essential for the growth of micro-organisms. It is needed for metabolic processes and to maintain cellular structures.
Other factors that affect microbial growth include light and electromagnetic radiation, atmospheric gases, and the presence of other organisms.
Some micro-organisms, depending on their metabolic needs, can live in extreme environments, such as high salt concentration, acidic or alkaline conditions, or even radiation.
The right combination of these factors leads to optimal microbial growth, while unfavourable conditions can inhibit growth or kill the micro-organism.

Remember, understanding these basic requirements of microbial growth is crucial to the prevention and control of infectious diseases in health and social care settings.