Institution Tallahassee Community College
Instructor Dr James Muchovej
Course MCB 2004
Microbiology nutrition and growth Microbiology is a branch of science that deals with the study of small micro-organism that cannot be seen through naked eyes but only through the use of a microscope. Some of the Micro-organism in the environment include; bacteria, viruses and fungi to mention but a few. Whereas some Micro-organisms are associated with causing of diseases others are known for destroying the balance in the ecosystem. However, this is not always the case because some of them are useful in recycling important nutrients back into the ecosystem. Just like human beings, for micro- organism to survival in the ecosystem certain conditions within the physical environment should prevail to facilitate growth and maturity of the organisms. The environment should be in a position to provide minimum nutritional elements where the organism can obtain their source of energy and generate their food (Martinko, 34). Food plays a pivotal role in the survival of any living thing because it helps in generating energy that is used to maintain other process in the organism body. The nutritional requirements of micro-organism that is used in energy generation is stored in form of microscopic elements such as Mg+, Na+ and k+ to highlight but a few within the cell membrane of the organism. These elements are required in small amounts in the body cell and are used to carry the various functions in the cell. In most cases they are used in making new cell structures as well as the formation of energy storing units. To facilitate the metabolic rate of the cells in the body trace elements, existing in the form of ions and cations, act as the cofactors in useful enzymatic chemical reactions in the cell body. Different enzymes have been realized to perform optimally when certain favourable conditions provided by the aforementioned trace elements are available in the environment. Lack of the cofactors in a chemical reaction lowers the normal metabolic rate thus decreasing the chance of survival of the organism due to lack of energy and food. Growth cannot take place without presence of food. Again, is evident enough that for food to be manufactured by the organism there must be a source of energy that converts various elements in the environment to form food. In this regard, the underlying principle is the presence of the source of energy that would initiate other process supposed to take place in the cell membrane. Certain micro-organism use light as their main source of energy in oxidizing food so that they can generate heat and energy that in turn maintain normal operation of the organism. Such micro-organisms are referred to as the photo troughs (Milton, 56). In case of light the rate of growth of these micro-organisms is always higher compared to when there is no enough light to carry out chemical reactions. On the other hand, there is correlation between growth rate and productivity in an ideal situation in the sense that, when favourable conditions are available there is high growth rate of the organism due to availability of food to sustain the entire population. Furthermore, availability of food leads to high birth rate that picks at the optimum point. Factors required for growth
Every living organism requires certain conditions for it to grow and develop effectively in the ecosystem. Various elements in varied proportions are also provided by different physical environment where different species of organisms live. However, there are three main factors that influence the growth and development of any given organism. These includes; Amino acids, purines and vitamins. Amino acids are used in the formation of proteins; purines are used in the synthesis of nucleic acids and vitamins used as co-enzymes factors in chemical reactions. If the three main components of growth are available, it is evident that the rate of growth of micro-organism would be faster compared to situations where there is deficient of one or more components. Deficiency leads to retarded growth or in severe cases it may lead to death of the organism. It has been noticed that vitamins plays a crucial role in initiating growth and development in many living organism. If an organism cannot produce the required vitamins automatically, it must be provided artificial so that it cannot die. Factors that influence growth of micro-organism
The effect of physical environment on growth
As we have mentioned before growth is a greatly determined by the living conditions surrounding an organism. Certain micro-organism thrives in conditions that are deprived oxygen, sunlight and warmth. But on the contrarily, others do thrive in this conditions. The variation in terms of irritability is a concept has been articulated to adaptation and survival mechanism of an organism. Oxygen
Oxygen is a universal component in the universe that is used by organism to carry out their chemical reactions. However, certain micro-organism oxidizes food in presence of oxygen while others in the absence of oxygen. Those organisms that use oxygen in oxidization of food are referred to as aerobes whereas those that fail to oxidize food in presence of oxygen are referred to anaerobes. If an anaerobe micro-organism is confined in a place full of oxygen it would experience low growth rate and in extreme conditions it may even die. The change in PH levels
A PH level is the degree of acidity or alkalinity that prevails in a given condition. There are other category of micro-organism that would grow effectively when in acidic condition whereas others would not and vice versa. In gauging whether an organism can live in a particular condition, researchers use three main points. They include; minimum, optimum and maximum points. Minimum point is considered as the lowest PH level where an organism survives. At optimum level the rate of growth is high because the prevailing condition favours the micro-organism (Schleifer, 143). In fact an increase in growth rate has been noticed to exist between the minimum point and the optimum point and thereafter there is drastic change in the rate of growth. Temperature
The effect of temperature on growth rate can be related to that one of PH levels. It has been established that bacteria and other micro-organism have the ability to survive under different conditions. Some of the micro-organism is well adapted to live in areas that have high temperatures whereas others have the ability to thrive in low temperatures (Rehm, 45). In regions where temperatures are optimal there is tremendous change in growth rate and vice versa. A good example is the functioning of enzymes in the body. When enzymes are exposed to high temperatures they are denatured those lowering the rate of chemical reaction. On the other hand, when they placed in optimum temperature the metabolic rate increases. Most of the preservation methods used today employs the principle of denaturisation where enzymes responsible for bacteria growth are killed through heating effect. In conclusion living organism requires nutritional requirements for their growth and enhancement of their survival. But for effective growth to take place there should be interplay of both the physical and environmental factors in ensuring that appropriate elements are available for growth.
Martinko, J. Brock Biology of Microorganisms. Prentice Hall.2005. Milton, Scott. An Alternative View of the Early History of Microbiology. 2001: 52. pp. 333–55. Schleifer, K.H. "Phylogenetic identification and in situ detection of individual microbial cells without cultivation". Microbiol. 2001:Rev. 59 (1): 143–169 Rehm B.H. Microbial Production of Biopolymers and Polymer Precursors: Applications and Perspectives. Caister Academic Press. 1999.