The primary aim of culture preservation is to maintain the organism alive, uncontaminated, and without variation or mutation, that is, to preserve the culture in a condition that is as close as possible to the original isolate. Once a microorganism has been isolated and grown in pure culture, it becomes …
Read More »Control of Microorganisms
Control of Microorganism by Heat Heat generally appears to kill micro-organisms by denaturing their enzymes: the resultant changes to the three-dimensional shapes of these proteins inactivate them. Heat resistance varies among different microbes. These differences can be expressed through the followings; Thermal death point (TDP) is the lowest temperature at …
Read More »Growth of Bacteria
Generation Time The time required for a cell to divide or a population to divide is known as the generation time. For bacteria it is the time, required for a complete fission cycle. Generation time depends on nutrient media, pH, temperature etc. The generation time “g” can be determined from …
Read More »Cultivation of Microorganisms
Culture medium Solid, liquid, gel (semisolid) designed to support the growth and supply nutrients to any cell or microorganism is culture medium. Culture medium is special medium used in microbiological laboratories to grow different microorganisms. Criteria for microbiological culture medium A microbiological culture medium must contain: Source of energy (chemicals …
Read More »General Methods of Microbial Isolation
Isolation In Microbiology, the term isolation refers to the speration of a strain from a natural, mixed population of living microbes, as presents in the environment, in order to identify the microbes of interest. Isolation can be done from, for example water or soil flora or from living beings with …
Read More »Measurement of Microbial Growth
Direct microscopic count The direct total cell count involves counting the number of cells in a simple microscopically. This technique is very similar to that used in blood cell counts. Scientists perform a direct microscopic count using a specially designed slide called a Petroff-Hausser cell counter/ counting chamber/ cytometer/ hemacytometer …
Read More »Microbiology of Food
Food is any substance consumed to provide nutritional support for the body. Food contains essential nutrients such as carbohydrates, fats, proteins, vitamins or minerals. Food is ingested by an organism and assimilated by the organisms cells to provide energy, maintain life or stimulate growth. Classifications of food According to Martin …
Read More »Microbial Water Pollution
Water pollution is any undesirable changes in physical, chemical and biological characteristics of water that may harmfully affect the life or create a potential health hazard for living organisms. When the pollutant is undesirable microorganisms, the phenomenon is called microbial water pollution. Through ordinary exposure to air, soil and effluent …
Read More »Microbiology of Milk
Milk is a highly nutritious food that can be obtained from a variety of animal sources such as cows, goats, sheep, and buffalo, as well as humans, for human consumption. However, the high nutrient content of these milk, which includes proteins, fats, carbohydrates, vitamins, minerals, and essential amino acids all …
Read More »The Selfish Gene: The Mean of Existence
Part-1 This is more of a book review than just an article sharing including intuitive visualizations from the other sources related to “The Selfish Gene” (1976) on evolutionary biology by the evangelist of biological science Richard Dawkins. Unfortunately, this book wasn’t too popular from the day of it’s publications because …
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