Microbes

Bacteria (singular: bacterium) are microscopic unicellular organisms that thrive in a variety of environments. These organisms can live in the soil, in the ocean and in the human gut. This organisms are available almost everywhere on our earth and are important to the planet’s ecosystems. Some species can live under …

Bacteria (singular: bacterium) are classified as prokaryotes. They are single-celled life/body with a simple core-less internal structure and contain DNA that swims freely in a twisted, thread-like matter called a nucleoid, or in circular parts called plasmids. Bacteria are single-celled microscopic life/organisms that grow in different environments, and these organisms can live in …

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 …

Flagella Most prokaryotes are motile by swimming, and this function is typically due to a structure called the flagellum. The plural form of this word is flagella which means whip. Bacterial flagellum is a threadlike locomotor appendages extending outgrowth from the plasma membrane and cell wall. Bacterial flagella are thin, …

In 1675, on June 9, 10, 11 Antony van Leeuwenhoek first observed smaller particles and called them Animalcules. He presented his findings in the Royal Society of London on October 9 in 1676. Finally, Robert Hook and Nehemiah Grew observed bacteria during work with chilies water on 15 November 1677. …

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 …

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 …

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 …

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 …

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 …