Online microbiology notes by SAGAR ARYAL
Koch’s postulates and its limitations Koch’s postulate forms the very basis of the pathogenic microbiology. The causality of almost all infectious diseases is based on the postulate and theories developed by Robert Koch, who is rightly called the “father of pathogenic microbiology,” and his contemporaries. Developed in the late 19th century, it has stood the … Read moreKoch’s postulates and its limitations
Degradation and Deterioration Nature has always provided, in considerable amounts and variety, polymeric materials with interesting compositions and structures. These natural polymers include polysaccharides, such as cellulose, chitin, starch, alginate, galactan, hyaluronic acid, dextran, and gellan, obtained from plants, animals, and microbial sources and polyesters, such as poly(b-hydroxybutyrate) and poly(b-hydroxybutyrate-co-b–hydroxyvalerate), produced by numerous bacteria. In biological … Read moreDegradation and Deterioration
General Aseptic Techniques in Microbiology Laboratory Aseptic technique is a set of routine measures that are taken to prevent cultures, sterile media stocks, and other solutions from being contaminated by unwanted microorganisms (i.e., sepsis). While such actions are sometimes called “sterile technique,” that terminology is appropriate only in reference to preventing the introduction of any … Read moreGeneral Aseptic Techniques in Microbiology Laboratory
Direct Microscopic Counts Studies involving the analysis of materials including food, water, milk, and, in some cases, air require quantitative enumeration of microorganisms in the substances. Many methods have been devised to accomplish this, including direct microscopic counts, use of an electronic cell counter such as the Coulter Counter, chemical methods for estimating cell mass … Read moreDirect Microscopic Counts
Classification of Protozoa The sub kingdom Protozoa which was originally included in the kingdom protista includes unicellular, non-photosynthetic, eukaryotic microorganism that are considered single celled, The Protozoan Animals. The Protozoa may be defined as ‘microscopic, acellular animalcules existing singly or in colonies without tissues and organs, having one or more nuclei. When in colonies, they … Read moreClassification of Protozoa
Darkfield Microscopy Microbiology, the branch of science that has so vastly extended and expanded our knowledge of the living world, owes its existence to Antoni van Leeuwenhoek. In 1673, with the aid of a crude microscope consisting of a biconcave lens enclosed in two metal plates, Leeuwenhoek introduced the world to the existence of microbial … Read moreDarkfield Microscopy
Bacterial and Fungal Preservation Methods Biopreservation is the process of preserving the integrity and functionality of cells. Most bacteriological laboratories maintain stock cultures of microorganisms for educational, research, bioassay, industrial, or other purposes. A wide variety of techniques are available for the preservation of bacteria and it may be difficult to choose a method for a … Read moreBacterial and Fungal Preservation Methods
Bergey’s Manual of Systematic Bacteriology and Determinative Bacteriology Bacterial systematics has undergone several changes and is continuously in a state of flux as our knowledge of microorganism is far from complete and new information is being added every day. In 1923 David Hendricks Bergey, professor of bacteriology at the University of Pennsylvania and four colleagues … Read moreBergey’s Manual of Systematic Bacteriology and Determinative Bacteriology
Spread Plate Technique A variety of techniques has been developed for the isolation of microorganism, mainly the bacteria, from the specimen or from the sample cultures. The spread plate method is a technique to plate a liquid sample containing bacteria so that the bacteria are easy to count and isolate. A successful spread plate will have a countable number … Read moreSpread Plate Technique
Classification of Bacteria on the basis of Nutrition Nutrition is substances used in biosynthesis and energy production and therefore are required for all living things. Bacteria, like all living cells, require energy and nutrients to build proteins and structural membranes and drive biochemical processes. Bacteria require sources of carbon, nitrogen, phosphorous, iron and a large … Read moreClassification of Bacteria on the basis of Nutrition