Microbiology Notes | Biochemistry,Immunolgy,Cell biology

  Bacterial Morphology - Bacteria Size, Shape and Arrangement Definition Bacteria are microscopic unicellular organism they are true living organism that belongs to the kingdom prokaryotes.   (Singular: bacterium) are a large group of unicellular microorganisms. They lack membrane-bound organelles like those found in eukaryotes. They are extremely tiny thus they cannot be seen individually unless viewed through microscope. When cultured on agar, the bacteria grow as colonies that contain many individual cells. These colonies appear as spots of varying size, shape and colour, depending on the microorganism. Bacterial Size In general, bacteria are between 0.2 and 2.0 um - the average size of most bacteria. Research studies have shown their size to play an important role in survival over time. There are some that hold this to range between 1 and 10 micrometers. E. coli bacteria range between 1.1 and 1.5 um in diameters, B. anthracis range betwe...

What Is Xenobiotic Compound? Xenobiotic compounds are man-made chemicals that are present in the environment at unnaturally high concentrations. The xenobiotic compounds are either not produced naturally, or are produced at much lower concentrations than man. Microorganism have the capability of degrading all naturally occurring compounds; this is known as the principle of microbial infallibility proposed by Alexander in 1965. Microorganisms are also able to degrade many of the xenobiotic compounds, but they are unable to degrade many others. The compounds that resist biodegradation and thereby persists in the environment are called recalcitrant The evolution of microbial catabolic enzymes cannot keep pace with the rapid introduction of novel compounds into the environment. These new synthetic compounds that are slowly biodegradable or non-biodegradable are known as recalcitrant compounds, and range from simple halogenated hydrocarbons to complex polym...

For biotoxification or Biodegradation of toxic substances Required a special enzyme which contain encoded gen on Plasmid Dr. Ananda Mohan Chakrabarty  and his co-workers are isolated a specific organism which is known as Pseudomonas putida in 1989.which can utilize some toxic chemical substances such as 3 chlorobenzene,ethylene etc. Pseudomonas putida  is a Gram-negative, rod-shaped, saprotrophic soil bacterium. V A variety of  P. putida , called multiplasmid hydrocarbon-degrading  Pseudomonas , is the first patented organism in the world. Because it is a living organism, the patent was disputed and brought before the United States Supreme Court in the historic court case  Diamond v. Chakrabarty , which the inventor, Ananda Mohan Chakrabarty, won . P. putida is a multiplasmid containing orgamism which contain more then one plasmid they introduce by genetic engineering different types of plasmid into a cell and forme...

Transposable elements (TEs), also known as “jumping genes” or transposons, are sequences of DNA that move (or jump) from one location in the genome to another. A transposon may be defined as: “a DNA sequence that is able to move or insert itself at a new location in the genome.” The phenomenon of movement of a transposon to a new site in the genome is referred to as transposition. Barbara McClintock’s discovery of these jumping genes earned her a Nobel Prize in 1983. Classification On the basis of their transposition mechanism, transposons may be categorized into following types: ( i) Cut-and-Paste Transposons/Nonreplicative Transposons:   They transpose by excision (cutting) of the transposable sequence from one position in the genome and its insertion (pasting) to another position within the genome Examples: – cut-and-paste type of transposons are IS-elements, P-elements in maize, hobo-elements in Drosophila etc. (ii) Replicative Transpos...

Genetic - Transduction: Definition,Clasification. Definition T ransduction is a process in which involve the genetic element is transfer from a donor bacterial cell to a recipient cell through a bacteriophage. In transduction process the bacteriophage first Infects the donor cell and then carries some genome of donor cell with it,when it Infects another new cell it inject the genome of previous cell into new one. Classification Transduction is classified into two classes – Generalized Transduction Specialized Transduction 1. Generalized Transduction The generalized transduction occurs during the lytic Cycle of viral temperate phage,and it can transfer any part of bacterial chromosome from donor cell to recipient cell. Mechanism Generalized Transduction When the phage infect the host bacterial cell it initiate the lytic cycle. Then this phages are started to synthesis new viral genome, enzymes, capsid, head tail and tail fibers. The enzymes of viral phage...

Lymphocytes Lymphocytes are white blood cells that are also one of the body's main types of immune cells. They are made in the bone marrow and found in the blood and lymph tissue. It constitute 10-20% immuno cells of body and 99% of the lymph. Types of lymphocytes  There are present three type of lymphocyte cell this are; B - Cell T - Cell  Natural killer Cell. 1. B-Cell  The B lymphocyte derived its letter designation from its site of maturation, in the bursa of Fabricius in birds; the name turned out to be apt, for bone marrow is its major site of maturation in a number of mammalian species, including humans and mice Mature B cells are defi nitively distinguished from other lymphocytes and all other cells by their synthesis and display of the B-cell receptor (BCR), a membrane-bound immunoglobulin (antibody) molecule that binds to antigen.  The number of B-Cell receptor on surface is approximately 1.5–3 105. B lymphocytes also can improve...