Tobacco mosaic virus (TMV)

TMV was the first virus to be discovered by the Dimitri Ivanowski in 1892 and crystallized by the W.M Stanley. It causes mosaic disease in tobacco plant. It belongs to tobamo virus group. It is rod shaped, containing no envelope measuring about 300nm in length and 15-17 nm in diameter. It has a protein capsid constituting of 95% of virus and a core of nucleic acid. The capsid is in the form of a tube with a cavity measuring about 2nm in diameter. It is composed of 2130 identical capsomers which are closely packed and arranged in the form of a regular spiral or helix. There are about 49 capsomers for every 3 turns that is about 16 per turn...

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Microsystis

Kingdom: Monera Division: Cynophysia Class: Cynophyceae Order: Chrococcales Family: Chrococcaceae Genus: Microsystis Microsystis is a free floating or planktonic blue green algae commonly found in fresh water bodies such as ponds pools lakes, etc. which maybe contaminated by sewage water. It generally forms dense water grooms. It is colonial form and the colonies are irregular. Each colony consists of a large number of densely packed small cells that are evenly distributed through out a common thin watery, gelatinous matrix. On mucilaginous matrix which is colourless and homogenous. The colony has many air space also called pseudo vacuoles...

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Economic importance of genus Aspergillus.

Aspergillus has both harmful ans useful activities from the view of the human.Harmful activitiesMany species of Aspergillus such as A. glqaus A.flavus A. repns are responsible of spoilage of exposed food stuff like jams, jellies, bread, tobacco and many other product like leather & textiles. Many of the species are pathogenic to animals as well as human beigns. A. flavus, A. fumigates and A.niger causes diseases of respiratory tracks commonly refered to as aspergilloses. Aspergilloses is reported in birds, cattle, sheep, horses and human begins. Symptoms of Aspergillosis resembles those...

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Posted in: Microbiology