Nitrification is one of the crucial steps in the nitrogen cycle that occurs in soil. It is an aerobic process that involves two successive oxidation reactions, in which the ammonia first oxidizes into nitrites, and then nitrites get oxidized into nitrates. It occurs in the soil and includes members of autotrophic bacteria and archaea. The …
Prions are the sub-viral agents, which function as proteinaceous infectious particles without a genomic RNA or DNA. They are the mysterious pathogens whose accumulation within neurons cause severe fatal and transmissible neurodegenerative diseases in humans and animals. Prions solely possess PrP proteins. The term prion was coined by a scientist named Stanley Prusiner. Prion diseases …
Viroids are sub-viral agents, which exist as small infectious particles. They are somewhat similar to viruses but possesses some unique properties in their evolutionary origin, morphology and functions. In 1917, Diener was the first scientist who discovered and termed the non-bacterial infectious plant pathogens as “Viroids”. Potato spindle tuber viroids (PSTV) was the first viroid …
Tobacco mosaic virus or TMV belongs to the Tobamovirus group, which causes mosaic-like symptoms on tobacco leaves. TMV is a plant virus that disseminates via artificial inoculation rather than insect vectors. It was the first virus identified and the first virus ever purified. Since the late 19th century, it was believed that a non-bacterial infectious …
Potato dextrose agar media is primarily exercised for the growth and isolation of different yeasts and moulds. It can be practised in the form of a liquid broth and solid culture medium. PDA media serves as an ordinary growth medium for the yeasts and moulds, but it can be made selective by incorporating selective agents …
Bacterial growth factors primarily include temperature, pH, salt concentration, light source, nutritional and gaseous requirement etc. Microorganisms live in diverse natural habitats such as the atmosphere, hydrosphere and lithosphere. The environmental and nutritional factors may favour or restrict the growth of microorganisms. Some microbes survive in extreme conditions or the changing environment, while few can …
Bacterial flagella refer to the locomotory apparatuses, which help the bacteria to swim in the liquid nutrient medium. The bacteria possessing flagella are the motile organisms or flagellates. Conversely, the non-motile organisms or non-flagellates lack flagella. The width of bacterial flagella is much thinner and simpler than the eukaryotic flagella. The location, number and arrangement …
Synchronous culture is a technique of growing microorganisms at the same stage of their growth cycle under controlled conditions. Forced or mechanical selection methods induce synchrony in the microbial culture. Forced techniques induce synchrony in microorganisms by the shock treatment (temperature variation) or chemical treatment (nutritional difference). In contrast, the mechanical method uses filtration or …
B1 Vitamin or Thiamin is a kind of water-soluble vitamin that belongs to the vitamin B complex group. It was the first member of the vitamin B family isolated in 1926. Foods like poultry products, fortified cereals, nuts etc., are rich in thiamin content. Dietary supplements are also available to fulfil the demand for vitamin …
Vitamin B12 belongs to the Vitamin-B group. Structurally, vitamin B12 is the largest among all other vitamins (B1, B2, B3, B5, B6, B7 and B9) of the same group. Vitamin B12 is also known as Cobalamin, as it contains the mineral cobalt. Methylcobalamin and 5′ deoxyadenosylcobalamin are the two metabolically active forms of cobalamin. Bacteria …