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As microorganisms, in particular bacteria, are found virtually everywhere, harmful microorganisms may be reduced to acceptable levels rather than actually eliminated. In food preparation, microorganisms are reduced by preservation methods such as cooking, cleanliness of utensils, short storage periods, or by low temperatures.
Effects included stunted colony growth and darkening in color. Effects of climbazole on oats and turnip included stunted growth of the leaves and shoot, as well as turning darker in color. The aquatic ecotoxicity of climbazole can be classified as very toxic to Lemna and algae, toxic to fish, and harmful to Daphnia. [3]
Microorganisms including bacteria, [58] [59] fungi, and viruses are important as plant pathogens, causing disease to crop plants. Fungi cause serious crop diseases such as maize leaf rust, wheat stem rust, and powdery mildew. Bacteria cause plant diseases including leaf spot and crown galls. Viruses cause plant diseases such as leaf mosaic.
Several bacteriophages contain toxin genes that become incorporated into the host bacteria genome through infection and render the bacteria toxic. [9] Many well known bacterial toxins are produced from specific strains of the bacteria species that have obtained toxigenicity through lysogenic conversion, pseudolysogeny, or horizontal gene ...
Pathogenic bacteria are bacteria that can cause disease. [1] This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and many are beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. [2]
A biological hazard, or biohazard, is a biological substance that poses a threat (or is a hazard) to the health of living organisms, primarily humans.This could include a sample of a microorganism, virus or toxin that can adversely affect human health.
[2] [3] Typically, the term pathogen is used to describe an infectious microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. [4] [5] [6] Small animals, such as helminths and insects, can also cause or transmit disease. However, these animals are usually referred to as parasites rather than pathogens. [7]
Winogradsky was the first to develop the concept of chemolithotrophy and to thereby reveal the essential role played by microorganisms in geochemical processes. [22] He was responsible for the first isolation and description of both nitrifying and nitrogen-fixing bacteria. [2]