Archaea are the single-celled organism that lacks the nuclei. The differences between the bacteria and archaea are not well known. They are not well recognized so that the Archaea is classified with bacteria as a part of the kingdom Monera. The microbiologist Carl Woese in 1990 proposed the three domain system that divided the living things into bacteria, archaea and eukaryotes. Archaea differs from the bacteria in their genetics and biochemistry both. For example; the cell membrane of bacteria is made from phosphoglycerides with the ester bond while that of archaea is made of ether and lipids.
Archaea were originally described in the extreme environments such as hot springs but have since been found in all types of habitats. Only now scientist beginning to appreciate how common archaea are in the environment, with crenarchaeote being the most common form of life in the ocean dominating ecosystem below 150m in depth. These organisms are also common in soil and play a vital role in ammonia oxidation.
In Archaebacteria, there is an absence of murein i.e cell wall is absent and highly resistance to PH and salt concentration.
Cyanobacteria are also micro-organisms and commonly called as blue-green algae due to the presence of pigments. Cyanobacteria are larger in comparison to the bacteria. Usually, these bacteria are beneficial as they fix atmospheric nitrogen. Example: Nostoc, Anabaena .
1: Nostoc, Anabaena can fix the atmospheric nitrogen and increase the soil fertility i.e they are the sources of soil fertility.
2: Nostoc commune is consumed as a vegetable in China, Japan, and Korea.
3: Oscillatoria is used to kill mosquito larvae from ponds in which they grow.
4: Spirulina is cultivated in a tank as a protein-rich animal feed and it is also used as food in some parts of Africa.
1: Anabaena and Microcystis cause gastric trouble in human beings and animal.
2: Water blooms: blue-green algae grows abundantly in water reserves where an excess of nutrients is available to them. This algal growth floats on the water surface and looks like soap leather. It is called water bloom.
3: They cause water pollution and slimy to water and this leads to the extinction of fish from this water.
They are the fungi-like bacteria i.e they occupy the intermediate position between bacteria and fungi in morphology. They produce branched filamentous network which is sensitive to acidic soil. The growth of actinomycetes has the ability to attack the complex and resistant compounds like cellulose and chitin.
1: They decompose soil organic matter and release nutrients.
2: They are capable of synthesizing antibiotics. The genus Streptomyces is the very important as the number of antibiotics is based on it. Examples: Streptomycin.
They cause disease in human beings, animals, and plants.
|Humpy jaw of cattle||Actinomyces vovis|
|T.B of cattle||Mycobacterium fovis|
|scalps of potato||Actinomyces scabies|
A protozoan is a unicellular organism without a true cell wall. Protozoa infect other bacteria, fungi and other microbes. Protozoan digestion of bacteria and fungi influences the microbial population. The numerous protozoan found in soil help to control other minerals but also cause critical diseases. Protozoan is classified according to their method of movements.
a: Amoeba: by pseudopodia
b: Flagellates; by whips like a unit.
c: Ciliates: by the hair like structure i.e cilia
Harmful activities of protozoans;
1:Entamoeba histolytica causes diarrhea, dysentery, in human beings.
2: Escheria Coli causes gastrointestinal trouble or gastritis.
3: Balantidrum Coli causes diarrhea, balantidiases, and dysentery in human beings.
Fungi are the organism that lives on dead or living plants or animal tissues. They have the ability to use the sun for energy. These are effective lignin decomposers. Fungi may be divided into three groups. They are ascomycetes, zygomycetes, and basidiomycetes.
Ascomycetes include yeast and they do not play an important role in soil development growth of higher plants.
Zygomycetes are very important in decomposing the organic residues,molds. These are multicellular.
Basidiomycetes include the fungus that bears beside i.e basidiospores Example: mushroom. They help in decomposing cellulose lignin and protein .
Fungi decomposes organic residue better than bacteria. Fungi can oxidize ammonium compounds and fixed element nitrogen into combine form.
Fungi arr important to us as they affect our day to day life. Some of them are friendly and provides us food, life-saving drugs, and many other valuable items while other cause diseases in plants and human beings and spoil our belongings.
1: Fungi as food: Fungi provides us food which in rich in protein.
a: Mushroom: It contains 21-30% of protein and the proportion of fats and carbohydrates are relatively less. Mushroom are generally saprophytic and are considered as good food for diabetes and heart patients.
b: Yeast: They are rich in vitamins especially in B-complex. Dried yeast contains about 50% protein.
2: Soil fertility : Fungi like Aspergillus, Cladosporium etc have soil binding property. They along with bacteria help in the decomposition of dead organic matter. As a result of which the amount of humus increases in the soil and it becomes more fertile.
3: In biological research: Fungi like Neurospora is an ideal material for genetical n biochemical studies. It reproduces very rapidly and mutation can be induced very easily.
4: Decompositional importance: They form an important component of an ecosystem by decomposition the dead bodies of plants and animals and form humus which is the fertile organic component of the soil. Which is very important to increase the fertility of the soil and healthy growth of plants. They also break down the complex organic compound into simple one i.e by releasing hydrolytic enzymes into the ecosystem into the substratum and they release minerals which make plants able to recycle.
1: Spoilage of articles: saprophytic fungi like Mucor, Rhizopus, Aspergillus etc destroy leather articles, pickles,meat, the bread which make on feed to eat. In addition rubber, wool and books are also damaged by the species of Aspergillus, Penicillium, Alternaria etc.
2: Some species of mushroom are very poisonous and eating such mushroom sometimes lead to death.
3: Fungi are highly responsible for causing a number of serious diseases in plants, animals, and human beings. More than 80% diseases in plants are caused by fungi. Like late blight of potato is caused by Plethora infusions and early blight of potato is caused by Alternaria solani.
4: Animal and human disease: Fungi are highly responsible in causing skin disease, hair infection, hooves and horn of animals and internally also they infect animal and human being in organs like lungs, intestine, deep skin , brain etc
5: Mycosis and ringworm are the most common disease due to lungs in human beings. Helminthosporium, Aspergillus, Penicillium are responsible for these diseases.
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