The Microbes    in Microbiology

Microbiology is the study of microbes, organisms so small that we need a microscope  to study them. 

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Microorganisms lifestyle

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The majority of microorganisms live a free existence in habitats such as soil and water, where they are relatively harmless and often beneficial. Sometimes microorganism require interaction with other organisms, these microbes are termed parasites. They are harbored and nourished by other living organism called hosts.

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Cellular Organization

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As we know there are fundamentally two type of cells. The prokaryotic cells, they posses a much simpler morphology than eukaryotic and lack of a membrane delimited nucleus. All the bacteria are prokaryotic. The eukaryotic cells have a nucleus bounded by a membrane; are more complex and generally larger than prokaryotes. algae, fungi, and protozoa are eukaryotic cells. The majority of microorganism are single-celled (all prokaryotes and some eukaryotes), but some consist of a few cells. 

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The Microbes

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The major groups of organism studied in microbiology are bacteria, archea, algae, fungi, viruses and protozoa. 

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Bacteria: Are single-celled (prokaryotic) organisms with spherical, rod or spiral shapes, but a few types can form filaments. Many bacteria absorb nutrients from their enviromente, but some others make their own nutrients by photosynthesis or other synthetic processes. They are widely distributed in the nature. This microorganisms occasionally cause diseases.

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Archea: As bacteria, the archea are single-celled and do not have a nucleus. However, they are genetically and metabolically very different. They live in environments with extreme temperatures (extremophiles), pH and salinities. Archae are not proven to cause disease in humans.

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Algae: this microorganisms are single-celled, but some marine algae are large, relatively complex, multicellular organisms. They have a defined cell nucleus and numerous membrane-enclosed intracellular structures. All of them photosynthesize their own food as plants. Algae are of little medical importance; only one species, Prototheca, has been found to cause disease in humans.

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Fungi: Such as yeasts and molds, are single-celled (cell nucleus and intracellular structures) microscopic organisms. Some such as mushroom, are multicellular, adn macroscopic organisms. All of them absorb ready-made nutrients from the enviroment. They are widely distributed in water and soil as decomposes of dead organisms. Some are important on medicine either as agents of diseases or as sources of antibiotics.

 

Viruses:  Are acelular entities too small to be seen with a light microscope. They are composed of a nucleic acid and a few proteins. Viruses replicate themselves and display other properties of living organisms only when they invaded cells. 

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Protozoa: Single-celled, microscopic organisms with a least one nucleus and numerous intracellular structures. Many protozoa obtain food by engulfing or ingesting smaller microorganism. Most of them can move, but a few, cannot. They are found in a variety of water and soil environments, as well in animals.

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Helminths and arthropods: The helminths (worms) have microscopic stages in their life cycles that can cause disease, and the arthropods can transmit these stages, as well as other disease-causing microbes.