Search results
Results From The WOW.Com Content Network
Bacteria display a large diversity of cell morphologies and arrangements. Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea).
Microscopic image of gram-negative Pseudomonas aeruginosa bacteria (pink-red rods). Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. [1]
Antonie van Leeuwenhoek (1632–1723), the first microbiologist and the first person to observe bacteria using a microscope in 1676. Bacteria were first observed by the Dutch microscopist Antonie van Leeuwenhoek in 1676, using a single-lens microscope of his own design. He then published his observations in a series of letters to the Royal ...
Bacteria and archaea are almost always microscopic, while a number of eukaryotes are also microscopic, including most protists, some fungi, as well as some micro-animals and plants. Viruses are generally regarded as not living and therefore not considered to be microorganisms, although a subfield of microbiology is virology , the study of viruses.
It is described using terms like brittle, creamy, sticky and dry. Staphylococci are considered to have a creamy consistency, [1]: 173 while some Neisseria species are sticky, and colonies of diphtheroid bacteria and beta-hemolytic streptococci are typically dry. [1]: 167–8 Bacteria that produce capsules often have a slimy (mucoid) consistency.
Lactobacillus acidophilus image taken with a scanning electron microscope (SEM). A Lactobacillus acidophilus culture. Lactobacillus acidophilus is an immobile rod-shaped (bacillus), gram-positive organism that ranges in size from 2-10 μm in size.
The bacterial DNA is not packaged using histones to form chromatin as in eukaryotes but instead exists as a highly compact supercoiled structure, the precise nature of which remains unclear. [6] Most bacterial chromosomes are circular, although some examples of linear chromosomes exist (e.g. Borrelia burgdorferi). Usually, a single bacterial ...
Vibrio cholerae is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. [1] The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimp, and other shellfish.