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Bacteriological water analysis is a method of analysing water to estimate the numbers of bacteria present and, if needed, to find out what sort of bacteria they are. It represents one aspect of water quality. It is a microbiological analytical procedure which uses samples of water and from these samples determines the concentration of bacteria ...
Water activity, a thermodynamical value denoted a w, is defined as the partial water vapor pressure p in equilibrium with the substance relative to (divided by) the (partial) vapor pressure of pure water p* at the same temperature: The thermodynamical water activity is thus equal to the relative humidity (RH), and the chemical activity of pure ...
The minimum bactericidal concentration (MBC) is the lowest concentration of an antibacterial agent required to kill a particular bacterium. [1] It can be determined from broth dilution minimum inhibitory concentration (MIC) tests by subculturing to agar plates that do not contain the test agent.
Iron-oxidizing bacteria in surface water. Iron-oxidizing bacteria (or iron bacteria) are chemotrophic bacteria that derive energy by oxidizing dissolved iron. They are known to grow and proliferate in waters containing iron concentrations as low as 0.1 mg/L. However, at least 0.3 ppm of dissolved oxygen is needed to carry out the oxidation. [1]
Indicator bacteria can be cultured on media which are specifically formulated to allow the growth of the species of interest and inhibit growth of other organisms. Typically, environmental water samples are filtered through membranes with small pore sizes and then the membrane is placed onto a selective agar.
While the MIC is the lowest concentration of an antibacterial or antifungal agent necessary to inhibit visible growth, the minimum bactericidal concentration (MBC) is the minimum concentration of an antibacterial agent that results in bacterial death. It is defined by the inability to re-culture bacteria, and the closer the MIC is to the MBC ...
Bioluminescent bacteria are light-producing bacteria that are predominantly present in sea water, marine sediments, the surface of decomposing fish and in the gut of marine animals. While not as common, bacterial bioluminescence is also found in terrestrial and freshwater bacteria. [ 125 ]
Ishigaki and Sleigh (2001) found that C. roenbergensis ceased to reproduce when the concentration of bacteria that they were grazing on became less than 2.0×10 7 cells ml −1. [8] Other flagellates were able to multiply at much lower bacterial concentrations, indicating that bacterial concentration is a limiting factor for Cafeteria.