Bacteria growing

Vitamin B12 has been synthesized from scratch in the laboratory, but bacteria growing on sludge from municipal sewage plants do a much better job. 

In each cycle, the library of mutated genes is first inserted in a standard bacterial host such as Escherichia coli or Bacillus subtilis. Subsequently, bacterial colonies are plated out on agar plates and harvested individually by a colony picker. Each colony is placed in a separate well of a microtiter plate containing nutrient broth, so that the bacteria grow and produce the protein of interest. Because each colony originates... 

Most bacteria grow best at pH valnes of 7.4-7.6, on the alkaline side of neutrahty, but some bacterial species are able to grow at pH 1-2 or 9-9.5, although they are exceptional. 

The nitrite results from reduction of nitrate by bacteria abnormally present in the gastric mucosa and the gastric cavity. The bacteria grow situ because the pH is elevated as a result of loss of HCl secretion secondary to the loss of parietal cells and their replacement by intestinal-type epithelium. Parietal cells are lost as a result of chronic atrophic gastritis. What... 

Plaques are essentially windows in the lawn of confluent cell growth. With bacterial viruses, plaques may be obtained when virus particles are mixed into a thin layer of host bacteria which is spread out as an agar overlay on the surface of an agar medium. During incubation of the culture, the bacteria grow and form a turbid layer which is visible... 

Novicik, A. and Szilard, L. (1951). Genetic mechanisms in bacteria and bacterial viruses. I. Experiments on spontaneous and chemically induced mutations of bacteria growing in the chemostat. Cold Spring Harbor Symposia on Quantitative Biology 16 337-343. 

Figures 33.3-33.4 show the results at the end of the simulation, after groundwater composition and microbial activity across the aquifer have approached steady state. Once the sulfate initially present is consumed or flushed from the aquifer, the only source of sulfate is in the recharging groundwater. With time in the simulation, sulfate reducing bacteria grow into a community that consumes sulfate from the recharging groundwater and some of the acetate diffusing into the aquifer the acetate and sulfate are consumed in equal molar proportions, according to Reac-...

Production of biogenic amine by bacteria growing on media culture. 

Food may be contaminated with toxins produced by bacteria, such as botulinum toxin. This is produced by the bacterium Clostridium botulinum and is one of the two most potent toxins known to humans (the other being ricin). As little as one hundred-millionth of a gram (1 X 10-8 g) of the toxin would be lethal for a human. Fortunately, the toxin is destroyed by heat so that cooked food is unlikely to be contaminated (although the bacterial spores are quite resistant). The bacteria grow in the absence of air (they are anaerobic), and consequently, the foodstuffs most likely to be contaminated are those that are bottled or canned and eaten without cooking, for example, raw or lightly cooked fish. 

From Table 17.6, you find /imax is about 0.7 h l for some pond bacteria growing on PC. Unfortunately, you do not have any information on [B]0, although the total bacterial cell numbers are typically near 109 cells-L"1. Assuming 1% of this population participates in the use of PC as a growth substrate, we estimate ... 

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