Bacteria extraction

Fig. 7.14 Normalized decrease of the magnetization for magnetites of different origin. Whole cells refer to magnetotactic bacteria, extracted to biogenic magnetite extracted form these. The number indicates the size of synthetic magnetite crystals in nm (modified from Moskovitz etal., 1993, with permission).

Cloning a gene means making copies of the same DNA sequence. As described above, this can be done with PCR. Another way scientists clone DNA is to insert it into a plasmid with RE, use the plasmid to transform a bacterial culture, grow a large number of modified bacteria, extract the DNA, and then clip it back out with the appropriate RE. 

Lipoteichoic acids (from gram-positive bacteria). Extracted by hot phenol/water from disrupted cells. Nucleic acids that were also extracted were removed by treatment with nucleases. Nucleic resistant acids, proteins, polysaccharides and teichoic acids were separated from lipoteichoic acids by anion-exchange chromatography on DEAE-Sephacel or by hydrophobic interaction on octyl-Sepharose [Fischer et al. Eur J Biochem 133 523 7985]. 

Montagna, P.A., 1982. Sampling design and enumeration statistics for bacteria extracted from marine sediments. Appl. Environ. Microbiol., 43 1366-1372. 

Selenourea Se=CCNH2)2 Mammals and bacteria Extracted in urine... 

Isolation of Cord Factor.—In Bloch s first paper, it had been shown that a petroleum-ether treatment of living bacteria extracts a crude lipid having the particular toxicity of cord factor. As the yield in these extractions was rather low, other lipid fractions extracted from whole bacilli were examined and it was found that cord factor is present in preparations of wax C and wax D —principally, however, in the former. 

The existence in the Archaean of sulphate-reducing bacteria, producing a spread in S isotopes around b S = 0 5%o has long been accepted (e.g. Goodwin et al. 1976 Shen et al. 2001). Sulphate would have come from ambient water, with a component supply of metals and other nutrients from hydrothermal sources, as shown by the REE (Table 1). In modem microbial mats, sulphate-reducing bacteria extract sulphur from sea water, fractionating it by an amount that depends on the efficiency and rate of extraction. Conversely, sulphide-oxidizers reverse the process. 

In water bacteria use oxidation-reduction reactions to obtain the energy that they need for their own growth and reproduction. Some bacteria require oxygen for their metabolic needs and are called aerobic bacteria. Other anaerobic bacteria extract their oxygen from sources such as N03", S042 and other matter represented as CH20. The most common bacterially mediated reaction in water is the oxidation of organic matter ... 

Although the process requires the addition of a phosphate donor, such as glycerol-2-phosphate, it may be a valuable tool for cleaning water contaminated with radionuchdes. An alternative mode of uranium precipitation is driven by sulfate-reducing bacteria such as Desulfovibrio desulfuricans which reduce U(VI) to insoluble U(IV). When combined with bicarbonate extraction of contaminated soil, this may provide an effective treatment for removing uranium from contaminated soil (85). 

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Farm animals produce recombinant proteins less expensively than bacteria or cells in culture because the farm animals produce large volumes of milk containing up to 5 g/L of recombinant protein. In addition, modifications to the proteins that can be performed only by mammalian cells are made by the cells of the mammary gland. Therefore, numerous pharmaceuticals that previously could only be made by cells in culture or extracted from human tissue or blood are being produced by lactating farm animals. 

Beer taste can be spoiled by contaminating bacteria or yeasts. The most common bacteria are lactic and acetic acid producers and T ymomonas. Wild yeasts can be anything other than the intended strain S. uvarum is considered a contaminant of ale fermentations and S. cerevisiae a contaminant of lager fermentations. The common wild yeast contaminants are S. diastaticus and species of Picbia, Candida and Brettanomjces. It may be noted that the flavor of beer may be improved by the ability of yeast to adsorb bitter substances extracted from hops, such as humulones and isohumulones. 

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