Growth mediums

The serum in the medium is not only expensive but also can be the source of virus or mycoplasma contamination. Since the chemical nature of serum is not well defined, its contents may vary batch after batch, which can affect the result of culture. The presence of many different proteins in serum can also complicate the downstream separation processes. For these reasons, many attempts have been made to formulate serum-free media. These formulations contain purified hormones and growth factors which can substitute for serum supplements (Butler, p.ll, 1987). 

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Apphcations include ka olin clay dewatering, separation of fish oils from press Hquor, starch and gluten concentration, clarification of wet-process phosphoric acid, tar sands, and concentrations of yeast, bacteria, and fungi from growth media in protein synthesis (14). 

Besides a direct addition to growth media, there are other ways of utilizing SAH for example, coating of seeds and bare roots, drilling of germinated seeds in a swollen gel ( fluid drilling [14, 15]), plant nutrient media for hydroponics, etc. 

Microbial insecticides are very complex materials in their final formulation, because they are produced by fermentation of a variety of natural products. For growth, the bacteria must be provided with a source of carbon, nitrogen, and mineral salts. Sufficient nutrient is provided to take the strain of choice through its life cycle to complete sporulation with concomitant parasporal body formation. Certain crystalliferous bacilli require sources of preformed vitamins and/or amino acids for growth. Media for growing these bacilli may vary from completely soluble, defined formulations, usable for bench scale work, to rich media containing insoluble constituents for production situations (10,27). Complex natural materials such as cottonseed, soybean, and fish meal are commonly used. In fact, one such commercial production method (25) is based on use of a semisolid medium, a bran, which becomes part of the final product. 

A frequently observed response of plant cells exposed to saline stress is the accumulation of proline. Two cell lines of tobacco, one resistant and the other sensitive to growth inhibition by NaCl, accumulated proline when exposed to 1.5% w/v NaCl in the growth media (Dix Pearce, 1981). The NaCl sensitive line accumulated proline more rapidly than did the resistant line, though the levels accumulated were not adequate to provide osmotic protection against salt stress. The authors suggested that proline accumulation may have a protective role other than osmoregulation and may be symptomatic of stress injury, the nature of which was not discussed. 

Sample tests in the field. These include coupons, stressed samples, electrical-resistance probes exposed to the plant corroding medium, or samples exposed to the atmosphere, to soils, or to fresh, brackish, or saline waters. Samples for viable microbes involved in MIC must be processed immediately in the field into appropriate growth media. 

H. Sakai and T. Tadano, Characteristics of respon.se of acid phosphatase secreted by the roots of several crops to various conditions in the growth media. Soil Sci. Plant Nutr. 39 431 (1993). 

Mycobacteria are slow-growing organisms in the laboratory, they require special stains, special growth media, and long periods of incubation to isolate and identify... 

Surface Monitoring Contact (or Rodac) plates of growth media are applied to surfaces such as bench tops, walls, and personnel and then incubated. Colony-forming units (cfu) are counted and identified. 

Ramamoorthy, S. and Kushner, D.J., Binding of mercuric and other heavy metal ions by microbial growth media, Microb Ecol, 2 (2), 162-176, 1975. 

An interesting variation on the whole-cell MALDI approach was recently reported in a study aimed more at FTMS than TOF MS, but the results are nevertheless interesting and important to users of both methods for analysis of bacteria 40. Wilkins s group showed both MALDI-TOF and MALDI-FTMS spectra of whole bacteria grown on isotopic media depleted in C13 and N14. Because most bacterial identification protocols involve a culture step prior to analysis, it is possible to manipulate the sample based on control of the growth media. For mass spectral analysis manipulation of the isotope profile... 

Figure 13.10 Partial 9.4 T MALDI-FTMS spectrum of E. coli JM109, showing differences in observable desorbed proteins between natural abundance and isotopically depleted growth media.

Production of poly(3HB-co-3HV) co-polymer in plants has recently been demonstrated by the PHA group of Monsanto [27], which acquired the PHA business of Zeneca in 1996. In the commercial production of poly(3HB-co-3HV) from R. eutropha, propionate is added to the growth media in order to create an intracellular pool of propionyl-CoA which can be condensed to acetyl-CoA to form 3-ketovaleryl-CoA. The 3-ketovaleryl-CoA is then reduced by the aceto-acetyl-CoA reductase to give 3-hydroxyvaleryl-CoA, which is co-polymerized with 3-hydroxybutyryl-CoA to synthesize poly(3HB-co-3HV) (Fig. 1). For the synthesis of poly(3HB-co-3HV) in plants, it was thus necessary to create an endogenous pool of propionyl-CoA which could be used by the PHA pathway. 

B) mold growth inhibition number of colonies versus days (light shading - untreated and dark shading - treated growth media). 

Nichols, H. W. (1973). Growth media - fresh water. In Handbook of Phycological Methods, Culture Methods and Growth Measurement. J. R. Stein (ed), pp 7-24. Cambridge University Press, Cambridge, UK. 

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