Bacteria population

Luminol chemiluminescence has also been recommended for measuring bacteria populations (304,305). The luminol—hydrogen peroxide reaction is catalyzed by the iron porphyrins contained in bacteria, and the light intensity is proportional to the bacterial concentration. The method is rapid, especially compared to the two-day period required by the microbiological plate-count method, and it correlates weU with the latter when used to determine bacteria... 

The technology is based on the addition of low concentrations of a water-soluble nutrient solution that selectively stimulates the growth of an indigenous microbial population, thereby inhibiting the detrimental sulfate-reducing bacteria population that causes the generation of H2S. This deliberate and controlled modification of the microflora and reservoir ecology has been termed biocompetitive exclusion [835,1548]. 

If an open system with renewal of substrate, nutrients, water, and electron acceptors can be supplied, the growth rate of the bacteria population is able to continue for an extended period of time until the remediation is complete. The Monod equation describes the type of bacterial growth that can be expected in an open system ... 

An optimum retention time requires the development of technologies which provide the optimum conditions for the bacteria populations to attack the substrate. 

In an accompanying laboratory study on the kinetics of biologically induced hydrolysis of parathion. Nelson et al. (1982) found that bacteria populations increased to a maximum four to five days after parathion application, with the increase proportional to the concentration of parathion, followed by a decline. Figure 16.36 shows this behavior in remoistened Gilat soil after application of parathion in amounts of 10 to I60 Tg g dry soil. 

Fig. 16.36 Change in bacteria populations in remoistened Gilat soil after application of 10-160 pg parathion per g dry soil. Plotted points are means of three replicates standard error. Continuous curves represent model simulations. Values obtained in control soils to which hexane alone was added have been subtracted. Reprinted from Nelson LM, Yaron B, Nye PH (1982) Biologically-induced hydrolysis of parathion in soil. Soil Biol Biochem 14 223-227. Copyright 1982 with permission of Elsevier...

The bacteria population that accounts for BOD is constant, such that we do not need to include it explicitly in the model. 

Table 6.5 Evolution of bacteria population in sewage water 5, 20, and 60 min after treatment with DiaCell as a function of the treated fraction of the total volume (CO initial concentration Cx% concentration after treatment of x% of the total volume)...

Tartaric acid is relatively stable to bacterial activity and can only be metabolized by some Lactobacillus species with the production of acetic acid, lactic acid and succinic acid (Handler 1983). When tartaric acid is metabolised, the volatile acidity increases and the wine acquires an acetic aroma and a disagreeable taste this degradation can be total or partial depending on the bacteria population, but it always decreases wine quality. The tartaric acid degrading capacity is restricted to only a few species Radler And Yannissis (1972) found it in four strains of L. plantarum and one strain of L. brevis. 

The growth rate of microbes can be astoundingly rapid. The bacteria population, for example, will double every 20 to 30 min under ideal conditions (36-40 °C or 77-98 °F, pH 5-9). At this rate, one single bacteria cell can increase to 1 048 576 cells in just 7 hours. Therefore, antimicrobial finishes must be quick acting to be effective. 

Gonzalez, A., Hierro, N., Poblet, M., Mas, A., and Guillamon, J.M. 2005. Application of molecular methods to demonstrate species and strain evolution of acetic acid bacteria population during wine production. International Journal of Food Microbiology 102 295-304. 

Hypofluoric status, fluorine deficiency in humans, is characterized, along with tooth decay, by the development of osteoporosis (Gabovich and Ovrutskiy 1969). In the first case, acid environment is created by osteo-cytes in the second case, by bacteria populating the surface of tooth enamel. Attention should be paid to the role of bacteria in the development of caries, as disturbed microflora of the mouth cavity seems to be one of its prerequisites. Up-to-date methods of tooth decay prevention (toothpastes, pills) combine the eflfects on the enamel structure and tooth tissue in general, and on the microflora that causes acidity at the points of its location. In this respect, the adaptation of microorganisms to particular fluorine levels is most likely the phenomenon of most significance. 

Interpret Which composite reduced the E. coli population to zero How long does it take for each substance to reduce the bacteria population to zero ... 

TABLE 6. Effect of a Reduced Intestinal Bacteria Population on the Mutagenic Capacity of Cycasin in the Host-Mediated Assay ... 

Gala, E., Landi, S., SoUeri, L., Nocetti, M., Pulvirenti, A., Giudici, P. (2008). Diversity of lactic acid bacteria population in ripened Parmigiano Reggiano cheese. International Journal of Food Microbiology, 125, 347-351. 

Gonzalez-Arenzana, L., Lopez, R., Santamaria, R, Tenorio, C., Lopez-Alfaro, I. (2011). Dynamics of indigenous lactic acid bacteria populations in wine fermentation from La Rioja (Spain) during three vintages. Microbial Ecology, 63,12-19. 

Measurement of the respiration rate of a sludge-water suspension in a system (duration of measurement e.g. 15 minutes). With this method adaptations of the mixed bacteria population used are not taken into account. 

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