Acidogenic

In relation to PVC additives, the study concluded that heavy metal additives are more likely to be released under acidogenic conditions (compared with plasticizers, for example, which are released mainly during the anaerobic and methanogenic phases of landfill development). With respect to landfill emissions, it was concluded that organotin compormds carmot be directly attributed to the presence of PVC in landfills. 

Modeling and simulation of anaerobic filter process two-dimensional distribution of acidogens and methanogens... 

The values of most model parameters were adopted fix>m literature [2]. Subscripts 1 — sucrose 2 — acetate A — acidogens M — methanogens. 

In sewer networks without considerable amounts of sediments, the anaerobic processes are dominated by the acidogenic production of VFA and C02 and by sulfate reduction (hydrogen sulfide production). The methanogenic phase can normally be excluded as being of minor importance. These facts were verified by Tanaka and Hvitved-Jacobsen (1999) and Tanaka (1998) under sewer conditions in a number of laboratory experiments and in the field. 

Acidogenesis. The soluble organic monomers produced in the hydrolysis step are decomposed by means of acidogenic bacteria to produce acetate, VFA, CO2 and H2. 

Acidogenesis. The population of acidogenic bacteria (Xi) consumes the organic substrate (S i) and produces CO2 and volatile fatty acids S2)... 

Leedle JAZ, Greening RC. 1988. Methanogenic and acidogenic bateria in the bovine rumen postprandial changes after feeding high- or low-forage diets once daily. Appl Environ Microbiol 54 502-6. 

Duarte, S., Gregoire, S., Singh, A. P., Vorsa, N., Schaich, K., Bowen, W. H. and Koo, H. 2006. Inhibitory effects of cranberry polyphenols on formation and acidogenicity of Streptococcus mutans biofilms. FEMS Microbiology Letters, 257(1) 50-56. 

Lactobionic acid. This derivative is produced by oxidation of the free carbonyl group of lactose (Figure 2.25), chemically (Pt, Pd or Bi), electro-lytically, enzymatically or by fermentation. Its lactone crystallizes readily. Lactobionic acid has found only limited application its lactone could be used as an acidogen but it is probably not cost-competitive with gluconic acid-<5-lactone. It is used in preservation solutions for organs prior to transplants. 

The pH and the concentration of calcium in milk also vary, with consequential effects on the properties of renneted milk gels. The addition of CaCl2 to cheesemilk (0.02%) is widely practised and adjustment and standardization of milk pH by using the acidogen, gluconic acid-5-lactone (GDL), is recommended and commercially practised on a limited scale. 

Acid production is a key feature in the manufacture of all cheese varieties -the pH decreases to about 5 ( 0.3, depending on variety) within 5-20h, at a rate depending on the variety (Figure 10.11). Acidification is normally achieved via the bacterial fermentation of lactose to lactic acid, although an acidogen, usually gluconic acid-<5-lactone, alone or in combination with acid, may be used in some cases, e.g. Mozzarella. 

The contribution of these agents, individually or in various combinations, has been assessed in model cheese systems from which one or more of the agents was excluded or eliminated, e.g. by using an acidogen rather than starter for acidification or manufacturing cheese in a sterile environment to eliminate non-starter lactic acid bacteria (NSLAB). Such model systems have given very useful information on the biochemistry of ripening. 

On acidification to pH 4.6, the caseins coagulate, which is the principle used to manufacture of a family of cheeses which represent about 25% of total cheese consumption and are the principal cheeses in some countries (Appendix 10B). Acidification is traditionally and usually achieved by in situ fermentation of lactose by a Lactococcus starter but direct acidification by acid or acidogen (gluconic acid-d-lactone) is also practised. The principal... 

Ghosh, S. Sun, M. L. (1992). Anaerobic biodegradation of benzene under acidogenic fermentation condition. In Proceedings of the Conference on Hazardous Waste Research, ed. L. E. Erickson, S. C. Grant J. P. McDonald, pp. 208-18. Manhattan, KS Engineering Extension. 

Jensen, M. E. and Schachtele, C. F. 1983. The acidogenic potential of reference foods and snacks at interproximal sites in the human dentition. J. Dent. Res. 62, 889-892. 

Schachtele, C.F. and Jensen, M.E. (1981) Human plaque pH studies estimating the acidogenic potential of foods. Cereal Foods World, 26 14-18. 

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