Organic acids activity

Biogenic organic acids active in the breakdown of silicate rocks and minerals... 

Type of bacteria Sensitive to organic acid activity Resistant to organic acids Acid tolerance... 

Factors that influence organic acid activity... 

To demonstrate the organic acid activities at various pH values, a study done on the salts calcium propionate, sodium benzoate, and potassium sorbate is herewith discussed. These salts were found to be effective and to inhibit some isolates from bakery products at pH 4.5 when applied at concentration of 0.3%. In a sponge cake (an analogue of pH 6) addition of these same weak organic acids salts appeared to be effective only at low aw levels (Guynot et al., 2005). 

Inhibitory effects of organic acids can be adjusted by factors other than pH (Breidt, Jr., Hayes, and McFeeters, 2004). Temperature is a primary factor influencing organic acid activity as increasing temperature typically results in increased effectiveness (Krebs, Wiggins, and Stubbs, 1983 Brudzinski and Harrison, 1998 Uljas and Ingham, 1999). 

An additional phenomenon may also be important in the tropical forest C/P interaction. Humic molecules and organic acids actively compete with phosphorus for soil fixation sites. This means that increases in soil carbon density at higher [CO2] may serve to displace phosphate ions from sorption sites and into the soil solution, where they can then be utilized by plants. It is not inconceivable that this effect could give rise to a runaway positive feedback CO,-induced increases in tropical forest plant growth... 

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