Growth volatile constituent

Alcohol used for drinks is made primarily from potatoes, cereals and molasses. Distiller s yeast, especially the top fermenting culture (cf. 20.3.2.1), is used for fermentation. Since the fermentation proceeds in an unsterilized mash and at elevated temperatures and since the growth of yeast occurs in mash acidified with lactic or sulfuric acid (pH 2.5-5.5), the yeast must be highly fermentative, tolerant of elevated temperatures (<43 °C) and resistant to acids and alcohol. In addition to saccharification by malt which contains mainly P-amylase, high-activity microbial a-amylases are also used. Molasses does not require saccharification. The saccharified mash is cooled to 30 C and then inoculated with a yeast starter which has been cultured on a sulfuric or lactic acid medium of the mash or directly with distiller s yeast. After 48h of fermentation, the ethanol present at 6-10% by volume in the mash is distilled off along with the other volatile constituents. This step and the following rectification of the crude alcohol are achieved by continuous processes. 

In both cases one is dealing with condensed phases (in contrast, e.g., to the solubility of a gas in a solution), and therefore the volume difference is small. Therefore, the dependence of the solubility on pressure is usually very small. The reason for the application of an external pressure is therefore not to change the solubihty of the solute, instead it is to suppress the evaporation of the solvent, to increase its existence region as a hquid or to prevent the evaporation of volatile constituents from the melt This also holds true for hydrothermal crystal growth. The necessity of high pressure is only due to the high vapor pressure of the solvent at high temperatures, with the exceptions of diamond and GaN. 

Essential oils are known to have detrimental effects on plants. The inhibitory components have not been identified, but both alde-hydic (benzol-, citrol-, cinnamal-aldehyde) and phenolic (thymol, carvacol, apiol, safrol) constituents are suspected. Muller et al. (104) demonstrated that volatile toxic materials localized in the leaves of Salvia leucophylla, Salvia apiana, and Arthemisia californica inhibited the root growth of cucumber and oat seedlings. They speculated that in the field, toxic substances from the leaves of these plants might be deposited in dew droplets on adjacent annual plants. In a subsequent paper, Muller and Muller (105) reported that the leaves of S. leucophylla contained several volatile terpenes, and growth inhibition was attributed to camphor and cineole. 

In addition to thermal decomposition of the substrate, holding the system at elevated temperatures for long times can result in volatilization of desired constituents. As an example, Figure 5 shows the amount of phosphorus loss from In-P solutions in terms of a decrease in the liquidus temperature as a function of baking time at 670 °C (55). This level of evaporative loss is significant and must be accurately accounted for to control subsequent growth. In addition, the evaporating species can be transported downstream to other bins and alter the composition of these melts. 

Boselah, N.A.E. (1995) Effect of different levels of salinity on the growth, yield and volatile oil constituents of coriander (Coriandrum sativum L.) plants. Annals of Agricultural Science, Moshtohor 33(1), 345-358. 

But alt rapidly growing biomass, such as grass, cereals, leaves etc. contains more ashes and heteroatoms such as N, S, Cl, alkali and others, than wood. Ash constituents and volatile heteroatoms are needed in larger concentrations for a fast growth. Especially the ash-, K- and Cl-contents in herbaceous biomass can be higher up to one order of magnitude than in wood without bark. A typical con osition of wood and straw is compared in Table 2 [9, 10],... 

Owing to its high volatility, molinate must be immediately incorporated into the soil after its application. Plants rapidly absorb molinate through their roots, from where it is translocated to the leaves. In the leaves of rice it is rapidly metabolised to COj and naturally occurring plant constituents, while in weeds this metabolism is slower. In the soil it is degraded by the microbial pathway. Its mode of action is unknown. At low rates it inhibits the development and growth of leaves. It presumably inhibits protein synthesis, as do the other thiocarbamates. 

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