Washed bottom fraction particles

Furthermore, the rubber biosynthesis has also been proposed to occur with no requirement of the rubber particles prerequisite site but take place at the washed bottom fraction membrane (WBM), which was prepared from washed bottom fraction particles. This was supported by the higher rubber biosynthesis activity of WBM, compared to the rubber particles. It was interesting that the proteins precipitated at 20% acetone from WBM still had high rubber biosynthesis activity. Nonetheless, the molecular weight of the obtained rubber was not reported. 

Enzymatically active, partially purified (washed) rubber particles can be isolated such that, when provided with an appropriate APP primer, magnesium ion cofactor, and IPP monomer, rubber is produced in vitro [253-255]. Fresh latex can be separated by centrifugation into three phases. The bottom fraction (20% of the latex) contains membrane-bound organelles. The middle fraction is called the C-serum. The top fraction phase contains the rubber particles. Biochemical smdies have established that latex in this fractionated form is unstable. These smdies also suggest that the bottom fraction is required for initiation of polymer synthesis. 

Chromatography operates on the same principle as extraction, but one phase is held in place while the other moves past it.4-5 Figure 23-5 shows a solution containing solutes A and B placed on top of a column packed with solid particles and filled with solvent. When the outlet is opened, solutes A and B flow down into the column. Fresh solvent is then applied to the top of the column and the mixture is washed down the column by continuous solvent flow. If solute A is more strongly adsorbed than solute B on the solid particles, then solute A spends a smaller fraction of the time Dee in solution. Solute A moves down the column more slowly than solute B and emerges at the bottom after solute B. We have just separated a mixture into its components by chromatography. 

In the 300-gallon-per-day plant the mean ice particle sizes have been calculated from measurements of ice bed permeability and porosity made on the ice harvested at the top of the column. From these results the important design parameters can be calculated, such as particle diameters, linear ice velocities, residence time of ice in the column, frictional losses in the wash water flowing down the column and in brine flowing toward the screens in the bottom of the coltam, and the fraction of voids occupied by air above the liquid level in the column. Typical ranges for some of these measured or calculated quantities are shown in Table III from measurements in the 12-inch diameter column. 

The line-start technique has also been used to fractionate UO3 particles by measuring the radioactivity at the bottom of a tube, the settled powder being washed out at regular intervals without disturbing the sediment [85]. 

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