Easy Scale-Up

Scale-up factors as high as 500 have been claimed without any problem (Greenwood 1986 Dierendonck et al. 1988 and Table 2.1). The criterion that has been suggested is constancy of power input per unit volume (valid if the gas and the liquid are fully back mixed) or circulation number defined as QJV =n (/h) between 60 and 120 (/h) Dierendonck et al. 1988). 

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Yeast. The advantages of expression in yeast include potentially high level production of proteins, the abiUty to have expressed proteins secreted into the media for ease of purification, and relatively low cost, easy scale-up. A disadvantage is that plasmid instabiUty may be a problem which can lead to low product yield. Whereas post-translational modification occurs in yeast, proteins are quite often hyperglycosylated. This is generally a problem with expression in Saccharomyces cerevisiae but not for the more recently used yeast host Pichiapastoris (25) (see Yeasts). 

As far as industrial applications are concerned, the easy scale-up of two-phase catalysis can be illustrated by the first oxo aqeous biphasic commercial unit with an initial annual capacity of 100,000 tons extrapolated by a factor of 1 24,000 (batch-wise laboratory development production reactor) after a development period of 2 years [4]. 

Note that although the production of carbon nanotubes does not lend itself to an easy scale-up, the tunability of the carbon nanotube radii and the perfection of its structure could be important for their use as a template for the growth of inorganic nanotubes with a controlled radius. This property can be rather important for the selective catalysis of certain reactions, where either the reaction precursor or the product must diffuse through the (inorganic) nanotube inner core. 

Halobacterium salinarum Rapid expression Colorimetric expression Easy scale-up Cloning and transformation complicated Requires fusion protein strategy Lack of post-translational modifications... 

Saccharomyces cerevisiae Good secretion machinery Post-translational modifications Easy scale-up Selection procedure required Tendency to overglycosylation Thick cell wall complicates purification... 

This study presents catalytic properties of Pd and Pt for hydrogen adsorption. Metals were deposited by easy to perform procedure on powder materials. This method does not required use of hydrogen as reactant gas and can be easy scale-up. Presence of metal particles was verified by SEM experiment. Average size of noble metals was approximately 1pm. From experiment conditions amount of catalyst was found and it was revealed that mass of metal (Pt or Pd) do not exceed l %wt. 

The nickel hydroxide electrode has proved to be a versatile, inexpensive and facile applicable reagent, that allows an easy scale-up of the oxidation. It furthermore... 

The distinguishing feature of membrane emulsification technique is that droplet size is controlled primarily by the choice of the membrane, its microchannel structure and few process parameters, which can be used to tune droplets and emulsion properties. Comparing to the conventional emulsification processes, the membrane emulsification permits a better control of droplet-size distribution to be obtained, low energy, and materials consumption, modular and easy scale-up. Nevertheless, productivity (m3/day) is much lower, and therefore the challenge in the future is the development of new membranes and modules to keep the known advantages and maximize productivity. 

Main drivers for membrane emulsification development include high product quality - especially when labile molecules are involved, precise definition of droplet-size distribution, low energy input, equipment modularity and easy scale-up, and low equipment footprint. 

Tangential filtration of animal cell suspensions presents several advantages, such as easy scale-up, simple operation, and a permeate totally free... 

The design and operation of a bioreactor are mainly determined by biological needs and engineering requirements, which often include a number of factors efficient oxygen transfer and mixing, low shear and hydrodynamic forces, effective control of physico-chemical environment, easy scale-up, and so on. Because some of these factors can be mutually contradictory, it is difficult to directly employ a conventional microbial reactor to shear-sensitive plant tissue cultures. 

In this process, porous particles are easily formed. The porosity is controlled by changing the precursor concentration in the droplets or by adjusting temperature profile in the furnace. Hollow particles can also be prepared when the solute concentration gradient is created during evaporation of solvent. Easy scaling up is a major advantage of this method, too. 

The protected dipeptide Z-His-Phe-NH2 is a precursor for cyclo[-His-Phe-], which is known as a catalyst for addition of cyanide to aldehydes, with high enantiomeric excess.f l Such optically active cyanohydrins are valuable starting materials for the synthesis of a variety of chiral, bioactive compounds.The easy scale-up (to mole scale) of the suspension-to-sus-pension conversion approach has been demonstrated by the thermolysin-catalyzed synthesis of Z-His-Phe-NH2.[ ]... 

The partition coefficient of proteins can be increased selectively by chemically attaching affinity ligands to the hydroxyl groups of the PEG. The protein can then be back-extracted from this phase by adding a fresh salt phase under conditions where the protein prefers the salt phase or by immobilizing the ligand complex in Sepharose beads, which separate into the top phase. ° Liquid-liquid extraction is commonly used in the industry because of its low cost and easy scale-up potential, but it is rarely used for protein separation even though some proteins can be effectively partitioned in ATPS. 

The last examples demonstrated that the solid-to-solid photoinduced decarbonylation of crystalline ketones can have an important role in natural product synthesis and in green chemistry due to the high yield, the fewer steps involved and the easy scale-up of such reactions. 

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