Particulate substrate

Many researchers have used particulate preparations to study the biosynthesis of ASG. In some cases the centrifugal force used was 20,000-25,000 g and in others 100,000 g. It should be noted that such membrane preparations contain endogenous sterol acceptors (of glucose from UDP-Glc) and acyl donors. It is conceivable that other fiactions may have enzymatic activity but no endogenous substrate. Particulate preparations catalyze the formation of SG and ASG and are not stimulated by further addition of substrate. 

The enhancement of adhesion provided by asymmetric organotitanates and zirconates in reinforced composites appears to be a consequence of the interaction of multiple mechanisms, including ligand-specific interfacial wetting enhancement, primary chemical bond formation between the substrate particulate and resin matrix, and, in many instances, matrix repolymerization and reinforcement surface modification. The particular mechanism which is dominant in a specific application appears to... 

Cell culture substrates Eardrum plugs Synthetic cartilages Hemodialysis membranes Breast or other soft-tissue substrates Particulate carriers of tumor antibodies Vitreous humor replacements ... 

In some cases, a single chemical substance can serve both as a dye and as a pigment. For example, indanthrone [81-77-6] (Pigment Blue 60) functions as a blue pigment or as a dye. As a pigment, indanthrone is a particulate, insoluble soHd dispersed directly into a vehicle, whereas as a dye it is reduced to a base-soluble hydtoquinone derivative and then reoxidized onto a soHd substrate. 

Humidification of the gas stream is the preferred method of keeping the filter bed moist. Gas moisture is usually added to the incoming gas stream downstream of the particulate removal APC equipment by either water sprays or steam. Adding moisture directly to the top of the bed in order to maintain filter media moisture is not recommended since this can result in (I) locahzed drying of the substrate, and (2) cold water addition will reduce the ac tivity of the microorganisms until the water becomes warmed to the steady-state filter ed temperature. 

Fig. 4.11. Characteristic intensity profiles for three different kinds of concentration (a) bulk type (b) particulate type and (c) thin-layer type. The critical angle d>c is determined by total reflection at the substrate ([4.21], after Ref [4.44]).

These reactors contain suspended solid particles. A discontinuous gas phase is sparged into the reactor. Coal liquefaction is an example where the solid is consumed by the reaction. The three phases are hydrogen, a hydrocarbon-solvent/ product mixture, and solid coal. Microbial cells immobilized on a particulate substrate are an example of a three-phase system where the slurried phase is catalytic. The liquid phase is water that contains the organic substrate. The gas phase supplies oxygen and removes carbon dioxide. The solid phase consists of microbial cells grown on the surface of a nonconsumable solid such as activated carbon. 

Methane monooxygenase may exist in either soluble (sMMO) or particulate (pMMO) forms. These display different substrate ranges and different rates of transformation rates, and most methanotrophs express only the latter form of the enzyme (Hanson and Hanson 1996). The particulate form of methane monooxygenase contains copper, or both copper... 

ASSOCIATION OF BACTERIA WITH PARTICULATE MATERIAL "FREE" AND "BOUND" SUBSTRATES... 

A study using resuspended river sediment (Marchesi et al. 1991) illustrated the important interdependence of substrate attachment to particulate matter and its biodegradability. Addition of sodium dodecyl sulfate that is degradable resulted in a relative increase in the number of particle-associated bacteria, whereas this was not observed with the nondegrad-able analogs such as sodium tetradecyl sulfate or sodium dodecane sulfonate. 

The particulate enzyme from which this solubilized form is derived contains cyt-b, and can utilize formate as reducing substrate. 

Pigments are coloured, black, white or fluorescent particulate organic or inorganic sohds, which are insoluble in, and essentially physically and chemically unaffected by, the vehicle or substrate in which they are incorporated. They alter appearance by selective absorption and/or scattering of light. 

---