Downstream biological process

B. Atkinson and P. Saimer, "Downstream Biological Process Engineering. The Chem. Engineer. 410 (November 1982). 

Alternative 1 consists of preliminary treatment for heavy metals removal with the primary concern being iron removal (Figure 8.3). The levels of iron observed in the groundwater at this site would be very detrimental to the downstream treatment processes. This pretreated water would then be used for cooling tower makeup water followed by biological treatment. This approach would be the easiest and cheapest alternative. This combined process should provide effective removal of BTEX. 

The complexity of biological processes generally requires many stages to produce a final, purified product from a particular composition of raw materials. Although a typical bioprocess consists of two main parts, upstream fermentation and downstream product recovery, it is not unusual to have between 10 and 20 steps in the overall process. This reflects the complex nature of a typical fermentation broth, which will consist of an aqueous mixture of cells, intracellular or extracellular products, unreacted substrates, and by-products of the fermentation process. From this mixture, the desired... 

Concentrations may vary downstream through further additions or losses of pollutants (through sedimentation and biological processes). 

Spurious HTS hits can drain medicinal chemistry resources and downstream biological efforts. Screening at high concentration can be counterproductive in lead discovery. Early elimination of these hits from the screening process, or removal from the screening library can increase discovery productivity. There are several approaches that can be used to recognize and overcome false positive hits due to aggregate formation. 

While inhibition of formation of biosynthetic precursors upstream of FPP is possible, the j>otential deleterious effects are great given the widespread use of FPP in other biological processes within cells. However, selective inhibition of FPTase should be feasible and has the added implied advantage of having more beneficial and fewer harmful downstream consequences. This rationale has been the major impetus for identifying specific inhibitors of FPTase and has been the focus of many pharmaceutical companies and academic institutions. 

The evolutionarily conserved Wnt/p-catenin signal transduction cascade controls many biological processes [5]. A key feature of the Wnt/p-catenin pathway Is the regulated proteolysis of the downstream effector P-catenin by the P-catenin destruction complex. The principal components of the P-catenin destruction complex are adenomatous polyposis coli (APC), Axin, and glycogen synthase kinase-3 beta (GSIOp). In the absence of Wnt pathway activation, cytosolic P-catenin is constitutively phosphorylated by GSIOp and targeted... 

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