Industrial enzymes downstream processing

Downstream Processing Microfiltration plays a significant role in downstream processing of fermentation products in the pharmaceutical and bioprocessing industry. Examples are clarification of fermentation broths, sterile filtration, cell recycle in continuous fermentation, harvesting mammahan cells, cell washing, mycelia recovery, lysate recovery, enzyme purification, vaccines, and so forth. 

In the development of cell or enzyme-based processes, many process configurations exist, including batch, fed batch and continuous operation. In general, the conversion and the separation processes (downstream processing) are regarded as separate units, and most industrial processes are based on this approach. In the last decades, however, more attention is paid to the integration of conversion and separation, leading to the development of membrane bioreactors [49, 50], and some of these concepts have reached an industrial scale. The membranes used for this type of reactors are almost exclusively polymeric, as temperatures seldomly exceed 100 °C for obvious reasons. 

Frequently however, enzymes found in the fermentation broth at the time of harvesting are quite different from the state in which they can be used as industrial biocatalysts, reagents in clinical chemistry or as therapeutic agents, The recovery of an enzyme from microbial culture, its concentration and purification will require careful and effective sequential operations, which ate called downstream processing (Wheelwright, 1989). 

Lessons from these results are that carbohydrate processing enzymes can be optimized by site-directed and random mutagenesis in a more rational way for the production of tailored oligo- and polysaccharides under various aspects, also including up- and downstream processing for industrial purposes. 

The final formulation of liquid detergent enzymes includes addition of stabilizers, antimicrobial substances, and glycols. This is followed by a final polish filtration to provide a clear liquid. If the enzyme broth is slated for dry product, the concentrate can either be stored for later use or applied directly for granulates. As with fermentation and downstream processing, formulations are often kept as closely guarded trade secrets in the biotechnology industry, and few publications on new approaches or new technologies are available in the literature. 

In the downstream processing or recovery step, fermentation biomass is separated from the enzyme. Since most industrial enzymes are extracellular enzymes,... 

For industrial biotransformations, catalyst recovery and reuse are major issues. This may be desirable either for reasons of downstream processing or for repeated use in order to reduce the specific catalyst costs per kg of product produced. A very simple method is the use of membrane filtration. Because of the increasing number of membranes from different materials (polymers, metal or ceramics) this is an attractive alternative. Whereas for whole cells microfiltration or centrifugation can be applied, for the recovery of soluble enzymes ultrafiltration membranes have to be used120-221. Often immobilization on a support is chosen to increase the catalyst s stability as well as to facilitate its recovery. The main advantages of immobilization are ... 

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