Bioprocesses chromatography separation

Fermentation broths are complex, aqueous mixtures of cells, comprising soluble extracellular, intracellular products and any unconverted substrate or unconvertible components. Recovery and extraction of product is important in bioprocess engineering. In particular separation is a useful technique it depends on product, its solubility, size of the process, and product value. Purification of high-value pharmaceutical products using chromatography such as hormones, antibody and enzymes is expensive and difficult to scale up.1 Tire necessary steps to follow a specific process depend on the nature of the product and the characteristics of the fermentation broth. There are a few steps for product recovery the following processes are discussed, which are considered as an alternative for product recovery from fermentation broth. 

When planning an industrial-scale bioprocess, the main requirement is to scale up each of the process steps. As the principles of the unit operations used in these downstream processes have been outlined in previous chapters, at this point we discuss only examples of practical applications and scaling-up methods of two unit operations that are frequently used in downstream processes (i) cell separation by filtration and microfiltration and (ii) chromatography for fine purification of the target products. 

In any case, both biosensors and biosensing devices have been coupled to microdialysis and are considered among the non-separation-based methods [83]. The drawback of biosensing approaches is that they are usually able to measure just one analyte at a time, in contrast with separation-based methods such as chromatography and electrophoresis, which allow the detection of several analytes. However, if the primary interest is not the identification of unknown compounds, but, for example, the monitoring of variations in a single metabolite or drug, the optimization of therapeutic responses, or the control of a bioprocess via a marker analyte, the use of a specific sensor, which can be employed in a continuous manner, can provide useful information, and can also help to avoid the analysis of hundreds of samples or to reduce the number of animals necessary for a study. 

HPLC-UV diode-array detection (DAD) or HPLC-MS techniques take advantage of chromatography as a separation method and DAD or MS as identification and/or quantification methods. Both DAD and MS can rapidly provide on-line UV and MS information for each individual peak in a chromatogram. In most cases, the identification of the peaks can be made directly on-line by comparison with literature data or with standard compounds. However, when no standard compounds are available, the rapid preliminary identification process becomes significantly more complex. The general identification problem in bioprocess monitoring described below exists in all cases when a new biotechnological process is initiated and when the product is not available as a reference substance. 

We have developed a proprietary acoustic wave device which permits the detection of a specific analyte in a flowing system. By coupling specific chemistry (Protein A) to the surface of the device, the mass loading of the device by the target analyte (Human IgG) was detected as a shift in phase which was measured in real time. Using conditions which mimic a bioprocess separation for IgG, we were able to separate and detect Human IgG at 1 mg/ml and 100 ug/ml in the absence and presence of 10% Fetal Bovine Serum. Such a detector has the potential to increase productivity in process chromatography in biopharmaceutical applications. 

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