Fundamental Bioengineering

12Product Recovery from the Cultures

Sunil Nath

Summary

The vast field of bioproduct recovery is surveyed. The various unit operations and techniques available in the field are classified based on the underlying mechanism of separation. A large number of approaches for recovery of cell products are described for specific processes and products. The products include cells (baker's yeast), polysaccharides (xanthan gum), antibiotics (penicillin), and proteins (interferon and insulin). A detailed case study of the purification operations for the recovery of α-A interferon is presented along with information on the yields and purification factors attained after each step that help in understanding the complexities involved in the design of these processes. Taken together, the approaches and case study illustrate the principles that may be considered as the common elements of various bioproduct recovery processes.

12.0 Introduction

The goal of product recovery operations in downstream processing is to recover and purify the product to the desired specification levels while maximizing yield and minimizing costs. The nature of cell culture media has major implications for all downstream operations. While the use of crude fermentation materials may reduce upstream processing costs, they tend to raise substantially the costs of downstream processing and make it more complex. When the products are cells or are intracellular in nature, the presence of insoluble media materials will increase ...