Downstream Processes — Winter 2025

Define bioproducts and provide examples of small biomolecules and macromolecules.

Explain the importance of classifying bioproducts and provide examples of particulate and macromolecular bioproducts.

Describe how you would design a bioseparation process for isolating proteins from a microbial culture. Outline the stages involved and the techniques you would use at each stage to ensure maximum purity and yield.

List two techniques for measuring cell disruption.

Describe the structural differences between the cell walls of bacteria, yeast, and other fungi.

Discuss how you would address membrane fouling in an industrial-scale filtration system. Include preventive measures, troubleshooting strategies, and any design considerations to ensure system longevity and efficiency.

You are tasked with separating a highly charged biomolecule from a mixture using ion-exchange chromatography. Outline the steps involved in selecting the appropriate matrix, preparing the sample, and optimizing the elution process.

Differentiate between mechanical and non-mechanical cell disruption techniques.

Explain the role of high-pressure homogenizers and high-speed ball mills in large- scale cell disruption

Design a liquid-liquid extraction process to isolate a specific bioactive compound from a plant extract. Include your considerations for solvent selection, extraction equipment, and process optimization to maximize yield and purity.

Describe the role of filter media in filtration processes.

Describe the factors that influence membrane fouling and how it affects filtration system efficiency.

Design a molecular sieve chromatography setup to separate nucleic acids of different sizes. Describe the choice of materials, equipment, and operational settings necessary to achieve effective separation.

List the main components involved in affinity chromatography.

Differentiate between production centrifuges and ultracentrifugation in bioproduct separation processes.

Suppose you need to crystallize a protein for pharmaceutical applications. Describe the process design considerations, including crystallizer type, crystallization conditions, and strategies for optimizing crystal size and purity.1

What factors are considered in the solvent selection for liquid-liquid extraction?

Explain the concept of ion-exchange chromatography and its significance in the separation of charged biomolecules.

Imagine you are tasked with precipitating a protein from a solution using salt precipitation. Describe the procedure, choice of salt, factors affecting precipitation efficiency, and any post-precipitation steps to enhance protein purity.

Briefly explain the principle of hydrophobic chromatography.

Describe the theory and instrumentation involved in High Performance Liquid Chromatography (HPLC).

Develop a plan to use ultracentrifugation to separate subcellular components in a bacterial cell lysate. Explain rotor selection, centrifugation settings, and how to handle the fractionation process for accurate component isolation.

What is the purpose of a batch crystallizer?

Describe the design considerations involved in creating efficient filtration and drying systems for bioproduct processing.

For the recovery of microbial cells in a fermentation broth, design a flocculation and sedimentation process. Describe the selection of flocculants, operating parameters, and design considerations for efficient cell recovery.