Biochemical engineering

Biochemical engineering
Name	Biochemical Engineering
Caption	A modern stirred-tank bioreactor used for cell culture.
Activity sector	Biotechnology, Pharmaceutical industry, Environmental engineering
Formation	Mid-20th century
Related occupations	Chemical engineer, Microbiologist, Process engineer

Biochemical engineering. It is a branch of chemical engineering that applies engineering principles to the design, construction, and operation of processes involving biological agents or molecules. The field focuses on translating discoveries from molecular biology and biochemistry into large-scale manufacturing processes for products like pharmaceuticals, vaccines, and biofuels. Biochemical engineers work at the intersection of life sciences and process engineering, ensuring biological systems function efficiently and reproducibly in industrial settings.

Overview

The discipline emerged prominently in the 1940s with the development of large-scale penicillin production during World War II, which required novel fermentation techniques. It grew alongside advancements in genetic engineering in the 1970s, enabling the production of recombinant proteins like human insulin. Today, it is integral to the biotechnology industry, supporting the manufacture of monoclonal antibodies, gene therapies, and industrial enzymes. Key professional organizations include the American Institute of Chemical Engineers and the Society for Biological Engineering.

Core principles and concepts

Fundamental principles include stoichiometry and thermodynamics as applied to biological systems, often described by Monod kinetics for microbial growth. Mass transfer is critical, particularly oxygen transfer rate in aerobic fermentations, and is governed by concepts like the volumetric mass transfer coefficient. Reaction kinetics for enzyme catalysis are modeled using Michaelis–Menten kinetics. Process control relies on monitoring parameters like pH, dissolved oxygen, and temperature to maintain optimal conditions for cell viability and product formation.

Applications

In the pharmaceutical industry, it is essential for producing therapeutic proteins in mammalian cell culture systems, such as those used by Genentech and Amgen. Environmental engineering applications include wastewater treatment using activated sludge and anaerobic digestion for biogas production. The food and beverage industry utilizes it for producing citric acid via Aspergillus niger fermentation and brewery operations. Emerging areas include tissue engineering for organ fabrication and synthetic biology for designing novel metabolic pathways in organisms like Escherichia coli.

Bioreactor design and operation

Bioreactor design is central, with common types including stirred-tank reactors, airlift reactors, and packed-bed reactors. Design considerations involve achieving homogeneous mixing while minimizing shear stress on sensitive animal cells. Sterilization methods, such as autoclaving and sterile filtration, are paramount to prevent microbial contamination. Operation modes range from batch culture to continuous chemostat systems, each with implications for productivity and process control. Scale-up from laboratory to pilot plant to manufacturing facility follows principles of dimensional analysis and similarity theory.

Downstream processing

This involves isolating and purifying the target product from the fermentation broth or cell lysate. Initial steps include centrifugation and filtration for cell separation. Protein purification often employs chromatography techniques such as ion-exchange chromatography, affinity chromatography, and size-exclusion chromatography. Final product formulation may involve lyophilization or ultrafiltration for concentration. The integration of upstream and downstream processes is a key challenge, addressed through concepts like process intensification and continuous bioprocessing.

Education and training

Academic programs are typically offered within chemical engineering departments at institutions like the Massachusetts Institute of Technology and University of California, Berkeley. Core coursework combines transport phenomena, kinetics, and thermodynamics with cell biology and biochemistry. Practical training often occurs through collaborations with research centers such as the National Institute for Bioprocessing Research and Training. Professional accreditation is provided by bodies like ABET, and career paths lead to roles in process development, quality assurance, and regulatory affairs within organizations like the Food and Drug Administration.

Category:Chemical engineering Category:Biotechnology Category:Engineering disciplines