In its simplest definition, bioprocessing is any manufacturing process that uses living organisms or biological molecules in one or more procedures (typically, this definition excludes humans, or, otherwise, any process that includes human workers would be defined as a bioprocess). A related, and sometimes overlapping, field is biorefining, where biomass is converted into a variety of bioproducts. Often, these conversion processes include one or more bioprocesses.

Biosynthesis, Biotransformation or Biodegradation

I tend to group all bioprocessing activities into one of three groups:

• Biosynthesis – Synthesis of organic molecules by anabolic or catabolic processes
• Biotransformation – Conversion of a compound into a different compound while retaining most of the starting compound’s carbon skeleton
• Biodegradation – Degradation of organic molecules to simpler, often inorganic, molecules

Examples of biosynthesis include amino acid, organic acid, ethanol and industrial enzyme fermentations as well as whole-cell microbial pesticides. These processes almost always require a source of biological energy. Biotransformations include the conversion of glucose to fructose by glucose isomerase that occurs in inactivated cells without a source of biological energy. Biodegradation is primarily used as a means of waste disposal and is used in septic tanks, wastewater treatment plants and compost piles (all of which also actively biosynthesis microorganisms at the same time) as well as more specialized waste treatment processes.

Bioprocess Development

When setting out to develop a new bioprocess, it is important to understand the difference between biosynthesis, biotransformation and biodegradation. Without this understanding, and a complete understanding of the pathway, expensive mistakes can be made during the development process. For example, during early development of the Energy BioSystems biodesulfurization process, the researchers and company management did not understand the biochemistry of the process or the critical design differences between biotransformation and biodegradation. They rushed to build a $1 million desulfurization pilot plant, only to learn that, in fact, the process required an energy input. But, once you start feeding glucose and other nutrients to a tank full of diesel fuel in a non-aseptic environment, you get much more biodegradation than biotransformation. During my time there, I worked to educate the company management on these differences and eventually, the company tried to move in a different direction before finally going out of business.

The following PowerPoint presentation is an introduction to bioprocessing I put together a few years ago when I was a mentor to one of the University of Illinois at Chicago Chemical Engineering Senior Design Project groups. It provides a number of examples of the different classes of bioprocesses drawn from my own experience.