As engineers, however, we also want to see an emphasis on sound process design, process economics, and environmental impact assessment. Thayer School provides an ideal interdisciplinary environment for tackling these complex questions. One of Gerngross's approaches is to look at the sequence of reactions that a microbial cell uses to break down nutrients and synthesize products of commercial interest. The emerging field of metabolic engineering focuses on understanding and genetically manipulating this network of reactions. Metabolic engineering, however, requires not only a genetic and biochemical understanding of the cell, but also an appreciation of the dynamic environment in which the cell operates.
Fermentation remains the key to successful implementation of metabolic engineering strategies.
This class of biological polymers has similar properties to petroleum-derived plastics but offers substantial environmental advantages. We are interested in tailoring the properties of PHAs for specific applications. Some PHAs will be useful for biodegradable packaging and films, while others will be suitable for resorbable medical devices. The key enzyme of PHA biosynthesis is the PHA synthase, which incorporates activated monomer units into a growing polymer chain. We now know that PHA synthases from different microbes make polymers with different properties.