PROFESSOR GROSS’ RESEARCH
Scheme 1: General overview of group research
Enzyme technology offers environmental benefits
Industrial competitiveness increasingly depends on our ability to adapt and incorporate new technological advances. Furthermore, technological advances to reduce cost will often require reduction in toxic chemical by-products and metals as well as decreased energy consumption. Increased reaction efficiencies based on advances in catalysis will continue to be critical to industry. There is a need to pave new pathways that do more than provide incremental improvements in existing conditions. This was well stated in a quote by Professor Barry Trost “The issues cannot simply be addressed by minor tinkering with current processes to improve their performance although, undoubtedly, that is one of many of the strategies that will be helpful. Fundamental new science derived from basic research that creates new paradigms for synthesis is also required as well as everything in between” (Green Chemistry, 1998). Our laboratory has been exploring enzyme-based routes to monomers, prepolymers, polymer synthesis and modification. Guiding principles of this work are as follows. By using an expanding arsenal of enzymes to synthesize and modify polymers, important environmental, economic and product performance benefits will result. This will be a direct outcome of milder reaction conditions, increased reaction efficiencies, processes that require less discrete steps, the avoidance of heavy metals, and the ability to develop well defined highly functionalized polymeric materials.
Our laboratory has traditionally selected synthetic challenges that are academically challenging while being of practical importance. Therefore, successes that have occurred due to research conducted by our group have resulted in the formation of a new company, SyntheZyme LLC, founded to commercialize Prof. Gross’s research innovations. Gross’s work continues to explore fundamental questions that will help build a strong base for the further development of enzyme-catalysis as an alternative synthetic pathway to build and modify polymers by green chemistry. His work established new methods that can be generally applied to a broad based segment of chemical manufacturers. New polyol-polyesters prepared by lipase-catalysis may be used as reactive components in polyurethane foams and coatings. They also are under-evaluation for incorporation into cosmetic products. Polyesters prepared by lipase-catalysis from newly developed w-hydroxyl-fattyacid monomers produce strong-tough plastics that offer properties that mimic polyethylene. Polyesters prepared with carbohydrate terminal groups represent a new family of functional macromers. The discovery that lipases catalyze transesterification reactions can be applied to a wide array of hydroxyl or carboxyl terminated chains (e.g. polybutadiene, silicones) to create new and previously unavailable families of multiblock copolymers. Furthermore, polyol-polyesters from glycerol or sorbitol are currently under-study as bioresorbable and biocompatible implant materials.
This program has also found new ways to improve the usage of natural agro-based resources such as polyols (e.g. glycerol, sorbitol) and functional lipids (e.g. to produce ω- hydroxyl- and carboxyl-fattyacids). Furthermore, the methods developed offer new opportunities for usage of these and other renewable feedstocks.
References: Literature Reviews
- Dodds, D. R.; Gross, R. A., Chemicals from biomass. Science, 318 (5854), 1250-1251 (2007). (PDF)
- Gross, R. A., Kalra, B; “Biodegradable Polymers for the Environment”, Science, 297, 803-806 (2002). (PDF)
- R. A. Gross, A Kumar, B Kalra, "In-vitro Enzyme Catalyzed Polymer Synthesis", Chemical Reviews, 101(7), 2097-2124 (2001). (2004a).(PDF)
- R.A.Gross, B.Kalra, A. Kumar "In-vitro Lipase Catalyzed Polyester and Polycarbonate Synthesis" Applied Microbiology and Biotechnology; 55(6), 655-660 (2001).(PDF)
- Methods for conversion of fatty acids to w-hydroxy acids, ω-carboxyacids, oligomers and polymers.
- Biobased Polyol-Polyesters via Enzyme-Catalysis.
- Lipase-catalyzed transesterification reactions between polymers of high molecular weight.
- Use of carbohydrates as initiators for lactone ring-opening polymerization.
- Polyethylene-like polyesters from w-hyroxyfatty acids.
- Synthesis of Poly(carbonate-polyesters).
- Development of biocatalytic routes to silicone-sugar conjugates, silicone polyesters and silicone polyamides.
- Sophorolipids, a microbial glycolipid.
- Elucidation of cutinase structure-activity relationships.
- Cutinase-catalyzed polymer synthesis
- Protease-catalyzed routes to oligopeptides.
- Influences of surface interactions and macro-porous matrix physical characteristics on the activity and thermal stability of Candida antarctica Lipase B.
- Enzyme-catalyzed Lactone Ring-Opening: A New Tool for Polymer Chemists.
- Functional Polylactides for Biomedical Applications.
- In-Vivo Formation of Natural-Synthetic Diblock Copolymers.
- Microbial Synthesis of γ-poly(glutamic acid).
- Engineering the structure of emulsans via whole cell biotransformations.
- Exploring the Promiscuity of Polysaccharide Synthase Biosynthetic Pathways to Incorporate Unusual Sugars.
- Free-radical polymerizations mediated by peroxidases.
- Synthetic analogs: Syndiotactic Poly(3-hydroxybutyrate).
- Effect of substituent site on Polysaccharide Enzymatic Degradation.
- Developing Methods to Test the Biodegradability of Polymers.
- Effect of Polymer Stereochemistry and Crystallinity on it’s Enzymatic Degradability.
- Exploring the flexibility of bacterial polyester synthetic pathways.
- Intellectual Property.
- Controlling Lifetime of Biomaterials by Embedding Enzymes.