WARF: P100362US02

Bacteria Modified to Secrete Biologically Active Protein for Large-Scale Production


Sydnor Withers III, Miguel Dominguez, Matthew DeLisa, Charles Haitjema

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing bacteria modified to secrete biologically active, recombinant protein needed for bioenergy production, therapeutic biologics, research tools and other applications.
OVERVIEWE. coli is the most common prokaryote used to produce protein.  The expressed protein generally accumulates in the cytoplasm.  While this approach is useful for some proteins, not all proteins can be accumulated in the cytoplasm in an active state.  When the desired protein is produced at high levels, it may be toxic to the host cell or accumulate as an insoluble particle known as an inclusion body, making it difficult to recover in an active form.

One option is to engineer protein so it is secreted from the cell, but E. coli and other Gram-negative bacteria generally are considered poor hosts for secreted protein production.  No well-understood secretory pathways in E. coli to transport heterologous proteins to the extracellular environment currently exist.  The recent discovery of YebF-mediated secretion is the first report of a native E. coli system capable of secreting both the native protein YebF and translational fusions to YebF.  However, the expression level of YebF fusion proteins typically is low.
THE INVENTIONUW–Madison researchers have discovered E. coli mutations that substantially increase the amount of biologically active, recombinant protein secreted from cells.  The mutations disrupt genes in a YebF-mediated protein secretion pathway.  Bacteria modified to contain these mutations are useful for the production of secreted proteins.  They can be used to produce proteins that might otherwise not be expressed due to toxicity or folding errors.  They also can be used to produce secreted complexes of enzymes such as cellulases and xylanases for the manufacture of cellulosic biofuels.
  • Manufacturing proteins for bioenergy production, therapeutic biologics and research tools
  • Rapid, high throughput production of proteins on a commercial scale
  • Enables the production of proteins that might not otherwise be expressed due to toxicity or folding errors
  • Substantially increases the amount of biologically active, heterologous protein that can be secreted from E. coli and other bacteria
  • Suitable for Shigella, Yersinia, Salmonella and Escherichia sp. bacteria
  • May be readily employed in automated systems
  • Mutations do not affect bacterial growth.
  • Because proteins are exported, the levels of contamination, endotoxin, host cell proteins and nucleic acids are significantly lower, making purification easier and thus lowering production cost and time.
Contact Information
For current licensing status, please contact Jennifer Gottwald at or 608-960-9854.
The WARF Advantage

Since its founding in 1925 as the patenting and licensing organization for the University of Wisconsin-Madison, WARF has been working with business and industry to transform university research into products that benefit society. WARF intellectual property managers and licensing staff members are leaders in the field of university-based technology transfer. They are familiar with the intricacies of patenting, have worked with researchers in relevant disciplines, understand industries and markets, and have negotiated innovative licensing strategies to meet the individual needs of business clients.