Office for Technology Commercialization

Cost effective preparation of thermally stable, reusable enzymes

Technology #20180127

Questions about this technology? Ask a Technology Manager

Download Printable PDF

Image Gallery
Silica PDADMAC layer by layer depositionRight panels show a magnified view (scale bars 100 nm)
Alptekin Aksan, PhD
Professor, Mechanical Engineering
External Link (
Lawrence P. Wackett, PhD
Professor, Biochemistry, Molecular Biology, and Biophysics
External Link (
Managed By
Larry Micek
Technology Licensing Officer 612-624-9568
Patent Protection

PCT Patent Application Filed
Enhancement of biocatalyst activity and protection against stressors using a microbial exoskeleton
Scientific Reports, 9, Article number: 3158 (2019

Layer by layer process creates inorganic exoskeleton

A new process enhances non-native biocatalysis of a bacterial cell. Encapsulating bacteria in an inorganic shell prevents the membrane from being disrupted by forces such as heat or detergents. The layer by layer process creates an inorganic exoskeleton using silica and Poly(diallyldimethylammonium chloride) (PDADMAC). The shell permeabilizes the cell membrane while keeping it intact, protecting intracellular enzymes and proteins from freezing, protozoan predation, high temperature, osmotic shock and desiccation. Increased membrane permeability greatly enhances reaction rates—reaching values close to that of free enzymes—while protecting the enzyme against osmotic and thermal stresses.

Temperature and predator resistant, enhanced permeability and reaction rate

Bacterial biocatalysis is generally more expensive relative to conventional processes which use purified enzymes, and reaction rates are relatively slow due to very low membrane permeability. However, current processes to isolate enzymes are expensive and require significant investment in equipment. Purified enzymes are also more difficult to retain within a bioreactor and are likely to be used only once. While biological components can be used to catalyze desired reactions, they lack stability when subjected to various environmental conditions. This new technology provides a layer by layer technique to form a shell around the bacteria. The encapsulation allows repeated use of the biocatalyst (enzymes), is both temperature and predator resistant and enhances permeability. The reaction rate of the encapsulated bacterial biocatalyst is 2x higher than free cell/organism alone. Enhancing the biocatalysts’ effectiveness increases throughput per dollar, expands shelf life and potential applications.

Phase of Development

  • Proof of concept. Enzymatic activity confirmed.


  • Longer shelf life
  • Protection from detergents
  • Protozoa deterrent
  • Increased temperature stability
  • Increased membrane permeability
  • Increased cell rigidity


  • Encapsulates bacteria in an inorganic shell
  • Reaction rate is 2x higher than free cell
  • Protects intracellular enzymes and proteins from freezing, protozoan predation, high temperature, osmotic shock, desiccation, etc.


  • Diagnostic and testing kits
  • Biocatalysis
  • Pharmaceutical manufacturing
  • Biofuel production
  • Bioremediation processes

Interested in Licensing?
The University relies on industry partners to further develop and ultimately commercialize this technology. The license is for the sale, manufacture or use of products claimed by the patents. Please contact Larry Micek to share your business needs and licensing and technical interests in this technology.