Co-culture solar production of high-value products utilizing encapsulated, carbohydrate-secreting cyanobacteria

 

Executive Summary

 

Biobased plastics and chemicals offer an alternative solution to products traditionally made from fossil fuel sources. Fermentation generally uses heterotrophic organisms to convert carbohydrate-rich feedstocks like sugarcane, sugar beets, and corn into value-added compounds (e.g nutritional supplements, pharmaceuticals, etc.). Because these feedstocks often require premium land, water, and costly transportation, industry has looked for alternatives to food crop derived sugars. Cyanobacterial autotrophic fermentation systems are regarded as the most efficient platform and most promising route, but are hindered by separation and cell density issues that limit cost-effectiveness. Additionally, these synthetic microbial consortia are frequently fragile, functioning for only short time frames. MSU researchers have developed a technology to mitigate many of the costs and limitations with a “one-pot” co-culture system utilizing encapsulated cyanobacteria and a second ferementation organism.  The fermentative organism converts sucrose made by the encapsulated cyanobacteria into higher-value compounds.  The encapsulated cyanobacteria are active over a period of months, and are reusable after each harvest.

 

Description of Technology

 

This MSU technology is a flexible autotroph/heterotroph consortia platform for the creation of valuable biological products from solar energy. The synthetic co-culture utilizes a modular design in which cyanobacteria are contained in hydrogel beads. The cyanobacteria fix atmospheric or added CO2 and secret sucrose. The engineered strain of cyanobacteria exports up to 85% of the sucrose it makes, and its sucrose production rate exceeds that of sugarcane. The second organism is a heterotroph (e.g. E. coli, B. subtilis, or S. cervisiae) that uses the sucrose to form an end-product of choice, such as polyhydroxybuturate (PHB) or an industrial enzyme. Sucrose production by the cyanobacteria eliminates the need for any external carbohydrate feedstocks, and the novel hydrogel-bead technology allows easy separation and re-use of the cyanobacteria after each harvest, greatly reducing costs. The media and growth conditions have also been optimized to allow the co-cultures to persist over an extended time.

 

Key Benefits

  • Flexible modular platform allows a variety of end-products tailored to specific need
  • Co-cultures stable over time (up to months)
  • No external carbohydrate feedstock necessary
  • Consistent and continuous production (4x more productive, 20x faster than cyanobacteria alone)
  • Novel hydrogel bead technology allows for easy end-product extraction and re-use of cyanobacteria
  • Inexpensive to maintain

 

Applications

  • Synthetic cross-feeding consortia for solar production of:
  • Biochemicals, metabolites, and industrial enzymes
  • Pigments, vitamins, etc.
  • Advanced fuels

 

Patent Status:

 

Provisional application filed

 

Licensing Rights Available:

 

Full licensing rights available

 

Inventors: Daniel Ducat, Taylor Weiss, Eric Young

 

Tech ID: TEC2018-0024

 

Patent Information:

For Information, Contact:

Thomas Herlache
Assistant Director
Michigan State University
herlache@msu.edu
Keywords: