Rationally engineered synthetic coculture for improved biomass and product formation

PLoS One. 2014 Dec 3;9(12):e113786. doi: 10.1371/journal.pone.0113786. eCollection 2014.

Abstract

In microbial ecosystems, bacteria are dependent on dynamic interspecific interactions related to carbon and energy flow. Substrates and end-metabolites are rapidly converted to other compounds, which protects the community from high concentrations of inhibitory molecules. In biotechnological applications, pure cultures are preferred because of the more straight-forward metabolic engineering and bioprocess control. However, the accumulation of unwanted side products can limit the cell growth and process efficiency. In this study, a rationally engineered coculture with a carbon channeling system was constructed using two well-characterized model strains Escherichia coli K12 and Acinetobacter baylyi ADP1. The directed carbon flow resulted in efficient acetate removal, and the coculture showed symbiotic nature in terms of substrate utilization and growth. Recombinant protein production was used as a proof-of-principle example to demonstrate the coculture utility and the effects on product formation. As a result, the biomass and recombinant protein titers of E. coli were enhanced in both minimal and rich medium simple batch cocultures. Finally, harnessing both the strains to the production resulted in enhanced recombinant protein titers. The study demonstrates the potential of rationally engineered cocultures for synthetic biology applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / metabolism
  • Acinetobacter / genetics
  • Acinetobacter / growth & development
  • Acinetobacter / metabolism*
  • Biomass*
  • Carbon / metabolism*
  • Coculture Techniques / methods
  • Escherichia coli K12 / genetics
  • Escherichia coli K12 / growth & development
  • Escherichia coli K12 / metabolism*
  • Glucose / metabolism
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Hydrogen-Ion Concentration
  • Luminescent Measurements
  • Metabolic Engineering / methods
  • Models, Biological
  • Recombinant Proteins / metabolism
  • Reproducibility of Results
  • Time Factors

Substances

  • Acetates
  • Recombinant Proteins
  • Green Fluorescent Proteins
  • Carbon
  • Glucose

Grants and funding

The project was funded by Academy of Finland (project ProChassis 272602, URL: http://www.aka.fi/fi/A/), and by Suomen Kulttuurirahasto (URL: http://www.skr.fi/) to MK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.