Characterising complex metabolic responses in an engineered, cross-feeding microbial co-culture using quantitative...

Area of Science:

• Synthetic biology
• Microbial ecology
• Biotechnology

Background:

• Microbial communities are vital for biogeochemical cycles and bioproduction.
• Designing stable synthetic microbial consortia requires understanding inter-strain interactions, especially for engineered cross-feeding strains.

Purpose of the Study:

• To characterize the metabolic adaptations of a synthetic co-culture of Synechococcus elongatus and Azotobacter vinelandii.
• To investigate the stability and controllability of engineered microbial consortia for bioproduction.

Main Methods:

• A synthetic microbial co-culture was established using engineered Synechococcus elongatus PCC 7942 and Azotobacter vinelandii AV3.
• Label-free quantitative proteomics was employed to analyze metabolic changes in both strains during co-culture.
• Phenotypic changes and proteomic profiles were monitored over 16 days.

Main Results:

• Co-culturing induced significant shifts in carbon and nitrogen metabolism for both S. elongatus and A. vinelandii.
• Azotobacter vinelandii exhibited signs of stress, upregulating proteins related to polymer biosynthesis and potentially undergoing cell envelope remodelling or encystment.
• Contrasting growth dynamics were observed compared to monocultures, indicating complex adaptive responses.

Conclusions:

• Proteomic analysis provides insights into the adaptive restructuring of metabolism in synthetic microbial co-cultures.
• Physiological control of environmental parameters like oxygen and nutrient availability may be crucial for enhancing the stability of engineered consortia.
• Further research into inter-species interactions and metabolic regulation is needed for robust bioproduction systems.