Project PI: Dr. Marc Carnicer

Microbial cell factories are commonly used in industrial biotechnology to produce a broad diversity of compounds. Once the production microorganism has been developed (by genetic and metabolic engineering), upstream and downstream bioprocess technologies are essential to make production viable in terms of productivity and costs. Culture media design and optimization, and bioreactor operation conditions are central for high productivity in upstream processing. Our research focusses on the utilization of an alternative non-food feedstock, acetic acid, for the production of high value compound such as recombinant proteins, vitamins and glycolipids.

Acetic acid has traditionally been considered as cell growth inhibitor rather than a potential carbon source. Nevertheless, it has the potential to substitute sugar material because i) it can be sustainably produced from different sources like from natural gas, biomass or even through the electrochemical reduction of CO2, ii) it can be assimilated by a great variety of cells including the most common industrial hosts, iii) its lower price ($350 – 400 per ton) compared to glucose ($500 per ton) and iv) its easiness to handle and transport compared other sustainable alternatives such as lignocellulose or CO2.

However, although there are examples of acetate utilization in lower density cultures, currently there is a lack of industrial-like studies that hampers the certainty and the viability of acetate-based cultures, especially regarding the final productivities and yields. Our group aims to fill this gap by i) improving the product titters and the host acetate assimilation capacities by metabolic engineering and specially, ii) developing efficient culture strategies to optimize productivities using acetate as carbon source.

Selected publications: 

Quantitative metabolomics of the thermophilic methylotroph Bacillus methanolicus.
M. Carnicer, G. Vieira, T. Brautaset, J.-C. Portais, S.Heux.
Microbial Cell Factories 15, 92 (2016). Abstract

Charting the metabolic landscape of the facultative methylotroph Bacillus methanolicus.
B. Delépine, M.G. López, M. Carnicer, C. Vicente, V. Wendisch, S. Heux,
mSystems 5, e00745-20 (2020). Abstract