Metabolic Responses to Ethanol and Butanol in Chlamydomonas reinhardtii

Microalgae are among the most promising species for producing renewable biofuels and chemicals. Ethanol and butanol are clean energy sources and are good alternatives to gasoline. However, synthesis of these two biofuels has not been achieved due to low tolerance of algal cells to ethanol or butanol.

Researchers led by Yongguang Jiang from Shenzhen University investigated the metabolic responses of the model green alga Chlamydomonas reinhardtii to ethanol and butanol. The team detected proteins which were differentially regulated by ethanol and butanol. The team found 41 and 59 proteins that were consistently regulated by ethanol and butanol, respectively.

Multiple metabolic processes were affected by ethanol or butanol, and various stress-related proteins, transporters, cytoskeletal proteins, and regulators were induced as the major protection mechanisms against toxicity of the organic solvents.

The study is the first view of the metabolic mechanisms used by C. reinhardtii to defend against ethanol or butanol toxicity. The proteomic analysis provides a resource for investigating potential gene targets for engineering microalgae with enhanced ethanol and butanol tolerance.