, Volume 24, Issue 10, pp 2156–2174 | Cite as

Toxicological challenges to microbial bioethanol production and strategies for improved tolerance

  • Hannah Akinosho
  • Thomas Rydzak
  • Abhijeet Borole
  • Arthur Ragauskas
  • Dan Close


Bioethanol production output has increased steadily over the last two decades and is now beginning to become competitive with traditional liquid transportation fuels due to advances in engineering, the identification of new production host organisms, and the development of novel biodesign strategies. A significant portion of these efforts has been dedicated to mitigating the toxicological challenges encountered across the bioethanol production process. From the release of potentially cytotoxic or inhibitory compounds from input feedstocks, through the metabolic co-synthesis of ethanol and potentially detrimental byproducts, and to the potential cytotoxicity of ethanol itself, each stage of bioethanol production requires the application of genetic or engineering controls that ensure the host organisms remain healthy and productive to meet the necessary economies required for large scale production. In addition, as production levels continue to increase, there is an escalating focus on the detoxification of the resulting waste streams to minimize their environmental impact. This review will present the major toxicological challenges encountered throughout each stage of the bioethanol production process and the commonly employed strategies for reducing or eliminating potential toxic effects.


Toxicology Biofuels Bioethanol Fermentation Process engineering 



Funding for this review was provided by the Georgia Institute of Technology, Renewable BioProducts Institute Paper Science and Technology Fellowship and an Oak Ridge National Laboratory Laboratory Directed Research and Development grant. Additional funding was provided by the Bioenergy Science Center (BESC), which is a U.S. Department of Energy Bioenergy Research Center supported by the Office of Biological and Environmental Research in the DOE Office of Science. This manuscript has been authored by a contractor of the U.S. Government under contract DE-AC05-00OR22725.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest and that they have performed these studies in accordance with acceptable ethical procedures


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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Hannah Akinosho
    • 1
    • 2
  • Thomas Rydzak
    • 2
    • 3
  • Abhijeet Borole
    • 3
    • 4
    • 5
  • Arthur Ragauskas
    • 1
    • 2
    • 4
  • Dan Close
    • 3
  1. 1.Renewable BioProducts InstituteGeorgia Institute of TechnologyAtlantaUSA
  2. 2.BioEnergy Science CenterOak Ridge National LaboratoryOak RidgeUSA
  3. 3.Biosciences DivisionOak Ridge National LaboratoryOak RidgeUSA
  4. 4.Department of Chemical and Biomolecular EngineeringUniversity of TennesseeKnoxvilleUSA
  5. 5.Bredesen Center for Interdisciplinary Research and EducationUniversity of TennesseeKnoxvilleUSA

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