Title
Improving 1,3-butanediol production in E. coli using a protein engineering approach
Conference Dates
July 14-18, 2019
Abstract
Traditional chemical production processes have high yields but require harsh reaction conditions and use non-renewable feedstocks derived from petroleum [1, 2]. These processes have a negative impact on the environment, which motivates the development of more sustainable processes as replacements [2]. Advances in systems metabolic engineering over the past thirty years have given rise to bioprocesses where engineered microbes make chemicals from natural feedstocks under mild reaction conditions [1]. The promise of the field has also resulted in financial resources being made available to the development and commercialization of bioprocess. According to a recent report by Ontario Genomics [3], global investment in the field is projected to be at $38.7B in 2020, a 12-fold increase from what it was at in 2013. Recently, a novel aldolase-based pathway for producing 1,3-butanediol (BDO) in E. coli was reported by Nemr et. al [4, 5]. 1,3-BDO is a commercially viable product as it is used in formulations in cosmetics products, and as a precursor for pharmaceuticals [2]. This pathway involves the conversion of pyruvate to acetaldehyde via the EutE enzyme from E. coli, followed by the conversion of acetaldehyde to 3- hydroxybutanal via the enzyme BH1352 – a Deoxyribose-phosphate aldolase (DERA) – from Bacillus halodurans and subsequently by the conversion of 3-hydroxybutanal to 1,3-BDO via the enzyme PA1127 (an aldo-keto reductase) from Pseudomonas aeruginosa [5]. We examined the crystal structure of BH1352, which revealed key residues involved in catalytic activity in the substrate binding pocket. We show that two DERA mutants F160Y and F160Y/M173I improve the production of 1,3-BDO 5-fold and 6-fold respectively in bench-scale bioreactors [6]. References: 1. Bonk, B. M., Tarasova, Y., Hicks, M. A., Tidor, B., & Prather, K. L. (2018). “Rational design of thiolase substrate specificity for metabolic engineering applications”. Biotechnology and bioengineering, 115(9), 1–16. http://doi.org/10.1002/bit.26737 2. Burk, M. J. (2010). Sustainable production of industrial chemicals from sugars. International Sugar Journal, 112(1333), 30. 3. Ontario Genomics. (2017). Ontario Synthetic Biology Report 2016. Retrieved from: http://www.ontariogenomics.ca/syntheticbiology/Ontario_Synthetic_Biology_Report_2016.pdf 4. Nemr, K., Müller, J. E. N., Joo, J. C., Gawand, P., Choudhary, R., Mendonca, B., et al. (2018). Engineering a short, aldolase-based pathway for (R)-1,3-butanediol production in Escherichia coli. Metabolic Engineering, 48, 13–24. http://doi.org/10.1016/j.ymben.2018.04.013 5. Nemr, K. (2018). Metabolic Engineering of Lyase-Based Biosynthetic Pathways for Non-natural Chemical Production (Unpublished doctoral dissertation). University of Toronto, Toronto, ON, Canada. 6. Kim, T. (2019). Biochemical and Structural Studies of Microbial Enzymes for the Biosynthesis of 1,3-Butanediol (Unpublished doctoral dissertation). University of Toronto, Toronto, ON, Canada
Recommended Citation
Radhakrishnan Mahadevan, Taeho Kim, Kayla Nemr, Alexander Yakunin, and Radhakrishnan Mahadevan, "Improving 1,3-butanediol production in E. coli using a protein engineering approach" in "Biochemical and Molecular Engineering XXI", Christina Chan, Michigan State University, USA Mattheos Koffas, RPI, USA Steffen Schaffer, Evonik Industries, Germany Rashmi Kshirsagar, Biogen, USA Eds, ECI Symposium Series, (2019). https://dc.engconfintl.org/biochem_xxi/19