Production of (3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer from coffee waste oil using engineered Ralstonia eutropha
- 555 Downloads
Polyhydroxyalkonate (PHA) is a type of polymer that has the potential to replace petro-based plastics. To make PHA production more economically feasible, there is a need to find a new carbon source and engineer microbes to produce a commercially valuable polymer. Coffee waste is an inexpensive raw material that contains fatty acids. It can act as a sustainable carbon source and seems quite promising with PHA production in Ralstonia eutropha, which is a well-known microbe for PHA accumulation, and has the potential to utilize fatty acids. In this study, to make poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-co-HHx)), which has superior properties in terms of biodegradability, biocompatibility, and mechanical strength, engineered strain Ralstonia eutropha Re2133 overexpressing (R)-specific enoyl coenzyme-A hydratase (phaJ) and PHA synthetase (phaC2) with deletion of acetoacetyl Co-A reductases (phaB1, phaB2, and phaB3) was used to produce PHA from coffee waste oil. At a coffee oil concentration of 1.5%, and C/N ratio of 20, the R. eutropha Re2133 fermentation process results in 69% w/w of DCW PHA accumulation and consists of HB (78 mol%) and HHx (22 mol%). This shows the feasibility of using coffee waste oil for P(HB-co-HHx) production, as it is a low-cost fatty acid enriched waste material.
KeywordsPolyhydroxyalkonate Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Ralstonia eutropha
The authors acknowledge the KU Research Professor Program of Konkuk University, Seoul, South Korea for providing financial support to Dr. Shashi Kant Bhatia. This study was also supported by the National Research Foundation of Korea (NRF), funded by the Ministry of Education (2017R1A2A2A07000900, 2017M3A9E4077234, 2017R1D1A1B03030766), and R&D Program of MOTIE/KEIT (10048350). Consulting service from the Microbial Carbohydrate Resource Bank (MCRB, Seoul, Korea) was kindly appreciated.
- 18.Jeon J-M, Kim H-J, Bhatia SK, Sung C, Seo H-M, Kim J-H, Park H-Y, Lee D, Brigham CJ, Yang Y-H (2017) Application of acetyl-CoA acetyltransferase (AtoAD) in Escherichia coli to increase 3-hydroxyvalerate fraction in poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Bioprocess Biosyst Eng 1–9Google Scholar
- 21.Fiedler S, Steinbüchel A, Rehm BH (2002) The role of the fatty acid β-oxidation multienzyme complex from Pseudomonas oleovorans in polyhydroxyalkanoate biosynthesis: molecular characterization of the fadBA operon from P. oleovorans and of the enoyl-CoA hydratase genes phaJ from P. oleovorans and Pseudomonas putida. Arch Microbiol 178:149–160CrossRefGoogle Scholar
- 25.Bhatia SK, Yang Y-H (2017) Microbial production of volatile fatty acids: current status and future perspectives. Rev Environ Sci Bio 1–19Google Scholar
- 27.Jüngert JR, Borisova M, Mayer C, Wolz C, Brigham CJ, Sinskey AJ, Jendrossek D (2017) Absence of ppGpp Leads to increased mobilization of intermediately accumulated Poly(3-hydroxybutyrate) (PHB) in Ralstonia eutropha H16. Appl Environ Microbiol doi. https://doi.org/10.1016/j.ymben.2017.05.007 Google Scholar
- 31.Braunegg G, Sonnleitner B, Lafferty RM (1978) A rapid method for the determination of poly-β-hydroxybutyric acid in microbial biomass. Eur J Appl Microbiol Biotechnol 6Google Scholar
- 33.Bhatia SK, Lee B-R, Sathiyanarayanan G, Song H-S, Kim J, Jeon J-M, Kim J-H, Park S-H, Yu J-H, Park K, Yang Y-H (2016) Medium engineering for enhanced production of undecylprodigiosin antibiotic in Streptomyces coelicolor using oil palm biomass hydrolysate as a carbon source. Bioresour Technol 217:141–149CrossRefGoogle Scholar