Improvements of poly(3-hydroxybutyrate) production in an air-lift reactor using simple production media

Abstract

Background

Halomonas boliviensis is a halophilic microorganism that accumulates poly(3-hydroxybutyrate) (PHB) using different carbons sources when nitrogen is depleted from the culture medium. This work presents an improved production of PHB using an air-lift reactor (ALR) that was fed with a concentrated solution of a carbon source, and was supplemented with an adequate airflow rate.

Results

Simple production media were used to study PHB production by H. boliviensis in an ALR. Glucose was first used as the main carbon source and was fed during the exponential phase of cell growth. The maximum CDW and PHB content were 31.7 g/L and 51 wt%, respectively, when the airflow rate entering the reactor varied between 0.5 and 1.2 L/min. Changing the air inflow to 0.5–0.9 L/min resulted in an improvement in PHB accumulation (62 wt%). A cultivation was performed by using the latter range of airflow rate and feeding glucose only when nitrogen was depleted from the medium; a considerable enhancement in PHB content (72 wt%) and CDW (27 g/L) was achieved under these conditions. Moreover, PHB was also produced using molasses as the main carbon source. Residual cell mass was about the same to that achieved with glucose, however the PHB content (52 wt%) was lower.

Conclusions

PHB production by H. boliviensis in an ALR using a simple medium is possible. CDW and PHB content in H. boliviensis can be improved with respect to batch cultivations previously reported when a carbon source is fed to the reactor. The best strategy for the production of PHB consisted of starting the cultivation in a batch mode while glutamate was present in the medium; glucose should be fed when glutamate is depleted from the medium to keep an excess of the carbon source during the synthesis of PHB.

Keywords

Poly(3-hydroxybutyrate) / Halomonas boliviensis / Air-lift reactor / Halophilic bacterium

References

[1] Chanprateep S. Current trends in biodegradable polyhydroxyalkanoates. J Biosci Bioeng, 2010, 110: 621-632.

[2] Choi J, Lee S, Han K. Cloning of the Alcaligenes latus polyhydroxyalkanoate biosynthesis genes and use of these genes for enhanced production of poly(3-hydroxybutyrate) in Escherichia coli. Appl Environ Microbiol, 1998, 64: 4897-4903.

[3] Crueger W, Crueger A. Brock T. Substrates for industrial fermentation. Biotechnology: a textbook of industrial microbiology, 1990, Sunderland: Sinauer Associates, 59-62.

[4] Gahlawat G, Sengupta B, Srivastava A. Enhanced production of poly(3-hydroxybutyrate) in a novel airlift reactor with in situ cell retention using Azohydromonas australica. J Ind Microbiol Biotechnol, 2012, 39: 1377-1384.

[5] Geyer R, Jambeck J, Law K. Production, use, and fate of all plastics ever made. Sci Adv, 2017, 3: e1700782.

[6] Guzmán D, Balderrama-Subieta A, Cardona-Ortuño C, Guevara-Martínez M, Callisaya-Quispe N, Quillaguamán J. Evolutionary patterns of carbohydrate transport and metabolism in Halomonas boliviensis as derived from its genome sequence: influences on polyester production. Aquat Biosyst, 2012, 8: 9.

[7] Harding K, Dennis J, von Blottnitz H, Harrison S. Environmental analysis of plastic production processes: comparing petroleum-based polypropylene and polyethylene with biologically-based poly-beta-hydroxybutyric acid using life cycle analysis. J Biotechnol, 2007, 130: 57-66.

[8] Kim B, Lee S, Lee S, Chang H, Chang Y, Woo S. Production of poly(3-hydroxybutyric acid) by fed-batch culture of Alcaligenes eutrophus with glucose concentration control. Biotechnol Bioeng, 1994, 43: 892-898.

[9] Lee S. Bacterial polyhydroxyalkanoates. Biotechnol Bioeng, 1996, 49: 1-14.

[10] Liu F, Li W, Ridgway D, Gu T. Production of poly-β-hydroxybutyrate on molasses by recombinant Escherichia coli. Biotechnol Lett, 1998, 20: 345-348.

[11] Manavitehrani I, Fathi A, Badr H, Daly S, Shirazi A, Dehghani F. Biomedical applications of biodegradable polyesters. Polymers, 2016, 8: 20.

[12] Oehmen A, Keller-Lehmann B, Zeng R, Yuan Z, Keller E. Optimisation of poly-β-hydroxyalkanoate analysis using gas chromatography for enhanced biological phosphorus removal systems. J Chromatogr A, 2005, 1070: 131-136.

[13] Perez-Zabaleta M, Sjöberg G, Guevara-Martínez M, Jarmander J, Gustavsson M, Quillaguamán J, Larsson G. Increasing the production of (R)-3-hydroxybutyrate in recombinant Escherichia coli by improved cofactor supply. Microb Cell Fact, 2016, 15: 91.

[14] Pradella J, Taciro M, Mateus A. High-cell-density poly(3-hydroxybutyrate) production from sucrose using Burkholderia sacchari culture in airlift bioreactor. Bioresour Technol, 2010, 101: 8355-8360.

[15] Quillaguamán J, Hashim S, Bento F, Mattiasson B, Hatti-Kaul R. Poly(β-hydroxybutyrate) production by a moderate halophile, Halomonas boliviensis LC1 using starch hydrolysate as substrate. J Appl Microbiol, 2005, 99: 151-157.

[16] Quillaguamán J, Doan-Van T, Guzmán H, Guzmán D, Martín J, Everest A, Hatti-Kaul R. Poly(3-hydroxybutyrate) production by Halomonas boliviensis in fed-batch culture. Appl Microbiol Biotechnol, 2008, 78: 227-232.

[17] Quillaguamán J, Guzmán H, Van-Thuoc D, Hatti-Kaul R. Synthesis and production of polyhydroxyalkanoates by halophiles: current potential and future prospects. Appl Microbiol Biotechnol, 2010, 85: 1687-1696.

[18] Rabnawaz M, Wyman I, Aurasa R, Chenga S. A roadmap towards green packaging: the current status and future outlook for polyesters in the packaging industry. Green Chem, 2017, 19: 4737-4753.

[19] Rivera-Terceros P, Tito-Claros E, Torrico S, Carballo S, Van-Thuoc D, Quillaguamán J. Production of poly(3-hydroxybutyrate) by Halomonas boliviensis in an air-lift reactor. J Biol Res, 2015, 22: 8.

[20] Ross A. Dinitrophenol method for reducing sugars. Potato processing, 1959, Westport: AVI Publishing Co., Inc., 469-470.

[21] Siege M, Robinson C. Application of airlift gas-liquid-solid reactors in biotechnology. Chem Eng Sci, 1992, 47: 3215-3229.

[22] Steinbüchel A, Füchtenbusch B. Bacterial and other biological systems for polyester production. Trends Biotechnol, 1998, 16: 419-427.

[23] Tan D, Xue Y, Aibaidula G, Chen G. Unsterile and continuous production of polyhydroxybutyrate by Halomonas TD01. Bioresour Technol, 2011, 102: 8130-8136.

[24] Tavares L, da Silva E, da Cruz Pradella J. Production of poly(3-hydroxybutyrate) in an airlift bioreactor by Ralstonia eutropha. Biochem Eng J, 2004, 18: 21-31.

[25] Urtuvia V, Villegas P, González M, Seeger M. Bacterial production of the biodegradable plastics polyhydroxyalkanoates. Int J Biol Macromol, 2014, 70: 208-213.

[26] Wang F, Lee S. Poly(3-hydroxybutyrate) production with high productivity and high polymer content by a fed-batch culture of Alcaligenes latus under nitrogen limitation. Appl Environ Microbiol, 1997, 63: 3703-3706.

[27] Yin J, Chen J, Wu Q, Chen G. Halophiles, coming stars for industrial biotechnology. Biotechnol Adv, 2015, 33: 1433-1442.

[28] Yue H, . A seawater-based open and continuous process for polyhydroxyalkanoates production by recombinant Halomonas campaniensis LS21 grown in mixed substrates. Biotechnol Biofuels, 2014, 7: 108.

Funding

Swedish International Development Cooperation Agency (Sida)