Valorisation of CO2-rich off-gases to biopolymers through biotechnological process

• Published in: FEMS microbiology letters 2017-11, Vol.364 (20)
• Main Authors: Garcia-Gonzalez, Linsey, De Wever, Heleen
• Format: Article
• Language: English
• Subjects: Alternative energy sources; Autotrophic Processes; Bioconversion; Biodegradable Plastics - chemistry; Biodegradable Plastics - metabolism; Bioplastics; Biopolymers; Biopolymers - chemistry; Biopolymers - metabolism; Bioreactors; Biotechnology; Biotechnology - methods; Carbon - chemistry; Carbon - metabolism; Carbon dioxide; Carbon Dioxide - chemistry; Carbon Dioxide - metabolism; Carbon dioxide emissions; Carbon sequestration; Carbon sources; Cupriavidus necator - metabolism; Electrolysis; Emissions; Fermentation; Gases; Gases - chemistry; Gases - metabolism; Glucose - metabolism; Heterotrophic Processes; Hydroxybutyrates - chemistry; Hydroxybutyrates - metabolism; Impurities; Microbiology; Organic carbon; Organic chemistry; Plastics; Point sources; Pollution sources; Polyhydroxybutyrate; Polyhydroxybutyric acid; Polymers; Substrates
• ISSN: 1574-6968; 0378-1097; 1574-6968
• DOI: 10.1093/femsle/fnx196

Abstract As one of the key enabling technologies, industrial biotechnology has a high potential to tackle harmful CO2 emissions and to turn CO2 into a valuable commodity. So far, experimental work mainly focused on the bioconversion of pure CO2 to chemicals and plastics and little is known about the tolerance of the bioprocesses to the presence of impurities. This work is the first to investigate the impact of real CO2-rich off-gases on autotrophic production of polyhydroxybutyrate. To this end, two-phase heterotrophic-autotrophic fermentation experiments were set up, consisting of heterothrophic cell mass growth using glucose as substrate followed by autotrophic biopolymer production using either pure synthetic CO2 or industrial off-gases sampled at two point sources. The use of real off-gases did not affect the bacterial performance. High biopolymer content (up to 73%) and productivities (up to 0.227 g/lh) were obtained. Characterisation of the polymers showed that all biopolymers had similar properties, independent of the CO2 source. Moreover, the CO2-derived biopolymers’ properties were comparable to commercial ones and biopolymers reported in literature, which are all produced from organic carbon sources. This study aims to apply carbon capture and utilisation by converting CO2 from industrial point sources and renewable H2 and O2 from electrolysis energy into biopolymers through biotechnological process for high-end applications.