Carbon dioxide bioconversion into single cell oils (lipids) in two reactors inoculated with Acetobacterium woodii and Rhodosporidium toruloides. Issue 52 (October 2021)

• Record Type: Journal Article
• Authors: Robles-Iglesias, Raúl; Veiga, María C.; Kennes, Christian
• Is Part Of: Journal of CO₂ utilization. Issue 52(2021)
• Publication Date: 2021-10
• Subjects: Acetogenesis -- Biodiesel -- Fatty acid methyl ester -- Greenhouse gas -- Yeast; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2021.101668
• Languages: English
• ISSNs: 2212-9820

Abstract

Highlights: Bioconversion of CO2 for the production of lipids as valuable products was shown. Acetogens can efficiently convert CO2 to > 20 g/L acetic acid in bioreactors. Acetic acid from acetogens can be metabolized by non-conventional yeasts. Lipids were obtained from CO2 from the combination of anaerobic and aerobic strains. Carbon dioxide showed good potential for its use in the manufacturing of biofuels. Abstract: Acetobacterium woodii was able to produce high concentrations of acetic acid, i.e., > 20 g/L, from CO2, in the presence of H2 as an energy source, which was favoured by maintaining a near-optimal pH of 7.8 in an automated bioreactor. This allows the mitigation of CO2 emissions for their conversion to acetic acid, which was then further used to produce lipids (single cell oils) by Rhodosporidium toruloides in the next assay. The yeast, grown on acetic acid, efficiently accumulated lipids in A. woodii' s medium, and further improved bioconversion would result in a highly promising process. Acetic acid inhibitory studies performed with R. toruloides, at different initial concentrations of the acid, using the fermented broth of A. woodii grown on CO2, showed that the yeast maintained a constant growth rate and substrate consumption rate up to acid concentrations of 15 g/L. Both rates remained roughly constant at higher initial acetic acid concentrations; except for a more extended lag phase observed in batch assays before the yeast entered in its exponential growth phase.