Engineered yeast for enhanced CO2 mineralization

Abstract

In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented.

Engineered Escherichia coli with Periplasmic Carbonic Anhydrase as a Biocatalyst for CO2Sequestration

“…Interestingly, the precipitation rate was also slightly but meaningfully enhanced by the negative-control cells, even though they did not have a detectable CO 2 hydration activity. This result is not surprising, because the E. coli cell surface carries a net negative charge (46), and this can accelerate the rate of CaCO 3 crystal growth, presenting another advantage of using a whole-cell system for CO 2 mineralization (26,47). These results collectively demonstrate that our design concept is useful in developing an efficient catalyst for accelerating CO 2 sequestration in CaCO 3 .…”

“…Recently, the first detailed investigation on the economic impact of the biologically catalyzed system on the process cost for CO 2 mineralization was reported (26). The bCA surface-displaying yeast cells were constructed, and it was predicted that a process using the engineered yeast is ϳ10% more cost-effective than a process without biocatalytic acceleration.…”

“…There are two pioneering studies on construction of microbial cells with recombinant CA for CO 2 mitigation and/or mineralization (25,26). In both, whole cells were constructed using a surface display system, which resulted in quite low CA activities.…”

Strategizing Carbon-Neutral Mines: A Case for Pilot Projects

“…An alternative means of increasing CO 2 supply involves the direct use of CA, which catalyzes the hydration of aqueous CO 2 , for carbon mineralization. CA is produced by prokaryotes and eukaryotes and is actively being investigated as an additive for accelerating carbonate precipitation, typically as part of an industrial process [39,[127][128][129][130][131]. A challenge associated with elevated CO 2 concentrations is that dissolving CO 2 into water decreases pH, and therefore decreases carbonate mineral saturation.…”

Identification of a new thermostable and alkali-tolerant α-carbonic anhydrase from Lactobacillus delbrueckii as a biocatalyst for CO2 biomineralization

“…The first detailed investigation on the economic impact of using biologically catalyzed systems for mineralization was recently reported (Barbero et al 2013). The study demonstrates that expenditure can be further reduced (by 4 %) if the precipitation catalyst can be used for longer times.…”