Prospective CO2 and CO bioconversion into ectoines using novel microbial platforms

Abstract

Microbial conversion of CO2 and CO into chemicals is a promising route that can contribute to the cost-effective reduction of anthropogenic green house and waste gas emissions and create a more circular economy. However, the biotechnological valorization of CO2 and CO into chemicals is still restricted by the limited number of model microorganisms implemented, and the small profit margin of the products synthesized. This perspective paper intends to explore the genetic potential for the microbial conversion of CO2 and CO into ectoines, in a tentative to broaden bioconversion platforms and the portfolio of products from C1 gas fermentations. Ectoine and hydroxyectoine can be produced by microorganisms growing at high salinity. They are high-value commodities for the pharmaceutical and medical sectors (1000–1200 €/kg). Currently microbial ectoine production is based on sugar fermentations, but expansion to other more sustainable and cheaper substrates is desirable. In this work, a literature review to identify halophilic microbes able to use CO2 and CO as a carbon source was performed. Subsequently, genomes of this poll of microbes were mined for genes that encode for ectoine and hydroxyectoine synthesis (ectABCD, ask, asd and ask_ect). As a result, we identified a total of 31 species with the genetic potential to synthesize ectoine and 14 to synthesize hydroxyectoine. These microbes represent the basis for the creation of novel microbial-platforms that can promote the development of cost-effective and sustainable valorization chains of CO2 and CO in different industrial scenarios.

A Review of the Recent Advancement of Bioconversion of Carbon Dioxide to Added Value Products: A State of the Art

“…However, there has recently been an increase in research to improve and advance bacterial-based BioCon CO 2 technology. Both aerobic and anaerobic bacteria grew autotrophically on gas components and followed a specific pathway to produce fuels and chemicals from inorganic waste gases [82,83]. Closed and open photobioreactors were used as advanced biological technologies for BioCon CO 2 [84].…”

Electrochemical CO2reduction with ionic liquids: review and evaluation

“…Therefore, carbon capture and utilization via conversion (CCU) has become an important strategy to mitigate CO 2 emissions and produce carbonbased chemicals and fuels. [2][3][4] Several methods have been proposed to convert CO 2 , including thermal, 5 chemical, 6 and bio-conversion 7 Developing IL-based CO 2 R has been conducted. It was found that, when ILs were immobilized into the cathode catalyst, the cell operating current was increased by a factor of two or more, and FE was enhanced by 20-30 %, indicating that ILs could effectively promote CO 2 R. 42 Rosen et al 50 were the first to report that the use of 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF 4 ]) increased the selectivity for CO and lowered the overpotential.…”

“…Therefore, carbon capture and utilization via conversion (CCU) have become an important strategy to mitigate CO 2 emissions and produce carbon-based chemicals and fuels. [2][3][4] Several methods have been proposed to convert CO 2 , including thermal, 5 chemical, 6 and bio-conversion 7 as well as electrocatalytic, [8][9][10] photocatalytic, 11 and photoelectric 12 conversions and coconversions. Among them, electrochemical CO 2 reduction (CO 2 R) is among the most promising owing to the mild reaction conditions, as well as easy and flexible controllability.…”

Enrichment of halotolerant hydrogen-oxidizing bacteria and production of high-value-added chemical hydroxyectoine using a hybrid biological–inorganic system

“…Furthermore, halotolerant bacteria are known to accumulate compatible solutes, such as ectoine, hydroxyectoine, glycine betaine, and proline betaine, to counteract osmotic stresses. These compounds are commercially relevant because they have potential uses as moisturizers and protein stabilizers in the cosmetics and food industries ( Liu et al, 2019 ; Sekar and Kim, 2020 ; Cantera et al, 2022 ).…”