The potential of CO2-based production cycles in biotechnology to fight the climate crisis

Abstract

Rising CO2 emissions have pushed scientists to develop new technologies for a more sustainable bio-based economy. Microbial conversion of CO2 and CO2-derived carbon substrates into valuable compounds can contribute to carbon neutrality and sustainability. Here, we discuss the potential of C1 carbon sources as raw materials to produce energy, materials, and food and feed using microbial cell factories. We provide an overview of potential microbes, natural and synthetic C1 utilization pathways, and compare their metabolic driving forces. Finally, we sketch a future in which C1 substrates replace traditional feedstocks and we evaluate the costs associated with such an endeavor.

Single carbon metabolism – A new paradigm for microbial bioprocesses?

“…Methane and syngas are way more abundantly available, however to a large extent from fossil resources. The renewable production of methanol and formate [ [85] , [86] , [87] ], as well as syngas [ 88 ] is on the rise, but still need to be massively upscaled to serve as feedstocks for a C1 biotechnology that has a relevant impact on the global carbon balance [ 89 ] ( Fig. 2 ).…”

Efficient production of itaconic acid from the single-carbon substrate methanol with engineered Komagataella phaffii

“…Sustainable resources of interest include various waste products such as crude glycerol [ 11 ], lignocellulosic biomass [ 12 ], food waste [ 13 ] and more unconventionally single-carbon (C1) substrates derived from CO 2 [ 14 ]. Valorising CO 2 and its derived C1 substrates is a growing area of interest, being developed in various biotechnological [ 4 , 15 – 17 ] and chemical fields [ 18 ]. Methanol (MeOH), a low-cost renewable single-carbon feedstock, is gaining attention for bio-production of commodity chemicals.…”

“…Alternative, more sustainable substrates for production with A. terreus or alternative hosts have long been under investigation, with MeOH being one of the least explored [ 30 , 38 , 40 , 41 ]. Production using the C1-substrate could potentially lower manufacturing costs, contribute to a circular economy and improve the overall production sustainability [ 15 , 16 , 20 ]. Hence, K. phaffii as a natural methylotroph and established production host in biotechnology is a promising candidate for producing itaconic acid from MeOH.…”

The Serine Shunt enables formate conversion to formaldehydein vivo

“…This should be addressed by reducing CO2 emissions and by capturing CO2 from the atmosphere, followed by its storage or valorization. Biotechnological valorization of captured CO2 is a promising alternative to long-term storage as it recycles CO2 and minimizes the need for fossil or plantderived products (Bachleitner et al, 2023). Here, reduced one-carbon (C1) molecules like formate or methanol could become important mediators as they can be electrochemically produced from CO2 and present favorable characteristics for microbial cultivation.…”

“…Here, reduced one-carbon (C1) molecules like formate or methanol could become important mediators as they can be electrochemically produced from CO2 and present favorable characteristics for microbial cultivation. In recent years, the field of C1 biotechnology has emerged as a subdiscipline which aims to combine chemical CO2 reduction with biotechnological conversion of C1 molecules to value-added products (Bachleitner et al, 2023;Orsi et al, 2023). The model of a formatebased bioeconomy proposes to explore formate as a favorable C1 substrate for the sustainable biotechnology (Yishai et al, 2016) In nature, several bacteria grow aerobically on formate via the Serine Cycle (Anthony, 2011).…”