From Science & Research biogenic CO 2 streams – are converted into biosuccinic acid. This will translate into the opportunity to close the carbon loop of the process and to obtain a valuable building block that Novamont can integrate into its production of biodegradable and compostable biomaterials for application in different sectors (e.g. packaging, biowaste collection, agriculture) to further enhance the renewable content of the final biobased products. In this way, the biogenic CO 2 becomes a valuable feedstock, allowing additional reduction of GHG emissions of the process and boosting Novamont implementation to become a nearly zero-waste biorefinery. Nutrition Science is a private company that supplies sustainable and economically viable solutions for the efficient production of animal feed and feed ingredients within the food value chain. Their participation in VIVALDI provides the project with an excellent opportunity to evaluate the potential of CO 2 -based bio-lactic acid in the animal feed industry while at the same time giving Nutrition Science a platform to explore the conversion of farm-generated gases to value-added compounds that can be utilised at the site. Lactic acid is added to the feed for two reasons: to improve the taste and as a result also the organoleptic perception and the feed intake and to inhibit the growth of pathogens in the gut. The downstream processing is designed to ensure that the produced lactic acid fulfils the requirements of specific legislation and does not contain any critical contaminants. Overall, the CO 2 -based industry aiming at the production of bioplastics provides an exciting opportunity in the view of a more sustainable chemical industry. The main sources of reduction of GHG emissions reduction are: • preventing CO 2 release, • decreasing the use of fossil-based resources for their chemical synthesis and • designing efficient fermentation and downstream processing. For example, for most acids, recovery should be carried out at low pH (below the product pKa) and yeasts, such as P. pastoris, can tolerate such low pH conditions, which was found to have a significantly lower impact on energy utilisation (38–51 %) and climate change (67–92 %) in the posterior downstream processing when compared to the petrochemical counterparts [8]. www.vivaldi-h2020.eu References [1] European Commission, A European Strategy for Plastics, Eur. Com. (2018) 24. https://doi.org/10.1021/acs.est.7b02368. [2] P. Izadi & F. Harnisch. “Microbial| electrochemical CO 2 reduction: To integrate or not to integrate?”. Joule (2022) In press. https://doi. org/10.1016/j.joule.2022.04.005 [3] COWI A/S, Utrecht University, Environmental impact assessment of innovative bio-based products – Summary of methodology and conclusions, 2018. https://doi.org/10.2777/83590. [4] B.G. Hermann, K. Blok, M.K. Patel, Producing bio-based bulk chemicals using industrial biotechnology saves energy and combats climate change, Environ. Sci. Technol. 41 (2007) 7915–7921. https://doi.org/10.1021/ es062559q. [5] E. Mancini, S.S. Mansouri, K. V Gernaey, J. Luo, M. Pinelo, From second generation feed-stocks to innovative fermentation and downstream techniques for succinic acid production, Crit. Rev. Environ. Sci. Technol. 50 (2020) 1829–1873. https://doi.org/10.1080/10643389.2019.1670530. [6] J. Becker, A. Lange, J. Fabarius, C. Wittmann, Top value platform chemicals: bio-based production of organic acids, Curr. Opin. Biotechnol. 36 (2015) 168–175. https://doi.org/https://doi.org/10.1016/j.copbio.2015.08.022. [7] 2021 Global Forecast for Succinic Acid Market (2022-2027 Outlook) – High Tech & Emerging Markets Report, Barnes reports. [8] B. Cok, I. Tsiropoulos, A.L. Roes, M.K. Patel, Succinic acid production derived from carbohydrates: An energy and greenhouse gas assessment of a platform chemical toward a bio-based economy, Biofuels, Bioprod. Biorefining. 8 (2014) 16–29. https://doi.org/10.1002/bbb.1427. [9] R.A. de Oliveira, A. Komesu, C.E.V. Rossell, and R. Maciel Filho, Challenges and opportunities in lactic acid bioprocess design—From economic to production aspects. Biochemical Engineering Journal 133 (2018) 219–239. https://doi.org/10.1016/j.bej.2018.03.003 [10] Grand View Research (GVR). (2021). Lactic acid market size, share & trends analysis report by raw material (sugarcane, corn, cassava), by application (PLA, food, & beverages), by region, and segment forecasts, 2021–2028. [11] A. Djukić-Vuković, D. Mladenović, J. Ivanović, J. Pejin, & L. Mojović, Towards sustainability of lactic acid and poly-lactic acid polymers production. Renewable and Sustainable Energy Reviews 108 (2019) 238–252. https://doi.org/10.1016/j.rser.2019.03.050 [12] F. K. Adom, & J. B. Dunn, Life cycle analysis of corn-stover-derived polymer-grade l-lactic acid and ethyl lactate: greenhouse gas emissions and fossil energy consumption. Biofuels, Bioproducts and Biorefining 11(2) (2017) 258–268. https://doi.org/10.1002/bbb.1734 [13] T. Gassler, M. Sauer, B. Gasser, M. Egermeier, C. Troyer, T. Causon, S. Hann, D. Mattanovich& M.G. Steiger, The industrial yeast Pichia pastoris is converted from a heterotroph into an autotroph capable of growth on CO2. Nature Biotechnology 38(2) (2020) 210–216. https://doi.org/10.1038/s41587- 019-0363-0. 24 bioplastics MAGAZINE [01/22] Vol. 17
Engineered bacteria Upcycle carbon waste into commodity chemicals You might not recognize the words acetone and isopropanol (IPA), but the chances are that you use them. While these chemicals are beneficial – serving as the building blocks for thousands of products, including fuels, materials, acrylic glass, fabrics, and even cosmetics – they are generated from fossil inputs, leading to emissions of climate-warming CO 2 into the air. Researchers led by LanzaTech (Skokie, IL, USA), Northwestern University (Evanston, IL, USA), and Oak Ridge National Lab (Oak Ridge, TN, USA) have developed an efficient new process to convert waste gases, such as emissions from heavy industry or syngas generated from any biomass source, into either acetone or IPA. The secret to the new platform is Clostridium autoethanogenum, or C. auto, a bacterium engineered at LanzaTech that can convert waste carbon selectively into either ethanol, acetone, or IPA. Their methods, including a pilot-scale demonstration and life cycle analysis (LCA) showing the economic viability, are published in the journal Nature Biotechnology. The new technology actually uses greenhouse gas (GHG) emissions destined for the atmosphere, avoids burning fossil fuels and removes CO 2 from the air. According to LCA, this carbon-negative platform could reduce GHG by over 160 %, playing a critical role in helping the USA reach a netzero emissions economy. “This discovery is a major step forward in avoiding a climate catastrophe”, said Jennifer Holmgren, LanzaTech CEO. “Today, most of our commodity chemicals are derived exclusively from new fossil resources such as oil, natural gas, or coal. Acetone and IPA are two examples with a combined global market of USD 10 billion. The acetone and IPA pathways and tools developed will accelerate the development of other new products by closing the carbon cycle for their use in multiple industries”. Acetone and IPA are necessary industrial bulk and platform chemicals. For example, acetone is used as a solvent for many plastics and synthetic fibres, thinning polyester resin, cleaning tools, and nail polish remover. IPA is a chemical used in antiseptics, disinfectants, and detergents and can be a pathway to commercial plastics such as polypropylene, used in both the medical and automotive sectors. Both are used in acrylic glass. IPA also is a widely used disinfectant, serving as the basis for one of the two World Health Organization (WHO) – recommended sanitiser formulations, which are highly effective against SARS-CoV-2. The collaborators developed a gas fermentation process for carbon-negative production of either acetone or IPA by reprogramming LanzaTech’s commercial ethanolproducing bacterial strain through cutting-edge synthetic biology tools, including combinatorial DNA libraries and cell-free prototyping advanced modelling, and omics. The scientists relied on a three-pronged approach that comprised innovations in pathway refactoring, strain optimization, and process development to achieve the observed level of performance. “These innovations, led by cell-free strategies that guided both strain engineering and optimization of pathway enzymes, accelerated time to production by more than a year”, said Michael Jewett, the Walter P. Murphy Professor of Chemical and Biological Engineering at Northwestern’s McCormick School of Engineering and director of the Centre of Synthetic Biology. The optimized process was scaled up to the pilot plant, and LCA showed significant GHG savings. “Conversion pathways for the production of any biofuel or bioproduct, including acetone and IPA, inevitably involve chemical byproducts that can cause or be the result of major bottlenecks”, said ORNL’s Tim Tschaplinski. “We used advanced proteomics and metabolomics to identify and overcome these bottlenecks for a highly efficient pathway. This approach can be applied to create streamlined processes for other chemicals of interest”. By proving scalable and economically viable bulk chemical production, the researchers have set the stage for implementation of a circular economic model in which the carbon from agriculture, industrial and societal waste streams can be recycled into a chemical synthesis value chain to perpetually displace ever-increasing volumes of products made from virgin fossil resources. Thereby, chemical synthesis would become a path to capturing, recycling, and utilizing waste carbon resources. The acetone strain and process development, genomescale modelling, life cycle analysis, and initial pilot runs were supported by the Bioenergy Technologies Office in DOE’s Office of Energy Efficiency and Renewable Energy. The cell-free prototyping and omics analyses were funded by the Biological and Environmental Research program in DOE’s Office of Science. DNA sequencing and synthesis were supported by the Joint Genome Institute, a DOE Office of Science User Facility. AT The journal article can be found at https://www.nature.com/articles/s41587-021-01195-w. Genome Mining www.lanzatech.com | www.northwestern.edu | www.ornl.gov Pathway optimization Engineered enzymes Combinatorial library Strain optimization Cell-free prototyping Omics m/z Metabolic modeling Process optimization Fermentation development & scale-up Life cycle analysis How it works: the team took a three-pronged optimization approach to increase fermentation efficiency and output. (Courtesy: FE Liewet al/Nature Biotechnology) LCA From Science & Research bioplastics MAGAZINE [03/22] Vol. 17 25
