Cell: Make bacteria a self-contained creature! Grow by consuming carbon dioxide

https://doi.org/10.1016/j.cell.2019.11.009self-breeding and hetero-organisms
organisms are divided into self-breeding organisms (converting organic carbon into biomass) and alien organisms (consuming organic compounds)Self-sustaining organisms control the planet's biomass, supply food and fuel, better understand the principles of self-sustaining and ways to promote self-cultivation are critical to the path to sustainable developmenta great challenge in synthetic biology is to turn heterogeneous organisms into synthetic self-cultivationDespite widespread interest in renewable energy storage and more sustainable food production, past efforts to design industry-related hetero-model organisms to use carbon dioxide as the only source of carbon have failed, and previous attempts to establish a fixed cycle of self-catalytic carbon dioxide in heterogeneous organisms have always required the addition of multi-carbon organic compounds for stable growth"transform" EcoliIn this study, the researchers' main goal is to create a convenient scientific platform to enhance the fixation of carbon dioxide, which could help address issues related to global warming caused by sustainable production of food and fuel and carbon dioxide emissionsEcoli as a major force in biotechnology, its carbon source from organic carbon to carbon dioxide is an important step towards building such a platformas a result, the researchers used metabolic rewiring and laboratory evolution to convert Ecoli into self-supporting organismsEngineered strains collect energy from metachemically produced by renewable resources, which is an organic one-carbon compound that cannot be used as a carbon source for Ecoli, and therefore does not support heterobreeding pathwaysThe researchers also engineered the strain to produce non-natural enzymes for carbon fixation and reduction and energy harvesting from formic acidHowever, these changes alone are not sufficient to support self-supporting, as the metabolism of Ecoli adapts to heterogeneous growthTo overcome this challenge, researchers use adaptive laboratory evolution as a metabolic optimization toolBy inactivation of the central enzyme involved in the heterotropha, bacteria are more dependent on self-cultivation pathways, and cells are cultured in chemical thermostats containing large amounts of foreacids and 10% carbon dioxide, using a limited amount of xylitos (sources of organic carbon) to inhibit the heterogeneous pathwayThe initial supply of about 300 days of xylitose is sufficient to support cell proliferation to initiate evolutionengineered schematic of the chemically self-contained Ecoli
in this environment, self-breeding organisms have a significant selective advantage over heterogenous organisms that rely on xylitose as a source of growing carbon, producing biomass from carbon dioxide as the only carbon source, and the researchers used isotope markers to confirm that isolated bacteria are real self-contained bacteriaexperiments using 13C isotope markers showed that all biomass components were produced by carbon dioxide as the only carbon source
in order for the general method of laboratory evolution to succeed, researchers had to combine the required changes in cellular behavior with adaptive advantagesBy sequencing the genomes and plasmids of evolutionary self-grown cells, only 11 mutations were obtained during evolution: one type of mutation was a gene that encodes enzymes associated with carbon fixation cycles;this study is the first to describe the successful transformation of the way bacteria grow, allowing gut bacteria to survive in a plant-like waySurprisingly, the number of genetic changes required to make this transition is relatively smallfuture work
authors say the limitations of the study are mainly that bacteria consume more of foremost from methyl acid than carbon fixationIn addition, more research is needed before the scalability of industrial methods can be discussedIn future work, researchers will work to address carbon dioxide emissions through renewable power sources, determine whether ambient conditions can support self-cultivation, and try to reduce the mutations most associated with self-cultivation this feat opens up new prospects for the use of engineered bacteria to convert products we consider waste into fuels, foods or other compounds, and can also serve as a platform to better understand and improve the molecular machines that undertest human food production, thereby helping to increase agricultural production." References: s1 s-laboratory-evolved bacteria switch toconsuming carbon dioxide for growth s.