Microorganisms convert industrial waste gas into general-purpose chemicals | Chemistry

Chemicals cost more than just money. Today, petrochemical production produces almost 2% of the world’s greenhouse gas emissions. Now, researchers have taken an important step to significantly reduce their footprint by using bacteria and waste gas from steel mills rather than petroleum as starting components for dozens of general-purpose chemicals. .. So far, this process has been used for three general-purpose chemicals. But as researchers may be able to extend it to others, it may help the chemical industry escape its dependence on fossil fuels and effectively remove carbon from the sky.

“It’s really exciting to use biology to use waste gas to produce industrial chemicals,” said Corinnus, a biofuel expert at Lawrence Berkeley National Laboratory, who was not involved in the study. Coun says. “The difficulty of decarbonization is the simultaneous pursuit of two sectors, steel production and industrial chemicals. It addresses a difficult problem.”

Humans have used microorganisms for thousands of years to produce products such as alcohol, cheese, and yogurt. However, industrial-scale biotechnology did not really spread until the early 1900s, when chemist Chaim Weizmann designed several organisms, for example. Clostridium Bacteria that convert starch and sugar to acetone. This is an essential ingredient for making cordite, a smokeless alternative to gunpowder. (Wiseman’s success was the key to the Allied victory in World War I and gained his fame. Wiseman, a Zionist politician and chemist, finally came to Israel in 1949. However, the rise of the oil industry in the 1950s and 1960s gave chemical makers cheaper starting materials for dozens of commercial chemicals, driving most microorganisms into industrial waste bins. ..

Not all.Today with yeast E. coli It is widely used in the production of various general-purpose chemicals, such as ethanol for fuels and compounds used in the production of pharmaceuticals and plastics. However, these flagship industrial products have a unique environmental footprint because fermenting sugar and starch are derived from crops such as corn and sugar cane. By 2026, corn grown to produce ethanol in the United States will occupy up to 19% of the country’s agricultural land.

Synthetic biologists are now trying to grow microorganisms in a more environmentally friendly diet using industrial waste gas, dumps, and crop production, said Lanzatech, a synthetic biologist at biotechnology company. One Michael Kepke says. In the 1990s, researchers Clostridium autoethanogenum ((((C. Automatic), A bacterium originally concentrated from rabbit droppings that produces ethanol from hydrogen gas and carbon monoxide (CO). Since then, researchers have slowly improved ethanol yields and commercialized the process. In June 2018, LanzaTech opened the first production plant to use bacteria to produce ethanol from steel mill waste gas (mainly a mixture of CO, carbon dioxide and hydrogen gas). The company is currently using this technology to produce approximately 90,000 tonnes of ethanol annually.

not yet, C. Automatic Is not comparable to the versatility of E. coli Or yeast. “Engineering so far Clostridium It was hard, “says Michael Jewett, a synthetic biologist at Northwestern University. Bacteria grow slowly and die when exposed to oxygen. In addition, researchers have few genetic editing tools tuned to alter the metabolism of microorganisms.

not anymore. Jewett, Köpke, and his colleagues guided using a multi-step strategy. C. Automatic Stir acetone and isopropanol (IPA), which are colorless liquids contained in disinfectants and detergents.They started with a collection of 272 sugar-eating Clostridium A strain maintained by retired South African microbiologist David T. Jones, one of Weizmann’s last postdoctoral assistants. The research team has broken down bacterial cells and mined enzymes that may play a role in acetone biosynthesis.They sequenced 30 genes for these enzymes and inserted their combination into C. Automatic Through a gene delivery medium called a plasmid.Apart from this, researchers C. AutomaticMetabolism to prevent carbon and hydrogen building blocks from making other unwanted chemicals. Eventually, Jewtett, Köpke, and their colleagues generated and screened 247 genetic variants of the bacterium to find the best chemical producers.As a result, they report today Nature biotechnology,am C. Automatic That stock Continuous conversion of steel waste gas With enough acetone and IPA to make them a viable candidate for large-scale commercial production.

Jewett predicts that the same process could produce a variety of other chemicals in the bacteria, such as butanol used in varnishes and propanediol in cosmetics. Scown adds that new synthetic biology technologies could also help turn other awkward microorganisms into the industry’s flagship product. “We, [microbial] A host that may become viable in the future, “she says.

This advance could also open the door for manipulating microorganisms that can supply other waste gases, such as those produced by urban solid waste and agricultural debris.And if C. Automatic, These microorganisms use more carbon in the production of their products than they release into the atmosphere. Production of industrial chemicals could one day change from a greenhouse gas villain to a champion.