Toughening Industrial Microbes to Create Chemical Powerhouses
In Biofuels Digest's recent series on the new biorefinery project, they emphasized the need for biofuels makers to incorporate renewable chemicals manufacture early in the game -- for crucial early profit streams.
If we have learned anything from the stories of hot companies like Amyris, LS9, Gevo, Solazyme, ZeaChem, Algenol, or Cobalt Technologies, as well as exciting pure-plays like Segetis, Elevance, GlycosBio or Rivertop Renewables, it is the importance of producing chemicals or other bio-based materials first to generate revenues, before taking the company further down the cost curve and up in scale in order to make competitively-priced renewable fuels. _BiofuelsDigestMicrobes will be instrumental in the changeover from dependence on petroleum to a widespread utilisation of sustainable bio-derived fuels. But before microbes become the prime producers of liquid fuels, they will be crowned king of chemicals. High value chemicals bring in more profits than bulk commodity fuels, and will be correctly targeted by the new industrial microbes as profit cows -- on the way to large scale bio-fuels production. Here is one challenge: making the microbes tough enough to survive the chemicals they are creating.
Microorganisms can sometimes produce chemicals and fuels as cheaply as conventional methods, while using sugar instead of petroleum. Technology developed by researchers at Argonne National Laboratories could help reduce the cost of production of chemicals or fuels made using microorganisms, and potentially increase the range of such materials. It does this, in part, by keeping the bugs alive for longer. The researchers recently announced that Nalco, a company based in Naperville, Illinois, will commercialize the technology.
The new tool uses an advanced form of electrodeionization (EDI), a technology used to make ultrapure water. The advanced EDI provides a better way to control the acidity of the solution in which an organism grows, and this helps optimize the microbe-driven production process. It also efficiently removes the chemicals that microorganisms make, allowing the process to run continuously. By creating a less harmful environment for growth, the tool could make it easier to engineer microorganisms for producing new chemicals.
...The Argonne researchers have developed what they call resin wafers, which combine multiple resins, binding agents, and additives to improve the conductivity and porosity of the material. The approach also keeps electricity costs low--just a few cents of electricity is needed to produce a pound of a chemical that sells for a dollar, says Seth Snyder, who is leading the project at Argonne.
The technology could be used first for cheaper fermentation. One of the biggest industrial applications of fermentation is the production of plastics precursors such as succinic acid, and food additives such as citric acid. But these acids need to be counteracted by adding large quantities of base materials, such as calcium hydroxide, which are then converted in the process to waste products such as gypsum.
...The Argonne technology also makes continuous production possible. In conventional fermentation, organisms are grown in a tank where they excrete a product until it reaches a concentration that is toxic to the organism. The contents of the fermentation tank are then poured out, and the process starts again. With the new EDI tool, the chemical product can be removed as it is made, so concentrations stay low. Microorganisms can continue producing chemicals for 10 times longer.
The new tool may also aid in engineeing organisms for new applications. It makes it unnecessary to use acid-resistant organisms, or organisms that can tolerate high concentrations of the chemical they produce.
The Argonne researchers have demonstrated the production and purification of chemicals at a small pilot-scale plant. The partnership with Nalco will make production versions of the system available for companies and other researchers. _TechnologyReview