Intermediaries in biofuel production can be eliminated

Thread Content

This post was last edited by alexpolymer on 2010-8-5 13:46 Paraffins are the main components of gasoline and diesel, and many organisms can produce them by themselves. Recently, American researchers have modified E. coli through genetic engineering methods, allowing it to avoid the intermediate steps of producing biofuels and directly use simple sugars or weeds to produce alkanes. Relevant research was published in the latest issue of the American magazine Science. While many biodiesels made from crops and fatty acids can be fed directly into car engines, they are not suitable for current refineries and pipelines. Stephen Dele Kadaye of LS9 Biotech in San Francisco, USA, said that using the current fuel infrastructure to make biofuels requires a very expensive chemical conversion process. Organisms such as cyanobacteria may hold the key to solving the problem. A few years ago, it was discovered that several cyanobacteria naturally produce alkanes, and therefore, these cyanobacteria also have the potential to produce biofuels through photosynthesis. If one could find the gene responsible for this conversion process, Dele Kadaye said, one could manipulate the bacterium to produce alkanes on a large scale. Recently, a research team led by Andrews Hilmer of LS9 compared different strains of 10 cyanobacteria that can produce alkanes with one cyanobacterium that cannot produce alkanes. When the research team eliminated the genomes of cyanobacteria that could not produce paraffins from the genomes of cyanobacteria that could produce paraffins, they found 17 genes that were only present in cyanobacteria that produced paraffins. Although scientists already know the function of some of these genes, their role in producing alkanes is not clear yet. So the team inserted these genes into a new E. coli host. E. coli, which is easy to grow in the laboratory, is suitable for industrial production. Its natural ability to synthesize fatty acids will also be used in the production of biofuels. The researchers found that the reprogrammed E. coli began making enzymes that produce alkanes. Hilmer said that this experiment shows that in the industrial production process, paraffins can be obtained through a very simple one-step method. The input is "feed" such as sugar, and the output is fuel that can be directly used by cars. So far, researchers have obtained 10 liters of paraffins using a 1,000-liter demonstration fermenter. The researchers hope to use this method to build a larger demonstration plant within a few years to enable large-scale production of paraffins.