Mar 29 2010
In the spring meeting of the Society for General Microbiology in Edinburgh, researchers described how alcohols could be obtained from sugars through engineered yeast making the production of biofuels cost-effective as well as environmentally friendly.
Professor Eckhard Boles and Dr Christian Weber from the Frankfurt University in Germany explained how they have found a way to alter yeast cells in order to successfully transform a broader range of sugars from plant waste such as rice straw and wheat into alcohol that can be utilized as biofuels.
Non-food raw materials are used to produce bioalcohols though microbial fermentations and are called as second generation biofuels. Plant waste comprises a mix of complex sugars including pentoses and hexoses that can be converted to alcohol through fermentation. Large quantities of plant waste are easily available. Dr Weber explained that the major portion of processing costs is for these feedstocks and what is needed right now is an efficient and rapid conversion technology for all the sugars present. At present, there are no microbes that will transform both pentoses and hexoses efficiently into ethanol, Dr. Weber said.
Beverage industry is using Saccharomyces cerevisiae, also known as baker’s yeast, to transform hexose sugars into ethanol efficiently. Genes from bacteria that break down pentose naturally were transferred by Dr Weber's team to modify S. cerevisiae to ferment both hexose and pentose sugars successfully. Since significant amount of pentoses are available in the feedstock, for the same quantity of feedstock a substantial amount of ethanol is derived through the engineered yeast, he said.
Further modifications of the yeast are being tried to enhance its biofuel potential. It is being engineered to produce butanol, another bioalcohol, instead of ethanol. Professor Boles commented that butanol has superior properties when compared to ethanol for its biofuel potential.
Source: http://www.sgm.ac.uk/