Nikkei. Japanese biotechnology start-up Neo-Morgan Laboratory Inc. has developed a new process for breeding Saccharomyces cerevisiae yeasts that can efficiently produce bioethanol from pentose (five-carbon) sugars, the sugars contained in cellulosic biomass.
Most bioethanol-producing yeasts break down glucose and other hexose (six-carbon) sugars obtained from the edible parts of plants such as sugarcane and corn.
Developing an organism that can ferment both pentose and hexose sugars would greatly increase the ethanol yield from a given amount of biomass, and is the focus of numerous research efforts.
For example, researchers at Delft University of Technology also are genetically modifying S. cerevisiae to enable the anaerobic fermentation of five- and six-carbon sugars. (Earlier post.)
A yeast capable of processing both five- and six-carbon sugars could increase production efficiency by 70%, according to Neo-Morgan.
Neo-Morgan focuses on its “disparity of theory of evolution” in its work with organisms. The disparity theory, as developed earlier by company Chairman and Chief Science Officer Mitsuru Furusawa, holds that DNA is replicated semiconservatively using the leading and discontinuous lagging strands of the molecule.
According to our disparity theory of evolution, the existence of a sufficient fidelity difference between the leading and lagging strands is advantageous in terms of evolution, because the diversity of genotypes is enlarged but genotypes that have occurred in the past are guaranteed. In theory, by artificially increasing the fidelity difference between the leading and lagging strand (disparity mutator), evolution is accelerated while avoiding the extinction of the population. Using a disparity mutator, we should be able to improve living things, including multicellular organisms, within constrained conditions. A double-stranded algorithm, which mimics the structure and replication manner of DNA, is promising for solving optimization problems.—M. Furusawa M and H. Doi, 1998
Using genetic engineering based upon that theory, Neo-Morgan says it can improve the quality and capabilities of yeasts in a short time. It has already developed yeast that feeds on five-carbon sugars and is hurrying genetic analysis and field testing to boost efficiency.
Neo-Morgan is negotiating with Petrobras to supply its technology to improve the Brazilian oil company’s yeasts. Brazil accounts for nearly 40% of world ethanol-fuel consumption, and is the second-largest producer behind the US.
Neo-Morgan aims to commercialize its work in fiscal 2008 as a technology for mass-producing bioethanol at low cost.
“Asymmetrical DNA replication promotes evolution: disparity theory of evolution”; Furusawa M, Doi H.; Genetica. 1998;102-103(1-6):333-47