New technologies for cellulose and ethanol produced by microorganisms

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The Japanese company Gekkeikan has developed a new technology for producing ethanol from cellulose, in which only microorganisms are used to ferment inedible plants. The first step in this research was to produce large amounts of cellulase using Aspergillus in solid culture. The company claims that they transferred the gene for cellulose-degrading enzymes into Aspergillus, and that a promoter sequence was found on the Aspergillus chromosome that can significantly increase the production of these enzymes. Gekkeikan Company refers to Aspergillus with this gene as \"super Aspergillus\". The first step in producing bioethanol from cellulose is to degrade cellulose into glucose. Due to the relatively stable chemical properties and complex structure of cellulose, the methods currently used for its degradation require the addition of sulfuric acid or treatment under high temperature and pressure. This process requires a large amount of water to dissolve the raw materials, and additional energy is needed for distillation to purify ethanol after fermentation. In Japanese brewing plants, molds are first cultivated in solid rice; the enzymes produced by these molds break down the rice flour into glucose, and finally yeast ferments this glucose to produce alcohol. Inspired by this process, Gekkeikan Company developed new strains that can be cultured in a solid state and degrade cellulose into glucose. This process does not require a large amount of water, and it also saves the energy needed for distillation after fermentation. In March 2008, the company developed a strain of super yeast capable of breaking down water-soluble cellulose into glucose, which is needed for ethanol fermentation. During the pretreatment process, solid cellulose is dissolved into water-soluble cellulose. Super molds and super yeasts can be used together: first, the mold degrades cellulose into water-soluble cellulose, and then the yeast ferments it into alcohol. Gekkeikan Company stated that it will continue to focus on research aimed at increasing the production of cellulase by super molds. Gekkeikan Company and its collaborators will present their research findings at the conference held by the Japanese Society for Biotechnology from August 27 to 29, 2008.