In the production of cellulose ethanol from plant biomass, the cellulose in the plant matter is broken down into simple sugars, so that microorganisms can convert these sugars into ethanol. This breakdown step (also known as "saccharification" or "hydrolysis") is usually achieved by the addition of cellulose-degrading enzymes, called "cellulases". The cost of cellulase enzymes is considered to be one of the factors contributing to the high production cost of cellulose ethanol. This factor is also considered as one of the reasons why full commercial-scale production of cellulose ethanol has not yet completely taken off. Recently, Genencor (a global biotechnology company) launched a new class of enzyme (called "Accelerase 1500"), which can reportedly help reduce the cost of cellulose ethanol production. "Accelerase 1500" is an improved enzyme product with higher activity which can translate to "higher ethanol yields and effective operation in a wider variety of processes." The cellulase enzymes in the product are obtained by a fermentation process using a genetically modified microbial strain of Trichoderma reesei..