NOVELTY - A transformed microorganism capable of: (a) converting an aldopentose to a ketopentose at a higher rate than the equivalent microorganism prior to transformation; (b) a higher growth rate in the presence of aldopentose than the equivalent microorganism prior to transformation; and (c) a higher metabolism of aldopentose than the equivalent microorganism prior to transformation, is new.    USE - The microorganism is useful for the production of a pentose derived product and for the production of a biofuel (all claimed).    ADVANTAGE - The transformed microorganism is capable of converting an aldopentose to a ketopentose at a higher rate than the equivalent microorganism prior to transformation, is capable of a higher growth rate in the presence of aldopentose than the equivalent microorganism prior to transformation, and is capable of a higher metabolism of aldopentose than the equivalent microorganism prior to transformation (all claimed). The microorganism allows an increase in the rate of inter-conversion between aldopentose anomers and the intracellular conversion of aldopentoses to ketopentoses; it relieves a rate-limiting constraint, which in turn allows for a faster and more efficient production of ethanol by the pentose phosphate pathway than compared to the equivalent microorganism prior to modification.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are:    (1) an inoculum comprising the microorganism;    (2) a culture medium comprising the microorganism;    (3) a method for preparing a transformed microorganism capable of producing a pentose derived compound;    (4) a method for preparing a transformed microorganism capable of converting an aldopentose to a ketopentose at a higher rate than the equivalent microorganism prior to transformation;    (5) a method for preparing a transformed microorganism capable of a higher growth rate in the presence of aldopentose than the equivalent microorganism prior to transformation;    (6) a method for preparing a transformed microorganism capable of a higher metabolism of aldopentose than the equivalent microorganism prior to transformation;    (7) a method for producing a pentose derived compound comprising culturing in a culture medium the microorganism;    (8) a method for producing a biofuel comprising culturing in a culture medium the microorganism; and    (9) a biofuel obtained by the method above.