NOVELTY - A recombinant Zymomonas mobilis 31821/pZB5 strain (I) derived from Z. mobilis ATCC 31821 capable of producing ethanol upon fermentation of xylose to enhance xylose utilization, comprising exogenous genes encoding xylose isomerase, xylulokinase, transaldolase and transketolase, the genes fused to promoter recognized by Zymomonas which regulates the expression of genes, is new.    USE - (I) is useful for producing ethanol from fermentable carbohydrate substrate medium by culturing in the medium without pH control or at a pH range of 4.5- 6.5, (I) which is characterized by ethanol productivity at 25-45 degrees Centigrade and utilizes 99% or 96% of xylose to effect a fermentation reaction to provide improved yields of ethanol, and recovering the ethanol produced. The temperature is from about 30-37 degrees Centigrade. The fermentable carbohydrate substrate is xylose or a mixture of glucose and xylose. Glucose is present in about 1.5% and xylose is present in about 3.5%, preferably in about 5%. The fermentation reaction is carried out for about 69 hours. The pH is about 5.5 and the temperature is about 30 degrees Centigrade. The glucose is present in an amount of about 12 weight% (wt.%) and the xylose is present in an amount of about 3 wt.% (claimed).    DETAILED DESCRIPTION - (I) derived from Z. mobilis ATCC 31821 or its derivative capable of producing ethanol upon fermentation of a carbohydrate medium containing xylose to provide enhanced xylose utilization and enhanced ethanol process yield, the strain or its derivative comprising exogenous genes encoding xylose isomerase, xylulokinase, transaldolase and transketolase, the genes are fused to at least one promoter recognized by Zymomonas which regulates the expression of at least one of the genes, is new.    INDEPENDENT CLAIMS are included for the following:    (1) production of (I); and    (2) a biofuel (II) comprising a combination of a mixture of (I) and ethanol.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic of the pathways required to enable Z. mobilis to ferment xylose.