NOVELTY - Making a biofuel comprises providing a biocatalyst selected to convert a feedstock into the biofuel at a yield of at least 80% of theoretical, a productivity of at least 0.75 grams biofuel per liter per hour, and a titer equivalent to a lower one of a solubility limit of the biofuel in water under the process conditions and 2% (w/w) of the biofuel in water; providing the biocatalyst; and recovering the biofuel.    USE - The method is useful for producing or making a biofuel (claimed). Specifically, the method is useful for producing biofuel from biomass.    ADVANTAGE - The invention provides a method for economical production of biofuel from biomass.    DETAILED DESCRIPTION - Making a biofuel comprises providing a biocatalyst selected to convert a feedstock into the biofuel at a yield of at least 80% of theoretical, a productivity of at least 0.75 grams biofuel per liter per hour, and a titer equivalent to a lower one of a solubility limit of the biofuel in water under the process conditions and 2% (w/w) of the biofuel in water; providing the biocatalyst selected to have at least two properties from: (a) the biocatalyst selected to convert at least two sugars, including each of at least one of a six-carbon sugar and a six-carbon sugar oligomer, and at least one five-carbon sugar, derived from at least one of starch, cellulose, hemicellulose, and pectin into the biofuel; (b) the biocatalyst exhibiting a fewer level of endotoxin toxicity or exotoxin toxicity, where the level of endotoxin or exotoxin toxicity in the biocatalyst has a median lethal dose (LD50) of at least 1000-fold more than the amount present in 1 kilogram of at least one of distillers dried grains (DDG) and distillers dried grains and soluble (DDGS) product; (c) the biocatalyst containing no DNA markers; (d) the biocatalyst operable to produce the biofuel free of byproducts that would require additional processing steps for removal from the biofuel; (e) the biocatalyst operable at a pH value between about 2-10 to produce the biofuel; (f) the biocatalyst selected to have a recoverable productivity from a sudden change of about 1 pH unit from the first pH; (g) the biocatalyst operable within a temperature range of about 20-60 degrees C to produce the biofuel; (h) the biocatalyst selected to have a recoverable productivity from a sudden change of about 5 degrees C from the first temperature; (i) the biocatalyst operable in a medium comprising feedstock; (j) the biocatalyst selected to have a growth rate of at least 0.2 per hour; (k) providing a facultative anaerobic biocatalyst operable at dissolved oxygen concentrations across a range of about 0% to about 0.01% air saturation to produce the biofuel; and (l) providing an anaerobic biocatalyst selected to have a productivity that recovers from an exposure to more than 1% air saturation that lasts for up to three hours; and cultivating the biocatalyst in a culture medium until a recoverable quantity of the biofuel is produced; and recovering the biofuel. INDEPENDENT CLAIMS are: (1) a biofuel produced by the method comprising a 14C/12C ratio of 1:0 to about 0:11; (2) an isolated or recombinant biocatalyst comprising a recombinant biochemical pathway to produce isobutanol from fermentation of a suitable bio-mass, where the recombinant biochemical pathway comprises elevated activity of: (a) a KARI as compared to a parental microorganism; and (b) acetolactate synthase (ALS) as compared to a parental microorganism, where the biocatalyst produces recoverable amounts of isobutanol; where the recombinant biochemical pathway comprises decreased activity of: (a) a dihydroxyacid dehydratase (DHAD) as compared to a parental microorganism; and (b) a kivd as compared to a parental microorganism, where the biocatalyst produces recoverable amounts of isobutanol; or where the recombinant biochemical pathway comprises decreased activity of: (a) DHAD as compared to a parental microorganism; and increased activity of: (b) ALS is broader as compared to a parental microorganism; and (c) KARI as compared to a parental microorganism; (3) an isolated or recombinant biocatalyst comprising a genotype of Escherichia coli BW25113, and further comprising a genotype of delta-ldhA-fnr::FRT, delta-adhE::FRT, delta-frd::FRT, delta-pta::FRT, pflB::FRT, delta-mdh::FRT, delta-aceF::FRT F'(laclq+), pSA55, and pSA69, where the isolated or recombinant biocatalyst produces isobutanol from a carbon source; and (4) an isolated or recombinant nucleic acid comprising pLlacO1:alsS::ilvC::ilvD, p15A, and Cm; an isolated or recombinant nucleic acid comprising pLlacO1::kivd::ilvDco, pSC101, and kanamycin resistance cassette (Kan); an isolated or recombinant nucleic acid comprising PLlacO1::alsS::iivCco, CoIE1, and Amp; or an isolated or recombinant nucleic acid comprising pLlacO1::pntAB, pSC101, and Kan.