NOVELTY - An isolated bacterial, fungal or yeast cell having increased upstream cys P ((putative oxidoreductase) UcpA) activity as compared to a reference bacterial, fungal or yeast cell, where the bacterial, fungal or yeast cell having increased UcpA activity exhibits increased tolerance to furfural and/or 5-hydroxymethylfurfural (5-HMF), is new.    USE - The isolated bacterial, fungal or yeast cell is useful for producing desired products chosen from ethanol, lactic acid, succinic acid, malic acid, acetic acid, 1,3-propanediol; 2,3-propanediol; 1,4-butanediol; 2,3-butanediol, butanol, pyruvate, dicarboxylic acid, adipic acid and amino acid (all claimed).    ADVANTAGE - The isolated bacterial, fungal or yeast cell has increased UcpA activity and furfural and/or 5-HMF resistance. The isolated bacterial, fungal or yeast cell exhibits increased production of the desired products as compared to the reference bacterial, fungal or yeast cell in the presence of furfural and/or 5-HMF.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) preparation process of the above-mentioned isolated bacterial, fungal or yeast cell;    (2) method (M1) for growing bacterial, fungal or yeast cell, involves culturing the above-mentioned bacterial, fungal or yeast cell under conditions that allow growth of the bacterial, fungal or yeast cell;    (3) method (M2) for producing desired product from biomass, hemicellulosic biomass, lignocellulosic biomass, cellulosic biomass or an oligosaccharide source, involves contacting the above-mentioned biomasses with the above-mentioned isolated bacterial, fungal or yeast cell, and producing the desired product by fermenting the biomasses in presence of the bacterial, fungal or yeast cell; and    (4) method (M3) for increasing furfural and/or 5-HMF resistance in the bacterial, fungal or yeast cell, involves increasing UcpA activity in the bacterial, fungal or yeast cell, as compared to reference bacterial, fungal or yeast cell, where the bacterial, fungal or yeast cell having increased UcpA activity increases resistance of the bacterial, fungal or yeast cell to furfural and/or 5-HMF.