Overexpression of a dhaT gene or its isozyme is a strategy that has been frequently applied to various Klebsiella strains, in order to improve their performance during glycerol fermentation. In a paper by Hao et al. [47] overexpression of homologous dhaTin K. pneumoniae caused no changes in 1,3-PD titer, but trig-gered significant redistribution in by-products: 2,3-butanediol andsuccinic acid levels were higher, whereas lactic acid, acetic acid,and ethanol levels were decreased in the recombinant compared to the parental strain. Similarly in Ref. [49], overexpression ofhomologous dhaT in K. pneumoniae did not affect the final concen-tration of 1,3-PD, but the concentrations of lactic acid, ethanol, and