Occurrence of plasmids in Zymomonas mobilis.

Abstract

A bacterium Zymomonasmobilis, which is used to make alcoholic palm wines in the tropics, produces up to 1.9 mol of ethanol from a mole of glucose through the Entner-Doudoroff pathway.1} Current interest in ethanol as a potential fuel from renewable resources has stimulated research on the organism. Recently, Rogers et al.2) have reported that Z. mobilis has a considerable higher ethanol productivity than yeasts. However, the range of fermentable sugars is limited merely to glucose, fructose and sucrose. Therefore, it is necessary to breed an organism able to produce alcohol from various sugar materials. Skotnicki et al. have selected a starting strain of Zymomonasfor genetic improvement of ethanol production,^and indicated the conjugal transfer of Rplasmid to Zymomonas.4) However, plasmid vectors suitable for genetic improvement of Zymomonashave not so far been found. In this paper we describe the occurrence of plasmids in three strains of Z. mobilis, subsp. mobilis IFO 13756, subsp. mobilis ATCC10988, and subsp. pomaceae IFO 13757.