A 1.7 kb DNA fragment containing both the zliE and zliS genes complements the sucrose-deficiency of the mutant, Z6C-S2, derived from Zymomonas mobilis ATCC 29191, and the mutant containing both genes produces sucrose-hydrolyzing enzymes extracellularly. The mutant containing zliE accumulates the enzymes within the cells, while that containing zliS does not produce the enzymes (Kondo, T. et al., Biosci. Biotech. Biochem., 58, 526-530, 1994). In the mutant cells containing zliE, most of the sucrose-hydrolyzing enzymes were bound on the cell surface, and these enzymes were liberated when incubated with either washing, suspension or extract of the cells containing zliS. These results suggest that a product of the zliS gene affects the cell membrane to stimulate the liberation of cell-associated proteins.