Figure 4 suggested that the level of trehalose increased with the changes of the salt concentration within a certain range. The original strains S and T could accumulate most trehalose in corn juice in 9% salt, while the mutants was in 12% salt. And if out of the certain range, it would decrease which might be due to that trehalose was used as a carbon source, or the metabolism of yeast changed and the glucose was used to synthesize other compatibility substances.