Patterns of protein synthesis in the moderately halophilic bacterium Deleya halophila in response to sudden changes in external salinity

Exposure of the moderately halophilic bacterium, Deleya halophila, to high NaC1 concentrations (2 or 2.5 M) resulted in a transient cessation of cell division. The time taken for the cells to adapt and grow depended on the final salt concentrations. During the initial phases of adaption to high salt both the rate of protein synthesis and amino acid uptake were transiently inhibited. The extent and duration of the inhibition was dependent on the magnitude of the salt shock. Alterations in the patterns of pulse-labelled proteins were observed during adaption to high salt. The response of Deleya halophila cells to decreasing salinity (2.5 to 1 M NaC1) was also characterized by distinct changes in the protein profiles, whereas minor changes in the protein patterns were observed during adaptation from 1 M to 0.5 M NaC1. The labelled protein patterns of cells grown in 1 M or 2.5 M NaC1 appear to be similar but not identical.