Growth and Induction of Salt-tolerance in Escherichia coli under Environment of Sea Water

Abstract

Escherichia coli cells (ATCC-9637) grew well in the artificial sea water (ASW) containing yeast extract (1 %), but the cell growth was repressed with increasing concentration of ASW; complete inhibition was observed in 2.5-fold strength ASW (× 2.5 ASW). However, if the cells had been previously incubated with the normal concentration of ASW for a short time (30min), they exhibited salt-tolerance and grew well even in the high salinity medium (×2.5 ASW). This induction of salt-tolerance was dependent on both the concentration of ASW and the suitable organic solutes such as yeast extract. The salt-tolerance was maintained for up to 2 weeks when cell were suspended in ASW, but not in distilled water. NaCl as an osmolyte, and Mg2+/Ca2+ were suggested to be important for the maintenance of the salt-tolerance. © 1996, Japanese Society of Microbial Ecology & The Japanese Society of Soil Microbiology. All rights reserved.