RESPONSE OF AZOSPIRILLUM-BRASILENSE CD TO SODIUM-CHLORIDE STRESS

Citation
V. Rivarola et al., RESPONSE OF AZOSPIRILLUM-BRASILENSE CD TO SODIUM-CHLORIDE STRESS, Antonie van Leeuwenhoek, 73(3), 1998, pp. 255-261
Citations number
24
Categorie Soggetti
Microbiology
Journal title
ISSN journal
00036072
Volume
73
Issue
3
Year of publication
1998
Pages
255 - 261
Database
ISI
SICI code
0003-6072(1998)73:3<255:ROACTS>2.0.ZU;2-H
Abstract
Growth of Azospirillum brasilense Cd in the presence of different NaCl concentrations showed that it tolerates up to 200 mM NaCl in the medi um, without appreciable decline in growth rate. At 300 mM NaCl, a decr ease of 66% in growth was observed at 24 h of culture. At 48 h of cult ure, bacteria in the presence of 300 mM NaCl reached the maximum optic al density value that was attained at 12 h by control cultures. This i nvestigation was designed to elucidate the effect of saline stress on Azospirillum brasilense Cd and the physiologic mechanism involved in i ts possible salinity tolerance. For this reason, studies of other osmo lytes, as well as of putrescine metabolism and protein patterns were d one with bacteria grown with this NaCl concentration in the medium, at 24 and at 48 hours. A. brasilense responded to saline stress elevatin g the intracellular concentration of glutamate at 24 h, and of K+ at 4 8 h. Glucan pattern, putrescine metabolism, and total and periplasmic protein patterns of the treated group showed several changes with resp ect to the control. In spite of the several cellular functions affecte d by saline stress, the results imply that A. brasilense Cd shows sali nity tolerance in these experimental conditions.