Abstract
Seven isolates from the histoplane (Cs-1, Cs-2, Cs-3, Cs-4) and rhizoplane (RCs-1, RCs-2, RCs-3) of Convolvulus arvensis, growing in saline area were obtained. They were gram-negative motile rods (except Cs-2 which was gram negative motile cocci) and could tolerate 2.0-3.0M NaCI in the medium. Optimal salt concentration for their growth was 0.5M (Cs-2. Cs-3, RCs-1, RCs-3), 1.0M (Cs-4, RCs-3) and 1.5M (Cs-1). hence all of them were moderately halophilic bacteria. Strains Cs-4 and RCs-2 shared characters with genus Haloinonus. while others belonged to group gram-negative facultative anaerobic rods (except Cs-2). Tolerance level to salts such as NaHCO3, Na)SO4, MgSO4, KNO3 and KC1 varies for different strains. Depending upon the strain temperature for maximum growth of these bacteria was 28`C (Cs-4, RCs-2). 32°C (RCs-1, RCs-3), 37°C (Cs-2, Cs-3) or 42°C (Cs-1), They exhibited wide pH range with optimal pH 8 (except for Cs-2 where it was 9) in the presence of 1M NaCI, thus belonging to moderately alkaliphilic -.bacteria. However their pH optima varied from 5-10 m the absence of NaCI. These strains confer resistance to kanamycin in the presence of 1M NaCI but not in its absence. Whereas resistance behaviour to ampicilline was different for different strains. They also exhibited multiple resistance to different metallic salts. Apart from Cs-2, other strains harbor plasmid/s.
AZRA YASMIN , SHAHIDA HASNAIN . (1998) ROOT ASSOCIATED MODERATELY HALOPHILIC AND ALKALIPHILIC BACTERIA FROM CONVOLVULUS ARVENSIS, Punjab University Journal of Zoology, Volume 13, Issue 1.
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