Authors: M.S.I. Khan*, Zahed U.M.
Khan and D. Khanam
Abstract
The experiment was
conducted at Soil Microbiology Laboratory of Soil Science Division of
Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during 2007. Ten
Rhizobium strains namely; S1
(KKP/06), S2 (SKP/06), S3 (CHB/07), S4 (MKP/07), S5
(SMP/07, S6 (MNP/07), S7 (KAB/07), S8 (BAB/07),
S9 (LLB/07) and S10 (PAB/07) were isolated from coastal
saline areas of Bangladesh. Morphological and bio-chemical characteristics of
the strains were studied in the experiment. It was identified that the Rhizobium
strains in the study were rod shaped, motile and gram negative. The isolates S1,
S3, S5 and S7 showed heavy and S2
and S10 showed medium growth in mannitol and sucrose and minimum
growth in glucose. The strains did not absorb dye. Most of the strains
hydrolyzed starch but not gelatin. The multiplication of the strains decreased
with increasing levels of salinity. The strains S1, S3 and
S10 showed more salt tolerance up to 12 dS m-1 salinity followed
by the strains S2, S5 and S6 (<8 dS m-1)
and S4 (<4 dS m-1). But
all the strains were tolerant or partially tolerant to acid medium and disliked
alkaline medium.