Study the growth of bacteria and salt-tolerant ability in nitrogen fixation among the salt air.


Salinity tolerant bacteria were isolated from salinity affected soil samples byAshby's medium. The isolates were purified and identified based on morphologyand biochemical's tests. Results showed five isolates related to, Azotobacter Spp.Their salt tolerance capability tested in growth and nitrogen fixation with mediumscontent 0.0%, 1.5% , 3.0% , 4.5% , 6% , 7.5% and 10.0% NaCl,. Results showedall isolates could grow in 0.0% - 3.0% NaCl ,and A1 , A4 isolates could grow in4.5% NaCl. While only A1 isolate can grow in 6.0 % NaCl .The isolate A1 wassuperior in Nitrogen fixation (6.70 mg N gm-1) whereas the lowest amount ofnitrogen fixation (1.98mg N gm-1 )was with A3 isolate. Salinity tolerantAzotobacter Spp. has attracted the attention of agriculturists as soil inoculums toimprove the plant growth and yield in salinity soils.