Phosphorous (P) is an essential nutrient element and plays an
important role in plant growth and development, it mostly presented in
form unavailable for plants. Phosphate Solubilizing Bacteria (PSB) can
be successfully used for solubilizing such forms rendering them available
for plants. Thirty-two PSB strains were isolated on a Pikovskaya (PKV)
agar medium containing Tricalcium Phosphate (TCP) and examined
for plant growth promoting effects. A high portion of isolates (68.8%)
produced Indole Acetic Acid (IAA) in contents ranging from 5 to 15
μgmL-1 and 12.5% produced salicylic acid (SA) in contents < 100 μgmL-1
while 50.0% fixed gaseous N2 nitrogen in medium deprived completely
of nitrogen. A portion of 28.1% produced cellulose enzyme and 15.6%
produced chitinase enzyme. In vitro tests showed that isolates were
capable in controlling some fungus plant pathogens and isolates were
resistance to some adverse conditions involving pH, temperature and
salinity. Use of 16s rDNA analysis and other procedures showed that
the most 3 effective isolates were Bacillus megaterium-MH142578,
Acinetobacter lwoffii-MH142579 and Acinetobacter lwoffii-MH142580.
The results of cluster analysis (Similarity index) showed that were high
and low similar values between the bacterial genera under studies. |
