Bacillus sp.BCLRB2: An efficient diazotrophic Halotolerant PGPB strain

Abstract

Novel agricultural technologies are required to improve food production in saline and dry soils. Based on a finding made by farmers who noticed a good growth and a reduced incidence of phytopathogenic infections of wheat grown between the rows of olive trees, we have screened diazotrophic endophytic PGPB associated with olive tree for plant stress tolerance improving capability. Strains were selected following a biochemical characterization of plant growth promotion activities such as ability of antimicrobial production, azote fixation, ACC deaminase production, growth hormone production, Phosphate solubilization… Among the selected strains, BCLRB2 was the strain that shown the most efficient capacity to fix atmospheric nitrogen, which is the most prominent factor of all plant growth parameters under stressful environments. The strain BCLRB2, identified as Bacillus sp, had ACC deaminase, and highly stimulatory effect in vitro associated with high production of hydrolytic enzymes, AIA, and solubilization of tricalcium phosphate. The efficiency of BCLRB2 strain was explored for in vivo pot plant growth. As a result, inoculated plants with Bacillus sp. BCLRB2, showed the best growth of durum wheat seedlings compared to a control under salt stress and natural conditions. Total length, fresh weight, and total dry weight were significantly higher in inoculated plants compared to uninoculated ones. The Bacillus sp.BCLRB2 is approved to be an efficient diazotrophic Halotolerant PGPB strain