Isolation and characterization of efficient Phosphate Solubilizing Bacillus (PSB) from different agro-ecological zones of Tigray soil, Ethiopia

  • F.G. Kibrom
  • W. Alemayehu
  • V.R. Prakasam
  • W. Kiros


Applications of biofertilizer have great practical importance for increasing fertility of the soil and reducing environmental pollution. Screening and characterizing phosphate solubilizing Bacillus (PSB) strains from different agroecologies of Tigray  soil and in vitro assessment for the adaptability under different abiotic stress would help in selecting the most efficient strain for use as biofertilizer. A total of 64 soil  samples were collected from different agro-ecological zones of Tigray and checked for the presence, capability and efficiency of PSB. Out of 64 soil samples 21 of them were phosphate solubilizing. These phosphate solubilizing strains again incubate at 37˚C for 48h on pikovskaya medium to see efficacy of phosphate solubilization.  Highest efficiency was recorded in MUB28, MUB47and MUB64 isolates and also  tolerant to acidity and alkaline up to pH4 and pH8, respectively. And difference was  recorded in saline tolerance among the strains: MUB47 is the most saline tolerance strain which tolerate saline up to 513mM of sodium chloride (NaCl) but MUB28 and MUB64 have tolerated saline up to 340mM of NaCl. The identification of efficient PSB candidate strains with salt & pH tolerant features in the soil sample could have an implication on the end-users to obtain the desired beneficial effect such as maintaining soil healthy, provision of adequate phosphorus from soil to the plant and improving crop yield of Tigray Agriculture. Based on the morphological, microscopic, biochemical and physiological characterization, it may be inferred that the diversity among these efficient PSB strains is low.

Keywords: Biofertilizer, Phosphate solubilizing Bacillus, Efficiency, Diversity, Agroecology, Adaptability, Ethiopia.


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eISSN: 2073-073X
print ISSN: 2073-073X