conclusions: it was concluded that increasing the concentration of zinc in the agricultural soil is harmful to beneficial microorganisms and reduces the soil fertility. a 20-ppm zinc concentration in soil is suggested to be optimal. background: zinc is an essential micronutrient used in the form of zinc sulfate in fertilizers in the agriculture production system. nitrogen-fixing microorganisms ...

This study aimed to select and characterize bacterial strains with multiple plant growth promotion properties able to tolerate drought and salinity stress in order to improve plant growth performance under abiotic stresses. Plant growth promoting activities were evaluated in 106 bacterial strains isolated by soil, compost, lignocellulosic biomasses and food matrices. Two strains A. chroococcum ...

Asymbiotic and associative diazotropic bacteria such as Azotobacter and Azosprillum, respectively are widely distributed in different rhizospheric and nonrhizospheric soils and help in growth and development of plants. Sixty two soil samples were collected from different crop rotations namely Rice-Wheat, Vegetables, Agro forestry and Grassland from the districts Chandauli, Jaunpur,Ballia, Ghazi...

abstract soil beneficial microorganisms such as plant growth promoting rhizobacteria (pgpr) are able to enhance plant growth. the research was conducted using a randomized complete block design as split plot factorial with three factors (nutrient management, azospirillum and azotobacter strains) .in this experiment the effect of azospirillum and azotobacter inoculation on yield and yield compon...

Detection of viable Azotobacter in soils stored in the laboratory for more than 10 years suggests that these bacteria can remain dormant in nature for prolonged periods of time. Studies of dried cultures show that cysts of A. vinelandii 12837 remain viable for at least 10 years, whereas vegetative cells do not survive for even 1 year under the same conditions.

Protein turnover occurs during differentiation of Azotobacter vinelandii 12837 to the extent of 50% during encystment and 7% during germination. The addition of rifampin at the initiation of encystment prevents encystment and inhibits turnover. In germinating cysts, protein turnover is essential owing to an apparent lack of certain amino acid biosynthetic enzymes. The capacity to synthesize sul...

The temperature characteristic of respiration of Azotobacter vinelandii possesses a constant value of 19,330 +/- 165 over the temperature range 20-30 degrees C. This value is independent of pH, oxygen tension, age of culture, and other factors within the limits studied. The optimum temperature of respiration is 34-35 degrees C., with limits at about 10 degrees and 50 degrees C.