Fe protein (dinitrogenase reductase) activity is reversibly inactivated by dinitrogenase reductase ADP-ribosyltransferase (DraT) in response to an increase in the ammonium concentration or a decrease in cellular energy in Azospirillum brasilense, Rhodospirillum rubrum, and Rhodobacter capsulatus. The ADP-ribosyl is removed by the dinitrogenase reductase-activating glycohydrolase (DraG), promoti...

<p>The use of N<sub>2</sub>-fixing bacteria and growth hormone-producing rhizobacteria delivers nitrogen, enhances nutrients absorption by plants, reduces the usage inorganic fertilizers. Implementing biofertilizer in hydroponic system as a means to reduce application synthetic nutrient is recently interest due economic, food safety, sustainability factors. This study determin...

Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria which have the ability to colonize the roots and either promote plant growth through direct action or via biological control of plant diseases (Kloepper and Schroth 1978). They are associated with many plant species and are commonly present in varied environments. Strains with PGPR activity, belonging to genera Azoarcus, Azospi...

Plant growth promoting rhizobacteria (PGPR) have originally been defined as root-colonizing bacteria that cause either plant growth promotion or biological control of plant diseases. The mechanisms by which PGPR promote plant growth are not fully understood, but it is believed that the plant growth promoting rhizobacteria enhance plant growth and yield either by direct or indirect mechanisms. T...

This study was carried out during 2004 and 2005 seasons on eight years old Arabi pomegranate trees grown in sandy soil to investigate the influence of microbial biofertilization on tree growth, yield, fruit quality and leaf minerals content. Microbial inoculum (Azotobacter spp. Azospirillum spp. and Bacillus megatherium which found in (Biogein, Nitrobine, phosphorein), in addition, arbuscular m...

This paper presents the efficacy of PGPR (Azospirillum and Pseudomonas) and its modulation by salicylic acid. Two hybrids of sunflower (Hysun and Parsun) were inoculated with Azospirillum spp. and Pseudomonas spp. prior to sowing. Salt stress (20 dSm) was applied 28 d after sowing followed by foliar spray of salicylic acid (100 μM) after 4 h of salt treatment. Azospirillum and Pseudomonas inocu...

Two free-living nitrogen-fixing bacterial strains, N6 and N7(T), were isolated from corn rhizosphere. A polyphasic taxonomic approach, including morphological characterization, Biolog analysis, DNA-DNA hybridization, and 16S rRNA, cpn60 and nifH gene sequence analysis, was taken to analyse the two strains. 16S rRNA gene sequence analysis indicated that strains N6 and N7(T) both belonged to the ...

The glnZ mutant of Azospirillum brasilense (strain 7611) showed only partial recovery (20 to 40%) after 80 min of ammonia-induced nitrogenase switch-off, whereas the wild type recovered totally within 10 min. In contrast, the two strains showed identical anoxic-induced switch-on/switch-off, indicating no cross talk between the two reactivation mechanisms.