The objectives of this study were to count and culture Azotobacter spp. in sampled soils, to determine the nitrogen (N) fixing capacity byAzotobacter spp. in pure culture and different soils, and to explore the relationships between N fixation capacity of Azotobacter spp. and microbiological properties of soils in Northern Anatolia, Turkey. Statistically significant relationships were found bet...

In order to evaluate the effects of inoculants and chemical fertilizer on quantitative and qualitative yield, a bread wheat cultivar treated with Azotobacter, arbuscular mycorrhiza fungi (AMF) and nitrogen sources by using split plot on the basis of randomized complete block design with three replications in Fars Agricultural Research Station during 2007-2008. Main plots consisted of nitrogen f...

In crude cell-free extracts of Azotobacter chroococcum, nitrogenase was much less sensitive to irreversible inactivation by O2 than was the purified enzyme. When nitrogenase was partially purified by anaerobic discontinuous sucrose-density-gradient centrifugation, O2-tolerance was retained. This preparation was considerably enriched in four polypeptides, three of which were derived from the Mo-...

Microbial communities in rhizosphere interact with each other and form a basis of a cumulative impact on plant growth. Rhizospheric microorganisms like Piriformospora indica and Azotobacter chroococcum are well known for their beneficial interaction with plants. These features make P. indica/A. chroococcum co-inoculation of crops most promising with respect to sustainable agriculture and to und...

The presence of Azotobacter sp. in soils has beneficial effects on plants, but the abundance of these bacteria is related to many factors, especially soil pH and fertility. The presented study evaluated the abundance of Azotobacter sp. in various soils of southern Poland and confirmed the relationship between soil properties and the presence of these bacteria. Diagnostic tests indicate that all...

Four types of utilization of nitrate nitrogen were observed with fourteen strains of the azotobacter. These were: (a) Those which utilize NO;-N with no or only a short lag; three strains of Azotobacter winelandii, a stock culture of A. chroococcum C-77, and seven strains of A. chrmoccum freshly isolated from soil were in this group; (b) A single strain, a stock culture of A. chroococcum C-44, w...

Strains of aerobic, microaerobic, nonsymbiotic, and symbiotic dinitrogen-fixing bacteria were screened for the presence of alternative nitrogenase (N2ase) genes by DNA hybridization between genomic DNA and DNA encoding structural genes for components 1 of three different enzymes. A nifDK gene probe was used as a control to test for the presence of the commonly occurring Mo-Fe N2ase, a vnfDGK ge...