Intercropping and plant growth-promoting rhizobacteria improve sustainability of agro-ecosystems. To evaluate the effect of AZOTOBACTER (AZOTOBACTER chroococcum) inoculation on productivity of a peanut /maize intercropping system, a two-year study was design as a randomized complete block in a factorial arrangement with three replicates at Astaneh-ye Ashrafiyeh, Guilan province. Factors were AZOTOBACTER inoculation [control (non-inoculated) and inoculated with AZOTOBACTER chroococcum) and intercropping pattern (Sole cropping of peanut and maize, additive intercropping pattern at three levels (100% peanut + 100% maize, 100% peanut + 50% maize, and 50% peanut + 100% maize), and replacement intercropping pattern at three levels (50% peanut + 50% maize, 67% peanut +33% maize, and 33% peanut + 67% maize). Results showed that gain yields of maize and peanut were significantly affected by AZOTOBACTER inoculation and intercropping pattern. Inoculation with AZOTOBACTER chroococcum significantly increased grain yields of peanut and maize by 10% and 16%, respectively. Maximum and minimum of land equivalent ratio (LER) were observed at 100% peanut + 50% maize and 50% peanut + 50% maize, respectively and inoculated intercropped plots with AZOTOBACTER chroococcum had 12-16% grater LER that non-inoculated ones. Regards to impossibility of mechanical weed control by machines in additive intercropping patterns, to obtain the highest productivity in maize/peanut intercropping system, intercropping pattern of 100% peanut + 50% maize along with AZOTOBACTER application will be suitable in fields with low weed density. Otherwise, based on LER and grain yield of peanut, the intercropping pattern of 67% peanut + 33% maize along with AZOTOBACTER application will be suitable.

Introduction Bean (Phaseolus vulgaris L. ) is one of the richest seeds in legumes. Scientific and correct use of bio and organic fertilizers are a strategy to reduce the accumulation of chemical materials in agricultural products, soil and water resources and living organisms. Mycorhizal fungi, Phosphate and Zn solubilizing bacteria are the sample of these bio fertilizers. The most important beneficial effects of mycorrhizal symbiosis is increase the nutrient uptake, water use efficiency, productivity, improve plant nutrition and resistance to environmental stresses. The results of mycorrhizae symbiosis research in different plants show that the increase uptake of nitrogen (N), Phosphorus (P), Potassium (K), Iron (Fe), Zn, Copper (Cu) and Manganese (Mn). Mycorrhizal fungi and plant growth promoting rhizobacteria (PGPR) such as AZOTOBACTER spp., and Pseudomonas spp. are able to increase uptake of nutrient elements particularly when they are applied with others. Phosphate and Zinc solubilizing bacteria facilitate uptake of slowly diffusing nutrient ions such as P, Zn, Fe and increase their availabilities usually by increasing volume of soil exploited by plants, spreading external mycelium, secreting organic acids, production of dehydrogenase and phosphates enzymes and reducing rhizosphere acidity. The main objective of this farm study was to evaluate the effect of using of P and Zn chemical and bio-fertilizers on yield, concentration and uptake of nutrient elements for the first time in two cultivars of bean in the Chaharmahal-va-Bakhtiari province. Material & Methods This field experiment was carried out as a factorial based on a randomized complete block design (RCBD) with three replications. The treatments of this research consisted of two cultivars of Chiti bean (Talash and Sadri), four levels of P (P0: Control, P1: Chemical fertilizer on the basis of soil test, P2: 50 percent of recommended P + bio-fertilizer (P), and P3: bio-fertilizer (P)), three levels of Zn (Zn0: Control, Zn1: 50 kg ha-1 Zinc sulphate, and Zn3: bio-fertilizer (Zn)). Bio-fertilizer (P) treatment consisted of using inoculum of P solubilizing bacteria from AZOTOBACTER chroococcum strain 5 and three species of mycorrhizal fungi from Glomus species (Clariodeoglumus etunicatum, Rhizophagus intraradices and Funneliformiss mosseae). Zn bio-fertilizer treatment consisted of using inoculum of Pseudomonas aeruginosa strain MPFM and Pseudomonas fluorescent strain 187. Chemical fertilizers were applied from TSP at a rate of 100 and 50 kg ha-1 in P1 and P2 respectively, 50 kg ha-1 ZnSO4. 7H2O in Zn1. After harvesting the seed yield and nutrient concentration were measured. The nutrient uptake was measured by multiple seed yield on nutrient concentration. Statistical analysis was done with SAS statistical software. Duncan’ s multiple range test was used to compare means. Results & Discussion The results of this experiment showed that there were significant difference between two cultivars on seed yield, nutrient concentration and nutrient uptake. The maximum values of studying parameters were obtained for Sadri cultivar (table 2 and 4). The effect of P treatment was significant on studying parameters, in a way P2 treatment in comparison with control treatment caused to increase seed yield (29%) Nitrogen (39%), P (98%), K (59%), Fe (32%), Zn (57%), Mn (45%) and Cu (22%) Uptake (Table 2 and 4). These results were agreement with findings of other researches. The effect of Zn treatment was significant on seed yield and nutrient concentration except Mn and nutrient uptake except P and Mn. The maximum nutrient uptake and bio enrichment except Fe was obtained from Zn1 (Table 2 and 4). Bean is one of the sensitive plants to Zn deficiency. In this study, the response to using Zn fertilizer was showed because of low soil Zn content. The antagonistic effect between P and Zn caused to decreasing concentration and uptake of P in Zn1 and Zn2. The interaction effect between P and Zn was significant on seed yield, nutrient concentration and uptake except P and Fe uptake. The maximum of studying parameters was obtained from P2Zn1 (Table 3 and 5). In this study, the dual inoculation with phosphate and Zn bio-fertilizers caused to increase nutrient concentration and uptake and improve seed enrichment especially elements with slowly diffusion ions such as P and Zn. It can be done with increasing mycorrhizal symbiosis, root colonization, phytosiderophores secretion, organic acids and chelated compounds production. Conclusion The results of this research revealed that individual and dual use of phosphate and Zn bio-fertilizers caused to increase seed yield, nutrient concentration and uptake in two studied cultivars of bean. Microorganisms used in biological treatments caused to increase the availability, concentration and uptake of nutrient elements. It can be done with increasing mycorrhizal symbiosis, root colonization and enhance secretion of siderophore compounds, organic acids and chelate compounds. Also, plant hormones and enzymes promoting growth increased with using of these bio treatments. In this research, the best treatment was using of mycorrhizal fungi with AZOTOBACTER inoculant and 50 kg ha-1 TSP and 50 kg ha-1 ZnSO4. 7H2O. (P2Zn1 treatment). With using integrated bio and chemical-fertilizers of P and Zn in addition to reduce chemical P fertilizers application can be produce health grain with high quality and rich of nutrients.

In the current work, AZOTOBACTER beijerinckii microorganism provided from Germany microbial bank is used.According to previous reports and the experiments conducted, it is inferred that the microorganism is able to accumulate poly (hydroxyl butyrate) granules in media containing high amounts of carbon sources and limited amounts of nitrogen sources. The effect of the different concentrations of carbon and nitrogen sources (glucose and ammonium chloride) on the cell dry weight (CDW), the amount of glucose used by the microorganism, and the amount of the produced biopolymer is investigated. Ammonium chloride with concentrations of 0.5 and 2 g.l-1 and glucose with concentrations of 30, 40, 50, and 60 g.l-1 were used as nitrogen and carbon sources respectively. The most of biopolymer was produced by glucose with a concentration of 60 g.l-1 and ammonium chloride with a concentration of 0.5 g.l-1. The highest biomass efficiency (Yx/s) was obtained by glucose with a concentration of 30 g.l-1 and ammonium chloride with a concentration of 2 g.l-1 and the highest production efficiency (Yp/s) was gained using a concentration of 30 g.l-1 of glucose and a concentration of 0.5 g.l-1 of ammonium chloride. The maximum productivity (Qp) was acquired in the media containing glucose with a concentration of 50 g.l-1 and ammonium chloride with a concentration of 1 g.l-1. The amount of biopolymer obtained through laboratory method was compared with response surface statistical method and the precision of the experiments conducted were examined. After extraction, Fourier-transform infrared (FT-IR) spectra and nuclear magnetic resonance (NMR) spectroscopy both verified the formation of biopolymer.

A field experiment was conducted at Rasht, in 2014, to investigate controlling weeds in native Hashemi cultivar paddy fields by different methods of herbicide applications and inoculated withAZOTOBACTER chroococcum. The factorial experiment based on a randomized complete block design with three replicates was performed.Factors were AZOTOBACTER application with two levels (inoculation with or without AZOTOBACTER chroococcum) and weed management regimes with six levels (pretilachlor plus a supplementary hand weeding, bensulfuron methyl plus a supplementary hand weeding, and pretilachlor+bensulfuron methyl plus a supplementary hand weeding, hand weeding during rice growing period+no herbicide, un-weeded during rice growing period+no herbicide). Results indicated that paddy rice yield was significantly increased by 16% afterAZOTOBACTER chroococcum inoculation. Rice paddy yield was significantly reduced in un-weeded plots compared to hand weeded and herbicide treated plots. ANOVA also revealed that there was no interaction effect between AZOTOBACTER chroococcumapplications and weed management regimes on paddy and biological yields, indicating that the herbicides had no adverse effect on AZOTOBACTER efficiency in promoting growth and paddy yield of rice. Weed dry weight was reduced by 88, 91, 92, and 94 percentages in weeded plot and plots treated with pretilachlor, bensulfuron methyl, and pretilachlor+bensulfuron methyl, respectively, compared to un-weeded plots.AZOTOBACTER chroococcum inoculation had no significant effect on weed biomass. Overall, the result of this experiment confirmed the feasibility of chemical weed control in paddy fields inoculated withAZOTOBACTER chroococcum.

The potential of three AZOTOBACTER chroococcum strains for whey degradation and alginate production were investigated. After dilution, samples were spread plated on isolation agar and Manitol agar and incubated at 30 °C for 24 h. Microorganisms were screened for their ability to whey degradation and alginate production based on colony morphology, negative and capsule staining, ability to decrease the apparent turbidity of the fermentation broths in batch and semi continuous culture by spectrophotometer assay at 400 nanometer and tensiometer assay. Of the three strains tested for whey degradation, only AZOTOBACTER chroococcum 1723 produced significant apparent growth on whey broth and could decrease about 70% of turbidity in fermentation broth during 6 days in batch culture. Colonies of this strain was characteristically yellow, large, moucoid and slimy on whey agar than Manitol agar after 24 h at 30°C. Transmission electron microscopy assay and Carbazole reagent were used to recognize the alginate biopolymer. After optimizing environmental factors such as pH, salt concentration and temperature, this strain was able to produce exopolysaccharide greater than 5 mg/mL. Optimum results were obtained when using whey broth as a fermentation medium without extra salt, temperature at 35 °C and pH 7. Increasing inorganic and organic nitrogen sources (yeast extract and NH4NO3) reduced whey degradation at least 30%. Transmission electron microscopy assay showed a net-structured polysaccharide capsule around the cells. Semi-continuous culture results demonstrated that, alginate production as well as whey degradation was decreased (1 mg/mL and 30 %).

AZOTOBACTER is an important bacteria in crop rhizosphere. This research aimed the isolation of local AZOTOBACTER under cultivation of soybean plant in Golestan province and their potential growth promoting-ability. After identification of 30 isolates their ability to molecular nitrogen fixation were tested with Acetylene to Ethylene reduction method. Their ability in auxin production and solubilizing the mineral P were tested with colorimetric method and sidrephore production potential was tested with Cas-agar medium. The maximum nitrogen fixation was in Az26 (428.23 nm.vial.h-1 ethylene) and minimum in Az27 (21.39 nm.vial.h-1 ethylene). Auxin production was highest in Az4 isolate (27.3 mg/l) and lowest in Az20 isolate (0.0157 mg/l). Also maximum sidrephore production was in Az9 and minimum in Az18 observed with diameter halo on colony of 6.36 and 2.24 in 72 hours respectively.