Archaea, bacteria and termite, nitrogen fixation and sustainable plants production

Certain bacteria and archaea are responsible for biological nitrogen fixation. Metabolic pathways usually are common between archaea and bacteria. Diazotrophs are categorized into two main groups namely: root-nodule bacteria and plant growth-promoting rhizobacteria. Diazotrophs include free living bacteria, such as Azospirillum, Cupriavidus, and some sulfate reducing bacteria, and symbiotic diazotrophs such Rhizobium and Frankia. Three types of nitrogenase are iron and molybdenum (Fe/Mo), iron and vanadium (Fe/V) or iron only (Fe). The Mo-nitrogenase have a higher specific activity which is expressed better when Molybdenum is available. The best hosts for Rhizobium legumiosarum are Pisum, Vicia, Lathyrus and Lens; Trifolium for Rhizobium trifolii; Phaseolus vulgaris, Prunus angustifolia for Rhizobium phaseoli; Medicago, Melilotus and Trigonella for Rhizobium meliloti; Lupinus and Ornithopus for Lupini, and Glycine max for Rhizobium japonicum. Termites have significant key role in soil ecology, transporting and mixing soil. Termite gut microbes supply the enzymes required to degrade plant polymers, synthesize amino acids, recycle nitrogenous waste and fix atmospheric nitrogen. The positive effects of Arbuscular mycorrhizal (AM) fungi such as growth promotion, increased root length, leaf area, stem diameter, transplant performance and tolerance to stresses have been reported previously.

Complete Genome Sequence of Rhizobium japonicum Podophage Pasto

ABSTRACT Rhizobium japonicum is a Gram-negative bacterium of interest for research into nitrogen fixation in legumes. This article describes the isolation, sequencing, and annotation of R. japonicum podophage Pasto. While it shows no significant similarity to identified phages, genomic analysis indicates that Pasto may be temperate and is a novel T7-like podophage.

Karakteristik Bakteri Rhizobium japonicum Bintil Akar Kedelai pada Cekaman Salinitas Bertingkat

Kenaikan suhu permukaan bumi berimbas pada naiknya permukaan air laut ke daratan, hal inilah yang menyebabkan garam-garam yang dikandung oleh air laut akan mengalami sedimentasi di tanah yang dilewatinya. Tanaman kedelai yang tercekam salin dapat menurunkan hasil produksi tanaman karena garam yang terlarut dapat menurunkanpotensial larutan tanah sehingga tanaman mengalami kekurangan air. Teknologi khusus yang digunakan untuk menunjang pertubuhan dan hasil tanaman kedelai di lahan salin adalah penggunaan pupuk hayati, yang salah satunya berasal dari Rhizobium japonicum.Rhizobium japonicum merupakan bakteri rizosfer yang mampu menguraikan nitrogen bebas di udara menjadi unsur yang mampu terserap oleh tanaman. Nitrogen adalah unsur hara yang sangat penting dalam proses fotosintesis tanaman untuk menghasilkan fotosintat yang berguna untuk pertumbuhan dan produksi yang optimal. Penelitian ini bertujuan untuk mengisolasi dan mengkarakterisasi bakteri Rhizobium japonicum pada tingkat salinitas tertentu pada media YEMA+Congo Red,penelitian ini dilakukan pada bulan Juni 2019 sampai dengan September 2019 di Laboratorium Biosain Politeknik Negeri Jember. Penelitian ini dilakukan dengan menggunakan rancangan non parametrik dengan berbagai macam tingkat cekaman salinitas pada media yaitu: 0 ppm, 1000 ppm, 2500 ppm, 4000 ppm, dan 8000 ppm. Hasil penelitian menunjukkan koloni bakteri Rhizobium japonicum berbentuk bulat cembung berwarna putih sampai merah muda dan ukuran sel 2µ-4µ.

Zinc Oxide Nanoparticles (ZnONPs) as Nanofertilizer: Improvement on Seed Yield and Antioxidant Defense System in Soil Grown Soybean (Glycine max cv. Kowsar)

Herein, we investigated potential phytotoxicity of zinc oxide nanoparticles (ZnONPs) on seed yield, focusing on particle size-, morphology-, and concentration-dependent responses of multiple antioxidant defense biomarkers, in soil-grown soybean (Glycine max cv. Kowsar) during its lifecycle. To this end, we synthesized three types of morphologically unique ZnONPs (spherical/ 38nm, floral-like/ 59nm, and rod-like/ >500nm); all with high purity, triclinic crystal structure and negative surface charge; and compared the toxicity with Zn2+ ions. Each pot received two seeds, placed in soil inoculated with N-fixing bacteria (Rhizobium japonicum) and grown outdoor for 120 days. Our findings demonstrated a significant particle size-, morphology-, and concentration-dependent influence of ZnONPs on seed yield, lipid peroxidation, and various antioxidant biomarkers in soybean. Our spherical 38nm ZnONPs were the most protective compared to the floral-like 59nm ZnONPs, rod-like >500nm ZnONPs, and Zn2+ ions, particularly up to 160 mg/kg. However, at the highest concentration of 400 mg/kg, spherical 38nm ZnONPs elicited the highest oxidative stress responses (H2O2 synthesis, MDA, SOD, CAT, POX) in soybean compared to the other two morphologically different ZnONPs tested. The concentrationresponse curves for the three types of ZnONPs and Zn2+ ions were nonlinear (nonmonotonous) for all the endpoints evaluated. The results also suggest differential nano-specific toxicity of ZnONPs compared to ionic Zn2+ toxicity in soybean. Our higher NOAEL value of 160 mg/kg indicates the potential for ZnONPs to be used as a nanofertilizer for crops grown in Zn-deficient soils to improve crop yield, food quality and address malnutrition, globally.HighlightsParticle size-, morphology-, and concentration-dependent effects of ZnONPs tested.All Zn compounds (ZnONPs, Zn2+) promoted seed yield up to 160 mg/kg.Spherical 38nm ZnONPs elicited the least oxidative stress, except at 400 mg/kg.Concentration-response curves for all Zn compounds were non-linear.ZnONPs may serve as nanofertilizer for enriching Zn-deficit soil with Zn.Abstract FigureTOC Art

The Influence of the Tillage System and Fertilization on Soybean Yield at ARDS Turda, 2015-2017

Soybean is currently one of the most important agricultural crops being used in human and animal nutrition, as a raw material for industry but also has agro-phyto-technical importance because it contributes to the raising of soil fertility by fixing atmospheric nitrogen by symbiosis between soybeans and Rhizobium japonicum bacteria, which forms root-nodules. To achieve the aims, a poly-factorial experience has been placed during the period 2015-2017 at ARDS Turda, with the factors: Factor A - the tillage system (a1 the classical tillage system by plowing with the return of the furrow and a2 the minimum tillage system, chisel variant; factor B- the fertilization (b1-N20P20K0 100 kg/ha, applied simultaneously with sowing, b2-N20P20K0 100 kg/ha, applied simultaneously with the sowing + N20P20K0 100 kg/ha, applied in the 4-6 leaves phenophase, b3-N20P20K0 100 kg/ha applied simultaneously with sowing + N30 100 kg/ha, applied in the 4-6 leaves phenophase and b4-N20P20K0 100 kg/ha applied simultaneously with sowing + N20 100 kg/ha, applied in the 4-6 leaves phenophase, factor C-climatic conditions in the experimental years (c1-2015; c2-2016; c3-2017). The soybean variety studied was Malina TD. Following the application of the minimum tillage system, the yield decreases with a significant difference of 86 kg/ha compared to the conventional tillage system. A very significant influence in the yield of superior quantitative yields is fertilization, in the three variants where the supplementary fertilization was applied, there were obtained very significant yield increases of over 199 kg/ha compared to the control variant which produced a yield of 2373 kg/ha.

The Effect of Rhizobium japonicum on the Growth of Soybean Cultivars in Coastal Area

The natural resources of the coastal area in Indonesia have the potential to be developed as an agricultural land with the support of both cultivation technology and land processing, which one of them was done by using Rhizobium japonicum bacteria to meet the need of nitrogen in the soybean plants. This study aimed to determine the characteristics of nitrogen fixation in various soybean cultivars planted in the coastal area. The research was conducted in Mancingan, Parangtritis, Kretek, Bantul, DIY. The study was designed in Completely Randomized Design which consisted of two factors and was repeated three times. Factor I was Rhizobium japonicum inoculation (with inoculation and without inoculation); factor II was 10 various cultivars of soybean (Grobogan, Burangrang, Argomulyo, Anjasmara, Dena 1, Gema, Kaba, Wilis, Sinabung, Gepak Kuning). The results showed that the inoculation of Rhizobium japonicum in soybean cultivars in a coastal area could increase the number of root nodule, dry weight of root nodule, dry seed weight per plant, and harvest index. Burangrang cultivar planted in the coastal area was the most responsive to Rhizobium japonicum inoculation among other soybean cultivars tested.