scholarly journals NITROGEN FIXING BACTERIA OF SPRING WHEAT ROOT ZONE

2013 ◽  
Vol 17 ◽  
pp. 7-20
Author(s):  
O. V. Nadkernychna ◽  
E. P. Kopylov

The paper presents the study of active nitrogen fixation bacteria of genera Azotobacter, Azospirillum, Bacillus, Flavobacterium, Enterobacter and Pseudomonas isolated from root zone of spring wheat plants. The ability of selected diazotrophs to form associative systems with spring wheat was investigated. The most significant increase of molecular nitrogen fixation activity in root zone of plants was observed under the Azospirillum species background.

1988 ◽  
Vol 34 (7) ◽  
pp. 886-890 ◽  
Author(s):  
Wung Yang Shieh ◽  
Usio Simidu ◽  
Yoshiharu Maruyama

Four strains of marine nitrogen-fixing bacteria were isolated from the roots of eelgrass (Zostera marina) and from sediments in an eelgrass bed in Aburatsubo Inlet, Kanagawa Prefecture, Japan. Significant levels of nitrogenase activity were detected in all four strains after a few hours of incubation under anaerobic conditions. Nitrogenase activity in all cases was Na+ dependent. These strains grew anaerobically or under conditions of low oxygen, using molecular nitrogen as the sole nitrogen source. Bacterial growth in liquid nitrogen-free medium was accompanied by a marked pH decrease during the exponential growth phase. Neither yeast extract nor vitamins were required for the nitrogen fixation activity of these strains. Taxonomically, all strains were facultatively anaerobic, Gram-negative rods. They were motile in liquid medium by means of a single polar flagellum and required NaCl for their growth. These characteristics, as well as the guanine + cytosine content of their DNA (43.5 – 44.8 mol%), placed them in the family Vibrionaceae. These strains, however, could not be identified to the genus level because they were distinct from the two halophilic genera Vibrio and Photobacterium of the family Vibrionaceae by a variety of characteristics.


2011 ◽  
Vol 12 ◽  
pp. 181-192
Author(s):  
O.O. Shahovnina

Potential activity of nitrogen fixation on washed roots of investigated varieties of spring triticale determined in field experiments has characterized by considerable fluctuations both during single phenophase in different years of research and throughout the vegetative period, that was caused by the influence of environment factors as well as by the existence of variability within the cultivar. The cultivar Oberig kharkovsky possesses the considerable polymorphism by the nitrogen fixation activity index in root zone of plants. Presowing inoculation of triticale seeds with active strain Azospirillum sp. 10 results in the increase of number of plants with higher nitrogen fixation activity on the washed roots.


2008 ◽  
Vol 6 ◽  
pp. 29-38
Author(s):  
V.V. Volkogon ◽  
O.I. Bakun ◽  
E.I. Volkogon ◽  
N.P. Shtanko ◽  
P.G. Dulnev

The influence of plant growth regulator triman-1 on nitrogen fixing bacteria and nitrogen fixation process in barley root zone was studied in the laboratory and field conditions. It was shown that triman- 1 enhances associative nitrogen fixation activity when mineral nitrogen fertilizers (N30) was used. The use of triman-1 increases efficiency of associative symbiosis more effectively with the use of carboammonium salts rather than with ammonium nitrate.


2009 ◽  
Vol 9 ◽  
pp. 138-146
Author(s):  
O.O. Shahovnina ◽  
O.V. Nadkernichna ◽  
Y.O. Vorobey ◽  
V.V. Krivopisha

Use of new strain of nitrogen fixing bacteria Azospirillum sp. 77 for inoculation of spring wheat and spring triticale permitted to form an effective associative system diasotroph - plant. The bacterization promoted the reliable increase of potential nitrogenase activity in root zone of plant by 38-220 %, activated the biosynthetic processes, in particular, glutamine synthetase activity increased by 57,0-71,9 %, content of protein in leaves - by 9,7-16,3 %, top of the plants - by 11,9- 18,9 %, weight of the roots - by 7,2-7,3 %.


2021 ◽  
Vol 25 (2) ◽  
pp. 56-63
Author(s):  
Ivana Pajčin ◽  
Vanja Vlajkov ◽  
Jelena Dodić ◽  
Aleksandar Jokić ◽  
Jovana Grahovac

Nitrogen is one of the essential elements for plant growth and development in terms of DNA and protein synthesis. Its main reservoir in nature is the atmosphere; however, inert molecular nitrogen present in the air isn't a suitable nitrogen form for plants' nutrition. Therefore it has to be chemically transformed to NH4 + or NO3 - ion by the process known as biological nitrogen fixation. Nitrogen fixation is carried out by free-living or symbiotic nitrogen-fixing prokaryotes (diazotrophs), including bacteria, archaea and cyanobacteria. In order to be used as plant inoculants for nitrogen fixation, the biomass of these prokaryotes must be produced and formulated appropriately through different biotechnological processes. The aim of this study is to summarize the main aspects of biotechnological production of plant inoculants based on nitrogen-fixing bacteria in terms of upstream processing, cultivation and downstream processing, with a special emphasis on cultivation media composition, cultivation conditions, biomass separation and formulation techniques.


1999 ◽  
Vol 65 (11) ◽  
pp. 4926-4934 ◽  
Author(s):  
Moriya Ohkuma ◽  
Satoko Noda ◽  
Toshiaki Kudo

ABSTRACT Nitrogen fixation by the microorganisms in the gut of termites is one of the crucial aspects of symbiosis, since termites usually thrive on a nitrogen-poor diet. The phylogenetic diversity of the nitrogen-fixing organisms within the symbiotic community in the guts of various termite species was investigated without culturing the resident microorganisms. A portion of the dinitrogenase reductase gene (nifH) was directly amplified from DNA extracted from the mixed population in the termite gut. Analysis of deduced amino acid sequences of the products of the clonally isolated nifHgenes revealed the presence of diverse nifH sequences in most of the individual termite species, and their constituents were considerably different among termite species. A majority of thenifH sequences from six lower termites, which showed significant levels of nitrogen fixation activity, could be assigned to either the anaerobic nif group (consisting of clostridia and sulfur reducers) or the alternative nif methanogen group among the nifH phylogenetic groups. In the case of three higher termites, which showed only low levels of nitrogen fixation activity, a large number of the sequences were assigned to the most divergent nif group, probably functioning in some process other than nitrogen fixation and being derived from methanogenic archaea. The nifH groups detected were similar within each termite family but different among the termite families, suggesting an evolutionary trend reflecting the diazotrophic habitats in the symbiotic community. Within these phylogenetic groups, the sequences from the termites formed lineages distinct from those previously recognized in studies using classical microbiological techniques, and several sequence clusters unique to termites were found. The results indicate the presence of diverse potentially nitrogen-fixing microbial assemblages in the guts of termites, and the majority of them are as yet uncharacterized.


2017 ◽  
Vol 25 ◽  
pp. 18-24
Author(s):  
V. V. Volkohon ◽  
A. M. Moskalenko ◽  
S. B. Dimova ◽  
M. A. Zhurba ◽  
K. I. Volkohon ◽  
...  

The paper covers the study of direct impact and after-effect of 40 t/ha of cattle manure on theorientation of nitrogen fixation and biological denitrification processes in the root zone of potatoes,spring barley, pea, and winter wheat plants in rotation in a stationary field experiments on leachedblack soil. Application of manure had significantly increased the nitrogen fixation activity, whilepromoting a high level of N2O emission. The use of microbial preparations for pre-seeding bacterization of seeds optimizes the course of biological nitrogen transformation process — through theenhancement of nitrogen fixation activity and reduction of gaseous nitrogen losses (with the exception of Biogran use on potatoes in the year of manure application). Introduction with manure of alarge number of microorganisms to the soil offsets the positive effect of biopreparations use. Yieldrecords and estimation of grain output per hectare within the crop rotation cycle indicates the practicability of combined application of manure and microbial preparations (excluding the year of direct effect of organic fertilizer) in organic agriculture.


2014 ◽  
Vol 1 (3) ◽  
pp. 57-61
Author(s):  
E. Kopylov

Aim. To study the specifi cities of complex inoculation of spring wheat roots with the bacteria of Azospirillum genus and Chaetomium cochliodes Palliser 3250, and the isolation of bacteria of Azospirillum genus, capable of fi xing atmospheric nitrogen, from the rhizospheric soil, washed-off roots and histoshere. Materials and meth- ods. The phenotypic features of the selected bacteria were identifi ed according to Bergi key. The molecular the polymerase chain reaction and genetic analysis was used for the identifi cation the bacteria. Results. It has been demonstrated that during the introduction into the root system of spring wheat the strain of A. brasilensе 102 actively colonizes rhizospheric soil, root surface and is capable of penetrating into the inner plant tissues. Conclusions. The soil ascomucete of C. cochliodes 3250 promotes better settling down of Azospirillum cells in spring wheat root zone, especially in plant histosphere which induces the increase in the content of chlorophyll a and b in the leaves and yield of the crop.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  

AbstractPrevious studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.


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