Gluconacetobacter diazotrophicus : a natural endophytic diazotroph of Nile Delta sugarcane capable of establishing an endophytic association with wheat (original) (raw)
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Microbiological Research, 2004
Endophytic bacteria were isolated from the tissues of surface sterilized roots, stems, and leaves of fifty different crop plants. Phenotypic, biochemical tests and speciesspecific PCR assay permitted identification of four isolates of Gluconacetobacter diazotrophicus from root tissues of carrot (Daucus carota L.), raddish (Raphanus sativus L.), beetroot (Beta vulgaris L.) and coffee (Coffea arabica L.). Further the plant growth promoting traits such as nitrogenase activity, production of phytohormone indole acetic acid (IAA), phosphorus and zinc solubilization were assessed. Significant nitrogenase activity was recorded among the isolates and all the isolates produced IAA in the presence of tryptophan. Though all the four isolates efficiently solubilized phosphorus, the zinc solubilizing ability differed among the isolates.
Journal of experimental botany, 2001
Sugar cane (Saccharum spp.) variety SP 70-1143 was inoculated with Gluconacetobacter diazotrophicus strain PAL5 (ATCC 49037) in two experiments. In experiment 1 the bacteria were inoculated into a modified, low sucrose MS medium within which micropropagated plantlets were rooted. After 10 d there was extensive anatomical evidence of endophytic colonization by G. diazotrophicus, particularly in lower stems, where high numbers of bacteria were visible within some of the xylem vessels. The identity of the bacteria was confirmed by immunogold labelling with an antibody raised against G. diazotrophicus. On the lower stems there were breaks caused by the separation of the plantlets into individuals, and at these 'wounds' bacteria were seen colonizing the xylem and intercellular spaces. Bacteria were also occasionally seen entering leaves via damaged stomata, and subsequently colonizing sub-stomatal cavities and intercellular spaces. A localized host defence response in the form of...
Delta Journal of Science
Gluconacetobacter diazotrophicus (G.d) is a nitrogen-fixing, endophytic and non-nodulating bacterium isolated from sugarcane. The aim of this study was to investigate the effect of different G.d concentrations on tomato plants grown at very low nitrogen levels to examine its ability to colonize plant tissues and improve crop yield. Tomato seeds were inoculated with different doses of G.d (10 9 , 10 10 , and 10 11 CFU/ml) and grown in the glasshouse under nitrogen deficiency conditions. Estimation of endophytic bacterial population was performed by bio-PCRs analysis using specific primers for G.d. Three months after sowing, significant variations in the phenotypes and biomass production were observed: the inoculated plants with 10 10 and 10 11 of G.d-Nfix-3%sucrose showed increased plant height, root length, nitrogen content, and flower number. They also exhibited a healthier phenotype and higher fruit production in comparison to 10 9 of G.d-Nfix-3%sucrose and non-inoculated control plants. These results showed that coating tomato seeds with specific concentrations of G.d-Nfix-3%sucrose (10 10 and 10 11 CFU/ml) was an effective enhancer for crop production at low nitrogen levels and proved the ability of G.d to enhance production of tomato fruits. In conclusion, this study aimed to develop a natural nitrogen fixing seed coating technology to provide a sustainable solution to fertilizer overuse and nitrogen pollution. This technology is environmentally friendly because it based on a food-grade bacterium (G.d) derived from sugarcane. It aims to address the need of international market for sustainable agricultural fertilizers. Moreover, it provides a cost benefit to the farmers via reduced fertilizer costs and improved crops yields.
Studying the antagonistic activity of some Gluconacetobacter isolates and their
The family Acetobacteriaceae currently includes three known nitrogen-fixing species, Gluconacetobacter diazotrophicus, G. johannae and G. azotocaptans. In the present study, nitrogen fixing bacteria were isolated from sugarcane and rice roots cultivated in Aswan and Qalubia Governorates, respectively. Seven isolates from sugarcane roots and three isolates from rice roots gave the basis phenotypic characteristics of Gluconacetobacter sp. These isolates were examined for plant growth promotion activities such as indole acetic acid (IAA) and gibberellins (GA3) production in addition to their putative endophytic features such as cellulase and pectinase production. Rice seeds (Oryza officinalis) colonizing ability with the ten Gluconacetobacter isolates in vitro was examined. The ten Gluconacetobacter isolates were examined for their antagonistic activity against pathogenic fungi and bacteria in addition to their ability to produce hydrogen cyanide (HCN) and siderophores.Sodium dodecyle sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) is a technique used for the characterization and analysis of proteins for identification of bacterial isolates and yielding valuable information on the similarity and dissimilarity amongst bacterial cultures.
African Journal of Biotechnology, 2017
The genus Gluconacetobacter comprises different species with agricultural and industrial importance. This study aims at determining the presence of Gluconacetobacter diazotrophicus and Gluconacetobacter sacchari in sugarcane and tomato crops considering their potential biotechnological applications. Bacteria were isolated from roots, stems and leaf tissues and identified using phenotypic and biochemical evaluations, and molecular and phylogenetic analyses. Isolates were characterized by the production of indolic compounds, nitrogenase activity and phosphate solubilization. For this, G. diazotrophicus ATCC 49037 was used as the reference strain. The results showed that all isolates of native G. diazotrophicus exhibited equal or better phosphate solubilization index (SI) for CaCO 3 and AlPO 4 than reference strain. For G. sacchari, GIBI031 isolate displayed better SI for both phosphate sources and GIBI014 isolate had better SI only for AlPO 4. G. diazotrophicus GIBI029 had a greater production of indolic compounds than ATCC 49037 strain in the presence of tryptophan. All isolates except G sacchari GIBI031, showed better nitrogenase activity than the control. These results constitute the first report confirming the presence of G. diazotrophicus and G. sacchari associated with sugarcane in Colombia. In addition, this is the first report on the presence of G. sacchari in tomato under natural conditions. Finally, one G. sacchari isolate presented nitrogenase activity despite the fact that this is a differential characteristic between G. diazotrophicus and G. sacchari. These findings have ecological significance and will advance research towards the evaluation of plant-soil interactions involving these bacteria in crops other than sugarcane. The isolates found are potential candidates for the development of novel biotechnological processes for production of new alternative biofertilizers considering the significant plant-growth promotion properties determined in this work.
Isolation and Biochemical Characterization of Endophytic Bacterium Gluconacetobacter diazotrophocus from Native Sugarcane Cultivar of middle Gangetic Plains of India, 2024
The study focused on the isolation and characterization of Gluconacetobacter diazotrophocus, an endophytic bacterium obtained from various parts of a native sugarcane cultivar in India's middle Gangetic plains. Using conventional culturing methods, isolated and screened 115 isolates, ultimately selecting 15 highly efficient isolates based on their production of growth-promoting hormones. Among these, GdS08S, isolated from sugarcane cultivar CoP-9301, exhibited the highest nitrogen-fixing ability, with 153μg of N/mg of carbon used. Isolate GdS15S, from sugarcane cultivar Co-0238, produced the highest concentration of gibberellic acid (8.19μg/25ml). Additionally, GdS07R displayed notable phosphorus and zinc solubilization zones, measuring 4.22 cm and 4.52 cm, respectively. Gluconacetobacter diazotrophocus, residing within sugarcane tissues, plays a pivotal role in promoting rooting, cell elongation, and overall sugarcane growth through the biosynthesis of indole-3-acetic acid (IAA) and gibberellic acid (GA). Furthermore, it actively fixes atmospheric nitrogen, offering a significant nitrogen supply to the growing crops. This research underscores the significance of G. diazotrophocus as a potential biofertilizer for native sugarcane cultivars in the middle Gangetic plains of India, contributing to sustainable agriculture practices.
Endophytes are plant-associated prokaryotes that form association with their host plants by colonizing the internal tissues, which has made them valuable for agriculture as a tool in improving crop performance. Although the interaction between endophytes and host plants has not been fully understood, many bacterial species are reported to promote plant growth and the mechanism attributed includes nitrogen fixation, production of growth-promoting substances and increased resistance to pathogens and parasites. They have been reported from numerous plant species including sugarcane. Gluconacetobacter diazotrophicus (syn. Acetobacter diazotrophicus) -sugarcane association represents a model system for monocot-diazotrophic associations. This allows experimentation to answer questions pertaining to their establishment, colonization process, biological nitrogen fixation, growth promotion, etc. The main objective of this review is to summarize the recent works on this bacterium with special emphasis on its interaction with sugarcane. The topics being covered range from the sources of G. diazotrophicus, its classification and characteristics, genetic analysis, in planta colonization and detection, inoculation experiments with suggestions for future research.
Endophytes are plant-associated prokaryotes that form association with their host plants by colonizing the internal tissues, which has made them valuable for agriculture as a tool in improving crop performance. Although the interaction between endophytes and host plants has not been fully understood, many bacterial species are reported to promote plant growth and the mechanism attributed includes nitrogen fixation, production of growth-promoting substances and increased resistance to pathogens and parasites. They have been reported from numerous plant species including sugarcane. Gluconacetobacter diazotrophicus (syn. Acetobacter diazotrophicus) -sugarcane association represents a model system for monocot-diazotrophic associations. This allows experimentation to answer questions pertaining to their establishment, colonization process, biological nitrogen fixation, growth promotion, etc. The main objective of this review is to summarize the recent works on this bacterium with special emphasis on its interaction with sugarcane. The topics being covered range from the sources of G. diazotrophicus, its classification and characteristics, genetic analysis, in planta colonization and detection, inoculation experiments with suggestions for future research.
African Journal of Microbiology Research, 2014
The objective of this study was to evaluate the viability of real-time polymerase chain reaction (PCR) to detect Gluconacetobacter diazotrophicus in sugarcane inoculated and non-inoculated with diazotrophs which are grown under field conditions. The primer pair PAL5F and PAL5R yielded a specific band of 189 bp using real time PCR with SYBER Green I. This primer pair was the most sensitive one to detect endophytic bacteria in sugarcane plants grown under field conditions and inoculated or not with bacterium. The lower limit of detection was 5 fg of template DNA, which corresponds to 12 bacterial cells. In contrast, a cultivation-dependent approach was not capable of detecting the bacteria in the same sample. The quantification of G. diazotrophicus from field grown plants using real-time PCR and a set of specific primers can be used to determine the number of bacterial cells that colonize endophytically the plant after inoculation. A highly sensitive and specific assay was developed to quantify G. diazotrophicus in sugarcane plants grown under field conditions. This assay can be used to evaluate the occurrence of the bacterium in different sample types.