Having a small genome relative to other endophytes, it is typical of facultative intracellular colonizers, with a life cycle that involves horizontal transfer to other high sucrose species via insects and potential vertical transfer through seeds. Significant cost benefit to the grower through reduced fertiliser costs and increased yields. As PhD students, we found it difficult to access the research we needed, so we decided to create a new Open Access publisher that levels the playing field for scientists across the world. The insects might become colonized during sap-feeding and then re-inoculate the bacteria to stems of other plants. Our team is growing all the time, so we’re always on the lookout for smart people who want to help us reshape the world of scientific publishing. Is environmentally friendly and contains no toxins. G. diazotrophicus has been isolated from arbuscular mycorhizal fungi (AMF) associated with sweet potato and sweet sorghum [96] and sorghum [17] but survival of G. diazotrophicus in soil appears to be limited. This is perhaps not surprising given its host plant, sugarcane and other high sucrose content host plants from which it has been isolated (Table 1), but for G. diazotrophicus to tolerate sucrose-induced stress, it has to have the mechanisms with which to cope. Bacteria in an early facultative intracellular stage of adaptation tend to have a median genome size ca. Certain strains of the obligate nitrogen-fixing bacterial endophyte Gluconacetobacter diazotrophicus have the necessary attributes for this role. Figures 1 and 2 clearly demonstrate that the G. diazotrophicus treated maize and wheat crops generated higher yields relative to the controls, irrespective of levels of nitrogen fertilizer applied. Studies of bacterial-insect symbiosis have demonstrated that the AAB are capable of establishing symbiotic relationships with insects that rely on a sugar-based diet [36]. G. diazotrophicus has only been found to occur naturally in a total of 19 plant species, mainly crops, across 15 plant families including, Poaceae, Convolvulaceae, Rubiaceae and Bromeliaceae (Table 1). Azotic’s technologies has a strong patent portfolio and an exiting intellectual property pipeline. High nitrogen doses lowered the diversity of G. diazotrophicus. Interestingly, however, this gene is considered only a secondary low affinity potassium transporter for bacteria generally and certainly has not been implicated in the regulation of osmotic stress [35]. The plant will not be passive in this process of colonization by the endophyte; plants have evolved molecular mechanisms to deal with challenges imposed by colonizing bacteria [85]. HeadquartersIntechOpen Limited5 Princes Gate Court,London, SW7 2QJ,UNITED KINGDOM. Alternative approaches however, based on the findings relating to G. diazotrophicus in Brazil in sugarcane offer some prospect for the development of non-legume crop symbiotic nitrogen fixation, not only to increase crop yields but also to potentially reduce nitrogen fertilizer use, and this prospect is now beginning to be realized [12]. It has been demonstrated that strains of G. diazotrophicus differentially affected growth parameters of sugarcane, with some strains improving germination, tiller number and plant height relative to others [14] and there is also evidence that G. diazotrophicus improves tolerance to the sugarcane pathogen Xanthomonas albilineans as a result of production of bacteriocin; as well as reducing galling caused by root knot nematodes (Meloidogyne incognita) in bottle gourds and cotton [15]. Nitrogen-fixing genes can be conserved in chromosomal DNA and within plasmids [64]. bacteria, including N2 fixation, phytohormone synthesis, P and Zn solubilization and biocontrol, are analysed. Genomic adaptation of bacterial endophytes for a symbiotic life cycle may include strategies for vertical transmission via the seed at the expense of competitiveness and ability to survive in most environments outside the plant. The symbiosome is created by the engulfment of the microorganism by a plant-derived membrane in a manner that resembles phagocytosis in animal cells [80]. However, studies using β-glucuronidase (GUS)-labeled G. diazotrophicus, demonstrate that this bacterium is also capable of intracellular colonization within membrane-bound vesicles in its host plant [24]. Typical of a facultative intracellular symbiont, G. diazotrophicus retains genetic flexibility through its genome and plasmids and can respire under a wide range of oxygen concentrations suitable for both an intracellular plant and insect habitat. This cluster represented the largest single grouping of genes required for nitrogenase structure and function, found in any diazotroph at that time [74]. In 1988, a fresh impetus arose from the discovery of Gluconacetobacter diazotrophicus (Gd), a non-nodulating, non-rhizobial, nitrogen-fixing bacterium isolated from the intercellular juice Firstly, sucrose: G. diazotrophicus has no sucrose transport system and in high sucrose concentration environments of around 10% the sucrose has a positive effect on nitrogenase activity protecting nitrogenase against inhibition by oxygen [123].