Nodule Formation Essay

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Institute of Biology, College of Science University of the Philippines Diliman, Quezon City 1101 Philippines “Effect of NOD gene integration on the nitrogen fixation activity of Klebsiella spp.“ Maevel M. Romero MS Microbiology Proponent Submitted to: Gil M. Penuliar Ph.D. Abstract Nitrogen is one of the two elements that can easily limit the biologically mediated carbon assimilation of photoautotrophs. This makes nitrogen fixation important and needing a continuous supply of fixed nitrogen available. Conversion of atmospheric nitrogen to its usable form is mediated by prokaryotes, such as bacteria and archaea, collectively called as associative nitrogen fixers or diazotrophs. Nodule formation are exhibited by symbiotic nitrogen fixers which is not present to free-living diazotrophs. A study showed that but preformed nodules made this free –living bacteria more colonizing leading to an increased plant yield. A demand for an alternative nitrogen source aside from commercially available nitrogen fertilizers are in need. There are current issues caused by these fertilizers pressing environmental stress. Altogether, the main objectives of this study includes isolation, purification of Klebsiella isolates from soil samples (corn field) and root nodules (alfalfa), with its proper…show more content…
K. pneumoniae and K. oxytoca are two of the established nitrogen fixer under this genus converting nitrogen to a form usable by plants (Ladha, Barraquio, & Watanabe, 1983). Attachment of this bacteria on the root hairs are found to be strong in comparison with surfaces on the zone of elongation and root cap mucilage where colonization is not likely to occur. Due to non-motile phenotype, high concentration of this organism shows that presence of flagella may induce plant defenses giving no-motility an advantage (Seo & Matthews,

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