Efeito da relação carbono/nitrogênio e da fonte de carbono no cultivo da bactéria Herbaspirillum seropedicae BR 11417

Abstract

Herbaspirillum seropedicae is a gram negative, vibroid bacterium belonging to the class Betaprote-obacteria. This bacterium has great economic potential to be used on a larger scale as an inoculum in agribusiness since it can perform biological nitrogen fixation (BNF), and can also produce phytohormones and solubilize phosphate. However, little is known about its nutritional requirements. Therefore, This work aimed to evaluate the effect of carbon sources and the Carbo-no/Nitrogen (C/N) ratio on the growth of H. seropedicae strain BR - 11417 in liquid culture medium and compare them with the generalist medium Dextrose – Yeast – Glucose – Sucrose – (DYGS). In the work, the carbon sources glycerol, glucose, mannitol and sucrose were tested in carbon and nitrogen ratios of 5:1 and 10:1, which sought to obtain the carbon source (s) and the CN ratio (s) that would provide greater production of colony forming units (CFU). It was verified that the sucrose carbon source provided a greater amount of colony-forming units, presenting a higher production in the CN 5:1 ratio, when compared to the CN 10:1 ratio (4.99 x 109 and 2.08 x 10 9 , respectively). Sucrose as a carbon source reduced operating costs both in the CN 5:1 ratio (6.19%) and in the CN 10:1 ratio (50%).