Production of indole-3-acetic acid in the culture medium of microalga Scenedesmus obliquus (UTEX 393)

Abstract

O acido indolacético (IAA) é uma auxina natural e um dos principais reguladores do crescimento de plantas superiores. A quantidade de ácido indolacético extracelular produzida pela cultura de microalga verde Scenedesmus obliquus foi estabelecida por cromatografia líquida de alta eficiência (HPLC). Avaliou-se o efeito de três variáveis de processo na produção de IAA extracelular nestas culturas usando planejamento fatorial 2 3 para uma metodologia de screening. As variáveis de planejamento experimental foram agitação, iluminância (intensidade do fluxo luminoso) e fonte de carvão (mistura CO 2 /air v/v (%)) em três diferentes níveis. A concentração de IAA e a taxa de crescimento específico foram usadas como variáveis de resposta. As análises de HPLC mostraram que em condições experimentais, a quantidade de IAA que foi liberada no meio pela alga S. obliquus depende somente da variável iluminância. Os efeitos da luz e as concentrações de carvão no meio de cultura foram significantes (p < 0.05) para uma taxa de crescimento específico.The indoleacetic acid (IAA) is a natural auxin and one of the main growth regulators in higher plants. The extracellular indoleacetic acid (IAA) amount produced by the green microalga Scenedesmus obliquus culture was detected by high performance liquid chromatography (HPLC). It was evaluated the effect of three process variables in the extracellular IAA production in these cultures using 2 3 factorial design for screening methodology. The experimental design variables were agitation, illuminance (intensity of luminous flux) and carbon source (CO 2 /air v/v (%) mixture) at three different levels. The IAA concentration and the specific growth rate were used as response variables. The HPLC analyses showed that under experimental conditions, the IAA amount that is released to the medium by S. obliquus depends only on the illuminance variable. The light effects and the carbon concentrations in culture medium were significant (p < 0.05) for specific growth rate.

Indole-3-Acetic Acid Is Produced by Emiliania huxleyi Coccolith-Bearing Cells and Triggers a Physiological Response in Bald Cells

“…IAA has also been detected in various microalgal chlorophytes, including Chlorella pyrenoidosa and Scenedesmus spp. (Mazur et al, 2001 ; Prieto et al, 2011 ). These studies have found evidence corroborating the hypothesis that evolution of auxin biosynthesis predates the divergence of land plants and some algal taxa.…”

Exogenous Application of Tryptophan and Indole Acetic Acid (Iaa) to Induce Root Nodule Formation and Increase Soybean Yield in Acid, Neutral and Alkaline Soil

“…According to Mishra et al (1999) the use of extragenous fitohormon shows positive response to the formation of root nodule. The indole acetic acid (IAA) is a natural auxin and one of the main growth regulators in higher plants (Prieto C et al, 2011). Plants synthetizing higher IAA showed a significant increase in shoot fresh weight and upregulation of nitrogenase gene (Bianco et al, 2014).…”

Characterization of Endogenous Auxins and Gibberellins Produced by Chlorella sorokiniana TH01 under Phototrophic and Mixtrophic Cultivation Modes toward Applications in Microalgal Biorefinery and Crop Research

“…[13,18], Scenedesmus sp. [12,20], and Acutodesmus dimorphus [21] has been reported recently. Phytohormones are usually present in microalgae at very low concentration with various structures, and thus determination of phytohormone levels in microalgae is extremely challenging.…”

“…It has been reported that microalgae could produce exogenous [12] and endogenous phytohormones [13][14][15][16][17][18].…”