Abstract
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 23 factorial design for screening methodology. The experimental design variables were agitation, illuminance (intensity of luminous flux) and carbon source (CO2/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.
Highlights
Microalgae are a valuable source of products such as phycobiliproteins, polysaccharides, proteins, hydrogen and other secondary metabolites.[1,2,3] Several studies describe the potential use of these microorganisms to produce bioactive compounds of high values.[4,5,6,7] Current applications for the isolated chemical compounds from various kinds of algae are enormous, and within those, ecological and functional chemistry is outstanding
Grew in conditions where all variables were placed in their lowest levels, the indoleacetic acid (IAA) concentration was the lowest (1.118 μmol L-1)
Scenedesmus obliquus (UTEX 393) was able to produce different IAA concentrations when it was grown under phototrophic conditions, suggesting that it is a potential source for obtaining this type of phytohormone
Summary
Microalgae are a valuable source of products such as phycobiliproteins, polysaccharides, proteins, hydrogen and other secondary metabolites.[1,2,3] Several studies describe the potential use of these microorganisms to produce bioactive compounds of high values.[4,5,6,7] Current applications for the isolated chemical compounds from various kinds of algae are enormous, and within those, ecological and functional chemistry is outstanding. In the design, four experiments (central point) were used to estimate the experimental error in response variables, which were the specific growth rate (μ in day-1) and the indoleacetic acid concentration (YA in μmol L-1). Indoleacetic acid concentration (YA) Specific growth rate (μ) μmol L-1 day-1
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
