Exogenous Indole-3-Acetic Acid Production and Phosphate Solubilization by Chlorella vulgaris Beijerinck in Heterotrophic Conditions

The role of soil-borne microalgae in the edaphic ecosystem is barely known, especially concerning their plant-growth-promoting traits, although they are used as biofertilizers. In this study, a microalgal strain isolated from soil cultivated with maize was evaluated an exogenous producer indole-3-acetic acid (IAA) potato dextrose broth—PD—and sugarcane molasses, or without tryptophan, and phosphate solubilizer (in ‘National Botanical Research Institute’s phosphate’—NBRIP—medium tricalcium phosphate)with under heterotrophic conditions. species microalga identified, by sequencing ITS region rDNA morphological characteristics, Chlorella vulgaris. Its growth significantly higher PD medium, slower molasses. addition tryptophan did not influence C. vulgaris either but it increased production IAA, mainly to 265 µg mL−1. grew medium insoluble phosphate, releasing phosphorus into (30 mg L−1 after 72 h). This first study on application solubilizer. More studies should be performed prospective microorganism, besides its ability produce further investigations conducted developing inexpensive culture media.