Cyanobacteria are a group of photoautotrophic prokaryotes which have the ability to biosynthesize plant growth regulators, especially Indole-3-acetic acid (IAA), and have not been focused on research yet in Vietnam. In this study, Arthrospira massartii (ARH strain) – a planktonic cyanobacterial strain isolated from a freshwater lake in Hue City, Thua Thien Hue Province, Vietnam – is showing good growth ability under…