our medium is acidic (pH = 2.5 to 4) and moderately hot (temperature = 35–45 C), employing a heterotrophic/
photoautotrophic microalga, Galdieria sulphuraria (hereafter
G. sulphuraria), originating in geothermal springs adapted to pH
of 1.0–4.0 and temperatures of 25–56 C