Screening and Selection of Antibiotics for Enhanced Production of Astaxanthin by Haematococcus lacustris

<i>Haematococcus lacustris</i> (Girod-Chantrans) Rostafinski (Chlorophyta) is the richest microalgal source of astaxanthin. Natural astaxanthin from <i>H. lacustris</i> has been widely studied and used for commercial production worldwide. In this study, we examined the effects of 11 antibiotics (dihydrostreptomycin sulphate, neomycin, chloramphenicol, penicillin, streptomycin, ampicillin, kanamycin, gentamycin, hygromycin B, tetracycline, and paromomycin) on the biomass dry weight, growth, and astaxanthin yield of <i>H. lacustris</i> using Jaworski's medium without a nitrogen source. Astaxanthin content in <i>H. lacustris</i> was improved in the presence of ampicillin (0.25 g/L, 0.5 g/L, 1 g/L), chloramphenicol (0.25 g/L), and penicillin (0.25 g/L, 0.5 g/L, 1 g/L) in comparison to the control on day 15. The greatest increase in astaxanthin content on day 15 (6.69-fold) was obtained with the addition of penicillin (0.5 g/L) in comparison to the control. Similarly, on day 15, the cell numbers were also the highest for the <i>H. lacustris</i> culture grown with the addition of penicillin (0.5 g/L).