Antioxidants enhance lipid productivity in Heveochlorella sp. Yu

In this study, crude lipids, including pigment accumulation, in Heveochlorella sp. Yu were evaluated after the addition of four antioxidants (melatonin, fulvic acid, butylhydroxytoluene and butylated hydroxyanisole). Melatonin enhanced crude lipid accumulation in this alga, with crude lipid productivity increasing by 31.83% (from 185.57 mg L-1 d(-1) to 244.63 mg L-1 d(-1)). Moreover, the level of reactive oxygen species was reduced and the concentration of nitric oxide increased with melatonin addition. Such changes in reactive oxygen species and nitric oxide concentration might regulate signaling pathways related to lipid biosynthesis. Furthermore, the expression levels of key genes (accD, ME and rbcL) associated with the lipid biosynthesis pathway were analyzed, and melatonin addition was found to enhance expression of these genes. Collectively, biochemical analyses suggest that nitric oxide and reactive oxygen species levels and expression of key genes involved in lipid biosynthesis are closely connected with lipid accumulation under melatonin treatment.

Automated summary

The addition of melatonin enhanced crude lipid accumulation in Heveochlorella sp. Yu, accompanied by changes in nitric oxide and reactive oxygen species levels. Moreover, key genes associated with lipid biosynthesis were found to have increased expression under melatonin treatment.