Enhancing lipid productivity of Chlorella vulgaris using oxidative stress by TiO2 nanoparticles

• Published in: The Korean journal of chemical engineering Vol. 31; no. 5; pp. 861 - 867
• Main Authors: Kang, Nam Kyu, Lee, Bongsoo, Choi, Gang-Guk, Moon, Myounghoon, Park, Min S., Lim, JitKang, Yang, Ji-Won
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.05.2014; 한국화학공학회
• Subjects: Biotechnology; Catalysis; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Materials Science; 화학공학; Nanoparticles; Fatty Acid Methyl Ester; TiO; Oxidative Stress
• ISSN: 0256-1115; 1975-7220
• DOI: 10.1007/s11814-013-0258-6

Ability to increase the lipid production in microalgae is one of the heavily sought-after ideas to improve the economic feasibility of microalgae-derived transportation fuels for commercial applications. We used the oxidative stress by TiO 2 nanoparticles, a well-known photocatalyst, to induce lipid production in microalgae. Chlorella vulgaris UTEX 265 was cultivated under various concentrations of TiO 2 ranging from 0.1 to 5 g/L under UV-A illumination. Maximum specific growth rate was affected in responding to TiO 2 concentrations. In the presence of UV-A, chlorophyll concentration was decreased at the highest concentration of TiO 2 (5 g/L TiO 2 ) by oxidative stress. The fatty acid ethyl ester (FAME) composition analysis suggested that oxidative stress causes the accumulation and decomposition of lipids. The highest FAME productivity was 18.2 g/L/d under low concentrations of TiO 2 (0.1 g/L) and a short induction time (two days). The controlled condition of TiO 2 /UV-A inducing oxidative stress (0.1 g/L TiO 2 and two days induction) could be used to increase the lipid productivity of C. vulgaris UTEX 265. Our results show the possibility of modulating the lipid induction process through oxidative stress with TiO 2 /UV-A.