Semi-continuous cultivation of Chlorella vulgaris using chicken compost as nutrients source: Growth optimization study and fatty acid composition analysis

• Main Authors: Tan, X.B., Lam, M.K., Uemura, Y., Lim, J.W., Wong, C.Y., Ramli, A., Kiew, P.L., Lee, K.T.
• Format: Article
• Published: Elsevier Ltd 2018
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85043473341&doi=10.1016%2fj.enconman.2018.03.020&partnerID=40&md5=8c72f25c5636ef66596d01291fefe9de; http://eprints.utp.edu.my/20921/
• Institution: Universiti Teknologi Petronas

In the present study, cultivation of Chlorella vulgaris was extensively explored under semi-continuous approach to enhance its growth. The microalgae were cultivated in a photobioreactor supplemented with compost derived from chicken waste as an alternative nutrients source in both batch and semi-continuous cultivations. It was found that Chlorella vulgaris grew well up to 17 cycles of semi-continuous cultivation based on the following conditions for each cycle (3 days per cycle): 30 (v/v) removal of cultivation medium and 0.04 L/L of chicken compost in cultivation medium of pH 3. The average biomass productivity attained through these conditions was 0.0736 g/L/day, which was higher than batch cultivation (0.0568 g/L/day). Besides, the average total lipid content from each cycle under semi-continuous cultivation was maintained in the range of 25�35 wt. The success of lipid extraction from the microalgae biomass was evidenced by the result of Fourier Transform Infrared Red (FT-IR) analysis that revealed lower peak intensity of carbon, especially in the range 2809�3012 cm�1 after lipid extraction. It was also worthwhile to mention that the fatty acid methyl ester (FAME) compositions of Chlorella vulgaris consisted mainly of C16:0 and C18:3 that were not significantly altered during the semi-continuous cultivation. Both saturated and unsaturated fatty acids in the harvested biomass accounted for approximately 26.3 and 73.3, respectively, within 5 cycles of the cultivation. © 2018 Elsevier Ltd