The optimization of biomass and lipid yields of Chlorella sorokiniana when using wastewater supplemented with different nitrogen sources.
The potential of nitrogen sources supplementing domestic wastewater for the cultivation of microalgae was assessed. Urea, potassium nitrate, sodium nitrate and ammonium nitrate were evaluated for their effect on cultivation and lipid production of Chlorella sorokiniana. Urea showed the highest biomass yield of 0.220 g L(-1) and was selected for further experimentation. Urea concentrations (0-10 g L(-1)) were assessed for their effect on growth and microalgal physiology using pulse amplitude modulated fluorometry. A concentration of 1.5 g L(-1) urea produced 0.218 g L(-1) biomass and 61.52% lipid by relative fluorescence. Physiological stress was evident by the decrease in relative Electron Transport Rate from 10.45 to 6.77 and quantum efficiency of photosystem II charge separation from 0.665 to 0.131. Gas chromatography analysis revealed that C16:0, C18:0, C18:1, C18:2 and C18:3 were the major fatty acids produced by C. sorokiniana. Urea proved to be an effective nitrogen supplement for cultivation of C. sorokiniana in wastewater.
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Luveshan
L
Ramanna
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Abhishek
A
Guldhe
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Ismail
I
Rawat
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa. Electronic address: faizalb@dut.ac.za.
Faizal
F
Bux
D018533:Biomass; D002708:Chlorella / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D004579:Electron Transport; D004952:Esters / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005470:Fluorometry; D008055:Lipids / Q000096:biosynthesis*; D009584:Nitrogen / Q000494:pharmacology*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D011789:Quantum Theory; D014508:Urea / Q000494:pharmacology; D062065:Wastewater / Q000382:microbiology*
D004952:Esters; D005227:Fatty Acids; D008055:Lipids; D009584:Nitrogen; D045332:Photosystem II Protein Complex; D014508:Urea; D062065:Wastewater
Biodiesel; Microalgae; PAM fluorometry; Urea; Wastewater