title: Effects of pH control and concentration on microbial oil production from Chlorella vulgaris cultivated in the effluent of a low-cost organic waste fermentation system producing volatile fatty acids.
abstract: The objective of this study was to investigate the feasibility of applying volatile fatty acids (VFAs) produced from low-cost organic waste to the major carbon sources of microalgae cultivation for highly efficient biofuel production. An integrated process that consists of a sewage sludge fermentation system producing VFAs (SSFV) and mixotrophic cultivation of Chlorella vulgaris (C. vulgaris) was operated to produce microbial lipids economically. The effluents from the SSFV diluted to different concentrations at the level of 100%, 50%, and 15% were prepared for the C. vulgaris cultivation and the highest biomass productivity (433±11.9 mg/L/d) was achieved in the 100% culture controlling pH at 7.0. The harvested biomass included lipid contents ranging from 12.87% to 20.01% under the three different effluent concentrations with and without pH control. The composition of fatty acids from C. vulgaris grown on the effluents from the SSFV complied with the requirements of high-quality biodiesel. These results demonstrated that VFAs produced from the SSFV are favorable carbon sources for cultivating C. vulgaris.
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea.
authors.forename: Hyun Uk
authors.initials: HU
authors.lastname: Cho
authors.affiliation: Department of Civil Engineering, Dong-A University, Nakdong-daero, Saha-gu, Busan 604-714, Republic of Korea.
authors.forename: Young Mo
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea.
authors.forename: Yun-Nam
authors.initials: YN
authors.lastname: Choi
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea.
authors.forename: Xu
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea.
authors.forename: Dong Yun
authors.initials: DY
authors.lastname: Shin
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea; Department of Chemical Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea; Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Hyoja-dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea. Electronic address: jmpark@postech.ac.kr.
authors.forename: Jong Moon
authors.initials: JM
authors.lastname: Park
mesh_terms: D064751:Ammonium Compounds / Q000302:isolation & purification; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D048408:Chlorella vulgaris / Q000254:growth & development / Q000378:metabolism*; D003365:Costs and Cost Analysis; D005227:Fatty Acids / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000096:biosynthesis* / Q000191:economics; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D009821:Oils / Q000378:metabolism*; D010710:Phosphates / Q000302:isolation & purification; D012722:Sewage / Q000382:microbiology; D012995:Solubility; D014865:Waste Disposal, Fluid; D014866:Waste Products / Q000191:economics*
chemical_list: D064751:Ammonium Compounds; D005227:Fatty Acids; D005232:Fatty Acids, Volatile; D009821:Oils; D010710:Phosphates; D012722:Sewage; D014866:Waste Products
keywords: Chlorella vulgaris; Fatty acids; Microbial lipids; Sewage sludge; Volatile fatty acids (VFAs)