title: Algal-bacterial process for the simultaneous detoxification of thiocyanate-containing wastewater and maximized lipid production under photoautotrophic/photoheterotrophic conditions.
abstract: In this work, a cooperative algal-bacterial system that efficiently degrades thiocyanate (SCN(-)), a toxic contaminant, and exhibits high lipid productivity, was developed. A consortium of mixed bacteria (activated sludge) and microalgae was sequentially cultivated under photoautotrophic and photoheterotrophic modes. The hydrolysis of SCN(-) to ammonium (NH4(+))-nitrogen and subsequent nitrification steps were performed by the initial activated sludge under lithoautotrophic conditions. The NH4(+) and oxidized forms of nitrogen, nitrite (NO2(-)) and nitrate (NO3(-)), were then assimilated and removed by the microalgal cells when light was supplied. After the degradation of SCN(-), the cultivation mode was changed to photoheterotrophic conditions in a sequential manner. Algal-bacterial cultures containing Chlorella protothecoides and Ettlia sp. yielded significantly increased lipid productivity under photoheterotrophic conditions compared to photoautotrophic conditions (28.7- and 17.3-fold higher, respectively). Statistical methodologies were also used to investigate the effects of volatile fatty acids and yeast extract on biomass and lipid production.
authors.affiliation: Environmental and Energy Program, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Byung-Gon
authors.initials: BG
authors.lastname: Ryu
authors.affiliation: Center for Water Resources Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Jungmin
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Wasif
authors.initials: W
authors.lastname: Farooq
authors.affiliation: Department of Civil and Environmental Engineering, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jong-In
authors.initials: JI
authors.lastname: Han
authors.affiliation: Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea; Advanced Biomass R&D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Yang
authors.affiliation: Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea. Electronic address: elshine@kaist.ac.kr.
authors.forename: Woong
authors.initials: W
authors.lastname: Kim
mesh_terms: D000704:Analysis of Variance; D052818:Autotrophic Processes / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D056890:Eukaryota / Q000187:drug effects / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D005232:Fatty Acids, Volatile / Q000494:pharmacology; D052836:Heterotrophic Processes / Q000187:drug effects; D008055:Lipids / Q000096:biosynthesis*; D009584:Nitrogen / Q000302:isolation & purification; D012722:Sewage / Q000382:microbiology; D013861:Thiocyanates / Q000302:isolation & purification*; D014835:Volatilization; D062065:Wastewater / Q000382:microbiology*
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A; D005227:Fatty Acids; D005232:Fatty Acids, Volatile; D008055:Lipids; D009584:Nitrogen; D012722:Sewage; D013861:Thiocyanates; D062065:Wastewater; C031760:thiocyanate
keywords: Algal–bacterial mixed culture; Lipid productivity; Photoautotrophic/photoheterotrophic conditions; Thiocyanate wastewater; Volatile fatty acid