title: Magnesium aminoclay enhances lipid production of mixotrophic Chlorella sp. KR-1 while reducing bacterial populations.
abstract: Improving lipid productivity and preventing overgrowth of contaminating bacteria are critical issues relevant to the commercialization of the mixotrophic microalgae cultivation process. In this paper, we report the use of magnesium aminoclay (MgAC) nanoparticles for enhanced lipid production from oleaginous Chlorella sp. KR-1 with simultaneous control of KR-1-associated bacterial growth in mixotrophic cultures with glucose as the model substrate. Addition of 0.01-0.1g/L MgAC promoted microalgal biomass production better than the MgAC-less control, via differential biocidal effects on microalgal and bacterial cells (the latter being more sensitive to MgAC's bio-toxicity than the former). The inhibition effect of MgAC on co-existing bacteria was, as based on density-gradient-gel-electrophoresis (DGGE) analysis, largely dosage-dependent and species-specific. MgAC also, by inducing an oxidative stress environment, increased both the cell size and lipid content of KR-1, resulting in a considerable, ∼25% improvement of mixotrophic algal lipid productivity (to ∼410mgFAME/L/d) compared with the untreated control.
authors.affiliation: Biomass and Waste Energy Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea; Department of Fine Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 34134, Republic of Korea.
authors.forename: Bohwa
authors.initials: B
authors.lastname: Kim
authors.affiliation: Biomass and Waste Energy Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea; Department of Chemistry and Bioengineering, Tampere University of Technology, Tampere 33720, Finland.
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Praveenkumar
authors.affiliation: Biomass and Waste Energy Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea.
authors.forename: Jiye
authors.initials: J
authors.lastname: Lee
authors.affiliation: Biomass and Waste Energy Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea.
authors.forename: Bora
authors.initials: B
authors.lastname: Nam
authors.affiliation: Department of Fine Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 34134, Republic of Korea.
authors.forename: Dong-Myung
authors.initials: DM
authors.lastname: Kim
authors.affiliation: Graduate School of Energy Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea.
authors.forename: Kyubock
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of BioNano Technology, Gachon University, Seongnam-Si, Gyeonggi-do 13120, Republic of Korea.
authors.forename: Young-Chul
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Biomass and Waste Energy Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea. Electronic address: ykoh@kier.re.kr.
authors.forename: You-Kwan
authors.initials: YK
authors.lastname: Oh
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D018533:Biomass; D049108:Cell Enlargement / Q000187:drug effects; D002708:Chlorella / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D056831:Coordination Complexes / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000096:biosynthesis; D008274:Magnesium; D058086:Microalgae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D059013:Microbial Consortia / Q000187:drug effects*; D053758:Nanoparticles / Q000378:metabolism*; D011437:Propylamines / Q000494:pharmacology*; D012821:Silanes / Q000494:pharmacology*
chemical_list: D056831:Coordination Complexes; D008055:Lipids; D011437:Propylamines; D012821:Silanes; D008274:Magnesium; C477625:amino-propyl-triethoxysilane
keywords: Aminoclay; Bacteria; Chlorella; Lipid; Mixotrophic culture