title: Strategies to enhance cell growth and achieve high-level oil production of a Chlorella vulgaris isolate.
abstract: The autotrophic growth of an oil-rich indigenous microalgal isolate, identified as Chlorella vulgaris C--C, was promoted by using engineering strategies to obtain the microalgal oil for biodiesel synthesis. Illumination with a light/dark cycle of 14/10 (i.e., 14 h light-on and 10 h light-off) resulted in a high overall oil production rate (v(oil)) of 9.78 mg/L/day and a high electricity conversion efficiency (E(c)) of 23.7 mg cell/kw h. When using a NaHCO(3) concentration of 1,500 mg/L as carbon source, the v(oil) and E(c) were maximal at 100 mg/L/day and 128 mg/kw h, respectively. A Monod type model was used to describe the microalgal growth kinetics with an estimated maximum specific growth rate (mu(max)) of 0.605 day(-1) and a half saturation coefficient (K(s)) of 124.9 mg/L. An optimal nitrogen source (KNO(3)) concentration of 625 mg/L could further enhance the microalgal biomass and oil production, leading to a nearly 6.19 fold increase in v(oil) value.
authors.affiliation: Dept. of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Kuei-Ling
authors.initials: KL
authors.lastname: Yeh
authors.forename: Huei-Meei
authors.initials: HM
authors.lastname: Su
authors.forename: Yung-Chung
authors.initials: YC
authors.lastname: Lo
authors.forename: Wen-Ming
authors.initials: WM
authors.lastname: Chen
authors.forename: Jo-Shu
authors.initials: JS
authors.lastname: Chang
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods*; D048408:Chlorella vulgaris / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D020459:Genes, rRNA; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D017440:Photoperiod; D010802:Phylogeny; D010938:Plant Oils / Q000378:metabolism*; D017680:Potassium Compounds / Q000378:metabolism; D017693:Sodium Bicarbonate / Q000378:metabolism
chemical_list: D009566:Nitrates; D010938:Plant Oils; D017680:Potassium Compounds; D002244:Carbon; D017693:Sodium Bicarbonate; D009584:Nitrogen; C023844:potassium nitrate