Factors affecting lipid accumulation by Nannochloropsis oculata in a two-stage cultivation process

Abstract

Reserve lipids of microalgae are promising for biodiesel production. However, optimization of cultivation conditions for both biomass yield and lipid production of microalgae is a contradictory problem because required conditions for both targets are different. In this study, a twostage cultivation strategy is proposed to enhance lipid production of the microalga Nannochloropsis oculata. Biomass growth and lipid production were carried out in two separate and non-interacting stages. In first-stage cultivation, microalgae were cultivated in optimal conditions for cell growth. Then, microalgae were harvested and transferred into a growth-limited environment, thus enhancing lipid production of microalgae. Here, optimization of the lipid production stage (second stage) with respect to different levels of inoculum concentration, salinity of culture broth, and intensity of irradiance was performed. The results show that irradiance exhibits a significant influence on lipid production. The highest lipid productivity of 0.324 g L −1 day −1 was obtained with an inoculum concentration of 2.3 g L −1 , a salinity of 35 g L −1 , and an irradiance of 500 μmol photons m −2 s −1 . The final yield of lipid obtained from the two-stage process was 2.82-times higher than that from traditional single-stage batch cultivation systems.

Major Lipid Body Protein: A Conserved Structural Component of Lipid Body Accumulated during Abiotic Stress in S. quadricauda CASA-CC202

“…The resulting hexane containing FAME was sequentially washed with sodium bicarbonate followed by water and dissolved using anhydrous sodium sulfate. The dried sample was dissolved in hexane, and fatty acid profile was analyzed by gas chromatography (Su et al, 2011;Xin et al, 2011;Anand and Arumugam, 2015).…”

Optimizing light regimes on growth and lipid accumulation in Ankistrodesmus fusiformis H1 for biodiesel production

“…Under nitrogenstarvation condition (0 mM), the lipid content (46.78%) was much higher than other treatments (Table 1). Nitrogen-starvation culture resulted in growth cessation of microalgae and animated a metabolic pathway favorable to partition the carbon into storage lipid (TAG) (Su et al, 2010;Li et al, 2011). With the consumption of nitrogen, higher lipid contents were simultaneously obtained in lower nitrogen concentration (4.47 mM), which was 35.62% in sodium nitrate and 38.28% in urea, respectively.…”

“…As vigorous growth and lipid accumulation are usually mutually exclusive in naturally occurring microalgae, so optimizing the cultivation strategy is the cornerstone to achieve biodiesel production. The information about lipid accumulation in microalgae under different initial incolumn density is rare, which is only mentioned in Nannochloropsis oculata (Su et al, 2010) and Chlorella zofingiensis (Feng et al, 2011), but how it comes to Ankistrodesmus sp. ?…”

SÍNTESIS DE LÍPIDOS DE LA MICROALGA Nannochloropsis oculata PARA SU USO POTENCIAL EN LA PRODUCCIÓN DE BIODIÉSEL

“…Se alcanzó hasta un 44.44 ± 0.76 % en peso en la biomasa obtenida en condiciones de irradiancia de 650 µmol E/m 2 /s, lo cual es el doble de lo obtenido a 80 µmol E/m 2 /s con un 21.17 ± 1.08 % de lípidos. Estos resultados son similares a los reportados por diversos autores, van desde un 6.6 hasta un 46.7 % en peso de lípidos acumulados para esta misma especie (Renaud et al 1991, Chiu et al 2009, Su et al 2011. La productividad de los lípidos (Fig.…”

“…Las condiciones principales que influyen en la productividad de biomasa y lípidos son la temperatura (Sukenik et al 2009), la salinidad (Pal et al 2011, Su et al 2011), la disponibilidad de nutrientes (Rezanka et al 2011, Yeesang y Cheirsilp 2011, Yuan et al 2011) y el color e intensidad de la luz (Simionato et al 2011).…”