Effects of light intensity and nitrogen starvation on growth, total fatty acids and arachidonic acid in the green microalga Parietochloris incisa

Abstract

The effects of light and nitrogen deficiency on biomass, fatty acid content and composition were studied in Parietochloris incisa, the unicellular freshwater chlorophyte accumulating very high amounts of arachidonic-acidrich triacylglycerols. P. incisa cultures grown on complete nutrient medium and under high light (400 μmol photons m − 2 s −1 ) showed the highest rate of growth in comparison to medium (200 μmol photons m −2 s −1 ) and low (35 μmol photons m −2 s −1 ) light intensity. Cultures grown under high light (on complete BG-11 medium) attained higher volumetric contents of total fatty acids and arachidonic acid due to greater increase in biomass. Nitrogen starvation brought about a strong increase in the arachidonic acid proportion of total fatty acids. Thus, adjustments to cultivation conditions could serve as an efficient tool for manipulation of yield and relative content of arachidonic acid in P. incisa. The significance of the changes in lipid metabolism for adaptation of P. incisa to high-light stress and nitrogen deficiency is also discussed.

Effects of Light Intensity on the Growth and Lipid Accumulation of Microalga Scenedesmus sp. 11-1 Under Nitrogen Limitation

“…They also found that the increase in PUFA and the decrease in MUFA were correlated with the increased neutral lipid content [33]. These results were similar to the study of Solovchenko et al [7] but opposite to the study of Lin et al [5]. Although the lipid containing a high content of PUFA may make the biodiesel susceptible to oxidation, it is easy to improve the saturation degree in certain chemical processes [1].…”

“…Therefore, it may be helpful in the dissipation of excess light energy and prevention of the photochemical damage of algal cells [27]. Thus, more carbon flux generated from the photosynthesis is channeled to the lipid accumulation on a unit biomass basis when individual cell is exposed to a large quantity of light energy [7,28]. Therefore, the high and medium lights could promote the final biomass yield, lipid content, and yield, especially neutral lipid content.…”

“…responded to different conditions, including nitrogen concentration and temperature [4,5]. In addition to nutrient levels and temperature, the light intensity is also an important factor affecting the growth and lipid accumulation, and it could also affect fatty acid composition in the microalgae Parietochloris incise and Dunaliella viridis [6,7]. However, effect of the light intensity on lipid production and fatty acid composition in Scenedesmus spp.…”

Effect of nutrients on total lipid content and fatty acids profile of Scenedesmus obliquus

“…PUFAs are one of the most nutritionally important and essential fatty acids because they are key nutrients in animal nutrition, and the most algae are rich in these acids 43 . Nitrogen and phosphate are two important macronutrients for phospholipids because nitrogen and phosphorus starvation shifts the lipid metabolism from membrane lipid synthesis to neutral lipid storage 39,[44][45][46] . Results of the present study also showed clearly that peaks in PUFAs are related to nitrogen and phosphorus, but its correlation with potassium and magnesium was more evident.…”

Growth comparison of microalgae in tubular photobioreactor and open pond for treating anaerobic digestion piggery effluent

“…The issue of secondary pollution is solved due to very efficient biomass reuse and nutrient recycling. Moreover, the versatility of microalgae is further exploited in the production of biofertilizers, feed for animals and fine chemicals [10,11]. However, the macromolecular composition (lipids, carbohydrates, proteins, nucleic acids) and pigments contents of microalgae biomass are influenced by growth conditions.…”