Marine microalgae growth and carbon partitioning as a function of nutrient availability

Abstract

To understand in which way the structural differences of three marine microalgae (Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp.) affect their carbon partitioning, growth and applicability; a stoichiometric imbalance was imposed by steady carbon and other nutrients variation. Towards high nutrients concentrations/low carbon availability a decrease of 12-51% in C/N microalgae ratio was observed and maximum cell densities were achieved. Moreover, linear correlation between the nutrient input and microalgae protein content were observed. The macromolecular ratios pointed that carbohydrate was the main contributor for the C/N decrement. Although lipid content in R. marina remained constant throughout the experiment, a rise of 37-107% in N. gaditana and Isochrysis sp. was verified. Lipid fractions revealed high percentages of glycolipids in all microalgae (57-73% of total lipids). The present study shows an easy way to understand and modulate microalgae carbon partitioning relying on the field of application.

Copepod nauplii use phosphorus from bacteria, creating a short circuit in the microbial loop

“…Carbon and phosphorus from phytoplankton were assimilated more efficiently than bacteria, even high C : P phytoplankton that had an extreme C : P ratio of 2115 : 1 AE 555. T. lutea has a flexible stoichiometry, when grown under nutrient-limited conditions, cell protein content decreased markedly and lipid content more than doubled (Fernandes et al 2016) and phytoplankton C : P stoichiometries similar to our experiments have been recorded in natural assemblages in freshwaters . Under high C : P conditions phytoplankton can develop grazing-resistant strategies, such as mucilage, or thicker cell walls, enabling passage through the gut without digestion (Van Donk et al 1997;Reynolds 2007).…”

How to combine CO2 abatement and starch production in Chlorella vulgaris

“…This confirmed that an excess of nitrogen supply does not lead to growth inhibition. However, our results show that C. vulgaris needs more nitrogen input than other microalgal species such as Nannochloropsis, Rhodomonas, Isochrysis or Choricystis to render the maximum biomass productivity [56,57]. Notwithstanding, we consider that this characteristic must be considered when using this microalga in wastewater treatments [58][59][60].…”

Growth and Nitrate Uptake in Nannochloropsis gaditana and Tetraselmis chuii Cultures Grown in Sequential Batch Reactors

“…N. gaditana has been documented to grow well in both indoor and outdoor conditions and has been studied for the optimization of lipid accumulation and pigment production. Under nitrogen starvation conditions, N. gaditana is known to accumulate lipids in the order of 40-60% (w/w) (Fabregas et al, 2002;Rocha et al, 2003;Benito et al, 2015;Fernandes et al, 2016) in the form of triacylglycerol and polyunsaturated fatty acids (PUFA) (Ma et al, 2016). The current market-relevant production of Nannochloropsis strains is mainly as food supplements for Eicosapentaenoic Acid (EPA), as aquaculture feed in the form of concentrates and pastes, and in skin care products (Enzing et al, 2014;Riveros et al, 2018).…”