High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

Abstract

Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids), tocopherols and carotenoids for potential use in aquaculture feed industry.

Investigation of Lipid Oxidation in the Raw Materials of a Topical Skin Formulation: A Topical Skin Formulation Containing a High Lipid Content

“…Fatty acid compositions in oil and Bligh and Dyer extracts were determined as described by Safafar, Hass, Møller, Holdt, and Jacobsen () ( n = 2). In brief, 1 g of Bligh and Dyer extract or 0.3 g of oil was weighed in test tubes.…”

Evaluation of the effect of agitation speed on the growth and high‐value LC‐PUFA formation of Porphyridium cruentum based on basic rheological analysis

“…Studies on the cultivation of microalgae so far have focussed mainly on the effects of growth conditions, such as light intensity, temperature, nutrient level, cultivation mode and cultivation-reactor type. [11][12][13][14] Amongst these growth conditions, the rheological properties of microalgal suspensions can affect both transport (transfer effect of nutrients within the suspensions) and downstream processes (harvesting and dewatering). 15 For example, Adesanya et al 16 examined the rheology of microalgal suspensions for biofuel processing and indicated that a scientific understanding of the fluid behavior of microalgal suspensions could promote effective microalgae growth and processing.…”

Microalgae processing for jet fuel production

“…17,31,32,33 Generally, the higher the biomass productivity, the higher the EPA productivity. 34,35,36 However, this is not always the case for all species because the lipid content is lower in most cases, as mentioned earlier. Increasing lipid content using a physiological manipulation technique is therefore very important for many species in order to generate the considerable amount of lipids necessary for biofuels production.…”