INTRODUCTION: Polyunsaturated fatty acids (PUFAs) are essential nutrients that humans obtain from their diet, primarily through fish oil consumption. However, fish oil production is no longer sustainable. An alternative approach is to produce PUFAs through marine microalgae. Despite the potential of algae strains to accumulate high concentrations of PUFAs, including essential fatty acids (EFAs), many aspects of PUFA production by microalgae remain unexplored and their current production outputs are frequently suboptimal. METHODS: In this study, we optimized biomass and selected ω-3 PUFAs production in two strains of algae, Schizochytrium marinum AN-4 and Schizochytrium limacinum CO3H. We examined a broad range of cultivation conditions, including pH, temperature, stirring intensity, nutrient concentrations, and their combinations. RESULTS: We found that both strains grew well at low pH levels (4.5), which could reduce bacterial contamination and facilitate the use of industrial waste products as substrate supplements. Intensive stirring was necessary for rapid biomass accumulation but caused cell disruption during lipid accumulation. Docosahexaenoic acid (DHA) yield was independent of cultivation temperature within a range of 28-34°C. We also achieved high cell densities (up to 9 g/L) and stable DHA production (average around 0.1 g/L/d) under diverse conditions and nutrient concentrations, with minimal nutrients required for stable production including standard sea salt, glucose or glycerol, and yeast extract. DISCUSSION: Our findings demonstrate the potential of Schizochytrium strains to boost industrial-scale PUFA production and make it more economically viable. Additionally, these results may pave the way for smaller-scale production of essential fatty acids in a domestic setting. The development of a new minimal culturing medium with reduced ionic strength and antibacterial pH could further enhance the feasibility of this approach.

• Klíčová slova
• bioreactors, docosahexaenoic acid, growth, health supplements, optimization, process automation, unicellular eukaryote,
• Publikační typ
• časopisecké články MeSH

In line with the growing interest in humans' nutrition, production of microalgae-based functional foods characterized by an increased content of bioactive substances is attractive. The aim of this study was to investigate the potential of microalgae as additives to feed for laying hens, to enrich the eggs with polyunsaturated fatty acids (PUFA) and selenium/carotenoid antioxidants. Our results showed that supplementation of hens by feed containing 1% of Trachydiscus minutus or 1% of Japonochytrium marinum leads to increase of long-chain PUFA in eggs by 26-66%. Addition of 1% of Scenedesmus obliquus to feed causes the increase of lutein and cantaxanthin in eggs by 48% and 18%, respectively, and addition of 0.5% selenium enriched Chlorella vulgaris increases the final content of organic selenium in eggs by 100-152%. As concerns selenium, it is important to notice that its bioavailability has to be considered. Despite the higher concentration of total selenium in Vischeria helvetica than in C. vulgaris, its bioaccessibility in Vischeria was limited, thus out of usage for feeding purposes. Administration of combinations of selenium enriched Chlorella + Japonochytrium and Chlorella + Schizochitrium verified the increased concentrations of organic selenium, PUFA, as well as carotenoids, with no adverse effect on quality and productivity of eggs. The study confirmed the potential of both traditional as well as new microalgae to be used as feed supplements for functional eggs production. The supplementation of hens by specific microalgae combinations could be advantageous in terms of spectrum of bioactive compounds present.

• Klíčová slova
• Carotenoids, Eggs, Feed, Microalgae, Polyunsaturated fatty acids, Selenium,
• Publikační typ
• časopisecké články MeSH