This MiniReview summarizes the latest marine yeast isolation methods and the industrial applications of marine yeasts.

Chlamydomonas reinhardtii is a green microalgae used as a model organism associated with biotechnological applications, yet its nutritional value has not been assessed. This study investigates the nutritional capacity of C. reinhardtii as an additional value for this species beyond its known potential in biofuels and bio-products production. The composition of key nutrients in C. reinhardtii was compared with Chlorella and Spirulina, the species widely regarded as a superfood. The results revealed that the protein content of C. reinhardtii (46.9%) was comparable with that of Chlorella (45.3) and Spirulina (50.4%) on a dry weight basis. C. reinhardtii contained all the essential amino acids with good scores based on FAO/WHO values (0.9–1.9) as in Chlorella and Spirulina. Unsaturated fatty acids predominated the total fatty acids profile of C. reinhardtii were ~74 of which ~48% are n-3 fatty acids. Alpha-linolenic acid (ALA) content in C. reinhardtii (42.4%) was significantly higher than that of Chlorella (23.4) and Spirulina (0.12%). For minerals, Spirulina was rich in iron (3.73 mg/g DW) followed by Chlorella (1.34 mg/g DW) and C. reinhardtii (0.96 mg/g DW). C. reinhardtii, unlike the other two species, consisted of selenium (10 µg/g DW), and had a remarkably lower heavy metal load. Moreover, C. reinhardtii contained relatively high concentrations of chlorophyll (a + b) and total carotenoids (28.6 mg/g DW and 6.9 mg/g DW, respectively) compared with Chlorella (12.0 mg/g DW and 1.8 mg/g DW, respectively) and Spirulina (8.6 mg/g DW and 0.8 mg/g DW, respectively). This study confirms that, based on its nutrient credentials, C. reinhardtii has great potential as a new superfood or ingredient for a food supplement.

This paper introduces an original, rapid, efficient and reliable HPLC method for the accurate and simultaneous quantification (g/L) of chloride in samples containing sugars, organic acids and alcohols. Separation was achieved using a HI-Plex H column at 35oC, with H2SO4 (0.005 N) as the mobile phase at a flow rate of 0.4 mL/min. The column effluent was monitored by a Refractive Index (RI) detector. A linear response was achieved over NaCl concentrations of 0.25 – 2.5 g/L and 5 – 40 g/L. The analytical method inter- and intra-run accuracy and precision were better than ±10.0%. Investigating the mechanism of detection using different chloride and sodium s reviled that this method can be used for determining the total concentration of chloride salts when in suspension. This method was successfully applied to 15 samples of commercial food products and the salt content obtained from this method was compared with 3 other methods for salt determination. The (HI-Plex H) column was designed for determining the concentrations of sugars, organic acids and alcohols when in solution. Hence, application of our new methodology would allow the determination of sugars, alcohols and organic acids in samples derived from seawater-based fermentation media as well as samples from salty food and dairy products

Current technologies for bioethanol production rely on the use of freshwater for preparing the fermentation media and use yeasts of a terrestrial origin. Life cycle assessment has suggested that between 1,388 to 9,812 litres of freshwater are consumed for every litre of bioethanol produced. Hence, bioethanol is considered a product with a high-water footprint. This paper investigated the use of seawater-based media and a novel marine yeast strain ‘Saccharomyces cerevisiae AZ65’ to reduce the water footprint of bioethanol. Results revealed that S. cerevisiae AZ65 had a significantly higher osmotic tolerance when compared with the terrestrial reference strain. Using 15-L bioreactors, S. cerevisiae AZ65 produced 93.50 g/L ethanol with a yield of 83.33% (of the theoretical yield) and a maximum productivity of 2.49 g/L/h when using seawater-YPD media. This approach was successfully applied using an industrial fermentation substrate (sugarcane molasses). S. cerevisiae AZ65 produced 52.23 g/L ethanol using molasses media prepared in seawater with a yield of 73.80% (of the theoretical yield) and a maximum productivity of 1.43 g/L/h. These results demonstrated that seawater can substitute freshwater for bioethanol production without compromising production efficiency. Results also revealed that marine yeast is a potential candidate for use in the bioethanol industry especially when using seawater or high salt based fermentation media.