Short‐term enrichment of microalgae with inorganic selenium and zinc and their effects on the mineral composition of microalgae and marine rotifer Brachionus plicatilis

Long‐term incorporation of Selenium and Zinc in microalgae Isochrysis galbana and Nannochloropsis oculata and its effects on rotifer

“…The amounts of zinc in the long-term enrichment of N. oculata and I. galbana with Zn sulphate and Na selenite obtained in this study are lower than those found using a short-term enrichment (Ghaderpour et al, 2021). However, it should also be noted that, despite the very high amounts of zinc bio-concentrated in the microalgae in previous experiments, the Zn content in rotifers fed with them was not high enough.…”

“…The mechanisms of mineral uptake, storage and excretion in rotifers are variable (Nordgreen et al, 2013), in agreement with the results of this experiment. Comparing the Se content in the previous trial (140.38 – 5101.44 µg g −1 DW) using short‐term enriched microalgae (Ghaderpour et al, 2021) with the results of the present one, we can conclude that long‐term enrichment of microalgae with these minerals reduces the amount of Se in the rotifer.…”

“…The content of Se (171.31 ± 5.83 µg g −1 DW) was higher in the rotifers fed the 5 mg L −1 treatment being the results higher than those found in a previous study (Ghaderpour et al, 2021) using short-term Zn and Se-enriched microalgae (140.38 -169.10 µg g −1 DW). On the other hand, Se content in the present trial was lower than its content in the rotifers fed algae enriched using a Se short-term enrichment protocol.…”

“…Long‐term Zn and Se enrichment of microalgae did not increase the Zn content in the rotifers if we compare with rotifers fed microalgae enriched with Zn for one hour. The highest amount of zinc in the rotifers was obtained using 10 mg L −1 enriched microalgae (82.28 ± 0.37 µg g −1 DW), which was lower than the maximum value obtained in the short‐term enrichment (Ghaderpour et al, 2021) with 80 mg L −1 of zinc sulphate and sodium selenite (96.89 ± 1.36 µg g −1 DW) and 120 mg Zn L −1 treatment (110.45 ± 1.92 µg g −1 DW). It should be noted that rotifers metabolize and excrete the ingested nutrients during the enrichment period leading to changes in the composition of rotifers after enrichment.…”

“…The chemical composition of microalgae depends on a wide range of species and culture conditions and is not an inherently fixed factor. Some microalgae have the capacity to adapt to changes in environmental conditions by changing their chemical composition in response to environmental variability (Bonachela et al, 2011; Ghaderpour et al, 2021). By changing environmental factors such as temperature, brightness, pH, CO 2 supply, salt and nutrients, the desired products can be largely accumulated in microalgae.…”