Intensive production of the harpacticoid copepod Tigriopus californicus in a zero-effluent ‘green water’ bioreactor
Abstract Aquaculture is looking for substitutes for fishmeal and fish oil to maintain its continued growth. Zooplankton is the most nutritious option, but its controlled mass production has not yet been achieved. In this context, we have developed a monoalgal ‘green water’ closed-loop bioreactor wit...
Published in: | Scientific Reports |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature Portfolio
2022
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Subjects: | |
Online Access: | https://doi.org/10.1038/s41598-021-04516-w https://doaj.org/article/124eca5a9f004b7aa79a01d8c7fe4989 |
Summary: | Abstract Aquaculture is looking for substitutes for fishmeal and fish oil to maintain its continued growth. Zooplankton is the most nutritious option, but its controlled mass production has not yet been achieved. In this context, we have developed a monoalgal ‘green water’ closed-loop bioreactor with the microalgae Tetraselmis chui that continuously produced the harpacticoid copepod Tigriopus californicus. During 145 days of operation, the 2.2 m3 bioreactor produced 3.9 kg (wet weight) of Tigriopus with (dry weight) 0.79 ± 0.29% eicosapentaenoic acid (EPA), 0.82 ± 0.26% docosahexaenoic acid (DHA), 1.89 ± 0,60% 3S,3’S-astaxanthin and an essential amino acid index (EAAI) of 97% for juvenile Atlantic salmon. The reactor kept the pH stable over the operation time (pH 8.81 ± 0.40 in the algae phase and pH 8.22 ± 2.96 in the zooplankton phase), while constantly removed nitrate (322.6 mg L−1) and phosphate (20.4 mg L−1) from the water. As a result of the stable pH and nutrient removal, the bioreactor achieved zero effluent discharges. The upscaling of monoalgal, closed-loop ‘green water’ bioreactors could help standardize zooplankton mass production to supply the aquafeeds industry. |
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