Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents
IntroductionUlva prolifera, a dominant species in green tides, exhibits remarkable nitrogen absorption capacity, yet its kinetics as a biofilter in recirculating aquaculture systems (RAS) remain unquantified.MethodsThis study systematically characterized NH4+-N, NO3−-N, and NO2−-N uptake kinetics in...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-08-01
|
| Series: | Frontiers in Marine Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2025.1654677/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849390372690591744 |
|---|---|
| author | Wei Liu Meijing Zhang Xian’an Xiong Chiquan He Jinlin Liu Peimin He |
| author_facet | Wei Liu Meijing Zhang Xian’an Xiong Chiquan He Jinlin Liu Peimin He |
| author_sort | Wei Liu |
| collection | DOAJ |
| description | IntroductionUlva prolifera, a dominant species in green tides, exhibits remarkable nitrogen absorption capacity, yet its kinetics as a biofilter in recirculating aquaculture systems (RAS) remain unquantified.MethodsThis study systematically characterized NH4+-N, NO3−-N, and NO2−-N uptake kinetics in nitrogen-starved (7-day). U. prolifera across eight concentration gradients (NH4+-N: 0.5–35 µmol·L−1; NO3−-N: 5–130 µmol·L−1; NO2−-N: 2.5–60 µmol·L−1).ResultMichaelis-Menten modeling revealed: NO3−-N achieved the highest maximum uptake rate (Vmax = 161.29 μmol·g−1·h−1), but the greatest half-saturation constant (Km = 29.40 µmol·L−1); NH4+-N showed the strongest affinity (Km = 4.60 μmol·L−1); NO2−-N absorption plummeted at >50 µmol·L−1 (41% removal after 6h). When the initial concentrations were below 20 µmol·L−1 for NH4+-N, or below 90 μmol·L−1 NO3−-N, or below 20 μmol·L−1 for NO2−-N, 1 g of Ulva prolifera in 1 L of seawater completely achieving 100% removal efficiency for each within 6 hours. Critical inhibition thresholds were identified: NH4+-N >20 µmol·L−1 reduced removal by 40–60%, NO3−-N >110 μmol·L−1 induced suppression, and NO2−-N >30 µmol·L−1 triggered acute inhibition.ConclusionWe propose optimized RAS protocols: maintain NH4+-N ≤20 μmol·L−1 and NO2−-N ≤30 µmol·L−1, with 1.5–2× increased algal biomass when high total inorganic nitrogen concentration to sustain >90% nitrogen removal. This work demonstrates U. prolifera’s nitrogen assimilation strategy—"high ammonium affinity, high nitrate capacity, nitrite sensitivity"—providing a mechanistic foundation for valorizing green-tide macroalgae in sustainable aquaculture. |
| format | Article |
| id | doaj-art-a12cdaf5c98746a09f6636c717cdf5a9 |
| institution | Kabale University |
| issn | 2296-7745 |
| language | English |
| publishDate | 2025-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj-art-a12cdaf5c98746a09f6636c717cdf5a92025-08-20T03:41:40ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452025-08-011210.3389/fmars.2025.16546771654677Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluentsWei Liu0Meijing Zhang1Xian’an Xiong2Chiquan He3Jinlin Liu4Peimin He5School of Environmental and Chemical Engineering, Shanghai University, Shanghai, ChinaCollege of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai, ChinaSchool of Environmental and Chemical Engineering, Shanghai University, Shanghai, ChinaSchool of Environmental and Chemical Engineering, Shanghai University, Shanghai, ChinaState Key Laboratory of Marine Geology, Tongji University, Shanghai, ChinaCollege of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai, ChinaIntroductionUlva prolifera, a dominant species in green tides, exhibits remarkable nitrogen absorption capacity, yet its kinetics as a biofilter in recirculating aquaculture systems (RAS) remain unquantified.MethodsThis study systematically characterized NH4+-N, NO3−-N, and NO2−-N uptake kinetics in nitrogen-starved (7-day). U. prolifera across eight concentration gradients (NH4+-N: 0.5–35 µmol·L−1; NO3−-N: 5–130 µmol·L−1; NO2−-N: 2.5–60 µmol·L−1).ResultMichaelis-Menten modeling revealed: NO3−-N achieved the highest maximum uptake rate (Vmax = 161.29 μmol·g−1·h−1), but the greatest half-saturation constant (Km = 29.40 µmol·L−1); NH4+-N showed the strongest affinity (Km = 4.60 μmol·L−1); NO2−-N absorption plummeted at >50 µmol·L−1 (41% removal after 6h). When the initial concentrations were below 20 µmol·L−1 for NH4+-N, or below 90 μmol·L−1 NO3−-N, or below 20 μmol·L−1 for NO2−-N, 1 g of Ulva prolifera in 1 L of seawater completely achieving 100% removal efficiency for each within 6 hours. Critical inhibition thresholds were identified: NH4+-N >20 µmol·L−1 reduced removal by 40–60%, NO3−-N >110 μmol·L−1 induced suppression, and NO2−-N >30 µmol·L−1 triggered acute inhibition.ConclusionWe propose optimized RAS protocols: maintain NH4+-N ≤20 μmol·L−1 and NO2−-N ≤30 µmol·L−1, with 1.5–2× increased algal biomass when high total inorganic nitrogen concentration to sustain >90% nitrogen removal. This work demonstrates U. prolifera’s nitrogen assimilation strategy—"high ammonium affinity, high nitrate capacity, nitrite sensitivity"—providing a mechanistic foundation for valorizing green-tide macroalgae in sustainable aquaculture.https://www.frontiersin.org/articles/10.3389/fmars.2025.1654677/fullRASUlva proliferanitrogen absorption kineticseutrophicationbiofiltergreen tide |
| spellingShingle | Wei Liu Meijing Zhang Xian’an Xiong Chiquan He Jinlin Liu Peimin He Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents Frontiers in Marine Science RAS Ulva prolifera nitrogen absorption kinetics eutrophication biofilter green tide |
| title | Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents |
| title_full | Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents |
| title_fullStr | Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents |
| title_full_unstemmed | Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents |
| title_short | Macroalga Ulva prolifera O.F. Müller: an efficient biofilter for nitrogen-enriched aquaculture effluents |
| title_sort | macroalga ulva prolifera o f muller an efficient biofilter for nitrogen enriched aquaculture effluents |
| topic | RAS Ulva prolifera nitrogen absorption kinetics eutrophication biofilter green tide |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2025.1654677/full |
| work_keys_str_mv | AT weiliu macroalgaulvaproliferaofmulleranefficientbiofilterfornitrogenenrichedaquacultureeffluents AT meijingzhang macroalgaulvaproliferaofmulleranefficientbiofilterfornitrogenenrichedaquacultureeffluents AT xiananxiong macroalgaulvaproliferaofmulleranefficientbiofilterfornitrogenenrichedaquacultureeffluents AT chiquanhe macroalgaulvaproliferaofmulleranefficientbiofilterfornitrogenenrichedaquacultureeffluents AT jinlinliu macroalgaulvaproliferaofmulleranefficientbiofilterfornitrogenenrichedaquacultureeffluents AT peiminhe macroalgaulvaproliferaofmulleranefficientbiofilterfornitrogenenrichedaquacultureeffluents |