Removing Constraints on the Biomass Production of Freshwater Macroalgae by Manipulating Water Exchange to Manage Nutrient Flux
Removing Constraints on the Biomass Production of Freshwater Macroalgae by Manipulating Water Exchange to Manage Nutrient Flux
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DOI：
10.1371/journal.pone.0101284
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发表时间：
2014-07-07
期刊：
影响因子：
3.7
通讯作者：
Paul, Nicholas A.
中科院分区：
文献类型：
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作者：
Cole, Andrew J.;de Nys, Rocky;Paul, Nicholas A.
淡水大型藻类代表了一个在很大程度上被忽视的群体的光养生物体，可以发挥重要作用，在工业生态环境中利用废物营养物质和水，并提供生物质的动物饲料和可再生化学品和燃料。本研究使用的水从集约化养殖的淡水鱼（澳洲肺鱼），以研究如何的生物量生产率和蛋白质含量的淡水macrocarpus Oedogonium响应增加通量的营养物质和碳，通过增加水交换率或通过补充氮和CO2。生物质生产率最高的低流速（0.1-1 vol.day（-1））使用原池塘水。向培养物中添加CO2使生物质生产率增加2 - 25%，这种效果在低水交换率下最强。奇怪的是，添加氮的文化降低生产力，特别是在低水交换率。鞘藻的最佳培养出现在0.5-1vol.day流速之间，其中氮的吸收速率峰值为1.09 g.m（-2）.day（-1），磷的吸收速率峰值为0.13 g.m（-2）.day（-1）。在这些流速下，鞘藻生物质对氮的吸收效率为75.2%，对磷的吸收效率为22.1%。在本研究中，维持鞘藻生长在16-17 g DW·m（-2）·d（-1）和粗蛋白含量25%的最低氮通量为1.45 g·m（-2）·d（-1），磷通量为0.6 g·m（-2）·d（-1）。一个简单的最小投入模型表明，对于每克干重生物量生产（g DW.m（-2）.day（-1）），鞘藻需要0.09 g.m（-2）.day（-1）的氮和0.04 g.m（-2）.day（-1）的磷来维持生长而不受养分限制，同时维持高的养分吸收速率和效率。因此，综合养殖淡水大型藻类与水产养殖的营养回收的目的是一个可行的解决方案，废水的生物修复和蛋白质资源的供应。
Freshwater macroalgae represent a largely overlooked group of phototrophic organisms that could play an important role within an industrial ecology context in both utilising waste nutrients and water and supplying biomass for animal feeds and renewable chemicals and fuels. This study used water from the intensive aquaculture of freshwater fish (Barramundi) to examine how the biomass production rate and protein content of the freshwater macroalga Oedogonium responds to increasing the flux of nutrients and carbon, by either increasing water exchange rates or through the addition of supplementary nitrogen and CO2. Biomass production rates were highest at low flow rates (0.1-1 vol.day(-1)) using raw pond water. The addition of CO2 to cultures increased biomass production rates by between 2 and 25% with this effect strongest at low water exchange rates. Paradoxically, the addition of nitrogen to cultures decreased productivity, especially at low water exchange rates. The optimal culture of Oedogonium occurred at flow rates of between 0.5-1 vol.day(-1), where uptake rates peaked at 1.09 g.m(-2).day(-1) for nitrogen and 0.13 g.m(-2).day(-1) for phosphorous. At these flow rates Oedogonium biomass had uptake efficiencies of 75.2% for nitrogen and 22.1% for phosphorous. In this study a nitrogen flux of 1.45 g.m(-2).day(-1) and a phosphorous flux of 0.6 g.m(-2).day(-1) was the minimum required to maintain the growth of Oedogonium at 16-17 g DW.m(-2).day(-1) and a crude protein content of 25%. A simple model of minimum inputs shows that for every gram of dry weight biomass production (g DW.m(-2).day(-1)), Oedogonium requires 0.09 g.m(-2).day(-1) of nitrogen and 0.04 g.m(-2).day(-1) of phosphorous to maintain growth without nutrient limitation whilst simultaneously maintaining a high-nutrient uptake rate and efficiency. As such the integrated culture of freshwater macroalgae with aquaculture for the purposes of nutrient recovery is a feasible solution for the bioremediation of wastewater and the supply of a protein resource.