Algal based wastewater treatment offers the opportunity to recover, in the form of biomass, the nutrients and internal chemical energy of wastewater. Recently, there has been a growing interest in the use of extremophilic microalgae, as they can easily adapt to difficult and often pollutant-rich environments. The thermo-acidophilic microalga Galdieria phlegrea is a species of recent discovery and great metabolic versatility, but it has still been poorly studied. Here, G. phlegrea was cultivated using raw municipal wastewater in 1 L Erlenmeyer flasks with 700 mL working volume at 37 °C for up to nine days. During the cultivation phase, biomass growth, phycocyanin content, ammonium and phosphate removal from the wastewater, lipid fraction, total carbon and nitrogen in the biomass, and variation in δ¹³C and δ¹⁵N isotopic ratios (a novel analytical contribution in these experiments) were monitored. Results indicated that G. phlegrea was able to grow in raw effluent, where it removed more than 50% ammonium and 20% phosphate in 24 h; total lipid content was in the range of 11–22%, while average C-N content was of 45% and 6%, respectively; isotopic analyses proved to be a useful support in identifying C and N metabolic pathways from effluent to biomass. Overall, G. phlegrea showed consistent performance with similar Cyanidiophyceae and is a potentially viable candidate for municipal wastewater valorization from a circular economy perspective.

中文翻译：

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用废水培养嗜酸微藻白化病菌：工艺产量

基于藻类的废水处理提供了以生物质的形式回收废水中的养分和内部化学能的机会。近年来，对极端微生物的使用引起了越来越多的兴趣，因为它们可以轻松适应困难且通常是污染物丰富的环境。热嗜酸微藻加勒弗氏菌是最近发现的一种，并且具有新陈代谢的多功能性，但对其的研究仍很少。在这里，G。phlegrea使用原始市政废水在1 L锥形瓶中以700 mL工作体积在37°C下培养长达9天。期间在δ的培养阶段，生物质生长，藻青素含量，铵和磷酸盐除去从废水中，脂质部分，在生物质总碳和氮，和变异¹³ C和δ ^15个Ñ同位素比率（在这些实验中的新颖分析贡献）进行了监控。结果表明，G。phlegrea能够在原始废水中生长，并在24小时内去除了50％以上的铵和20％磷酸盐；总脂质含量在11-22％的范围内，而CN的平均含量分别为45％和6％；同位素分析证明是确定从废水到生物质的C和N代谢途径的有用支持。总体而言，G. phlegrea表现出类似的性能一致温泉红藻纲，是从循环经济的角度市政污水稳定物价潜在可行的候选者。