Baldisserotto Costanza, Demaria Sara, Accoto Ornella, Marchesini Roberta, Zanella Marcello, Benetti Linda, Avolio Francesco, Maglie Michele, Ferroni Lorenzo, Pancaldi Simonetta
Department of Life Sciences and Biotechnology, University of Ferrara, C.so Ercole I d'Este, 32, 44121 Ferrara, Italy.
HERA SpA-Direzione Acqua, Via C. Diana, 40, Cassana, 44044 Ferrara, Italy.
Plants (Basel). 2020 Dec 18;9(12):1802. doi: 10.3390/plants9121802.
Microalgae are photosynthetic microorganisms and are considered excellent candidates for a wide range of biotechnological applications, including the removal of nutrients from urban wastewaters, which they can recover and convert into biomass. Microalgae-based systems can be integrated into conventional urban wastewater treatment plants (WW-TP) to improve the water depuration process. However, microalgal strain selection represents a crucial step for effective phytoremediation. In this work, a microalga isolated from the effluent derived from the thickening stage of waste sludge of an urban WW-TP was selected and tested to highlight its potential for nutrient removal. Ammonium and phosphate abatements by microalgae were evaluated using both the effluent and a synthetic medium in a comparative approach. Parallelly, the isolate was characterized in terms of growth capability, morphology, photosynthetic pigment content and photosystem II maximum quantum yield. The isolated microalga showed surprisingly high biomass yield and removal efficiency of both ammonium and phosphate ions from the effluent but not from the synthetic medium. This suggests its clear preference to grow in the effluent, linked to the overall characteristics of this matrix. Moreover, biomass from microalgae cultivated in wastewater was enriched in photosynthetic pigments, polyphosphates, proteins and starch, but not lipids, suggesting its possible use as a biofertilizer.
微藻是光合微生物，被认为是广泛生物技术应用的优秀候选者，包括从城市废水中去除营养物质，它们可以回收并将其转化为生物质。基于微藻的系统可以整合到传统的城市污水处理厂（WW-TP）中，以改善水净化过程。然而，微藻菌株的选择是有效植物修复的关键步骤。在这项工作中，从城市污水处理厂污泥浓缩阶段的流出物中分离出一种微藻，并对其进行测试，以突出其去除营养物质的潜力。采用比较方法，使用流出物和合成培养基评估微藻对铵和磷的去除情况。同时，从生长能力、形态、光合色素含量和光系统II最大量子产率等方面对分离物进行了表征。分离出的微藻显示出惊人的高生物量产量，并且对流出物中的铵离子和磷酸根离子具有很高的去除效率，但对合成培养基中的离子去除效率不高。这表明它明显倾向于在流出物中生长，这与该基质的整体特性有关。此外，在废水中培养的微藻生物质富含光合色素、多磷酸盐、蛋白质和淀粉，但不含脂质，这表明它可能用作生物肥料。
