ABSTRACT The goal of this study was to establish a system for co-culturing microalgae and crop plants with biogas digestate. We examined growth performances of E. gracilis and L. sativa co-cultured using a commercial liquid fertilizer designed for soilless culture supplemented with vitamins and ammonium. This solution simulated the filtrate of nitrified biogas digestate derived from the organic fraction of municipal solid waste but was supplemented with insufficient plant nutrients (Mg, Fe and Mn). The specific growth rate of the co-cultured E. gracilis was 0.761 ± 0.081 d−1 (mean ± SE), which was the same rate that E. gracilis achieved when grown as a sole culture. There were no significant differences between L. sativa cultured with E. gracilis until the stationary growth phase of E. gracilis was reached and those cultured alone relative to biomass, RGRs (relative growth rates), or relative to SPAD values of leaves. These results suggest that E. gracilis and L. sativa could be co-cultured with the biogas digestate after being nitrified and filtered. In addition, considering concentrations of plant macronutrients in the residual solution after the co-culturing E. gracilis and L. sativa, it could be re-used as the nutrient solution for co-culturing E. gracilis and L. sativa. GRAPHICAL ABSTRACT

中文翻译：

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用沼气消化物共培养 Euglena gracilis 和 Lactuca sativa L. 的可能性

摘要 本研究的目的是建立一个微藻和农作物与沼气共培养系统。我们检查了使用为无土栽培设计的商业液体肥料共培养的 E. gracilis 和 L. sativa 的生长性能，并补充了维生素和铵。该解决方案模拟了源自城市固体废物有机部分的硝化沼气消化液的滤液，但补充了不足的植物营养素（镁、铁和锰）。共同培养的 E. gracilis 的比生长率为 0.761 ± 0.081 d-1（平均值 ± SE），这与 E. gracilis 作为单独培养物生长时达到的增长率相同。与 E. gracilis 一起培养的 L. sativa 之间没有显着差异，直到 E. gracilis 的稳定生长期。达到了 gracilis 和单独培养的那些相对于生物量、RGR（相对生长率）或相对于叶子的 SPAD 值。这些结果表明 E. gracilis 和 L. sativa 在硝化和过滤后可以与沼气共培养。此外，考虑到纤细纤和苜蓿共培养后残留溶液中植物常量营养素的浓度，可以将其重新用作共培养纤细纤和苜蓿的营养液。图形概要 sativa，它可以重新用作共培养 E. gracilis 和 L. sativa 的营养液。图形概要 sativa，它可以重新用作共培养 E. gracilis 和 L. sativa 的营养液。图形概要