Guo Ling, Zhao Yonggui, Xiao Yao, Tian Xueping, Bao Shu, Wang Xinhui, He Kaize, Jin Yanling, Fang Yang, Zhao Hai
Department of Pediatric Hematologic Oncology and Respiratory, Children's Medical Center, The Affiliated Hospital of Southwest Medical University, Sichuan Clinical Research Center for Birth Defects, Southwest Medical University, Luzhou 646000, China.
Agricultural Microbial Agents Key Laboratory of Sichuan Province, National Engineering and Research Center for Natural Medicines, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China; School of Ecology and Environmental Sciences & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming 650091, China.
Bioresour Technol. 2025 Oct;434:132785. doi: 10.1016/j.biortech.2025.132785. Epub 2025 Jun 9.
This study presents a pilot-scale duckweed-based wastewater treatment system enhanced with CO fertilization to improve nutrient removal, CO capture, and biomass productivity. Three strains of Landoltia punctata were cultivated continuously for five months. In spring, CO supplementation significantly increased the biomass yield and starch and protein productivity (by more than 12.2, 2.4 and 3.5 g/m/d, respectively), representing increases of 189-259 %, 1,108-2,330 % and 143-166 %, respectively, compared with those of the control group. The removal rates of total nitrogen (TN) and total phosphorus (TP) increased by 28-71 % and 120-148 %, respectively, whereas CO capture improved by 196-264 %. Enhanced nutrient recovery was also observed, with N recovery increasing from 0.20-0.25 to 0.54-0.61 g/m/d and P from approximately 0.05 to 0.11 g/m/d. Enzyme activity and transcriptome analyses of strain 0202, which presented the highest starch content, revealed that CO fertilization upregulated key starch biosynthesis genes (ADP-glucose pyrophosphorylase (AGPase), Granule-bound starch synthase (GBSS), and Soluble Starch Synthase (SSS)), contributing to increased starch accumulation. It also promoted glutamine synthetase expression, increasing nitrogen assimilation and shifting nitrogen removal from microbial nitrification to duckweed uptake. As a result, microbial nitrification decreased significantly, and the proportion of NH-N removed via plant assimilation increased to over 69 %. These findings demonstrate that coupling CO fertilization with duckweed cultivation is an effective and scalable approach for wastewater treatment, carbon fixation, and renewable bioresource production.
本研究展示了一种中试规模的浮萍基废水处理系统，该系统通过添加二氧化碳施肥来提高养分去除率、二氧化碳捕获量和生物质生产力。三种品系的细绿萍连续培养了五个月。在春季，补充二氧化碳显著提高了生物质产量以及淀粉和蛋白质生产力（分别提高了超过12.2、2.4和3.5克/平方米/天），与对照组相比，分别增长了189%-259%、1108%-2330%和143%-166%。总氮（TN）和总磷（TP）的去除率分别提高了28%-71%和120%-148%，而二氧化碳捕获量提高了196%-264%。还观察到养分回收得到增强，氮回收量从0.20-0.25克/平方米/天增加到0.54-0.61克/平方米/天，磷从约0.05克/平方米/天增加到0.11克/平方米/天。对淀粉含量最高的0202品系进行的酶活性和转录组分析表明，二氧化碳施肥上调了关键淀粉生物合成基因（ADP-葡萄糖焦磷酸化酶（AGPase）、颗粒结合淀粉合酶（GBSS）和可溶性淀粉合酶（SSS）），有助于增加淀粉积累。它还促进了谷氨酰胺合成酶的表达，增加了氮同化，并将氮去除从微生物硝化作用转变为浮萍吸收。结果，微生物硝化作用显著降低，通过植物同化去除的NH-N比例增加到超过69%。这些发现表明，将二氧化碳施肥与浮萍培养相结合是一种用于废水处理、碳固定和可再生生物资源生产的有效且可扩展的方法。
