College of Material and Chemical Engineering, TongRen University, Tongren 554300, China.
State key laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
J Environ Sci (China). 2021 May;103:255-267. doi: 10.1016/j.jes.2020.11.010. Epub 2020 Dec 3.
In order to better understand the contribution of nutrients regeneration pathway, release potential and transformation pattern to cyanobacterial growth and succession, 7 sampling sites in Lake Chaohu with different bloom degree were studied every two months from February to November 2018. The carbon, nitrogen (N) and phosphorus (P) forms or fractions in surface, interstitial water and sediments as well as extracellular enzymatic activities, P sorption, specific microbial abundance and community composition in sediments were analyzed. P regeneration pathway was dominated by iron-bound P desorption and phosphorus-solubilizing bacteria solubilization in severe-bloom and slight-bloom area respectively, which both resulted in high soluble reactive phosphorus (SRP) accumulation in interstitial water. However, in severe-bloom area, higher P release potential caused the strong P release and algal growth, compared to slight-bloom area. In spring, P limitation and N selective assimilation of Dolichospermum facilitated nitrate accumulation in surface water, which provided enough N source for the initiation of Microcystis bloom. In summer, the accumulated organic N in Dolichospermum cells during its bloom was re-mineralized as ammonium to replenish N source for the sustainable development of Microcystis bloom. Furthermore, SRP continuous release led to the replacement of Dolichospermum by Microcystis with the advantage of P quick utilization, transport and storage. Taken together, the succession from Dolichospermum to Microcystis was due to both the different forms of N and P in water column mediated by different regeneration and transformation pathways as well as release potential, and algal N and P utilization strategies.
为了更好地了解营养物质再生途径、释放潜力和转化模式对蓝藻生长和演替的贡献，本研究于 2018 年 2 月至 11 月每隔两个月对巢湖 7 个不同水华程度的采样点进行了研究。分析了表层、间隙水和沉积物中的碳、氮（N）和磷（P）形态或组分以及细胞外酶活性、P 吸附、特定微生物丰度和沉积物中微生物群落组成。在重水华和轻水华区，P 再生途径分别以铁结合态 P 解吸和磷溶杆菌溶磷为主，导致间隙水中可溶性反应性磷（SRP）大量积累。然而，在重水华区，较高的 P 释放潜力导致了强烈的 P 释放和藻类生长，与轻水华区相比。在春季，水花生中 P 的限制和 N 的选择性同化促进了硝酸盐在表层水中的积累，为微囊藻水华的起始提供了足够的 N 源。在夏季，水花生水华期间细胞内积累的有机 N 被再矿化为铵，为微囊藻水华的可持续发展补充 N 源。此外，SRP 的持续释放导致具有 P 快速利用、运输和储存优势的微囊藻取代水花生。总之，水花生向微囊藻的演替是由于不同的 N 和 P 形态在水柱中受到不同的再生和转化途径以及释放潜力的影响，以及藻类的 N 和 P 利用策略。
