Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Int J Environ Res Public Health. 2022 Jun 7;19(12):6981. doi: 10.3390/ijerph19126981.
Cyanobacterial blooms caused by phytoplankton have occurred successively since 1980 in Lake Taihu, China, which has led to difficulty collecting clean drinking water. The effects of cyanobacterial scum-derived dissolved organic matter (DOM) on microbial population variations and of algal-derived filtrate and algal residual exudative organic matter caused by the fraction procedure on nutrient mineralization are unclear. This study revealed the microbial-regulated transformation of DOM from a high-molecular-weight labile to a low-molecular-weight recalcitrant, which was characterized by three obvious stages. The bioavailability of DOM derived from cyanobacterial scum by lake microbes was investigated during 80-d dark degradation. Carbon substrates provided distinct growth strategy links to the free-living bacteria abundance variation, and this process was coupled with the regeneration of different forms of inorganic nutrients. The carryover effects of cyanobacteria blooms can exist for a long time. We also found the transformation of different biological availability of DOM derived from two different cyanobacterial DOM fractions, which all coupled with the regeneration of different forms of inorganic nutrients. Our study provides new insights into the microbial degradation of cyanobacterial organic matter using a fractionation procedure, which suggests that the exudate and lysate from degradation products of cyanobacteria biomass have heterogeneous impacts on DOM cycling in aquatic environments.
自 1980 年以来，中国太湖的浮游植物相继爆发水华，导致难以收集清洁的饮用水。蓝藻水华衍生的溶解有机物质（DOM）对微生物种群变化的影响，以及藻类衍生的滤液和藻类残留渗出有机物质通过分馏程序对营养物质矿化的影响尚不清楚。本研究揭示了微生物对 DOM 的调控转化，从高分子量的易降解物质转化为低分子量的难降解物质，其特征是三个明显的阶段。在 80 天的黑暗降解过程中，研究了蓝藻水华衍生 DOM 的微生物生物可利用性。碳底物为游离细菌丰度变化提供了明显的生长策略联系，这一过程与不同形式无机养分的再生相耦合。蓝藻水华的残留效应可以持续很长时间。我们还发现了两种不同蓝藻 DOM 馏分衍生的 DOM 不同生物可利用性的转化，这两者都与不同形式无机养分的再生相耦合。我们的研究为使用分馏程序对蓝藻有机物质的微生物降解提供了新的见解，表明降解产物的渗出物和溶胞液对水生环境中 DOM 循环具有异质影响。
