The Effect of Paraburkholderia on the Nutrients in Eutrophic Lakes

Abstract

Cyanobacterial blooms in freshwater bodies are mainly attributed to the excess loading of nutrients. The microbes in sediments may affect nutrient migration and transformation during the growth of cyanobacteria. This study focused on the role of Paraburkholderia disturbance in affecting the sediment nutrient conditions and further contributing to cyanobacterial community succession in Meiliang Bay, Lake Taihu. The dissolving phosphorus and fixing nitrogen of Paraburkholderia with different concentration and characteristic capabilities, as well as the impact on nutrients (nitrogen (N), phosphorus (P), iron (Fe), etc.) in eutrophic lakes were determined. The results indicated that the various forms of phosphorus in the sediments showed total phosphorus (TP) > inorganic phosphorus (IP) > iron/aluminum-bound phosphate (NaOH-P) > algal-available phosphorus (AAP) > organic phosphorus (OP) > calcium-bound phosphate (HCl-P). Additionally, it was observed that with higher values of Paraburkholderia (OD600), the higher the corresponding risk of endogenous nutrient release from the sediments into the overlying water (but more is not always better), especially for the solubilization of HCl-P. The diffusion fluxes of TP, total nitrogen (TN) and Fe at the sediment–water interface (SWI) were all positive in the bacteria only experiment, with maximum values of 0.64, 15.0 and 5.02 mg/(m2d), respectively. Additionally, it was interesting that Paraburkholderia were able to produce organic acids, causing a decrease in pH. Furthermore, glucose levels can seriously affect water quality, especially the reduction in dissolved oxygen (DO) (down to 0.01 mg/L), leading to a series of side effects that have a huge impact on cyanobacterial community succession. These results provide a theoretical basis for the microbial ecological factors in eutrophic lakes.