Simulated bioavailability of phosphorus from aquatic macrophytes and hytoplankton by aqueous suspension and incubation with alkaline phosphatase

Authors: FENG, WEIYING - Chinese Research Academy Of Environmental Sciences; WU, FENGCHANG - Chinese Research Academy Of Environmental Sciences; He, Zhongqi; SONG, FANHAO - Chinese Research Academy Of Environmental Sciences; ZHU, YUANRONG - Chinese Research Academy Of Environmental Sciences; GEISY, JOHN - Chinese Research Academy Of Environmental Sciences; WANG, YING - Chinese Research Academy Of Environmental Sciences; QIN, NING - Chinese Research Academy Of Environmental Sciences; ZHANG, CHEN - Chinese Research Academy Of Environmental Sciences; CHEN, HAIYAN - Chinese Research Academy Of Environmental Sciences; SUN, FUHONG - Chinese Research Academy Of Environmental Sciences

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2017
Publication Date: 10/23/2017
Citation: Feng, W., Wu, F., He, Z., Song, F., Zhu, Y., Geisy, J.P., Wang, Y., Qin, N., Zhang, C., Chen, H., Sun, F. 2018. Simulated bioavailability of phosphorus from aquatic macrophytes and phytoplankton by aqueous suspension and incubation with alkaline phosphatase. Science of the Total Environment. 616-617:1431-1439.

Interpretive Summary: Phosphorus (P) was the stimulating nutrient element in most eutrophic lakes as excessive P was the determining factor that caused cyanobacterial blooming. Three typical aquatic macrophytes and three typical algae in Lake Tai, China were taken as examples for investigation of the biogeochemical cycle of organic P (Po) in eutrophic lakes. Simulating the natural Po release, the ground powders of the six samples were suspended in water and incubated with alkaline phosphatase. The changes of the P forms and quantities were evaluated by solution 31P- NMR spectroscopy. Per these data, the biogeochemical cycle of Po from aquatic macrophytes and algae and its relationship with algae blooming were discussed. The results suggested that the release of Po derived from algae debris should be the fastest way supplied bioavailable P for algae blooming again in a short time in eutrofic lakes. Knowledge derived from this work provided the important simulating information which would be helpful for control of the eutrophication levels in eutrophic lakes.

Technical Abstract: Bioavailability of phosphorus (P) in aquatic macrophytes and algae on lake eutrophication was studied by evaluation their P forms and quantities in their water suspensions and impact by alkaline phosphatase hydrolysis. using solution 31P-nuclear magnetic resonance (NMR). The laboratory suspension and enzyme incubation were assumed to simulate the natural P release from dead plant debris. Three aquatic macrophytes and thtree algae were collected from Lake Tai, China, for the simulation. We found that the trends of organic P (Po) hydrolysis were similar in aquatic macrophytes and algae after alkaline phosphatase. Most of monoester P (15.3% of total dissolved P) and pyrophosphate (1.8%) and polyphosphate (0.4%) and DNA (3.2%) were transformed into orthophosphate (14.3%). The major forms of monoester P were glycerophosphate (8.8%), nucleotide(2.5%), phytate (0.4%) and other monoester P(3.6%). However, the hydrolysis rates were different between algae and aquatic macrophytes as the portions of Po transformed to bioavailable P from algae and aquatic macrophytes were 22.6% and 6.0%, respectively. The hydrolysis rate of algal Po was about four times higher than that of the aquatic macrophyte Po, and s approximately twenty-five times higher than that of the sediment Po. Thus, the release of Po derived from algae debris should be the fastest way supplied bioavailable P for algae blooming again in a short time in eutrific lakes.