Understanding the dynamics of picophytoplankton is essential for assessing the ecological health of aquatic systems, particularly in clean reservoirs where community stability and high biodiversity are maintained due to low nutrient levels. Picophytoplankton, defined as photosynthetic organisms smaller than 2 µm, play a pivotal role in global material cycling and energy flow despite their microscopic size. Traditional monitoring methods such as chlorophyll-a measurement, turbidity assessment, and microscopy often lack precision and fail to capture species-level diversity. Molecular techniques like 16S rDNA sequencing have advanced microbial detection but remain limited in identifying eukaryotic picophytoplankton. This study presents a novel integrated methodology combining flow cytometry (FCM) with high-throughput 23S rDNA sequencing to enhance the accuracy and resolution of picophytoplankton monitoring in Jinze Reservoir, a critical drinking water source in southwest Shanghai.
Monthly sampling from April to September 2019 enabled temporal and spatial analysis of picophytoplankton communities across six sites representing distinct zones: raw water intake, pretreatment, ecological purification, and water transfer areas. FCM analysis revealed eight phenotypically distinct phytoplankton groups based on fluorescence profiles and cell size. These included pico- and nano-sized Cyanobacteria, Chlorophyta, Cryptophyta, Haptophyta, Dinoflagellates, and other eukaryotic groups. Notably, Pico-Cyanobacteria and Pico-Eukaryotes were significantly enriched, with pigment compound percentages rising from 8.2% to 76.3%, indicating effective suppression of heterotrophic interference during sorting. The method successfully detected previously overlooked low-abundance taxa, revealing a more comprehensive picture of community composition.
Phytoplankton were categorized into three groups: highly abundant and persistent taxa, low-abundance transient populations, and stable low-diversity groups.PSCA Antibody Description Dominant species included Synechococcus, Emiliania, Tetraselmis, and Thalassiosira, which exhibited distinct seasonal and spatial patterns. Synechococcus reached peak abundance in September, influenced positively by temperature, ammonia-N, and turbidity, while negatively affected by total nitrogen and dissolved oxygen. Pico-PE-rich Cyanobacteria and Nano-Eukaryotes showed abnormal summer increases, suggesting potential responses to thermal stratification and light availability. Environmental factors such as temperature, ammonia-N, nitrate-N, turbidity, and total nitrogen were identified as key drivers shaping community structure.CD185 Antibody In stock Additionally, certain picophytoplankton with specialized physiological traits demonstrated competitive advantages, contributing to ecosystem stability.PMID:34820859
This study also investigated off-flavor compounds—2-methylisoborneol (2-MIB) and geosmin (GEO)—which can compromise drinking water quality. Over 66.7% of samples exceeded the olfactory threshold for 2-MIB, and 20.8% did so for GEO. Chrysochromuina, Planktothrix, and Microcystis were identified as potential producers through correlation analyses and network modeling. The integration of FCM sorting with 23S rDNA sequencing not only improved taxonomic resolution but also enabled targeted investigation of functional groups linked to odor production. This approach provides a robust framework for early warning and risk assessment in drinking water reservoirs.
The findings highlight the importance of combining physical and molecular tools for accurate, real-time monitoring of picophytoplankton. By overcoming limitations of conventional methods, this hybrid strategy offers unprecedented insights into microbial community dynamics, ecological resilience, and contamination risks. It sets a new standard for environmental surveillance in sensitive freshwater ecosystems, supporting sustainable water management and public health protection.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com