Involved Member: Prof. Nora Fung Yee TAM

This study investigates the factors involved in shaping sediment biofilms in contaminated mangrove sediments through in-situ characterization of biofilm components and environmental factors. The pennate diatom Navicula plays a crucial role in balancing the abundance of Nitzschia and Cyclotella and producing bound-polysaccharides. The taxa composition shifts in a high N/P matrix, with the populations of pennate diatoms increasing but that of centric diatoms decreasing. High nutrient concentrations result in more diatoms and elevated levels of extracellular polymeric substances (EPS), which are consumed by bacteria and these bacteria tend to be more symbiotic with Nitzschia. The study also examines the response of biofilms to specific contaminants, which inhibit the abundance of bacteria and diatoms but enhance most EPS fractions except bound-polysaccharides. The findings contribute to understanding the microbial carbon loop of benthic biofilms in mangrove ecosystems under stress by nutrients and mixed contaminants.

Reference:
Yang, L., Yang, Q., Lin, L., Luan, T., Tam, N.F.Y., (2023). Characterization of benthic biofilms in mangrove sediments and their variation in response to nutrients and contaminants. Science of The Total Environment, 857, 159391. (impact factor: 10.754)