Advanced characterization of dissolved organic matter released by bloom-forming marine algae

Abstract

a b s t r a c tAlgal organic matter (AOM), produced by marine phytoplankton during bloom periods, may adversely affect the performance of membrane processes in seawater desalination. The polysaccharide fraction of AOM has been related to (bio)fouling in micro-filtration and ultrafiltration, and reverse osmosis membranes. However, so far, the chemical structure of the polysaccharides released by bloom-forming algae is not well understood. In this study, dissolved fraction of AOM produced by three algal species (Chaetoceros affinis, Nitzschia epithemoides and Hymenomonas spp.) was characterized using liquid chromatography-organic carbon detection (LC-OCD) and fluorescence spectroscopy. Chemical structure of polysaccharides isolated from the AOM solutions at stationary phase was analyzed using proton nuclear magnetic resonance ( 1 H-NMR). The results showed that production and composition of dissolved AOM varied depending on algal species and their growth stage. AOM was mainly composed of biopolymers (BP; i.e., polysaccharides and proteins [PN]), but some refractory substances were also present. 1 H-NMR spectra confirmed the predominance of carbohydrates in all samples. Furthermore, similar fingerprints were observed for polysaccharides of two diatom species, which differed considerably from that of coccolithophores. Based on the findings of this study, 1 H-NMR could be used as a method for analyzing chemical profiles of algal polysaccharides to enhance the understanding of their impact on membrane fouling.

The Fate of Dissolved Organic Matter (DOM) During Bank Filtration under Different Environmental Conditions: Batch and Column Studies

“…This indicates the impact of effluent organic matter (EfOM) on their organic compositions [32]. Though WEOM had the highest concentration of BP, only 42% can be considered protein (assuming the C:N is 3, and all organic nitrogen in BP originates from protein) [46]. However, the protein represents 51, 65, and 82% of the BP for DC, DCWW, and WW influent, respectively, which also reflects the impact of EfOM.…”

NMR Spectroscopy for Metabolomics Research

“…Additionally, NMR allows users to explore chemistry with much greater detail than any other method. It allows users to look at intact molecules at an atomic level and to see not just the 1 H atoms but also many other kinds of atoms ( 13 C, 15 N) or biologically reactive groups, including phosphate atoms ( 31 P) [42,43,44,45,46,47]. Furthermore, NMR spectroscopy can be used to assess unique classes of metabolites (especially protein-bound metabolites such as lipoprotein particles) and to measure certain inorganic metabolites or ions (metal ions and H+ ions via pH) that cannot be done via LC-MS or GC-MS [48,49].…”

A methodological review on the characterization of microalgal biofilm and its extracellular polymeric substances

“…FEEM is a non‐destructive and user‐friendly technique to detect the fluorophore‐associated molecules such as proteins and humic substances (Jacquin et al, 2017). The basic principle of FEEM relies on the broad emission spectra that is attributed to the excitation and emission boundaries of those EEM peaks associated with humic‐like, tyrosine‐like, fulvic‐like and tryptophan‐like compounds (Henderson et al, 2008; Rehman et al, 2017; Subhi et al, 2011). Humic substances are part of EPS participating in complexation of trace element and random flocculation in water environments (Flemming & Wingender, 2010).…”