New paper published in Environmental Science: Water Research & Technology journal
Nuisanace and Harmful Algae researchers Sara Imran Khan, Arash Zamyadi, Naras Rao, Richard Stuetz and Rita Henderson have published a paper titled “Fluorescence spectroscopic characterisation of algal organic matter: towards improved in-situ fluorometer development” in the prestigious Royal Society of Chemistry journal Environmental Science: Water Research & Technology. This publication complements the previous work from the group on the use of fluorometers for real-time monitoring of cyanobacterial blooms and enhanced real-time cyanobacterial fluorescence monitoring through chlorophyll-a interference compensation corrections.
This study investigates whether fluorescence can be applied to characterise the algal organic matter (AOM) released by cyanobacterial and algal species which, when combined with cell pigmentation measurements, may improve the specificity and robustness of these online methods. The AOM released by key cyanobacterial (Dolichospermum circinalis, Cylindrospermopsis raciborskii, four strains of Microcystis aeruginosa) and algal (Chlorella vulgaris) species were studied at lab scale throughout their growth using 3D-fluorescent excitation–emission matrix (F-EEMs) spectroscopy combined with parallel factor analysis (PARAFAC). The relevant wavelengths were shown to vary depending on the species; for example, the fluorescence of amino acid-like material at λex/em = 290/345 nm dominated in the AOM originating from C. vulgaris, while that of M. aeruginosa (CS-555) was dominated by fluorescence at λex/em = 355/475 nm which has previously been associated only with terrestrially delivered substances. Both these fluorescence signatures had significant correlations with the released AOM, measured as dissolved organic carbon (DOC), and dominated across the exponential and stationary phases relative to other PARAFAC components. With fluorescence probes on the market that measure fluorescence in AOM regions, there is an opportunity to monitor these key peaks simultaneously with pigment fluorescence to give further information on the released organic matter character and its treatability.