title: A comparison of the character of algal extracellular versus cellular organic matter produced by cyanobacterium, diatom and green alga.
abstract: This study investigated characteristics of algal organic matter (AOM) derived from three species (cyanobacterium Microcystis aeruginosa, diatom Fragilaria crotonensis and green alga Chlamydomonas geitleri) which dominate phytoplanktonic populations in reservoirs supplying drinking water treatment plants. Algal growth was monitored by cell counting, optical density and dissolved organic carbon concentration measurements. Extracellular organic matter (EOM) released at exponential and stationary growth phases and cellular organic matter (COM) were characterised in terms of specific UV absorbance (SUVA), peptide/protein and non-peptide content, hydrophobicity and molecular weight (MW). It was found that both EOM and COM were predominantly hydrophilic with low SUVA. COM was richer in peptides/proteins, more hydrophilic (with about 89% of hydrophilic fraction for all three species) and had lower SUVA than EOM. MW fractionation showed that both EOM and COM of all three species contain large portions of low-MW (<1 kDa) compounds and high-MW (>100 kDa) polysaccharides. Peptides/proteins exhibited narrower MW distribution than non-peptide fraction and it widened as the cultures grew. The highest amount of peptides/proteins with a significant portion of high-MW ones (22%) was observed in COM of M. aeruginosa. The results imply that the knowledge of AOM composition and characteristics predetermine which processes would be effective in the treatment of AOM laden water.
authors.affiliation: Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Pod Patankou 5, 166 12 Prague 6, Czech Republic. Electronic address: pivo@ih.cas.cz.
authors.forename: Martin
authors.initials: M
authors.lastname: Pivokonsky
authors.affiliation: Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Pod Patankou 5, 166 12 Prague 6, Czech Republic; Institute of Environmental Studies, Faculty of Science, Charles University, Benatska 2, 128 01 Prague 2, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Safarikova
authors.affiliation: Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Pod Patankou 5, 166 12 Prague 6, Czech Republic; Institute of Environmental Studies, Faculty of Science, Charles University, Benatska 2, 128 01 Prague 2, Czech Republic.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Baresova
authors.affiliation: Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Pod Patankou 5, 166 12 Prague 6, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Pivokonska
authors.affiliation: Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Pod Patankou 5, 166 12 Prague 6, Czech Republic; Institute of Environmental Studies, Faculty of Science, Charles University, Benatska 2, 128 01 Prague 2, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Kopecka
mesh_terms: D002244:Carbon / Q000032:analysis; D018929:Cell Culture Techniques; D000460:Chlorophyta / Q000737:chemistry*; D000458:Cyanobacteria / Q000737:chemistry*; D017377:Diatoms / Q000737:chemistry*; D005109:Extracellular Matrix / Q000737:chemistry*; D042541:Intracellular Space / Q000737:chemistry*; D011506:Proteins / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011506:Proteins; D002244:Carbon
keywords: Algal organic matter; Cellular organic matter; Extracellular organic matter; Hydrophobicity; Molecular weight fractionation; Peptide/protein content