Production of Fluorescent Dissolved Organic Matter by Microalgae Strains from the Ob and Yenisei Gulfs (Siberia)

Abstract

Dissolved organic matter (DOM) is an important component of aquatic environments; it plays a key role in the biogeochemical cycles of many chemical elements. Using excitation–emission matrix fluorescence spectroscopy, we examined the fluorescent fraction of DOM (FDOM) produced at the stationary phase of growth of five strains of microalgae sampled and isolated from the Ob and Yenisei gulfs. Based on the morphological and molecular descriptions, the strains were identified as diatoms (Asterionella formosa, Fragilaria cf. crotonensis, and Stephanodiscus hantzschii), green microalgae (Desmodesmus armatus), and yellow-green microalgae (Tribonema cf. minus). Three fluorescent components were validated in parallel factor analysis (PARAFAC): one of them was characterized by protein-like fluorescence (similar to peak T), two others, by humic-like fluorescence (peaks A and C). The portion of fluorescence intensity of humic compounds (peak A) to the total fluorescence intensity was the lowest (27 ± 5%) and showed little variation between species. Protein-like fluorescence was most intense (45 ± 16%), but along with humic-like fluorescence with emission maximum at 470 nm (28 ± 14%), varied considerably for different algae strains. The direct optical investigation of FDOM produced during the cultivation of the studied algae strains confirms the possibility of autochthonous production of humic-like FDOM in the Arctic shelf regions.

Carbon Footprint Reduction and Climate Change Mitigation: A Review of the Approaches, Technologies, and Implementation Challenges

“…Pelagic ecosystems of the world ocean, especially macro-and microalgae, are considered another important link in the sequestration of CO 2 from the atmosphere [134,139,173,174]. The net primary production of phytoplankton in the world ocean is ~60 × 10 3 Mt of organic carbon per year, which corresponds to ~200 × 10 3 Mt of CO 2 captured by primary producers from the atmosphere [175].…”

Recent Advances in the Integrative Taxonomy of Plants

“…A promising biotechnological direction is the study of algal-derived organic matter from biopolymers (polysaccharides and proteins), refractory compounds (humic-like substances), low-molecular-weight acid and neutral compounds [ 35 , 36 ]. The investigation of algal fluorescent fraction in dissolved organic matter in the Special Issue was presented by Lobus et al [ 37 ]. The authors analysed five strains of microalgae from the Ob and Yenisei Gulfs using molecular morphological investigations, and excitation–emission matrix fluorescence spectroscopy.…”