The aim of this study was to evaluate the characteristics of macroalgae (Cladophora rupestris, Furcellaria lumbricalis, Ulva intestinalis) and microalgae (Arthrospira platensis (Sp1, Sp2), Chlorella vulgaris) extracts, including micro- and macroelement transition to extract, antioxidant, antimicrobial properties, the concentrations of chlorophyll (-a, -b), and the total carotenoid concentration (TCC). In macroalgae, the highest TCC and chlorophyll content were found in C. rupestris. In microalgae, the TCC was 10.1-times higher in C. vulgaris than in Sp1, Sp2; however, the chlorophyll contents in C. vulgaris samples were lower. A moderate negative correlation was found between the chlorophyll-a and TCC contents (r = -0.4644). In macroalgae extract samples, C. rupestris and F. lumbricalis showed the highest total phenolic compound content (TPCC). DPPH antioxidant activity and TPCC in microalgae was related to the TCC (r = 0.6191, r = 0.6439, respectively). Sp2 extracts inhibited Staphylococcus haemolyticus; C. rupestris, F. lumbricalis, U. intestinalis, and Sp2 extracts inhibited Bacillus subtilis; and U. intestinalis extracts inhibited Streptococcus mutans strains. This study showed that extraction is a suitable technology for toxic metal decontamination in algae; however, some of the desirable microelements are reduced during the extraction, and only the final products, could be applied in food, feed, and others.
Keywords: Baltic Sea macroalgae; antimicrobial characteristics; antioxidant properties; microalgae; spirulina; trace elements.