Evaluation of Nutraceutical Properties of Eleven Microalgal Strains Isolated from Different Freshwater Aquatic Environments: Perspectives for Their Application as Nutraceuticals

Abstract

The increasing global population and the simultaneous growing attention to natural, sustainable, and healthier products are driving the food industry towards research on alternative food sources. In this scenario, microalgae are gaining worldwide attention as “functional feedstocks” for foods, feeds, supplements, and nutraceutical formulations, being a source of high-value metabolites including polyphenols and other antioxidant compounds. In this work, eleven microalgal strains from freshwater environments were evaluated for their nutraceutical properties, focusing on photosynthetic pigments, total polyphenols, and flavonoid content, as well as in vitro antioxidant activities. Data helped to select those strains showing the most promising features for simultaneous massive growth and bioactive compound production. Results highlighted that the microalgae have variable values for both biochemical parameters and antioxidant activities, mainly depending on the solvents and applied treatment rather than on the isolation sources or the phylogenetic attribution. According to our results, the putative best candidates for massive cultivation under laboratory conditions for the simultaneous extraction of different molecules with nutraceutical potential are strains F1 (Scenedesmaceae), F3 (Chlamydomonas debariana), R1 (Chlorella sorokiniana), and C2 (Chlorella-like).

Exploring the Physiological Multiplicity of Native Microalgae from the Ecuadorian Highland, Italian Lowland and Indoor Locations in Response to UV-B

“…Although some microalgae subjected to enhanced UV-B resulted in a decline in photosynthetic pigments and yield [ 26 ], others are also able to acclimate to UV-B by adjusting their metabolism and preventing damage [ 16 , 27 , 28 ]. In this study, the pigment content in Chlorella sorokiniana strains was differently inhibited by the continuous UV-B, where F4 was unexpectedly more susceptible than LG1 despite only the former having naturally grown in the presence of ambient UV-B [ 21 , 22 ]. In fact, the native habitat of strain F4 was a Mediterranean inland swamp at sea level with an average depth of 2 m and was historically affected by anthropogenic activities [ 29 ].…”

“…Four microalgal strains were used in this work ( Table 2 ). The Chlorella sorokiniana strains F4 and LG1 are part of the collection of the Institute of Agricultural Biology and Biotechnology of the Italian National Research Council located in Pisa and were previously described [ 21 , 22 ]. The strains PEC (related to Pectinodesmus pectinatus ) and ETI (related to Ettlia pseudoalveolaris ) were isolated from the Yahuarcocha lake (Ecuador) and then characterized as described below.…”

“…In the attempts to elucidate the mechanisms maintaining the microalgal cells’ photosynthetic activity in response to UV-B, the production of photosynthetic pigments (chlorophyll a , chlorophyll b , and carotenoids), total antioxidant capacity, total polyphenols, and chlorophyll a fluorescence were evaluated in four strains exposed to acute UV-B irradiation and compared with their control (absence of UV-B). The strains were isolated from different sources: two from the Ecuadorian Yahuarcocha Lake located at 2200 m asl (00°22′10″ N; 78°06′09″ W), one from a recycled cigarette butt’s substrate in a growth chamber [ 21 ], and the last one from the Mediterranean Fucecchio marshland at sea level (43°48′31″ N; 10°48′18″ E) [ 22 ]. Herein, we discuss the distinct ability of each native microalgal strain to cope with acute UV-B, which was related to their respective natural environment and genetic constitutions.…”

Remediation Capacity of Different Microalgae in Effluents Derived from the Cigarette Butt Cleaning Process

“…Six microalgal strains were used in this work (Table 1). Five of these strains were previously isolated and characterized [11], namely F1 (from the family Scenedesmaceae), F2 and F3 (both related to Chlamydomonas debaryana Goroschankin species), F4 and R1 (both related to Chlorella sorokiniana Shihira and R.W. Krauss species), and are currently part of the collection of the Institute of Agricultural Biology and Biotechnology of the Italian National Research Council located in Pisa.…”

Qualitative and Quantitative Studies on Biopigment Producing Algal Regime from Marine Water Resources of Sundarban Region

“…In this circumstance, there is a critical need to investigate new sustainable food sources, including algae. 2 The algal consortia live in several settings, including freshwater, marine water, and the surface of damp rocks. They grow quickly, live in difficult situations, and survive environmental stresses such as heat, cold, anaerobiosis, salt, photo-oxidation, osmotic pressure, and UV radiation.…”