Domesticated Populations of Codium tomentosum Display Lipid Extracts with Lower Seasonal Shifts than Conspecifics from the Wild—Relevance for Biotechnological Applications of this Green Seaweed

Abstract

In the last decades, the use of algae in biotechnology and food industries has experienced an exponential growth. Codium tomentosum is a green macroalgae with high biotechnological potential, due to its rich lipidome, although few studies have addressed it. This study aimed to investigate the seasonal changes in lipid and pigment profiles of C. tomentosum, as well as to screen its antioxidant activity, in order to evaluate its natural plasticity. Samples of C. tomentosum were collected in two different seasons, early-autumn (September/October) and spring (May), in the Portuguese coast (wild samples), and in a land-based integrated multitrophic aquaculture (IMTA) system (IMTA samples). Total lipid extracts were analysed by LC–MS, GC–MS, and HPLC, and antioxidant activity was screened through free radical scavenging potential against DPPH and 2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Wild samples showed a high seasonal variability, modifying their lipidome and pigment profiles according to environmental shifts, while IMTA samples showed a relatively stable composition due to early-stage culturing in controlled conditions. The lipids that contributed the most to seasonal discrimination were glycolipids (monogalactosyl diacylglycerol - MGDG and digalactosyl diacylglycerol - DGDG) and the lyso forms of phospholipids and glycolipids. Lipid extracts showed antioxidant activity ranging from 61 ± 2 to 115 ± 35 µmol Trolox g−1 of lipid extract in DPPH assay and from 532 ± 73 to 927 ± 92 µmol Trolox g−1 of lipid extract in ABTS assay, with a more intense antioxidant activity in wild spring samples. This study revealed that wild specimens of C. tomentosum presented a higher plasticity to cope with seasonal environmental changes, adjusting their lipid, pigment, and bioactivity profiles, while IMTA samples, cultured under controlled conditions, displayed more stable lipidome and pigment compositions.

Valuing Bioactive Lipids from Green, Red and Brown Macroalgae from Aquaculture, to Foster Functionality and Biotechnological Applications

“…The global increase in consumption of seafood products including macroalgae arises from consumers awareness that these products are an important source of nutrients including proteins, polysaccharides, vitamins and lipids [ 34 , 35 , 36 , 37 ]. In macroalgae, lipids are primary metabolites and accounted for approximately 0.2–8% dry weight (DW), while carbohydrates accounted for 12–71% DW and proteins for approximates 4.3–47% DW [ 19 , 38 ]. However, despite the lower abundance of lipids compared with the other primary metabolites, lipids from macroalgae are a natural source of PUFA, particularly omega-3 FA, being an interesting alternative to fish, especially macroalgae produced under sustainable aquaculture practices, because of its cultivation under controlled conditions [ 23 , 39 ].…”

“…The set of macroalgae covered in this study, originating from three different phyla (Chlorophyta, Rhodophyta and Ochrophyta) showed a FA profile consistent with previous studies [ 20 , 21 , 23 , 25 , 26 , 41 ]. In fact, FA are usually characteristic of each macroalga species, however the abundance of several FA species can change in relative amounts depending on season and/or growth conditions [ 19 , 23 ]. Although some of the studied species belong to the same phylum, there are clear species-specific FA profiles ( Table 1 ).…”

“…The most well-studied macroalgae bioactive compounds include abundant molecules such as polysaccharides and peptides, although minor constituents, such as alkaloids and lipids, have also been recognized for their nutritional and bioactive values [ 17 , 18 ]. Even though macroalgae have a low lipid content (which is variable among macroalgal species [ 19 , 20 , 21 , 22 , 23 ]), these compounds are recognized as an important source of polyunsaturated fatty acids (PUFA) including long-chain omega-3 FA, such as α-linolenic acid (18:3 n -3), eicosapentaenoic acid (20:5 n -3) and docosahexaenoic acid (22:6 n -3), that have been addressed as essential modulators to reduce the risk of cancer and cardiovascular diseases [ 24 ]. Omega-3 PUFA mostly occurs in their esterified form in polar lipids, mainly as glycolipids and phospholipids, which were recently identified in edible green, red and brown macroalgae species Ulva rigida, Codium tomentosum, Gracilaria sp.…”

“…Omega-3 PUFA mostly occurs in their esterified form in polar lipids, mainly as glycolipids and phospholipids, which were recently identified in edible green, red and brown macroalgae species Ulva rigida, Codium tomentosum, Gracilaria sp. , Palmaria palmata, Porphyra dioica and Fucus vesiculosus produced under controlled conditions on a sustainable land-based integrated multitrophic aquaculture (IMTA) system [ 19 , 20 , 21 , 23 , 25 , 26 ]. The polar lipidomic profiling performed in these studies unveiled the presence of potential bioactive lipid species belonging to glycolipid and phospholipid.…”

“…Previous studies have shown that macroalgae from different phyla, as well as from different species of the same phylum, display distinct lipid profiles, which can have an impact on the nutritional and functional value of the macroalgae’s biomass [ 19 , 20 , 21 , 23 , 26 ]. Understanding how these differences can be reflected in their bioactive potential is paramount to advance the state of the art of macroalgae’s potential.…”