Brown algae are vital structural elements and contributors to biodiversity in marine ecosystems. These organisms adapt to various environmental challenges by producing primary and secondary metabolites crucial for their survival, defense, and resilience. Besides their ecological role, these diverse metabolites have potential for biotechnological applications in industries including pharmaceuticals, cosmetics, and food. A literature review was conducted encompassing studies from 2014–2024, evaluating the effects of hydrodynamics, temperature, light, nutrients, seasonality, and salinity on the chemical profiles of various Phaeophyceae algae species. Thirty original articles spanning 69 species from the Sargassaceae, Dictyotaceae, Fucaceae, and Scytosiphonaceae families were analyzed and systematically arranged, with a focus on methodologies and key findings. This review furthers ecological discussions on each environmental factor and explores the biotechnological potential of metabolites such as polysaccharides, fatty acids, phenolics, diterpenes, and pigments. The information in this work is beneficial for metabolite bioprospecting and in vitro cultivation models as well as indoor and outdoor cultivation studies.

Ulva lactuca is an edible green macroalga (Chlorophyta) that can be produced in cultivation systems; it is a natural source of high-value molecules. Ulva lactuca produces metabolites including carotenoids, which are pigments with antioxidant properties that are in high demand in the health and nutraceutical industries and improve the nutritional quality of U. lactuca biomass. We studied the carotenoid and chlorophyll content in U. lactuca thalli collected in 3 different environments in the state of Rio de Janeiro, Brazil: the intertidal beds of the urban beaches of Arpoador and Boa Viagem and a continental integrated multi-trophic aquaculture (IMTA) facility. Carotenoid conservation was evaluated during 1 week, 2 weeks, and 4 weeks of storage. We compared the molecules in fresh U. lactuca collected during the dry season (July 2018) and rainy season (February 2019). The content of carotenoids, such as β-carotene + zeaxanthin, lutein + antheraxanthin, violaxanthin, neoxanthin, and their derivatives (aurochrome and auroxanthin), were analyzed in 100% acetone extracts by ultraviolet visible (UV/vis) spectrophotometry and monitored by thin layer chromatography (TLC) and proton nuclear magnetic resonance (1H-NMR). The extracts of dried U. lactuca produced in the IMTA facility presented higher pigment yields than the dried biomass collected from intertidal beds. Over 4 weeks of storage, carotenoids were well conserved in U. lactuca produced in the IMTA facility, in contrast to what was observed in U. lactuca collected from the intertidal beds, which showed carotenoid losses. In addition, we observed differences in carotenoid content between the dry and rainy seasons in U. lactuca collected from Boa Viagem Beach. However, the U. lactuca collected from Arpoador Beach or produced by the IMTA facility only exhibited significant differences in chlorophyll content. We conclude that U. lactuca produced by the IMTA facility constitutes a potential source of pigments such as β-carotene, lutein, and violaxanthin.

Lemna minor (duckweed) belongs to the family Lemnaceae and is a small, simple, perennial plant commonly found floating or submerged in freshwater environments. The growing interest in using L. minor as a biological model for various applications has led to a substantial body of literature covering its potential uses, bioproducts, chemical composition, and cultivation conditions in laboratory settings and open culture systems. However, the lack of comprehensive systematic reviews hampers the creation of a consistent database to assess research progress across different fields and its connection to global challenges related to the circular economy. Fifty articles obtained from a systematic search were categorized into predefined groups according to their application: ecotoxicology, phytoremediation, chemical composition/bioproducts, in addition to a section where studies on cultivation strategies were discussed. Some studies that update information on the taxonomic status and morphological characteristics of the species were also explored. This review aims to update, systematically organize and critically evaluate existing knowledge, as well as identify research gaps and highlight promising avenues for future investigations. Beyond summarizing advances, this work positions L. minor as a model species analyzed through the lens of major circular economy frameworks, highlighting how its biological versatility and bioproduct potential contribute to circular bioeconomy transitions, through its sustainable applications, innovative bioproducts and cultivation strategies. Graphical Abstract