Heavy metal (HM) accumulation in agronomic soils poses major abiotic stress that adversely affects agricultural yield. The application of seaweed represents a major eco-friendly strategy for mitigating HM stress. The potential role of seaweed extracts in alleviating HM stress in economically important crop plants such as Capsicum annuum L. has been little investigated. This study evaluated the role of aqueous extracts of the brown seaweed Colpomenia sinuosa in mitigating Ni and Cd stress and enhancing physiological and biochemical responses in C. annuum. The screening of aqueous extract of C. sinuosa revealed the presence of phytohormones including salicylic acid (647.31 μg mL⁻1) indole-3-acetic acid (56.38 μg mL⁻1), gibberellic acid (27.62 μg mL⁻1) and abscisic acid (43.0 μg mL⁻1), as well as substantial amounts of sugars, lipids and proteins. The C. sinuosa extract (6
As a high-value phycobiliprotein, phycoerythrin (PE) has considerable potential in food, biotechnology, and biomedical applications. This study developed an ATPS (aqueous two-phase system) for the direct recovery of PE from Porphyridium purpureum cell homogenate. A total of 53 formulations, including polymer/salt, polymer/polymer, DES (deep eutectic solvents)/salt, and DES/polymer systems, were initially screened for phase formation. Five systems exhibiting clear biphasic separation were subsequently evaluated for PE partitioning, among which PEG 6000/(NH4)2SO4 provided the most favorable balance between PE purity index and recovery percentage. The selected system was further optimized using single-factor experiments and RSM (response surface methodology), yielding optimal conditions of 11
Seaweed cultivation represents an emerging industry in Europe, where most biomass is still derived from wild harvesting. A potential approach to establishing a sustainable seaweed production industry involves improving seaweed strains. Temperature priming, introducing moderate stress to enhance subsequent performance, offers a rapid approach for improving growth. We examined the effect of three weeks temperature priming (0, 10, 20 °C) of gametophytes of Saccharina latissima on the early life stages (gametophyte growth, sporophyte recruitment, juvenile sporophyte growth). Cold priming (0 °C) stimulated gametogenesis and produced significantly larger microscopic sporophytes. This size advantage of the juvenile sporophytes was carried through a temperature gradient experiment (0–21 °C) over two weeks, especially under optimum temperatures (5–15 °C). In a second experiment with a similar gametophyte priming approach, we cultivated sporophytes for six months in mariculture and investigated size, biomass and biochemical composition. Biomass of sporophytes from 0 °C primed gametophytes was twofold higher than of 10, and fourfold higher than of 20 °C-primed gametophytes. The difference in mineral composition in sporophyte blades between priming treatments was variable. Heavy metals (As, Cd) were lower under warm priming (20 °C) and few macro- and trace elements (K, P, S, Mn) significantly increased under cold priming. The results demonstrate a transgenerational carry-over effect from haploid gametophytes to diploid sporophytes and underscore the significance of gametophyte cold exposure for the growth of S. latissima sporophytes. It suggests that cold priming of gametophytes may serve as a form of winter mimicry to enhance growth and to modify biochemical composition in kelp cultivation.
Monostromatic green macroalgae belonging to the genus Gayralia are both ecologically and economically important. However, our understanding of the diversity and aquaculture use of Gayralia species in Japan remains limited because of their complicated taxonomic history, in that they are recognized as another genus (Monostroma), and poor information on their ontogenetic pattern, which is an important taxonomic character. Here we report that unidentified Gayralia lineages examined across the Japanese archipelago, including the main cultivation areas, Mie and Okinawa, can be identified as Gayralia orientalis. The Gayralia strain collected from Okinawa exhibited sexual reproduction, a heteromorphic alternation of generations, and a filament–blade pattern of gametophyte ontogeny, which is consistent with that of G. orientalis. Combined with our molecular phylogeny based on the internal transcribed spacer regions of rDNA, we identified an unidentified lineage from Japan and East Asia, including Okinawa samples from wild and cultivated populations, as well as commercially marketed ones, as G. orientalis. We also report two previously undocumented, morphologically indistinguishable lineages within G. orientalis. A cryptic intraspecific lineage of G. orientalis was found alongside the previously reported species (Gayralia kuroshiensis) in Mie, indicating the overlapping distribution and aquaculture use of the two species. Together with previous studies, this study shows that G. orientalis, as well as G. kuroshiensis, is widespread and cultivated along the Japanese archipelago, providing basic information relevant to the future aquaculture improvement and industrial application of the genus Gayralia.
The present study evaluated the effects of dietary inclusion of the rhodophyte macroalga Palmaria palmata, untreated or pre-treated by high-solid loading for 30 min, on oxidative status, immune responses, and gut microbiota in European seabass (Dicentrarchus labrax) juveniles. For that purpose, five isoproteic (48
