Molecular techniques have become important tools to investigate cryptic diversity and phylogeographic patterns. Mitochondrial markers have revealed that the temperate red alga Asparagopsis armata ...contains two cryptic clades. The A. armata species complex is native to Australia and New Zealand and has been introduced around the world, particularly to Europe. Previous sequencing has focused on A. armata outside of its native range, and there are few sequences available from Australia and New Zealand. Our study investigated cryptic diversity and phylogeographic patterns for over 60 individuals from 7 locations around New Zealand using the mitochondrial cox2-3 spacer and plastid rbcL markers, and found that both cryptic clades within A. armata (L1 and L2) can be found in New Zealand. For the first time, our study has revealed haplotype variation (A and B) within each of the two cryptic A. armata clades. Asparagopsis armata L1A has been found in Australia, Europe and South Africa and is the only invasive lineage currently known, while A. armata haplotype L1B is found throughout New Zealand. In addition, A. armata L2A has been found only in Australia, and A. armata L2B has a southern distribution in New Zealand. The two mitochondrial lineages from New Zealand (L1B and L2B) were found to coexist in several locations. Further work is needed to characterize any differences in the morphology, physiology and biochemistry of the four genetically distinct mitochondrial lineages within the two cryptic clades, as well as their geographic and ecological distributions.
The nutraceutical value, and physicochemical profile as well as anti-inflammatory activity potential of Odonthalia floccose and Odonthalia dentata (red macroalgae) dry biomass were investigated in ...this study. Proximate composition study results revealed that the dry biomass of O. floccose and O. dentae were found to be as ash: 9.11 & 8.7 g 100 g-1, moisture: 8.24 & 8.1 g 100 g-1, total fat: 6.9 & 7.2 g 100 g-1, protein: 24.52 & 25.6 g 100 g-1, and total carbohydrate/polysaccharides: 53.84 & 48.85 g 100 g-1 of dry weight biomass respectively. Both algae biomass contain considerable quantity of minerals (Fe, Cu, Mg, and Zn). Furthermore, the major saturated fatty acids (6.24 & 5.82 g FAME 100 g-1 of total fat of O. floccose and O. dentate) (ΣFAs) present in the test algae were stearic acid, palmitic acid, and margaric acids. O. floccose and O. dentata also contain remarkable protein composition profile that compiled with considerable quantity of essential and non-essential amino acids. The vitamins such as vitamin A, B1, B2, B3, B6, B9, C, and E of O. floccose and O. dentate biomass were also identified at sufficient quantity level. The swelling capacity (SWC), water holding capacity (WHC), and oil holding capacity (OHC) properties of O. floccose and O. dentate at various temperature conditions (25 and 37 ᵒC) were found to be 8.11 & 7.02 mL g-1 and 8.95 & 7.55 mL g-1, 5.1 & 4.87 and 4.8 & 4.1 mL g-1, as well as 2.11 & 1.81 and 1.96 & 1.89 mL g-1 respectively. Among these two marine red macroalgae samples, the O. dentate showed better anti-inflammatory activity than O. floccose at 150 μg mL-1 dosage. Thus, this O. floccose and O. dentate biomass can be considerable as nutritional supplement and pharmaceutical product development related research.The nutraceutical value, and physicochemical profile as well as anti-inflammatory activity potential of Odonthalia floccose and Odonthalia dentata (red macroalgae) dry biomass were investigated in this study. Proximate composition study results revealed that the dry biomass of O. floccose and O. dentae were found to be as ash: 9.11 & 8.7 g 100 g-1, moisture: 8.24 & 8.1 g 100 g-1, total fat: 6.9 & 7.2 g 100 g-1, protein: 24.52 & 25.6 g 100 g-1, and total carbohydrate/polysaccharides: 53.84 & 48.85 g 100 g-1 of dry weight biomass respectively. Both algae biomass contain considerable quantity of minerals (Fe, Cu, Mg, and Zn). Furthermore, the major saturated fatty acids (6.24 & 5.82 g FAME 100 g-1 of total fat of O. floccose and O. dentate) (ΣFAs) present in the test algae were stearic acid, palmitic acid, and margaric acids. O. floccose and O. dentata also contain remarkable protein composition profile that compiled with considerable quantity of essential and non-essential amino acids. The vitamins such as vitamin A, B1, B2, B3, B6, B9, C, and E of O. floccose and O. dentate biomass were also identified at sufficient quantity level. The swelling capacity (SWC), water holding capacity (WHC), and oil holding capacity (OHC) properties of O. floccose and O. dentate at various temperature conditions (25 and 37 ᵒC) were found to be 8.11 & 7.02 mL g-1 and 8.95 & 7.55 mL g-1, 5.1 & 4.87 and 4.8 & 4.1 mL g-1, as well as 2.11 & 1.81 and 1.96 & 1.89 mL g-1 respectively. Among these two marine red macroalgae samples, the O. dentate showed better anti-inflammatory activity than O. floccose at 150 μg mL-1 dosage. Thus, this O. floccose and O. dentate biomass can be considerable as nutritional supplement and pharmaceutical product development related research.
The present study evaluated the production of R-phycoerythrin (R-PE) extracted from the macroalgae Solieria filiformis through a green technology (pressurized water method). The extraction process ...over time and the macroalgae structure were analyzed. Two samples (freeze-dried and wet biomass, with 1 % and 10 % m/v, respectively) were studied at pressures up to 500 bar. R-PE maximum yield was reached for lyophilized seaweed structure after 360 min, obtaining 0.67 mg of R-PE per gram of dry biomass. In contrast, wet biomass reached 0.05 mg of R-PE per gram of wet biomass. Crude and precipitated extracts were characterized using the following techniques: electrophoresis, circular dichroism, and FTIR. The carbohydrate content was also determined. The biomolecule showed R-PE characteristic spectra, fluorescence, and α-helix structure as the main element of its secondary structure (93.28–95.24 %), indicating the presence of other proteins in the precipitated extract. Precipitated extract's cytotoxic activity was assessed through an MTT assay against tumor cell lines of colorectal cancer (HCT116), prostate cancer (PC3), glioblastoma cancer (SNB-19), and HL60 (promyeloblast leukemia). The most prominent in vitro results were in HL-60 and HCT-116 cell lines.
•R-PE water pressurized extraction (at 500 bar) preserved the biofunctionality of biomolecule.•The lyophilization pre-treatment increased total protein concentration and R-PE yield.•R-PE structure was determined by different techniques.•The precipitated extract showed in vitro anticancer activity for leukemic cells (HL60).
Prasedya ES, Fitriani F, Saraswati PBA, Haqiqi N, Qoriasmadillah W, Hikmaturrohmi H, Nurhidayati SZ, Ariati PEP. 2023. Evaluation of bioprospecting potential of epiphytic Gracilaria edulis harvested ...from seaweed farm in Seriwe Bay, Lombok, Indonesia. Biodiversitas 24: 5343-5351. The seaweed industry is strategically important in Indonesia, comprising over 40% of the nation's aquaculture annual production. Despite the industry's promising growth, various challenges and problems remain, including intense epiphyte infestation. Hence, investigating the economic value of these epiphytes could provide new opportunities for potential industrial applications. Epiphytic algae is commonly found growing on commercial seaweeds which causes decreased biomass and increased risk of crop failure. Information regarding these epiphytic algae remains limited. This study investigates the molecular identification of the abundant epiphytic macroalgae found in one of the largest seaweed farms in, Seriwe Bay, Lombok, Indonesia. In addition, the epiphytic bioactive activity is also evaluated for further industrial potential. Molecular identification with the mitochondrial marker COX1 identifies the epiphytic macroalgae as Gracilaria edulis (S.G.Gmel.) P.C.Silva. The Indonesian G. edulis is closely related to the G. edulis specimens from Malaysia (JQ026083.1), Philippines (KY995636.1 and KY995635.1), and Thailand (JQ026088.1). The outgroup used was the G. edulis specimen from India (KP099563.1) because it shows the most distinct relationship to the other specimens. Extracted agar of Seriwe G. edulis shows moderate yield (21%) and low gel strength (134 g/cm2). The phytochemical content analyses show that G. edulis agar has a TPC value of 3.65 ± 0.52 mg GAE/g and promising antioxidant activity (DPPH IC50 = 797.40 ± 1.50 µg/mL; ABTS IC50 = 558.40 ± 1.44 µg/mL). Further phytochemical profiling with GCMS shows various promising major constituents such as tetradecanoic acid, neophyte diene, pentadecanoic acid, and hexadecanoic acid. Therefore, the findings suggest that G. edulis displays potential applications in the functional food and cosmetic industry.
Tagatose is a rare sugar with increasing commercial interest as sweetener. Biotechnological production of d-tagatose by enzymatic isomerization of d-galactose provides an alternative to chemical ...processes. In the last years, l-arabinose isomerases (L-AIs) from different origins have been studied to increase the effectiveness of tagatose production. In this work, the L-AI from Bacillus subtilis, previously reported to have unique substrate specificity for l-arabinose, was expressed in Escherichia coli and studied for isomerization of d-galactose to d-tagatose. The recombinant enzyme demonstrated, for the first time, tagatose bioconversion capacity, reaching ~59% conversion. Furthermore, a sustainable tagatose production strategy was developed by using Gelidium sesquipedale red seaweed and its undervalued processing residues as source of galactose. L-AI successfully converted the galactose-rich hydrolysate, obtained from direct acid hydrolysis of seaweed, to tagatose (50.9% conversion). Additionally, the process combining autohydrolysis of G. sesquipedale and acid hydrolysis of the remaining residue allowed a full integral valorisation of polysaccharides: 13.33 g of agar, an important hydrocolloid, coupled with the production of 5.97 g of tagatose. These results confirmed that seaweed biomass and waste-derived are promising substrates for tagatose production by L-AI, contributing to the advancement of circular economy and to the actual needs of food industry.
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•l-arabinose isomerase (L-AI) from B. subtilis was studied for tagatose production.•Recombinant L-AI can isomerize d-galactose to d-tagatose, with ~59% conversion.•Gelidium sesquipedale seaweed as a suitable source of galactose for tagatose production.•Production of tagatose and agar from red algae in a biorefinery approach.
Marine red macroalgae has attracted researchers’ consideration as a non-lignocellulosic feedstock for microbial growth to produce biofuels and biochemical products. Gelidium amansii is representative ...galactose-rich red macroalgae biomass but studies on its galactose utilization are currently scarce. Herein, we engineered Pseudomonas putida KT2440 as a functional chassis for assimilation of galactose in addition to glucose in G. amansii hydrolysate. P. putida KT2440 was confirmed owning high ability to oxidize galactose to galactonate by glucose dehydrogenase. Thereafter galactose-oxidation pathway was extended by introducing galactonate transport and metabolism modules from Pseudomonas rhodesiae NL2019. The recombinant strains NL910 and NL911 were able to grow on galactose with high cell densities and growth rates, and simultaneously upgrade all red macroalgae streams, which is essential to develop a sustainable and cost-effective bioprocess for valorization of red macroalgae.
•Gelidium amansii was pretreated to galactose-rich hydrolysate with yield of 86%.•Pseudomonas putida KT2440 was engineered for galactose assimilation.•A simplified modification strategy for galactose utilization was proposed.•Engineered strains can simultaneously upgrade all red macroalgae streams.•This process realized the valorization of macroalgae biomass.
Increased incomes, urbanization, and an aging population, are leading to changes in consumption patterns, resulting in a growing demand for proteins. From a sustainability perspective, there is a ...consensus that animal protein production has a disproportionately impact on the environment, particularly in intensive systems that require significant amounts of feed crops. Macroalgae have emerged as a promising feedstock for transitioning towards a blue bioeconomy. Red seaweed stands out as a particularly attractive action, as it can contain protein concentrations of up to 47 %, the highest among terrestrial plants and other algae divisions. These proteins offer a rich source of essential amino acids, making them excellent candidates for human food formulation. Nevertheless, compared to other major components such as carbohydrates, red macroalgae proteins remain underexploited. This review focuses on the potential of red algae as a protein source within an environmentally friendly biorefinery development strategy, primarily for food and biomedical applications. It also explores the strategies and limitations associated with protein extraction and purification, emphasizing the need for further in vivo and toxicological studies, particularly regarding the digestibility and bioavailability of red algal proteins.
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•Red macroalgae exploitation could positively impact on blue-bioeconomy transition.•Proteins from red macroalgae remain underexploited.•Red macroalgae represent the highest protein content among other algae divisions.•Phycobiliproteins, lectins and RuBisCO applications have been critically discussed.•Strategies and limitations of protein extraction and purification are described.
Marine macroalgae is one of the good sources of mycosporine-like amino acids (MAAs), especially red macroalgae. As a new type of active substances with commercial development prospect, extraction, ...isolation and characterization of MAAs are far from enough for the application. To obtain the extraction process of MAAs from four species of red macroalgae (Bangia fusco-purpurea, Gelidium amansii, Gracilaria confervoides, and Gracilaria sp.), a series of single-factor and orthogonal experiments were carried out to analyze the effects of extraction temperature, time, times and solid-liquid ratio on the yields of MAAs. The extraction process of MAAs was optimized, and the extracts were isolated and identified. The optimized extraction processes of MAAs were obtained as follows: 45 ℃, 3 h, 4 times, 1:25 g/mL. 45 ℃, 1 h, 4 times, 1:20 g/mL. 45 ℃, 2 h, 3 times, 1:15 g/mL. 40 ℃, 1 h, 3 times, 1:20 g/mL. Four MAAs extracts of red algae were prepared by using the above extraction process, and the yields were 249.3, 197.9,
Asparagopsis taxiformis
has potent antimethanogenic activity as a feed supplement at 2 % of organic matter in in vitro bioassays. This study identified the main bioactive natural products and their ...effects on fermentation using rumen fluid from
Bos indicus
steers. Polar through to non-polar extracts (water, methanol, dichloromethane and hexane) were tested. The dichloromethane extract was most active, reducing methane production by 79 %. Bromoform was the most abundant natural product in the biomass of
Asparagopsis
(1723 μg g
−1
dry weight DW biomass), followed by dibromochloromethane (15.8 μg g
−1
DW), bromochloroacetic acid (9.8 μg g
−1
DW) and dibromoacetic acid (0.9 μg g
−1
DW). Bromoform and dibromochloromethane had the highest activity with concentrations ≥1 μM inhibiting methane production. However, only bromoform was present in sufficient quantities in the biomass at 2 % organic matter to elicit this effect. Importantly, the degradability of organic matter and volatile fatty acids were not affected at effective concentrations.
3,6-anhydro-α-L-galactose (L-AHG) is one of the main monosaccharide constituents of red macroalgae. In the recently discovered bacterial L-AHG catabolic pathway, L-AHG is first oxidized by ...a NAD(P)+-dependent dehydrogenase (AHGD), which is a key step of this pathway. However, the catalytic mechanism(s) of AHGDs is still unclear. Here, we identified and characterized an AHGD from marine bacterium Vibrio variabilis JCM 19239 (VvAHGD). The NADP+-dependent VvAHGD could efficiently oxidize L-AHG. Phylogenetic analysis suggested that VvAHGD and its homologs represent a new aldehyde dehydrogenase (ALDH) family with different substrate preferences from reported ALDH families, named the L-AHGDH family. To explain the catalytic mechanism of VvAHGD, we solved the structures of VvAHGD in the apo form and complex with NADP+ and modeled its structure with L-AHG. Based on structural, mutational, and biochemical analyses, the cofactor channel and the substrate channel of VvAHGD are identified, and the key residues involved in the binding of NADP+ and L-AHG and the catalysis are revealed. VvAHGD performs catalysis by controlling the consecutive connection and interruption of the cofactor channel and the substrate channel via the conformational changes of its two catalytic residues Cys282 and Glu248. Comparative analyses of structures and enzyme kinetics revealed that differences in the substrate channels (in shape, size, electrostatic surface, and residue composition) lead to the different substrate preferences of VvAHGD from other ALDHs. This study on VvAHGD sheds light on the diversified catalytic mechanisms and evolution of NAD(P)+-dependent ALDHs.
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•3,6-anhydro-α-L-galactose (L-AHG) is the main monosaccharide constituent of red macroalgae and metabolized by marine bacteria.•AHGDs catalyze the first step of the bacterial L-AHG catabolic pathway with an unknown mechanism.•Crystal structures of VvAHGD were determined in apo and cofactor-bound states.•The catalytic mechanism of VvAHGD is proposed based on structural and mutational analyses.•VvAHGD and its homologs represent a new aldehyde dehydrogenase family.
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