Analysis of Minerals and Heavy Metals Using ICP-OES and FTIR Techniques in Two Red Seaweeds (Gymnogongrus griffithsiae and Asparagopsis taxiformis) from Tunisia

Analysis of Heavy Metal Accumulation in Ulva rigida and its Effects on Seed Germination of Pennisetum glaucum

The alga contains salt and heavy metals that are accumulated in algae poses a significant challenge to the safe use of algae in soil fertilization and other applications. This study examines the relevance of algal biomass as an environmentally friendly fertilizer, thereby contributing to sustainable coastal management practices. In this study, the hot and cold extraction method were done to obtain the Ulva rigida extract. Heavy metals such as vanadium, chromium, manganese, iron, nickel, cobalt, copper, zinc and cadmium etc. were analyzed using ICP-MS. Heavy metal analysis showed that the major metals such as manganese, iron, vanadium and zinc in Ulva rigida extract. The algae extract was used in different concentration (20, 40, 60 and 80 μL) to analyze the seed germination study in Pennisetum glaucum and it was found that theseed germination were 100 % at 5th day after sowing and the root and shoot length increased with increasing concentration of Ulva rigida extract and at 80 μL the shoot length of Pennisetum glaucum were decreased. The aqueous extracts of Ulva rigida are eco-friendly, safe method for recycling the algal biomass as a novel biofertilizer.

Comprehensive nutritional, anti-nutritional, ICP-MS and FTIR profiling of Ficus rumphii leaves: a potential source for dietary enhancement

Ficus rumphii is a plant belonging to the Moraceae family. This study aimed to profile the functional groups using FTIR, as well as nutritional, elements using ICP-MS technique, and anti-nutritional analyses of Ficus rumphii leaves. The results of nutritional analysis of Ficus rumphii leaves revealed that the leaves had a diverse proximate composition with derived nutritional value to be 314.11 ± 0.31 kcal/100g. The leaves demonstrated good levels of ash, crude fibre, carbohydrate, crude fat, moisture, crude protein and nutritive value. The anti-nutrients were present at proportions that are not dangerous. Furthermore, the ICP-MS analysis revealed that Ficus rumphii leaves were also abundant in essential elements. FTIR analysis identified several functional groups such as O-H, N-H, C-H, O = C = O, C = O, C = N, C = C, etc. Hence, the findings of this study indicate that the leaves of wild plant Ficus rumphii possess significant nutritional potential, making it an excellent plant for meeting dietary requirements.

Sulfate-reducing consortium HQ23 stabilizes metal(loid)s and activates biological N-fixation in mixed heavy metal-contaminated soil

Sulfate-reducing bacteria (SRB) are used in the remediation of mine pollution; however, the mechanism of stabilizing multiple heavy metal(loid)s by the SRB consortium under low oxygen conditions needs further study. Indigenous microflora were extracted from non-ferrous metal-contaminated soil co-inoculated with enriched SRB consortium and assembled as the HQ23 consortium. The presence of Desulfovibrio (SRB) in HQ23 was confirmed by 16S rRNA sequencing and qPCR. The effects of culture media, dissolved oxygen (DO), SO42¯, and pH on the HQ23 growth rate, and the SO42¯-reducing activity were examined. Data indicates that the HQ23 sustained SRB function under low DO conditions (3.67 ± 0.1 mg/L), but the SRB activity was inhibited at high DO content (5.75 ± 0.39 mg/L). The HQ23 can grow from pH 5 to pH 9 and can decrease mobile or bioavailable Cr, Cu, and Zn concentrations in contaminated soil samples. FTIR revealed that Cu and Cr adsorbed to similar binding sites on bacteria, likely decreasing bacterial Cu toxicity. Increased abundances of DSV (marker for Desulfovibrio) and nifH (N-fixation) genes were observed, as well as an accumulation of nitrate-N content in soils suggesting that HQ23 stimulates the biological N-fixation in soils. This study strongly supports the future application of SRB for the bioremediation of heavy metal-polluted sites.

Eco-innovative aquafeeds biofortified with Asparagopsis taxiformis to improve the resilience of farmed white seabream (Diplodus sargus) to marine heatwave events

Extreme weather events, like marine heatwaves (MHWs), are becoming more frequent and severe due to climate change, posing several challenges to marine ecosystems and their services. As disease outbreaks are often prompted by these acute phenomena, it is essential to develop eco-innovative strategies that can efficiently improve farmed fish resilience, especially under sub-optimal rearing conditions, thereby ensuring a sustainable aquaculture production. This study aimed to unveil farmed juvenile white seabream (Diplodus sargus, 28.50 ± 1.10 g weight, n = 150) immune and antioxidant responses under a category II MHW in the Mediterranean Sea (+4 °C, 8 days of temperature increase plus 15 days of plateau at the peak temperature) and to investigate whether a 30 days period of prophylactic biofortification with Asparagopsis taxiformis (1.5 %, 3 % and 6 %) enhanced fish resilience to these extreme events. Several biomarkers from different organization levels (individual, cellular, biochemical and molecular) were assessed upon 30 days of biofortification (T30), exposure (after 8 days of temperature increase + 15 days at peak temperature, T53) and recovery (8 days of temperature decrease, T61) from the MHW. Results showed that MHW negatively affected the fish physiological status and overall well-being, decreasing specific growth rate (SGR) and haematocrit (Ht) and increasing erythrocyte nuclear abnormalities (ENAs) and lipid peroxidation (LPO). These adverse effects were alleviated through biofortification with A. taxiformis. Seaweed inclusion at 1.5 % was the most effective dose to minimize the severity of MHW effects, significantly improving immune responses of D. sargus (i.e. increased levels of immunoglobulin M, peroxidase activity and lysozyme expression) and modulating antioxidant responses (i.e. decreased LPO, catalase and glutathione S-transferase activity). These findings confirm that A. taxiformis is a functional ingredient of added value to the aquaculture industry, as its inclusion in marine fish diets can beneficially modulate fish immunity and resilience under optimal and adverse rearing conditions.

Bioaccessibility of toxic heavy metals/metalloids in edible seaweeds: Exposure and health risk assessment

This study assesses the health risk due to heavy metals/metalloids (HMs/Ms) in edible seaweeds (Caulerpa racemosa, Kappaphycus alvarezii, and Ulva lactuca) through an in vitro bioaccessibility study. The percentage of bioabsorbed HMs/Ms in unprocessed and processed C. racemosa, U. lactuca, and K. alvarezii ranged from 3 % to 46 %, 3 % to 42 %, and 3 % to 40 %, respectively. The levels of HMs/Ms in seawater, sediment, and seaweeds were below the levels recommended by the European Commission (EC) and World Health Organization/Food and Agriculture Organization (WHO/FAO). The maximum accumulation of HMs/Ms was found during monsoons and post-monsoon seasons, and Cd, Pb, Hg, Cr, As, and Pb were predominant in all the samples. Tukey's post hoc test and t-test confirmed that thermal processing significantly reduced HMs/Ms in seaweeds. On the basis of the bioabsorption of HMs/Ms, the TTHQ values were found to be < 1, and the LCR values were within the acceptable limit (10-06 to 10-04), indicating no carcinogenic risks through seaweeds.

Dietary Ruminant Enteric Methane Mitigation Strategies: Current Findings, Potential Risks and Applicability

This review examines the current state of knowledge regarding the effectiveness of different dietary ruminant enteric methane mitigation strategies and their modes of action together with the issues discussed regarding the potential harms/risks and applicability of such strategies. By investigating these strategies, we can enhance our understanding of the mechanisms by which they influence methane production and identify promising approaches for sustainable mitigation of methane emissions. Out of all nutritional strategies, the use of 3-nitrooxypropanol, red seaweed, tannins, saponins, essential oils, nitrates, and sulfates demonstrates the potential to reduce emissions and receives a lot of attention from the scientific community. The use of certain additives as pure compounds is challenging under certain conditions, such as pasture-based systems, so the potential use of forages with sufficient amounts of plant secondary metabolites is also explored. Additionally, improved forage quality (maturity and nutrient composition) might help to further reduce emissions. Red seaweed, although proven to be very effective in reducing emissions, raises some questions regarding the volatility of the main active compound, bromoform, and challenges regarding the cultivation of the seaweed. Other relatively new methods of mitigation, such as the use of cyanogenic glycosides, are also discussed in this article. Together with nitrates, cyanogenic glycosides pose serious risks to animal health, but research has proven their efficacy and safety when control measures are taken. Furthermore, the risks of nitrate use can be minimized by using probiotics. Some of the discussed strategies, namely monensin or halogenated hydrocarbons (as pure compounds), demonstrate efficacy but are unlikely to be implemented widely because of legal restrictions.

Micro- and Macro-Algae Combination as a Novel Alternative Ruminant Feed with Methane-Mitigation Potential

This study was conducted to provide alternative high-quality feed and to reduce methane production using a mixture of the minimum effective levels of Euglena gracilis, EG, and Asparagopsis taxiformis, AT. This study was performed as a 24 h in vitro batch culture. Chemical analysis demonstrated that EG is a highly nutritive material with 26.1% protein and 17.7% fat. The results showed that the supplementation of AT as a feed additive at 1 and 2.5% of the diet reduced methane production by 21 and 80%, respectively, while the inclusion of EG in the diet at 10 and 25% through partially replacing the concentrate mixture reduced methane production by 4 and 11%, respectively, with no adverse effects on fermentation parameters. The mixtures of AT 1% with both EG 10% and EG 25% had a greater reductive potential than the individual supplementation of these algae in decreasing methane yield by 29.9% and 40.0%, respectively, without adverse impacts on ruminal fermentation characteristics. These results revealed that the new feed formulation had a synergistic effect in reducing methane emissions. Thus, this approach could provide a new strategy for a sustainable animal production industry.

Trace Element Quantification in Two Algerian Thymes (Thymus algeriensis Boiss & Reut. and Thymus capitatus (L.) Hoffm. & Link) Using EDXRF Spectrometry

In an attempt to know the elemental composition of two endemic Algerian thyme species, we analyzed eleven mineral and trace elements (Br, Ca, Cr, Cu, Fe, K, Mn, Rb, Sr, V, and Zn) in Thymus algeriensis Boiss & Reut. and Thymus capitatus (L.) Hoffm. & Link. These species are commonly used in Algeria as aromatic and medicinal shrubs. The total concentrations of chemical elements were determined by EDXRF spectrometry. The instrument calibration was assessed through the analysis of certified reference material CRM-336 (Lichen) from the IAEA, Vienna, Austria. The results show that the highest concentrations of the micronutrients (Br, Cr, Cu, Mn, Sr, V, and Zn) were registered in T. algeriensis, while the maximum concentrations of Ca, Fe, and the non-essential element, Rb, were found in T. capitatus. Potassium contents were similar in the two species. The concentrations of essential chemical elements in T. algeriensis leaves were found in the following order: K > Ca > Mn > Fe > Zn > Cu > Cr. However, the order of these elements in T. capitatus was Ca > K > Fe > Zn > Mn > Cu > Cr. Principal component analysis (PCA) showed that T. algeriensis was highly associated with Br, Cr, Cu, Mn, Sr, V, and Zn, while T. capitatus was correlated with Ca, Fe, K, and Rb. Dietary element intakes through ingestion of 1 teaspoon of dry powder (~ 10 g) were estimated and compared to recommended daily intakes and permissible limits under FAO/WHO guidelines. In all cases, these estimates were below those levels. These findings can enhance the dissemination of these medicinal plants, which have medicinal and organoleptic properties, and provide an experiment-based guidance to the pharmaceutical and food industries.

A review on network pharmacology based phytotherapy in treating diabetes- An environmental perspective

Diabetes has become common lifestyle disorder associated with obesity and cardiovascular diseases. Environmental factors like physical inactivity, polluted surroundings and unhealthy dieting also plays a vital role in diabetes pathogenesis. As the current anti-diabetic drugs possess unprecedented side effects, traditional herbal medicine can be used an alternative therapy. The paramount challenge with the herbal formulation usage is the lack of standardized procedure, entangled with little knowledge on drug safety and mechanism of drug action. Heavy metal contamination is a major environmental hazard where plants tend to accumulate toxic metals like nickel, chromium and lead through industrial and agricultural activities. It becomes inappropriate to use these plants for phytotherapy as it may affect the human health on long term consumption. This review discuss about the environmental risk factors related to diabetes and better implication of medicinal plants in anti-diabetic therapy using network pharmacology. It is an in silico analytical tool that helps to unravel the multi-targeted action of herbal formulations rich in secondary metabolites. Also, a special focus is attempted to pool the databases regarding the medicinal plants for diabetes and associated diseases, their bioactive compounds, possible diabetic targets, drug-target interaction and toxicology reports that may open an aisle in safer, effective and toxicity-free drug discovery.

Invasive Seaweeds in the Iberian Peninsula: A Contribution for Food Supply

The introduction of exotic organisms in marine ecosystems can lead to economic and ecological losses. Globally, seaweeds represent a significant part of these non-indigenous species (NIS), with 407 introduced algal species. Furthermore, the presence of NIS seaweeds has been reported as a major concern worldwide since the patterns of their potential invasion mechanisms and vectors are not yet fully understood. Currently, in the Iberian Peninsula, around 50 NIS seaweeds have been recorded. Some of these are also considered invasive due to their overgrowth characteristic and competition with other species. However, invasive seaweeds are suitable for industrial applications due to their high feedstock. Hence, seaweeds' historical use in daily food diet, allied to research findings, showed that macroalgae are a source of nutrients and bioactive compounds with nutraceutical properties. The main goal of this review is to evaluate the records of NIS seaweeds in the Iberian Peninsula and critically analyze the potential of invasive seaweeds application in the food industry.