Algal Content Research Articles

Algae content prediction based on transfer learning and mean impact value

To improve the prediction accuracies of algae contents in different water bodies, this paper proposes a chlorophyll-A prediction model method based on transfer learning(TL) and mean impact value(MIV) algorithm. Firstly, we preprocess the data collected from the Huai River, including remove the missing data and standardize the preserving data. Then, the MIV algorithm is used to reduce the dimensionality of the data and determine the input variables of the model. Based on the selected input variables, the TL algorithm is introduced to establish the chlorophyll-A prediction model. The developed method can effectively enhance the prediction accuracy, especially when the number of samples is small. The simulation results verify the effectiveness and feasibility of the proposed prediction model.

Pseudomonas ZY-1 and Bacillus FY-1 protecting the rice seedlings from the harm of Pseudomonas aeruginosa via indirect seawead lysis

The local ecosystems, fishery and human health are all threatened by water blooms, so effectively controlling water blooms has become an urgent and challenging issue. Biological control of water blooms is given priority due to its low cost, high efficiency and environmental friendliness. In this study, Pseudomonas ZY-1 and Bacillus FY-1, two highly-effective algicidal bacteria strains which are able to indirectly lyse algae by separating and screening from the vigorous water body in the paddy alga of Northeast China were obtained. The two bacterial strains have stronger ability to lyse alga in the bacterial liquid concentration of 106 CFU/ml, and the alga-lysing rate on 7 d reached 84.03% and 83.11% respectively. The active substance secreted by ZY-1 is not sensitive to the changes of temperature and pH value, while as FY-1 cell-free filtrate is not stable in high temperature above 50 ℃ and pH of 5, it requires the sun light to have the algaecidal effect. The cell-free filtrates of strains ZY-1 and FY-1 had the best lysis effect on Microcystis aeruginosa cells, and the chlorophyll a content of algae decreased to 0.13 ± 0.02 mg/L and 0.14 ± 0.03 mg/L respectively and the Fv/Fm of Microcystis aeruginosa decreased by 97.22% after 7 days. The algaecidal process of ZY-1 and FY-1 may be that the cell-free filtrate inhibits the photosynthesis of Microcystis aeruginosa, and meanwhile it avoids the regeneration and repair of photosynthesis of algal cells by affecting the gene expression and damaging the repair system of algal cells, so the membrane lipid peroxidation is exacerbated and then the membrane of algal cells is broken, the algal cells can’t do normal life activities, and finally the algal cell would be killed. The rice seedlings in the algal liquid treatment group are short and show root dysplasia, few roots and brown roots. After treated with cell-free filtrate of ZY-1 and FY-1, the oxidative damage of the rice is obviously reduced, and the harm from Microcystis aeruginosa is reduced, which has the repair effect to the roots of rice seedlings and its aboveground growth. The cell-free filtrate of FY-1 works better than ZY-1. The bacteria strains of ZY-1 and FY-1 have the indirect algaecide trait, which makes them the potential environmentally-friendly algaecidal bacteria and they show broad application in the agricultural production and the control of water blooms.

Risk assessment of As, Cd, Cr, and Pb via the consumption of seafood in Haikou

In order to mitigate the risk of excessive heavy metal intake, a study was conducted to assess the levels of arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) contamination in 23 edible seafood species obtained from markets in Haikou. The findings were analyzed to evaluate the potential health hazards posed to the local population through consumption. The metals were detected via inductively coupled plasma mass spectrometry (ICP-MS) for quantification. The non-carcinogenic and carcinogenic health risks in humans were assessed via target hazard quotient (THQ), combined target hazard quotient (CTHQ), and target cancer risk (TR). The results indicated that the rank order based on the median metal concentration was As > Cd > Cr > Pb. THQ and CTHQ showed that nine seafood species posed a non-carcinogenic risk regarding from As and Cd consumption separately, or the four targeted metals ingestion together. TR assessment indicated that the InAs in all the species presented a carcinogenic risk to coastal residents. The Cd content in bivalves, algae, and several crustacean (Mantis Shrimp, Orchid Crab, Red spot Swimming Crab) and fish species (Japanese Scad, Pacific Saury), and Cr levels in most bivalve species (Razor Clams, White Clams, Fan Shells, Oysters, Blood Clams) presented a carcinogenic risk. The As, Cd, Pb, and Cr levels of seafood in Haikou were assessed species presented a potential health risk. Necessitating stricter risk should be management and detection capability and monitoring will be improved.

Algae infused enhancement of PBAT stiffness: Investigating the influence of algae content on mechanical and thermal properties

AbstractThis study investigates the impact of algae loading on the properties of PBAT/algae bio‐composites produced through a melt extrusion process. The integration of algae as a filler demonstrated a reinforcing effect on the PBAT matrix, leading to an increase in modulus with higher algae loading. Concurrently, the tensile strength and maximum tensile strain of PBAT decreased with an increase in algae content. The thermal stability of PBAT was affected by adding algae, resulting in bio‐composites exhibiting an intermediate behavior compared with their neat precursors. The optimal formulation is achieved with 20 wt.% of algae incorporated into the PBAT matrix. The produced PBAT/algae bio‐composites, demonstrated versatile applications across a wide range of products.

The Effects of Algal Blooms on Oxygen Levels in Lakes Babati and Eyasi, Tanzania

Globally aquatic ecosystems are reportedly overwhelmed by algal blooms due to excessive deposition of nutrients which ultimately cause hypoxia, leading to massive fish death. This study aimed at assessing the relationship between algae contents and dissolved oxygen (DO) in Lake Babati which is threatened by anthropogenic activities, whereas Lake Eyasi was used as a control. Algae contents (chlorophyll a), DO and surface water temperature were measured using standard methods. Results revealed that the mean algae content was significantly higher (4.47±0.88 mg/L) in Lake Babati than in Lake Eyasi (1.6±0.45 mg/L) (P < 0.05) and was beyond the standard permissible levels for domestic water supply and healthy ecosystem. Conversely, DO was significantly lower in Lake Babati than in Lake Eyasi (P < 0.05). There was no significant difference in water temperature in the two lakes (P > 0.05). Furthermore, there was an inverse relationship between algae content and DO in Lakes Eyasi and Babati (r = -0.88 and r = -0.30, respectively) suggesting that algal bloom is partly responsible for lowering DO. Responsible authorities are advised to enforce management policies and regulations to control unsustainable activities around these lakes that contribute to nutrient loading resulting into overgrowth of algae.

Extraction and antioxidant capacity of mycosporine-like amino acids from red algae in Japan.

Mycosporine-like amino acids (MAAs) are the natural UV-absorbing compounds with antioxidant activity found in microalgae and macroalgae. We collected red algae Asparagopsis taxiformis, Meristotheca japonica, and Polysiphonia senticulosa from Nagasaki, where UV radiation is more intense than in Hokkaido, and investigated the effect of UV radiation on MAA content. It was suggested that A. taxiformis and M. japonica contained shinorine and palythine, while UV-absorbing compound in P. senticulosa could not be identified. The amounts of these MAAs were lower compared to those from Hokkaido. Despite an increase in UV radiation in both regions from February to April, MAA contents of red algae from Nagasaki slightly decreased while those from Hokkaido significantly decreased. This difference was suggested the amount of inorganic nitrogen in the ocean. Antioxidant activity of MAAs increased under alkaline conditions. The extract containing MAAs from P. senticulosa showed the highest antioxidant activity among 4 red algae.

Analysis of Total Flavonoid and Total Phenolic Content of Red Algae (Eucheuma denticulatum (Burman) Collins et Harvey) Extract and Tempeh Extract

The red seaweed Euchema denticulatum (commonly referred to by the trade name Spinosum) is primarily farmed for extraction of carrageenan for application in foods. Tempe is a fermented soybean dish that is well-known for having a lot of protein. In the world, there are various ways to make tempeh, including soaking it in vinegar before fermentation. This study aims to determine the levels of total flavonoids and total phenolics in red algae and tempeh samples. Total phenolic content test was carried out using the Folin-Ciocalteu method using UV-Vis spectrophotometry at a wavelength of 760.5 nm. Total Flavonoid content test for total phenolic content was carried out quantitatively using a uv-vis spectrophotometer at a wavelength of 370 nm. The results showed that the average total flavonoid content in red algae was 55.25 mg/kg, and the total phenolic content in red algae was 420.56 mg/kg. whereas in tempeh the average total flavonoid content in red algae was 223.20 mg/kg, and total phenolic in tempe was 736.40 mg/kg.

Global Chemical Characterization of Sargassum spp. Seaweeds from Different Locations on Caribbean Islands: A Screening of Organic Compounds and Heavy Metals Contents

Large-scale strandings of Sargassum spp. seaweeds occur annually on the beaches of the Caribbean islands and cause major environmental, health, and economic problems. In order to support an approach of valorisation of algae, an exhaustive characterisation of the composition of these seaweeds has been performed by analysing the contents in alginates, structural carbohydrates (fucans and glucans), minerals, proteins, lipids, mannitol, polyphenols, and heavy metals. Nine batches were collected at different harvesting sites over the years 2021 and 2022, to estimate the spatial and temporal variation in Sargassum composition. A batch of floats was harvested and analysed to estimate the differences in composition between floats and whole algae. Samples collected during the same year (floats or entire plant, freshly collected or stored) showed no significant differences in composition. However, slight differences were observed between batches collected in the two years. Some samples showed significant amounts of heavy metals, especially arsenic. A detailed structural carbohydrates analysis was carried out and discussed with literature data. As the nitrogen content of algae is an interesting parameter for food or agronomic uses, protein analysis enabled us to calculate a new nitrogen–protein conversion factor, specific to these algae species.

Trace elements in coralline algae as a new proxy for seawater chemistry and metal pollution

The abundances of some macronutrients, and trace elements (K, Al, P, V, Mn, Co, Ni, Cu, Zn, Rb, Sr, Mo, Cs, Ba, Pb, Th, U, Y and REE) were determined in a series of coralline algae (Lithothamnion corallioides) samples (n = 101) collected alive in the Bay of Brest and the Iroise Sea (Western Brittany, NW France), in order to assess the potential of these algae as archives of seawater chemistry and potential metal pollution. REE and Y (REY) patterns are similar in shape to those of local seawater, exhibiting similar La, Ce and Y anomalies, but with abundances ranging between 4 and 5 orders of magnitude higher than seawater values. Variations in La anomalies (La/La* = 1.29–2.08), Y anomalies (Y/Ho = 38.6–55.8), and heavy rare earth enrichments (Prsn/Ersn = 0.22–0.52) are consistent with mixing of seawater with rivers flowing into the Bay of Brest. The behavior of other trace elements, such as Al and Cs, also reflects this mixing. Other parameters and processes can control the abundances of the other elements measured. For example, the presence of organic matter in studied samples controls the abundances of K and Rb. The abundances of base metals (e.g., Co, Ni, Cu) are highly sensitive to the various pollutants present in the Bay of Brest. In particular, the Pb content of coralline algae clearly reflects the pollution caused by mining of a nearby Pb deposit from the 18th to the early 20th century. Our results demonstrate the potential of coralline algae not only for tracing water masses, but also for studying metal pollution.

Bio-Modified Bitumen: A Comparative Analysis of Algae Influence on Characteristic Properties

The main aim of this study was to identify and evaluate the characteristic properties of bitumen modified with algae. Two types of algae, each with distinct gradation and origin, were employed for this investigation. For each type of algae (noted as chlorella and microchlorella), three blends were created with varying algae contents (5%, 10%, and 15% by weight of bitumen), utilizing a 70/100 reference bitumen as the virgin material and a basis for comparison. The properties of the blends were investigated using the Penetration, Softening Point, Elastic Recovery, Force Ductility, Dynamic Viscosity, and Storage Stability tests, both before and after short-term ageing (TFOT). The test results were then used to calculate the Activation Energy (Ea), Viscosity-Temperature Susceptibility (VTS) Index, and Mixing Temperature (Tmixing), along with their respective Pearson Correlation Coefficient (PCC) and R2 and p-values. The main finding of the study was that the addition of a low algae content of 5% caused a change in the classification of the unaged bitumen from 70/100 to 50/70 according to EN 12591 and thus hardened the reference bitumen. Additionally, a strong linear statistical correlation was observed between Ea and the VTS index, suggesting that these values should be considered when characterizing the temperature susceptibility of algae-modified bitumen.

Design of compostable toughened PLA/PBAT blend with algae via reactive compatibilization: The effect of algae content on mechanical and thermal properties of bio‐composites

AbstractA binary blend of polylactic acid (PLA) and poly (butylene adipate‐co‐terephthalate) (PBAT), along with algae in their respective composites, were successfully produced using a melt extrusion process. The produced in‐house coupling agent was used to enhance interfacial adhesion and algae dispersion. The influence of algae content incorporated into the compatibilized binary blend was thoroughly investigated, focusing on the bio‐composites morphology, mechanical, and thermal properties. The addition of PLA‐g‐MA to the binary blend led to notable improvements in the storage modulus, mechanical strength, and thermal properties of the binary blend. Subsequently, the introduction of algae into the compatibilized binary blend further augmented the storage modulus, with an optimum algae concentration of 10 wt%. However, higher algae content led to decreased tensile strength, elongation at break, and impact resilience. The optimal balance of these properties was achieved at an optimal loading of 5–10 wt% of algae into the compatibilized binary blend. The thermal stability of the bio‐composites was notably impacted by algae concentration, with the 10 wt% algae bio‐composite exhibiting increased thermal stability. Increasing algae content correlated with decreased bio‐composite crystallinity. These findings underscore the potential of optimized biobased algae composites for achieving desired mechanical and thermal properties, contributing to the development of sustainable and eco‐friendly polymer bio‐composites.

Extraction and Quantification of Lipids from Plant or Algae.

In plants and algae, the glycerolipidome changes in response to environmental modifications. For instance, in phosphate starvation, phospholipids are degraded and replaced by non-phosphorus lipids, and in nitrogen starvation, storage lipids accumulate. In addition to the well-known applications of oil crops for food, algae lipids are becoming a model for potential applications in health, biofuel, and green chemistry and are used as a platform for genetic engineering. It is therefore important to measure accurately and quickly the glycerolipid content in plants and algae. Here we describe the methods to extract the lipid and quantify the fatty acid amount of the lipid extract and the different lipid classes that are present in these samples.

Effect of nano Fe3O4-(CMC-Na)-PFS coagulant on coagulation–ultrafiltration process for treatment of algae -rich water

A novel composite flocculant (PCNF) was prepared using nano Fe3O4 as the condensed core, sodium carboxymethyl cellulose (CMC-Na) as the binder, and polyferric sulfate (PFS). The results indicate that the mass ratio of Fe3O4 to PFS is the key factor determining the flocculation effect of PCNF. When the mass ratio of Fe3O4 to PFS is 1:3, the Zeta potential value is approximately − 1.5 mV, indicating better removal of algae through adsorption electroneutralization. The resulting floc, characterized by negative charge and a loose structure, forms a filter cake layer that is easily backwashed on the surface of the ultrafiltration membrane. This floc also creates strong electrostatic repulsion with the membrane surface. Experimental results demonstrate that the specific flux decreased to 0.69, the total relative pollution was 0.33, and the proportion of irreversible pollution was only 34.65%, all of which were superior to traditional flocculant like PACl. Through microinterface mechanism analysis, it is concluded that the new PCNF flocculant, in combination with algal matter, forms a floc structure critical for mitigating ultrafiltration membrane pollution caused by high algal content in natural surface water.

Characterization of red algae (Gracilaria verrucosa) on potential application for topical treatment of oral mucosa wounds in Rattus norvegicus.

Wound healing in the mouth has its challenges due to masticatory movements and the presence of bacteria that can inhibit its process. The aim of this study was to analyze the contents of red algae (Gracilaria verrucosa) from Indonesia, and its potential as a wound-healing agent for oral wounds using animal model. Red algae content was determined by phytochemical tests and gas chromatography-mass spectroscopy (GC-MS). The wound was made by making an incision on the gingival mucosa of Rattus norvegicus and the parameters assessed were bleeding time, number of fibroblast cells, and time of wound closure. Three doses of G. verrucosa gel were used (2.5%, 5%, and 10%) and the gels were applied twice a day, at 6:00 and 18:00. Application was carried out topically by applying 0.1 ml of gel to the incision wound using a 1 mL syringe. Our phytochemical test indicated that the G. verrucosa contained alkaloids, steroids, flavonoids, and phenols. The dominant contains of the G. verrucosa were glycerol (36.81%), hexadecenoic acid (20.74%), and cholesterol (7.4%). The hemostasis test showed that the 2.5% G. verrucosa extract gel had the shortest bleeding time, 33.98±2.66 seconds. On the seventh day of the initial proliferation phase, the number of fibroblasts was not significantly different among groups. On day 14, the number of fibroblasts was only significantly different between 10% G. verrucosa and untreated group (p=0.007). On day 28, however, both 5% and 10% G. verrucosa were significantly higher compared to untreated group, both had p=0.010. Daily clinical examination showed that animals that were given 2.5% and 5% of G. verrucosa extract gel experienced wound closure on day 10. Animals treated with 10% of extract gel, all wounds healed on day 9. This study suggested that G. verrucosa extract could accelerate wound closure and wound healing.

Potential Effect of Red Algae Content on Fibroblasts and Collagen Type 3 in Oral Mucosa Wound Healing Diabetes-Induced Rattus Norvegicus

Potential Effect of Red Algae Content on Fibroblasts and Collagen Type 3 in Oral Mucosa Wound Healing Diabetes-Induced Rattus Norvegicus

Toxicological Impacts of TiO2 Nanoparticles on Growth, Photosynthesis Pigments, and Protein and Lipid Content of the Marine Microalga Tetraselmis Suecica.

Regarding the widespread use of titanium dioxide nanoparticles (TiO2NPs) in industry, many concerns have been raised about the risks of their potential release into aquatic ecosystems. Among the marine primary producers, Tetraselmis suecica is an ecologically important microalgae species used also as live feed in the shrimp culture industry. In the present study, the impacts of TiO2NPs on growth performance, photosynthetic pigments, lipid and protein content and its interaction with the cells of T. suecica were assessed. Based on the preliminary tests and OECD suggestion, concentrations of 5, 10, 50, 100, 200 and 400mg/L TiO2NPs were applied to algal cells for 10 days. With increasing concentration, a decrease in T. suecica cell density was observed each day. TiO2NPs induced a half-maximal inhibitory concentration (IC50) of 106.26mg/L on algal cells on the 3rd day. Chlorophyll a and b contents of the microalga decreased up to 56.08% and 52.74%, respectively following the exposure to TiO2NPs at 400mg/L. TiO2NPs also decreased the algal contents of protein and lipid up to 7.21% and 50.64%, respectively at the highest concentration. Based on FTIR, FESEM with EDS and mapping analyses, the interaction of TiO2NPs with the T. suecica cells was revealed. The stocks of T. suecica could be damaged by the toxic effects of the released TiO2NPs affecting their application as live feed in mariculture.

When digestive physiology doesn't match “diet”: Lumpenus sagitta (Stichaeidae) is an “omnivore” with a carnivorous gut

What an animal ingests and what it digests can be different. Thus, we examined the nutritional physiology of Lumpenus sagitta, a member of the family Stichaeidae, to better understand whether it could digest algal components like its better studied algivorous relatives. Although L. sagitta ingests considerable algal content, we found little evidence of algal digestion. This fish species has a short gut that doesn't show positive allometry with body size, low amylolytic activity that actually decreases as the fish grow, no ontogenetic changes in digestive enzyme gene expression, elevated N-acetyl-glucosaminidase activity (indicative of chitin breakdown), and an enteric microbial community that is consistent with carnivory and differs from members of its family that consume and digest algae. Hence, we are left concluding that L. sagitta is not capable of digesting the algae it consumes, and instead, are likely targeting epibionts on the algae itself, and other invertebrates consumed with the algae. Our study expands the coverage of dietary and digestive information for the family Stichaeidae, which is becoming a model for fish digestive physiology and genomics, and shows the power of moving beyond gut content analyses to better understand what an animal can actually digest and use metabolically.

Fabrication of Bioplastics from Sea Weeds

Abstract: This research deals with the production of bio-plastics from sea weeds. The main objectives is to produce bio-plastics from sea weeds (marine algae). The research has got two specific objectives which are to produce plastics that are environmental friendly whereby the plastic produced can be at least decomposed to smaller substance by the living organism and also to check the stability of the bio-plastics produced via mechanical and physical testing. In this study, marine algae specifically brown algae such as sargasum are the raw materials. Other materials required are glycerol, starch, gelatin, and colors. Methods used were observation to identify what type of algae has high content of agar and green algae were most the most efficient type. Experimentation involved the chemical processes to extract agar content from the from the algae by addition of sodium hydroxide to a powder form of algae which was dried and grinded, thereafter the mixture was heated 100 degree centigrade and allowed to cool agar powder was extracted and mixed with starch (as strengthening materials) and glycerol (plasticizer) and heated at 100 degree centigrade to get the tough semi-solid that helps to mould the plastics on a modal vessel

Anti-inflammatory activity of Eucheuma denticulatum from Warambadi coast: In-vivo study model of carrageenan-induced paw oedema

Background: Chronic inflammatory diseases have been declared the leading cause of mortality in the world, with more than 50% of deaths associated with inflammatory cases. Based on previous studies, red algae contained antioxidants such as phenolics and flavonoids, which are correlated to their anti-inflammatory activity, including Eucheuma denticulatum. Objective: This study aims to analyse antioxidants and anti-inflammatory activity as well as the phenolic and flavonoid content of red algae E. denticulatum ethyl acetate extract (EDEE). Method: EDEE was macerated in ethyl acetate and the antioxidant activity was performed using the (2,2-diphenyl-1-picryl-hydrazyl-hydrate) DPPH method. Total phenolic and flavonoid content was quantified using the Folin-Ciocalteu and AlCl3 methods. The anti-inflammatory activity was analysed by measuring the percentage of anti-inflammatory activity in carrageenan-induced mice paw edema. Result: The results showed that the Inhibition concentration 50 (IC50) of EDEE was 1031.5 ppm with a total phenolic and flavonoid content of 81.34 ± 0.996mg gallic acid equivalents (GAE/g) and 5.64 ± 0.12 mg quercetin equivalents (QE/g) extract, respectively. In vivo study showed that EDEE of 20, 50, and 100mg/kg body weight (BW) provided the percentage of anti-inflammatory activity of 53.49%, 86.63%, and 78.49% respectively, which is significantly different (p<0.05) compared to the negative control. Conclusion: EDEE 50mg/kg BW had the highest anti-inflammatory activity due to the presence of phenolic compounds.

Synergistic Evolution of Palaeoenvironment—Bionts and Hydrocarbon Generation of Permian Saline Lacustrine Source Rocks in Jimusar Sag, Junggar Basin

This study focused on Middle Permian Lucaogou Formation saline lake source rocks, utilizing a combination of biomarkers and hydrocarbon generation thermal simulation to analyze their biological compositions, depositional environments, and hydrocarbon generation potential. The Pr/Ph ratio, Ph/nC18 ratio, and Pr/nC17 ratio indicate that the Lucaogou Formation was in a reducing environment during the deposition period, and the lower part of the Lucaogou Formation (P2l1) is more anoxic than the upper part of the Lucaogou Formation (P2l2). The maturity index 20S (%) and ββ (%) reflect that the maturity of organic matter in the P2l1 is slightly higher than that in the P2l2. The G/H index and the ETR index indicate that the stratification of the water column is better during the sedimentary period of Lucaogou Formation and the salinity of the P2l1 is higher than that of the P2l2. The biomarker parameters of nC21−/nC22+, CPI, S/H, and C22T/C21T reflect that the organic matter of the source rocks have a higher abundance of bacteria and algae than higher plants, and the contents of bacteria are more than that of algae. The (7- + 8-MMAs)/Cmax and (C28 + C29 − St)/St parameters indicate that cyanobacteria accounted for a certain proportion of bacteria, and the algae are mainly green algae. The co-evolution of the sedimentary environment and the biological composition reflects the control of the sedimentary paleoenvironment on biological composition. According to the relative content of cyanobacteria, green algae, and Rhodophyta, the source rocks of the upper and lower Lucaogou Formation correspond to the low-salinity type (LS-type) and the high-salinity type (HS-type), respectively. Compared with LS-type source rocks, HS-type source rocks have greater generation potential of oil and weaker gas generation potential. This study is valuable for the accurate assessment of source rocks and holds significant practical implications for the exploration of oil and gas resources.