An in-vitro experiment was conducted to assess the interaction between biochar and algae on a problem soil. Experiments were performed with and without algae to observe the effectiveness of algae for overcoming the ch...An in-vitro experiment was conducted to assess the interaction between biochar and algae on a problem soil. Experiments were performed with and without algae to observe the effectiveness of algae for overcoming the challenges posed by problem soils. At the end of incubation periods, the adsorption and desorption of phosphorus (P) on a problem soil vis-á-vis algal inoculation were determined. Our results showed that different types of biochars adsorbed different amounts of P suggesting that the source of biochar played a crucial role in determining its behavior towards P. Tannery waste biochar significantly adsorbed 147% and 35% more P compared to that of the chicken litter and orange peel biochars respectively. Significant reductions in adsorption were observed when the biochar was used in combination with the algae which could be due to the beneficial effects of algae leading to the amelioration of the problem soil. Adsorption was reduced to 34%, 24% and 20% for the orange peel biochar + algae, chicken litter biochar + algae and tannery waste biochar + algae, respectively compared to the corresponding biochars present as a single solid. Phosphorus (P) desorption was also reduced significantly in presence of algal inoculation. Overall our findings suggest that the application of algae along with biochar in the problem soil could reduce the adsorption of P which would influence the availability of P.展开更多
In the paper, under the framework of exploring the interaction between algae and bacteria, an algae-bacteria ecological model was established to analyze the interaction mechanism and growth coexistence mode between al...In the paper, under the framework of exploring the interaction between algae and bacteria, an algae-bacteria ecological model was established to analyze the interaction mechanism and growth coexistence mode between algicidal bacteria and algae. Firstly, mathematical work mainly provided some threshold conditions to ensure the occurrence of transcritical bifurcation and saddle-node bifurcation, which could provide certain theoretical support for selecting key ecological environmental factors and numerical simulations. Secondly, the numerical simulation work dynamically displayed the evolution process of the bifurcation dynamic behavior of the model (2.1) and the growth coexistence mode of algae and algicidal bacteria. Finally, it was worth summarizing that intrinsic growth rate and combined capture effort of algae population had a strong influence on the dynamic behavior of the model (2.1). Furthermore, it must also be noted that transcritical bifurcation and saddle-node bifurcation were the inherent driving forces behind the formation of steady-state growth coexistence mode between algicidal bacteria and algae. In summary, it was hoped that the results of this study would contribute to accelerating the study of the interaction mechanism between algicidal bacteria and algae.展开更多
Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)suc...Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)such as carrageenan,alginate,fucoidan,laminaran,agarose,rhamnan,and ulvan.When hydrolyzed,MAP generate marine algae oligosaccharides(MAO),which have attracted interest in recent years due to their superior solubility compared with MAP.Besides,MAO have been demonstrated numerous biological activities including antioxidant,antidiabetic,anti-inflammatory,antimicrobial,and prebiotic activities.Thus,this review summarizes the main chemical classes of MAO,their sources,and the main processes used for their production(i.e.,physical,chemical,and biological methods),coupled with a discussion of the advantages and disadvantages of these methods.Highlights of the biological activities of MAO and their potential applications in food,nutraceutical,and pharmaceuticals would also be discussed and summarized.展开更多
Due to climate change,it is necessary to develop plant varieties that are resilient to climate conditions and resistant to abiotic and biotic stresses.The use of microalgae,which are microorganisms that contain carboh...Due to climate change,it is necessary to develop plant varieties that are resilient to climate conditions and resistant to abiotic and biotic stresses.The use of microalgae,which are microorganisms that contain carbohydrates,proteins,lipids,and vitamins,against drought tolerance is a new approach.The aim of the current study was to determine the drought-related mechanisms in the conomon melon genotype and develop drought-tolerant melon cultivars.Morphological,physiological,pomological,and molecular analyses were carried out on the algae-treated genotypes.It has been determined that commercial algae application provides the best results in leaf temperature,leaf relative water contents(LRWC),plant height,fruit length,fruit diameter,and yield,while Cag Cag(a special river in the region)stream algae application gives better results in main stem diameter.It was determined that the number of nodes in the control(without algae)plots was higher than in the other two treatments.Yield and LRWC and plant height values of genotype 7 were the best values among other genotypes.The leaf temperature measurement was lower on genotype 9 than on the other genotypes.While the highest fruit length value was measured in genotype 1,genotype 8 was superior in the main stem diameter,fruit diameter,and the number of nodes among the remaining plant materials.In terms of yield,it was determined that the interaction between genotype 2 and the commercial algae resulted in the best outcomes.In addition,the results of the genetic evaluation revealed that the materials used were not genetically distant from each other and more detailed genetic evaluations are needed.The molecular kinship analysis revealed that the genotypes used in the study were divided into three distinct groups,with individuals within each group exhibiting a high degree of relatedness to one another.As a result of the study,it was found that the application of microalgae had significant effects on improving the drought tolerance of Cucumis melo subsp.agrestis var.conomon genotypes.展开更多
Aquatic plant communities, which largely determine the ecological state of aquatic ecosystems and the quality of their waters, are the most important components in the biological monitoring system. Lake Khadicha is a ...Aquatic plant communities, which largely determine the ecological state of aquatic ecosystems and the quality of their waters, are the most important components in the biological monitoring system. Lake Khadicha is a unique natural body of water that is used for growing commercial fish. In recent years, due to heavy loads of abiotic and anthropogenic factors, the lake water has become highly saline. This phenomenon greatly affects the biodiversity of aquatic organisms, in addition to algae. During 2019-2021, the algae flora of Lake Khadicha was studied. 216 species of algae were identified as part of the algal flora. Their relationship with external factors such as water temperature, salinity and pH was studied. The seasonal abundance and biomass of algal flora areas of the lake were determined. Quantitative indicators of the dominant species in each season and their bioecological characteristics are identified.展开更多
In this paper, an algae-fish harvested model with Allee effect was established to further explore the dynamic evolution mechanism under the influence of key factors. Mathematical theoretical work not only investigated...In this paper, an algae-fish harvested model with Allee effect was established to further explore the dynamic evolution mechanism under the influence of key factors. Mathematical theoretical work not only investigated the existence and stability of all possible equilibrium points, but also probed into the occurrence of transcritical and Hopf bifurcation. The numerical simulation works verified the effectiveness of the theoretical derivation results and displayed rich bifurcation dynamical behaviors, which showed that Allee effect and harvest have played a vital role in the dynamic relationship between algae and fish. In summary, it was expected that these research results would be beneficial for promoting the study of bifurcation dynamics in aquatic ecosystems.展开更多
Research in dermatology is exploring bio-compatible materials like alginate and calcium sulphate for use in skincare products, such as facial sheet masks. Alginate (from seaweed) has wound healing and hydration proper...Research in dermatology is exploring bio-compatible materials like alginate and calcium sulphate for use in skincare products, such as facial sheet masks. Alginate (from seaweed) has wound healing and hydration properties, while calcium assists in maintaining skin balance and protection. In this study we explore the effects of an algae-calcium based sheet mask on skin. Materials and Methods: In-vitro studies investigated the purpose, process and effectiveness of an algae-calcium dry sheet mask (Algae Mask-MedSkin Solutions Dr. Suwelack). The mask is made from brown algae and undergoes a lyophilization and stabilization process to form its final structure. The mask’s properties were tested using scanning electron microscopy (SEM) and its performance was assessed on human skin biopsies. Various tests were performed, such as measuring the release of ionic constituents and concentration of calcium ions, and the fibroblast cell-activating effect. Clinical evaluations and skin microbiome assessment were conducted on healthy volunteers to assess the mask’s effect on the skin. Results and Conclusion: The study validates the benefits of macro algae-based sheet masks for skincare, with significant cosmetic effects and high tolerance due to its composition. Notably, the algae based mask releases substantial calcium ions, hydrates, minimizes skin roughness and wrinkles, regulates pH levels, and maintains skin microbiome diversity. It also decreases Corynebacterium species found on the skin, suggesting potential to modify skin microbiome. .展开更多
Algae have become an area of intensive research in many fields of study. Areas of application are becoming increasingly diverse with the advent of technologies particularly in the mass production of algae biomass. Alg...Algae have become an area of intensive research in many fields of study. Areas of application are becoming increasingly diverse with the advent of technologies particularly in the mass production of algae biomass. Algae contain complex bioactive compounds and these are gaining importance in emerging technologies with nutritional and environmental applications. In this study, a preliminary investigation evaluated 15 species of algae from the major categories of marine and fresh water algae for their potential as inclusions in ruminant diets for management of greenhouse gas emissions. It was hypothesized that algae would positively affect rumen fermentation and gas production while reducing methane production. The hypothesis was tested using an Ankom automated gas monitoring system and rumen fluid from Bos indicus steers fed tropical forage diets. The results were variable between algae species with some showing a significant reduction in total gas and methane production, with others increasing gas and fermentation. The red and brown algae stand out as having potential for greenhouse gas mitigation with the brown alga Cystoseira having the most prominent effect. The effects observed on fermentation may be manipulated through dosage management and beneficial effects could be potentially maximized by preparing combinations of algal supplements. It has been demonstrated in this study that algae have the potential to assist in rumen fermentation management for improved gas production, and greenhouse gas abatement.展开更多
Ultraviolet(UV)filters are widely used in sunscreen and personal care products due to their ability to give protection to our skin from UV radiation.Oxybenzone,commonly known as benzophenone-3,is one type of UV filter...Ultraviolet(UV)filters are widely used in sunscreen and personal care products due to their ability to give protection to our skin from UV radiation.Oxybenzone,commonly known as benzophenone-3,is one type of UV filter found as the active ingredient in many pharmaceutical products.Although oxybenzone has been extensively studied as an environmental toxicant in the ecosystem,little is known about its toxicity effects on microalgae.The effects of oxybenzone on growth(measured as OD620 nm,chlɑand carotenoids)and macromolecular composition of polar microalgae(Chlorella UMACC 400 and Chlorella UMACC 401)and temperate microalgae(Chlorella sp.,Chlamydomonas reinhardtii,Scenedesmus quadricauda)were investigated.These microalgae were cultured in triplicate and exposed to different oxybenzone concentrations(0,100,200,300 and 400 mg·L-1),at 4℃and 18 for polar and temperate species respectively,for 96 h.The oxybenzone concentrations used℃represent a range from environmental to extreme concentrations to understand the impact of this toxicant on microalgae.The results showed that the highest concentration of oxybenzone(300 and 400 mg·L-1)had adverse effects on growth rate and biomass of these microalgae.However,exposure to oxybenzone concentrations ranging from 200 mg·L-1 to 400 mg·L-1 did not have significant effects on S.quadricauda growth.The exposure to oxybenzone at higher concentrations also led to changes in cell structure after 96 h.Generally,protein and carbohydrate content of all microalgae except S.quadricauda increased with increasing oxybenzone concentrations.Protein content increased significantly when cells were exposed to oxybenzone,though effects were greater in the polar species,suggesting that it could be one of the adaptive strategies that enabled these microalgae to tolerate oxybenzone.Further investigation is required to determine the effects of oxybenzone on other features of microalgal performance at relevant environmental concentrations.展开更多
Besides competing with algae for light and mineral nutrients (i.e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of ...Besides competing with algae for light and mineral nutrients (i.e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in “ A. tatarinowii water”, some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A. tatarinowii on algae were obvious and planting A.tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 μl/disc, the inhibitory rate was negative; if it was over 45 μl/disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 μl/disc and 45 μl/disc.展开更多
The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes ...The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes are undergoing a rapid increase in number and size. Human impacts and frequent algae blooms lead to it necessary to make a better constraint on their carbon cycles. Here, we make a primary estimation on the air–water CO_2 transfer flux through an algae bloom year for a subtropical man-made lake—Hongfeng Lake, Southwest China. To do this a new type of glass bottles was designed for content and isotopic analysis of DIC and other environmental parameters. At the early stage of algae bloom,CO_2 was transferred from the atmosphere to the lake with a net flux of 1.770 g·C·m^(-2). Later, the partial pressure(pCO_2) of the aqueous CO_2 increased rapidly and the lake outgassed to the atmosphere with a net flux of 95.727 g·C·m^(-2). In the remaining days, the lake again took up CO_2 from the atmosphere with a net flux of 14.804 g·C·m^(-2). As a whole, Lake Hongfeng released 4527 t C to the atmosphere, accounting for one-third of the atmosphere/soil CO_2 sequestered by chemical weathering in the whole drainage. With an empirical mode decomposition method, we found air temperature plays a major role in controlling water temperature, aqueous pCO_2 and hence CO_2 flux. This work indicates a necessity to make detailed and comprehensive carbon budgets in man-made lakes.展开更多
Chemical means were used to extract polyphenols from healthy brown algae collected in littoral seawater. Experiments on corrosion of A 3 steel, the time potential curve, and polarization curve in polyphenols seawater ...Chemical means were used to extract polyphenols from healthy brown algae collected in littoral seawater. Experiments on corrosion of A 3 steel, the time potential curve, and polarization curve in polyphenols seawater showed stronger cathodic polarization compared with that in common seawater. This indicates that brown algae polyphenols might feasibly be used as corrosion inhibitor in seawater.展开更多
Silver nanoparticles,endowed with powerful antimicrobial property,are the most widely used nanomaterial in consumer products,with associated risk of their easy access to environment and freshwater ecosystems by surfac...Silver nanoparticles,endowed with powerful antimicrobial property,are the most widely used nanomaterial in consumer products,with associated risk of their easy access to environment and freshwater ecosystems by surface runoff.Although toxic effects of nanosilver on bacterial,fungal and mammalian cells have been documented,its impact on algal growth remains unknown.Pithophora oedogonia and Chara vulgaris are predominant members of photosynthetic eukaryotic algae,which form major component of global aquatic ecosystem.Here we report for the first time that nanosilver has significant adverse effects on growth and morphology of these filamentous green algae in a dose-dependent manner.Exposure of algal thalli to increasing concentrations of silver nanoparticles resulted in progressive depletion in algal chlorophyll content,chromosome instability and mitotic disturbance,associated with morphological malformations in algal filaments.SEM micrographs revealed dramatic alterations in cell wall in nanoparticle-treated algae,characterized with cell wall rupture and degradation in Pithophora.Although these observations underscore severe deleterious effects of nanosilver on aquatic environment,the information can also be exploited as a bioengineering strategy to control unwanted and persistent growth of noxious algal weeds that clog the municipal water supply and water channels and produce fouling of water bodies.展开更多
Hollow B–SiO2@TiO2 composites were prepared by the wet chemical deposition method starting from TiCl4 and hollow B–SiO2 microspheres.TiO2 layers composed of anatase TiO2 nanoparticles were coated on the surfaces of ...Hollow B–SiO2@TiO2 composites were prepared by the wet chemical deposition method starting from TiCl4 and hollow B–SiO2 microspheres.TiO2 layers composed of anatase TiO2 nanoparticles were coated on the surfaces of the hollow B–SiO2 microspheres probably through the formation of Ti—O—Si and Ti—O—B bonds.A great number of—OH groups were also present at the TiO2 coating layers.The presence of Ti—O—Si bonds and Ti—O—B bonds resulted in the formation of defects in the TiO2 coating layers,which decreased the band gap of the TiO2 coating layers to ca.3.0 eV and endowed the TiO2 coating layers with visible light absorption performance.The buoyancy hollow B–SiO2@TiO2 composites exhibited high photocatalytic activities for the degradation of ammonia-nitrogen and green algae.The conversion of ammonia-nitrogen reached 65%when the degradation of ammonia-nitrogen(43 mg·L-1 at pH value of 8)was catalyzed by the B–SiO2@TiO2(100:10)composite under the simulated solar light irradiation at 35°C for 660 min.The green algae(5 mg·L-1)were almost completely degraded over the B–SiO@TiO2(100:20)photocatalyst under the visible light irradiation at 35°C for 510 min.展开更多
Objective:To identify the available phytochemicals and carotenoids in the selected green algae and evaluate the potential genotoxic/antigenotoxic effect using lymphocytes.Methods:Organic,solvent extracts of Chlorococc...Objective:To identify the available phytochemicals and carotenoids in the selected green algae and evaluate the potential genotoxic/antigenotoxic effect using lymphocytes.Methods:Organic,solvent extracts of Chlorococcum humicola(C.humicola)were used for the phytochemical analysis.The available carotenoids were assessed by HPLC,and LC-MS analysis.The genotoxicity was induced by the benzo(a)pyrene in the lymphocyte culture,the genotoxic and antigenotoxic effects of algal carotenoids with and without genotoxic inducer were evaluated by chromosomal aberration(CA),sister chromatid exchange(SCE)and micronucleus assay(MN).Results:The results of the analysis showed that the algae were rich in carotenoids and fatty acids.In the total carotenoids lutein,β-carotene andα-carotene were found to be present in higher concentration.The frequency of CA and SCE increased by benzo(a)pyrene were significantly decreased by the carotenoids(P<0.05 for CA,P<0.001 for SCE).The MN frequencies of the cells were significantly decreased by the treatment with carotenoids when compared with the positive controls(P<0.05).Conclusions:The findings of the present study demonstrate that,the green algae C.humicola is a rich source of bioactive compounds especially carotenoids which effectively fight against environmental genotoxic agents,the carotenoids itself is not a genotoxic substance and should be further considered for its beneficial effects.展开更多
Accumulation of heavy metals by algae had been studied extensively for biomonitoring or bioremediation purposes. Having the advantages of low cost raw material, big adsorbing capacity, no secondary pollution, etc., al...Accumulation of heavy metals by algae had been studied extensively for biomonitoring or bioremediation purposes. Having the advantages of low cost raw material, big adsorbing capacity, no secondary pollution, etc., algae may be used to treat industrial water containing heavy metals. The adsorption processes were carried out in two steps: rapid physical adsorption first, and then slow chemical adsorption. pH is the major factor influencing the adsorption. The Freundlich equation fitted very well the adsorption isotherms. The uptake decreased with increasing ionic strength. The principal mechanism of metallic cation sequestration involves the formation of complexes between a metal ion and functional groups on the surface or inside the porous structure of the biological material. The carboxyl groups of alginate play a major role in the complexation. Different species of algae and the algae of the same species may have different adsorption capacity. Their selection affinity for heavy metals was the major criterion for the screening of a biologic adsorbent to be used in water treatment. The surface complex formation model (SCFM) can solve the equilibrium and kinetic problems in the biosorption.展开更多
Brown algae is one of the three major types of marine algae and includes approximately 2000 species.It is widely dis-tributed in various seas around the world.Brown algae contain a plethora of active substances,such a...Brown algae is one of the three major types of marine algae and includes approximately 2000 species.It is widely dis-tributed in various seas around the world.Brown algae contain a plethora of active substances,such as polysaccharides,polyphe-nols,omega-3 fatty acids,and carotenoids.Laminarin,a type of storage carbohydrate found abundantly in brown algae,is mainly formed by glucose monomers linked byβ-1,3-glucosidic bonds and partialβ-1,6-glucosidic bonds.Laminarin and laminarin oligo-saccharides,which contain 2-10 saccharide units,have extensive biological activities,such as antitumor,antioxidant,anti-inflam-matory,and prebiotic properties.Moreover,both laminarin and laminarin oligosaccharides can be considered as ideal substrates for bioethanol production because they are composed of abundant glucose residues.Therefore,brown algae-derived laminarin and lami-narin oligosaccharides have various potential applications in the food,medicine,cosmetics,and bioenergy fields.This paper reviews the preparation methods of laminarin and laminarin oligosaccharides,as well as their biological activities and potential applications.展开更多
Coralline algae(CA),a type of primary calcifying producer presented in coastal ecosystems,are considered one of the highly sensitive organisms to marine environmental change.However,experimental studies on coralline a...Coralline algae(CA),a type of primary calcifying producer presented in coastal ecosystems,are considered one of the highly sensitive organisms to marine environmental change.However,experimental studies on coralline algae responses to elevated seawater temperature and reduced pH have documented either contradictory or opposite results.In this study,we analysed the growth and physiological responses of coralline algae Porolithon onkodes to the elevated temperature(30.8°C)and reduced pH(7.8).The aim of this analysis was to observe the direct and combined effects,while elucidating the growth and photosynthesis in this response.It was demonstrated that the algae thallus growth rate and photosynthesis under elevated temperature were depressed by 21.5%and 14.9%respectively.High pCO2 enhanced the growth and photosynthesis of the thallus at ambient temperature,while they were deceased when both temperature and pCO2 were elevated.CA is among the most sensitive organisms to ocean acidification(OA)because of their precipitate high Mg-calcite.We hypothesize that coralline algae could increase their calcification rate in order to counteract the effects of moderate acidification,but offset by the effect of elevated temperature.Accordingly,our results also support the conclusion that global warming(GW)is a stronger threat to algal performance than OA.Our findings are also proposed that coralline algae may be more resilient under OA than GW.展开更多
This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic...This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemor-rhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.展开更多
文摘An in-vitro experiment was conducted to assess the interaction between biochar and algae on a problem soil. Experiments were performed with and without algae to observe the effectiveness of algae for overcoming the challenges posed by problem soils. At the end of incubation periods, the adsorption and desorption of phosphorus (P) on a problem soil vis-á-vis algal inoculation were determined. Our results showed that different types of biochars adsorbed different amounts of P suggesting that the source of biochar played a crucial role in determining its behavior towards P. Tannery waste biochar significantly adsorbed 147% and 35% more P compared to that of the chicken litter and orange peel biochars respectively. Significant reductions in adsorption were observed when the biochar was used in combination with the algae which could be due to the beneficial effects of algae leading to the amelioration of the problem soil. Adsorption was reduced to 34%, 24% and 20% for the orange peel biochar + algae, chicken litter biochar + algae and tannery waste biochar + algae, respectively compared to the corresponding biochars present as a single solid. Phosphorus (P) desorption was also reduced significantly in presence of algal inoculation. Overall our findings suggest that the application of algae along with biochar in the problem soil could reduce the adsorption of P which would influence the availability of P.
文摘In the paper, under the framework of exploring the interaction between algae and bacteria, an algae-bacteria ecological model was established to analyze the interaction mechanism and growth coexistence mode between algicidal bacteria and algae. Firstly, mathematical work mainly provided some threshold conditions to ensure the occurrence of transcritical bifurcation and saddle-node bifurcation, which could provide certain theoretical support for selecting key ecological environmental factors and numerical simulations. Secondly, the numerical simulation work dynamically displayed the evolution process of the bifurcation dynamic behavior of the model (2.1) and the growth coexistence mode of algae and algicidal bacteria. Finally, it was worth summarizing that intrinsic growth rate and combined capture effort of algae population had a strong influence on the dynamic behavior of the model (2.1). Furthermore, it must also be noted that transcritical bifurcation and saddle-node bifurcation were the inherent driving forces behind the formation of steady-state growth coexistence mode between algicidal bacteria and algae. In summary, it was hoped that the results of this study would contribute to accelerating the study of the interaction mechanism between algicidal bacteria and algae.
基金financially supported by grants from the National Natural Science Foundation of China(31901692)2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(2020LKSFG02E)Natural Science Foundation of Guangdong Province,China(2021A1515011495)。
文摘Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)such as carrageenan,alginate,fucoidan,laminaran,agarose,rhamnan,and ulvan.When hydrolyzed,MAP generate marine algae oligosaccharides(MAO),which have attracted interest in recent years due to their superior solubility compared with MAP.Besides,MAO have been demonstrated numerous biological activities including antioxidant,antidiabetic,anti-inflammatory,antimicrobial,and prebiotic activities.Thus,this review summarizes the main chemical classes of MAO,their sources,and the main processes used for their production(i.e.,physical,chemical,and biological methods),coupled with a discussion of the advantages and disadvantages of these methods.Highlights of the biological activities of MAO and their potential applications in food,nutraceutical,and pharmaceuticals would also be discussed and summarized.
基金supported by the Scientific Research Coordinatorship of Siirt University with the Project Number 2018-SİÜFEB-022.
文摘Due to climate change,it is necessary to develop plant varieties that are resilient to climate conditions and resistant to abiotic and biotic stresses.The use of microalgae,which are microorganisms that contain carbohydrates,proteins,lipids,and vitamins,against drought tolerance is a new approach.The aim of the current study was to determine the drought-related mechanisms in the conomon melon genotype and develop drought-tolerant melon cultivars.Morphological,physiological,pomological,and molecular analyses were carried out on the algae-treated genotypes.It has been determined that commercial algae application provides the best results in leaf temperature,leaf relative water contents(LRWC),plant height,fruit length,fruit diameter,and yield,while Cag Cag(a special river in the region)stream algae application gives better results in main stem diameter.It was determined that the number of nodes in the control(without algae)plots was higher than in the other two treatments.Yield and LRWC and plant height values of genotype 7 were the best values among other genotypes.The leaf temperature measurement was lower on genotype 9 than on the other genotypes.While the highest fruit length value was measured in genotype 1,genotype 8 was superior in the main stem diameter,fruit diameter,and the number of nodes among the remaining plant materials.In terms of yield,it was determined that the interaction between genotype 2 and the commercial algae resulted in the best outcomes.In addition,the results of the genetic evaluation revealed that the materials used were not genetically distant from each other and more detailed genetic evaluations are needed.The molecular kinship analysis revealed that the genotypes used in the study were divided into three distinct groups,with individuals within each group exhibiting a high degree of relatedness to one another.As a result of the study,it was found that the application of microalgae had significant effects on improving the drought tolerance of Cucumis melo subsp.agrestis var.conomon genotypes.
文摘Aquatic plant communities, which largely determine the ecological state of aquatic ecosystems and the quality of their waters, are the most important components in the biological monitoring system. Lake Khadicha is a unique natural body of water that is used for growing commercial fish. In recent years, due to heavy loads of abiotic and anthropogenic factors, the lake water has become highly saline. This phenomenon greatly affects the biodiversity of aquatic organisms, in addition to algae. During 2019-2021, the algae flora of Lake Khadicha was studied. 216 species of algae were identified as part of the algal flora. Their relationship with external factors such as water temperature, salinity and pH was studied. The seasonal abundance and biomass of algal flora areas of the lake were determined. Quantitative indicators of the dominant species in each season and their bioecological characteristics are identified.
文摘In this paper, an algae-fish harvested model with Allee effect was established to further explore the dynamic evolution mechanism under the influence of key factors. Mathematical theoretical work not only investigated the existence and stability of all possible equilibrium points, but also probed into the occurrence of transcritical and Hopf bifurcation. The numerical simulation works verified the effectiveness of the theoretical derivation results and displayed rich bifurcation dynamical behaviors, which showed that Allee effect and harvest have played a vital role in the dynamic relationship between algae and fish. In summary, it was expected that these research results would be beneficial for promoting the study of bifurcation dynamics in aquatic ecosystems.
文摘Research in dermatology is exploring bio-compatible materials like alginate and calcium sulphate for use in skincare products, such as facial sheet masks. Alginate (from seaweed) has wound healing and hydration properties, while calcium assists in maintaining skin balance and protection. In this study we explore the effects of an algae-calcium based sheet mask on skin. Materials and Methods: In-vitro studies investigated the purpose, process and effectiveness of an algae-calcium dry sheet mask (Algae Mask-MedSkin Solutions Dr. Suwelack). The mask is made from brown algae and undergoes a lyophilization and stabilization process to form its final structure. The mask’s properties were tested using scanning electron microscopy (SEM) and its performance was assessed on human skin biopsies. Various tests were performed, such as measuring the release of ionic constituents and concentration of calcium ions, and the fibroblast cell-activating effect. Clinical evaluations and skin microbiome assessment were conducted on healthy volunteers to assess the mask’s effect on the skin. Results and Conclusion: The study validates the benefits of macro algae-based sheet masks for skincare, with significant cosmetic effects and high tolerance due to its composition. Notably, the algae based mask releases substantial calcium ions, hydrates, minimizes skin roughness and wrinkles, regulates pH levels, and maintains skin microbiome diversity. It also decreases Corynebacterium species found on the skin, suggesting potential to modify skin microbiome. .
文摘Algae have become an area of intensive research in many fields of study. Areas of application are becoming increasingly diverse with the advent of technologies particularly in the mass production of algae biomass. Algae contain complex bioactive compounds and these are gaining importance in emerging technologies with nutritional and environmental applications. In this study, a preliminary investigation evaluated 15 species of algae from the major categories of marine and fresh water algae for their potential as inclusions in ruminant diets for management of greenhouse gas emissions. It was hypothesized that algae would positively affect rumen fermentation and gas production while reducing methane production. The hypothesis was tested using an Ankom automated gas monitoring system and rumen fluid from Bos indicus steers fed tropical forage diets. The results were variable between algae species with some showing a significant reduction in total gas and methane production, with others increasing gas and fermentation. The red and brown algae stand out as having potential for greenhouse gas mitigation with the brown alga Cystoseira having the most prominent effect. The effects observed on fermentation may be manipulated through dosage management and beneficial effects could be potentially maximized by preparing combinations of algal supplements. It has been demonstrated in this study that algae have the potential to assist in rumen fermentation management for improved gas production, and greenhouse gas abatement.
基金the School of Biosciences,Taylor’s University for financial support for this Final Year Project。
文摘Ultraviolet(UV)filters are widely used in sunscreen and personal care products due to their ability to give protection to our skin from UV radiation.Oxybenzone,commonly known as benzophenone-3,is one type of UV filter found as the active ingredient in many pharmaceutical products.Although oxybenzone has been extensively studied as an environmental toxicant in the ecosystem,little is known about its toxicity effects on microalgae.The effects of oxybenzone on growth(measured as OD620 nm,chlɑand carotenoids)and macromolecular composition of polar microalgae(Chlorella UMACC 400 and Chlorella UMACC 401)and temperate microalgae(Chlorella sp.,Chlamydomonas reinhardtii,Scenedesmus quadricauda)were investigated.These microalgae were cultured in triplicate and exposed to different oxybenzone concentrations(0,100,200,300 and 400 mg·L-1),at 4℃and 18 for polar and temperate species respectively,for 96 h.The oxybenzone concentrations used℃represent a range from environmental to extreme concentrations to understand the impact of this toxicant on microalgae.The results showed that the highest concentration of oxybenzone(300 and 400 mg·L-1)had adverse effects on growth rate and biomass of these microalgae.However,exposure to oxybenzone concentrations ranging from 200 mg·L-1 to 400 mg·L-1 did not have significant effects on S.quadricauda growth.The exposure to oxybenzone at higher concentrations also led to changes in cell structure after 96 h.Generally,protein and carbohydrate content of all microalgae except S.quadricauda increased with increasing oxybenzone concentrations.Protein content increased significantly when cells were exposed to oxybenzone,though effects were greater in the polar species,suggesting that it could be one of the adaptive strategies that enabled these microalgae to tolerate oxybenzone.Further investigation is required to determine the effects of oxybenzone on other features of microalgal performance at relevant environmental concentrations.
基金TheNationalNaturalScienceFoundationofChinaandthe"Ninth five"significantBitem (No .KZ 95 1 B1 2 0 1)oftheChineseAcademyofScie
文摘Besides competing with algae for light and mineral nutrients (i.e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in “ A. tatarinowii water”, some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A. tatarinowii on algae were obvious and planting A.tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 μl/disc, the inhibitory rate was negative; if it was over 45 μl/disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 μl/disc and 45 μl/disc.
基金carried out with funding from the National Key Research and Development Project provided by the Ministry of Science and Technology of China through Grant 2016YFA0601000
文摘The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes are undergoing a rapid increase in number and size. Human impacts and frequent algae blooms lead to it necessary to make a better constraint on their carbon cycles. Here, we make a primary estimation on the air–water CO_2 transfer flux through an algae bloom year for a subtropical man-made lake—Hongfeng Lake, Southwest China. To do this a new type of glass bottles was designed for content and isotopic analysis of DIC and other environmental parameters. At the early stage of algae bloom,CO_2 was transferred from the atmosphere to the lake with a net flux of 1.770 g·C·m^(-2). Later, the partial pressure(pCO_2) of the aqueous CO_2 increased rapidly and the lake outgassed to the atmosphere with a net flux of 95.727 g·C·m^(-2). In the remaining days, the lake again took up CO_2 from the atmosphere with a net flux of 14.804 g·C·m^(-2). As a whole, Lake Hongfeng released 4527 t C to the atmosphere, accounting for one-third of the atmosphere/soil CO_2 sequestered by chemical weathering in the whole drainage. With an empirical mode decomposition method, we found air temperature plays a major role in controlling water temperature, aqueous pCO_2 and hence CO_2 flux. This work indicates a necessity to make detailed and comprehensive carbon budgets in man-made lakes.
文摘Chemical means were used to extract polyphenols from healthy brown algae collected in littoral seawater. Experiments on corrosion of A 3 steel, the time potential curve, and polarization curve in polyphenols seawater showed stronger cathodic polarization compared with that in common seawater. This indicates that brown algae polyphenols might feasibly be used as corrosion inhibitor in seawater.
基金supported by grants received by Anjali Dash from DST Women Scientist Scheme (DST WOSA)by D.Dash from the Department of Biotechnology (DBT),Govt.of Indiathe Indian Council of Medical Research (ICMR)
文摘Silver nanoparticles,endowed with powerful antimicrobial property,are the most widely used nanomaterial in consumer products,with associated risk of their easy access to environment and freshwater ecosystems by surface runoff.Although toxic effects of nanosilver on bacterial,fungal and mammalian cells have been documented,its impact on algal growth remains unknown.Pithophora oedogonia and Chara vulgaris are predominant members of photosynthetic eukaryotic algae,which form major component of global aquatic ecosystem.Here we report for the first time that nanosilver has significant adverse effects on growth and morphology of these filamentous green algae in a dose-dependent manner.Exposure of algal thalli to increasing concentrations of silver nanoparticles resulted in progressive depletion in algal chlorophyll content,chromosome instability and mitotic disturbance,associated with morphological malformations in algal filaments.SEM micrographs revealed dramatic alterations in cell wall in nanoparticle-treated algae,characterized with cell wall rupture and degradation in Pithophora.Although these observations underscore severe deleterious effects of nanosilver on aquatic environment,the information can also be exploited as a bioengineering strategy to control unwanted and persistent growth of noxious algal weeds that clog the municipal water supply and water channels and produce fouling of water bodies.
基金Supported by the National Natural Science Foundation of China(21506078).
文摘Hollow B–SiO2@TiO2 composites were prepared by the wet chemical deposition method starting from TiCl4 and hollow B–SiO2 microspheres.TiO2 layers composed of anatase TiO2 nanoparticles were coated on the surfaces of the hollow B–SiO2 microspheres probably through the formation of Ti—O—Si and Ti—O—B bonds.A great number of—OH groups were also present at the TiO2 coating layers.The presence of Ti—O—Si bonds and Ti—O—B bonds resulted in the formation of defects in the TiO2 coating layers,which decreased the band gap of the TiO2 coating layers to ca.3.0 eV and endowed the TiO2 coating layers with visible light absorption performance.The buoyancy hollow B–SiO2@TiO2 composites exhibited high photocatalytic activities for the degradation of ammonia-nitrogen and green algae.The conversion of ammonia-nitrogen reached 65%when the degradation of ammonia-nitrogen(43 mg·L-1 at pH value of 8)was catalyzed by the B–SiO2@TiO2(100:10)composite under the simulated solar light irradiation at 35°C for 660 min.The green algae(5 mg·L-1)were almost completely degraded over the B–SiO@TiO2(100:20)photocatalyst under the visible light irradiation at 35°C for 510 min.
基金supported by Bharathiar University.Tamilnadu,India
文摘Objective:To identify the available phytochemicals and carotenoids in the selected green algae and evaluate the potential genotoxic/antigenotoxic effect using lymphocytes.Methods:Organic,solvent extracts of Chlorococcum humicola(C.humicola)were used for the phytochemical analysis.The available carotenoids were assessed by HPLC,and LC-MS analysis.The genotoxicity was induced by the benzo(a)pyrene in the lymphocyte culture,the genotoxic and antigenotoxic effects of algal carotenoids with and without genotoxic inducer were evaluated by chromosomal aberration(CA),sister chromatid exchange(SCE)and micronucleus assay(MN).Results:The results of the analysis showed that the algae were rich in carotenoids and fatty acids.In the total carotenoids lutein,β-carotene andα-carotene were found to be present in higher concentration.The frequency of CA and SCE increased by benzo(a)pyrene were significantly decreased by the carotenoids(P<0.05 for CA,P<0.001 for SCE).The MN frequencies of the cells were significantly decreased by the treatment with carotenoids when compared with the positive controls(P<0.05).Conclusions:The findings of the present study demonstrate that,the green algae C.humicola is a rich source of bioactive compounds especially carotenoids which effectively fight against environmental genotoxic agents,the carotenoids itself is not a genotoxic substance and should be further considered for its beneficial effects.
文摘Accumulation of heavy metals by algae had been studied extensively for biomonitoring or bioremediation purposes. Having the advantages of low cost raw material, big adsorbing capacity, no secondary pollution, etc., algae may be used to treat industrial water containing heavy metals. The adsorption processes were carried out in two steps: rapid physical adsorption first, and then slow chemical adsorption. pH is the major factor influencing the adsorption. The Freundlich equation fitted very well the adsorption isotherms. The uptake decreased with increasing ionic strength. The principal mechanism of metallic cation sequestration involves the formation of complexes between a metal ion and functional groups on the surface or inside the porous structure of the biological material. The carboxyl groups of alginate play a major role in the complexation. Different species of algae and the algae of the same species may have different adsorption capacity. Their selection affinity for heavy metals was the major criterion for the screening of a biologic adsorbent to be used in water treatment. The surface complex formation model (SCFM) can solve the equilibrium and kinetic problems in the biosorption.
基金This work was supported by the National Natural Science Foundation of China(No.31922072)National Key Research and Development Program of China(Nos.2019YFD0901902 and 2019YFD0901904)+1 种基金Taishan Scholar Project of Shandong Province(No.tsqn201812020)the Fundamental Research Funds for the Central Universities(No.201941002).
文摘Brown algae is one of the three major types of marine algae and includes approximately 2000 species.It is widely dis-tributed in various seas around the world.Brown algae contain a plethora of active substances,such as polysaccharides,polyphe-nols,omega-3 fatty acids,and carotenoids.Laminarin,a type of storage carbohydrate found abundantly in brown algae,is mainly formed by glucose monomers linked byβ-1,3-glucosidic bonds and partialβ-1,6-glucosidic bonds.Laminarin and laminarin oligo-saccharides,which contain 2-10 saccharide units,have extensive biological activities,such as antitumor,antioxidant,anti-inflam-matory,and prebiotic properties.Moreover,both laminarin and laminarin oligosaccharides can be considered as ideal substrates for bioethanol production because they are composed of abundant glucose residues.Therefore,brown algae-derived laminarin and lami-narin oligosaccharides have various potential applications in the food,medicine,cosmetics,and bioenergy fields.This paper reviews the preparation methods of laminarin and laminarin oligosaccharides,as well as their biological activities and potential applications.
基金The National Natural Science Foundation of China(NSFC)under contract Nos 41306144 and 41676150the National Key Research and Development Plan under contract No.2017YFC0506301+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA13020402the Guangdong Basic and Applied Basic Research Foundation under contract No.2019A1515011532
文摘Coralline algae(CA),a type of primary calcifying producer presented in coastal ecosystems,are considered one of the highly sensitive organisms to marine environmental change.However,experimental studies on coralline algae responses to elevated seawater temperature and reduced pH have documented either contradictory or opposite results.In this study,we analysed the growth and physiological responses of coralline algae Porolithon onkodes to the elevated temperature(30.8°C)and reduced pH(7.8).The aim of this analysis was to observe the direct and combined effects,while elucidating the growth and photosynthesis in this response.It was demonstrated that the algae thallus growth rate and photosynthesis under elevated temperature were depressed by 21.5%and 14.9%respectively.High pCO2 enhanced the growth and photosynthesis of the thallus at ambient temperature,while they were deceased when both temperature and pCO2 were elevated.CA is among the most sensitive organisms to ocean acidification(OA)because of their precipitate high Mg-calcite.We hypothesize that coralline algae could increase their calcification rate in order to counteract the effects of moderate acidification,but offset by the effect of elevated temperature.Accordingly,our results also support the conclusion that global warming(GW)is a stronger threat to algal performance than OA.Our findings are also proposed that coralline algae may be more resilient under OA than GW.
文摘This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemor-rhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.
