Algal Species Research Articles

Progress on the biological characteristics and physiological activities of fucoxanthin produced by marine microalgae

BackgroundFucoxanthin is a carotenoid found in seaweed. Its unique chemical structure gives it a variety of properties. Thus fucoxanthin have attracted the attention of companies and researchers.MethodsScientific papers were collected from the database. Duplicates and unavailable literature were excluded first. Then the remaining literature was categorized for referencing in the review.ResultsThis article contains a summary of the microalgae species producing fucoxanthin and their progress in breeding and cultivation modes. Additionally, the review summarized the progress of research on physiological activities and organized the experimental models used in these studies.ConclusionsThese present findings may provide information for the upstream production of fucoxanthin from algal species selection to process optimization. The analysis of the physiological activity results will help advance subsequent physiological and biochemical experiments. Furthermore, it intends to pique researchers’ enthusiasm for fucoxanthin and enrich related research data to accelerate the development of this natural product.

Tropical bloom-forming mesoalgae Cladophoropsis sp. and Laurencia sp.-responses to ammonium enrichment and a simulated heatwave.

Algal blooms are increasing worldwide, driven by elevated nutrient inputs. However, it is still unknown how tropical benthic algae will respond to heatwaves, which are expected to be more frequent under global warming. In the present study, a multifactorial experiment was carried out to investigate the potential synergistic effects of increased ammonium inputs (25 μM, control at 2.5 μM) and a heatwave (31°C, control at 25°C) on the growth and physiology (e.g., ammonium uptake, nutrient assimilation, photosynthetic performance, and pigment concentrations) of two bloom-forming algal species, Cladophoropsis sp. and Laurencia sp. Both algae positively responded to elevated ammonium concentrations with higher growth and chlorophyll a and lutein concentrations. Increased temperature was generally a less important driver, interacting with elevated ammonium by decreasing the algaes'%N content and N:P ratios. Interestingly, this stress response was not captured by the photosynthetic yield (Fv/Fm) nor by the carbon assimilation (%C), which increased for both algae at higher temperatures. The negative effects of higher temperature were, however, buffered by nutrient inputs, showing an antagonistic response in the combined treatment for the concentration of VAZ (violaxanthin, antheraxanthin, zeaxanthin) and thalli growth. Ammonium uptake was initially higher for Cladophoropsis sp. and increased for Laurencia sp. over experimental time, showing an acclimation capacity even in a short time interval. This experiment shows that both algae benefited from increased ammonium pulses and were able to overcome the otherwise detrimental stress of increasingly emerging temperature anomalies, which provide them a strong competitive advantage and might support their further expansions in tropical marine systems.

Replacing soybean meal with microalgae biomass in diets with contrasting carbohydrate profiles can reduce in vitro methane production and improve short-chain fatty acid production

The objective of this study was to evaluate the interaction of dietary carbohydrate profile and soybean meal (SBM) replacement with either Chlorella pyrenoidosa (CHL) or Spirulina platensis (SPI) on in vitro fermentation. This experiment was conducted as a randomized complete block design, with fermentation run (3 runs) considered as blocks. The treatments were arranged in a 2 × 5 factorial design, where the first factor was the carbohydrate profile, which was composed of diets containing 42.5% NDF and 26.8% starch (HF-LS) or 26.8% NDF and 40.6% starch (LF-HS) and the second factor was the protein source, in which a control diet (100% SBM), partial replacement of SBM with CHL (1/2 CHL) or SPI (1/2 SPI), or total replacement of SBM with CHL or SPI were used. All experimental diets were formulated to have 17% crude protein. The ruminal fluid was collected from 2 lactating Holstein cows, buffered with Van Soest medium at a ratio of 1:2 and added to serum bottles containing 0.50 g of the experimental diets. Bottles were incubated at 39°C for 24 and 48 h in triplicate; headspace pressure was measured, along with gas collection for methane (CH4) quantification at 0, 2, 4, 8, 16, 24, 36, and 48 h after incubation. The final medium was used to measure pH, ammonia, and volatile-fatty acid (VFA). After incubation, feed bags were recovered and used for estimation of degradability of DMD, NDF, and OMD. Statistical analysis was carried out using the MIXED procedure of SAS, with carbohydrate profile, protein source, assay, and its interactions as fixed effects, with run and bottle as random effects. Orthogonal contrasts were used to compare carbohydrate profile, algae species, carbohydrate profile × algae interaction, and linear and quadratic effects of SBM replacement with CHL or SPI. There was no interaction effect between carbohydrate profile and algae source. LF-HS improved gas production, degradability of nutrients, and VFA, mainly increasing the production of butyrate and propionate. When compared with CHL, SPI had a greater degradability of nutrients and branched VFA, along with reduction in total gas production and tended to reduce total CH4 yield. The replacement of SBM with algae linearly reduced the degradability of nutrients, along with a linear reduction in gas production. When replacement of SBM with only SPI was evaluated, SPI slightly reduced the degradability of nutrients; however, it promoted a linear reduction in CH4 yield, as well as reduction in CH4 yield by unit of degraded DM, NDF, and OM. In summary, there was no interaction of carbohydrate profile and protein source, which means that SBM replacement had a similar effect, regardless of dietary carbohydrate profile. Spirulina may be a more suitable algae source when compared with Chlorella due to the potential to reduce CH4.

Extraction of chlorophyll a from Tetradesmus obliquus—a method upgrade

Nowadays, the use of algae is prevalent for both industrial and agricultural purposes. The determination of chlorophyll (Chl) content is a commonly used method for estimating the phytoplankton abundance in different water bodies or biomass density of algal cultures. The aim of the present work is to optimise the efficiency of the Chl extraction from the green alga Tetradesmus obliquus using methanol as extracting solvent. The extraction efficiency was estimated by measuring the Chl a concentration of the extracts using fluorescence spectroscopy. To increase the extraction yield, glass fibre filters with algal cells on top were treated with 10% (v/v) formalin prior to the extraction. We found that this pretreatment significantly enhanced the extraction yield of Chl without its chemical decomposition. We also found that the optimal cell concentration for Chl determination ranged from 1.44 × 104 to 3.60 × 105 cells/mL and the extraction efficiency was lower when the cell density of the culture was out of this range. These results highlight the importance of the optimization of the pigment extraction for the studied algal species.

Predicting phosphorus accumulation and proposing conditions needed for an algal-based phosphorus uptake process

ABSTRACT Algal-based waste stabilisation ponds (WSP) are a common wastewater treatment system for small communities but have poor phosphorus removal. Under certain conditions algae in WSPs will perform ‘luxury uptake’ increasing their phosphorus content to over 3% (gP/gSS) by storing polyphosphate. For the first time in the literature this paper presents a systematic study which determines the conditions needed to maximise phosphorus accumulation within WSP biomass taking into account the interactions between key variables. The key variables of temperature, phosphorus concentration, light intensity, mixing intensity, organic load, and pH were evaluated in 40 batch factorial experiments using a WSP algal culture. All six variables examined had significant main effects or interactions on the phosphorus content of the biomass. These were incorporated into a regression equation which was successfully validated against independent data sets from the literature. The conditions required to maximise the phosphorus content of the biomass were predicted for both summer (high light and high temperature) and winter (low light and low temperature) scenarios. The required conditions were revealed to be high phosphorus concentration, high mixing intensity, no supplementary CO2 addition, and low organic load. Interestingly, these conditions were consistent for both summer and winter suggesting that year-round treatment is possible. Practical methods of achieving these conditions were proposed. While further work will be needed to evaluate the effect of growth and potential influence of algal species, the findings presented provide a vital step towards developing a new phosphorus removal treatment process based on an enhanced understanding of environmental biotechnology.

Abundance of Vibrio aestuarianus, water temperature, and stocking density are associated with summer mortality of Pacific oysters in suspended culture

High mortality rates of cultured Pacific oysters (Crassostrea gigas) during the summer months have regularly occurred on oyster farms in British Columbia, Canada over the last 10 years, but little is known about the microbial and environmental conditions that contribute to such mortality events. The objective of the study was to determine correlative factors associated with the onset of a summer mortality event in oysters (mean ± SD shell height: 14.2 ± 0.5 mm) grown in suspended culture at four stocking densities (150, 300, 450, 600 oysters tray−1) from May 11 to September 17, 2018. Variables examined included both biotic (oyster growth, mortality, reproductive development, and microbiome (approximately every week); Vibrio and harmful algal species abundance) and abiotic (temperature, salinity, turbidity, dissolved oxygen, pCO2, pH, and aragonite saturation) ones. Both the absolute abundance of V. aestuarianus and the relative abundance of Vibrio spp. increased with observed oyster mortality and declining health. Mortality was highest on August 12 and associated with a prior period of elevated temperatures (i.e., increasing temperatures from early July to early August) and increased oyster growth/reproductive development. At that time, systemic mixed microbial infections and necrotic gill tissue in histological cross sections were observed in 19% of oysters that appeared healthy macroscopically. Cumulative percent mortalities per tray ranged from 34 to 75%, the highest-density trays having significantly less mortality and smaller shell width, shell length, and gonad length than lower-density trays. This study demonstrates the significant impact of summer mortality on Pacific oysters and highlights the biotic (host growth, reproductive development, and microbiome composition as well as Vibrio spp. abundance) and abiotic (water temperature) factors associated with the observed mortality in this region.

Comparison of Nitrate Biosorption in the Aqueous Solutions by Three Algae Species (Hypnea charaoides Lamx, Cheatomorpha antennina Borgessen, and Champia Kotschyana Harvey) and Application of Selected Alga in a Channel

Comparison of Nitrate Biosorption in the Aqueous Solutions by Three Algae Species (Hypnea charaoides Lamx, Cheatomorpha antennina Borgessen, and Champia Kotschyana Harvey) and Application of Selected Alga in a Channel

Critical factors driving spatiotemporal variability in the phytoplankton community structure of the coral habitat in Dongshan Bay, China.

This study investigated the spatiotemporal distribution of the phytoplankton in the coral habitat of Dongshan Bay (China), along with critical factors affecting the distribution, during June, August, and December 2022. Phytoplankton abundance in Dongshan Bay exhibited considerably temporal variation, peaking in June 2022, gradually decreasing thereafter, and reaching its lowest point in December 2022. The abundance of bottom-layer phytoplankton consistently exceeded that of the surface layer throughout all seasons. The average phytoplankton abundance in the coral habitat of Dongshan Bay was lower than that in non-coral habitat areas. Fluctuations in the Zhangjiang River and coastal upwelling influenced the diversity and community structure of the phytoplankton. Critical factors causing spatiotemporal variability in phytoplankton community structure included nutrient concentrations and seawater temperature. Nutrients played key roles in influencing various phytoplankton groups. Dominant diatom species, such as Thalassionema nitzschioides and Thalassiosira diporocyclus, were positively correlated with ammonia nitrogen, seawater salinity, coral cover, and the number of coral species present. In winter, Calanus sinicus exhibited a negative correlation with harmful algal bloom species. Additionally, it was found that both in the coral habitat and surrounding open sea, currents, nutrients, and zooplankton may play crucial roles in determining the spatiotemporal variability in the phytoplankton community structure.

Cryopreservation of the collector urchin embryo, Tripneustes gratilla

The collector urchin, Tripneustes gratilla, is an ecologically important member of the grazing community of Hawai'i's coral reefs. Beyond its ability to maintain balance between native seaweeds and corals, T. gratilla has also been used as a food source and a biocontrol agent against alien invasive algae species. Due to overexploitation, habitat degradation, and other stressors, their populations face local extirpation. However, artificial reproductive techniques, such as cryopreservation, could provide more consistent seedstock throughout the year to supplement aquaculture efforts. Although the sperm and larvae of temperate urchins have been successfully cryopreserved, tropical urchins living on coral reefs have not. Here, we investigated the urchin embryos' tolerance to various cryoprotectants and cooling rates to develop a cryopreservation protocol for T. gratilla. We found that using 1 M Me2SO with a cooling rate of 9.7 °C/min on gastrula stage embryos produced the best results with survival rates of up to 85.5% and up to 50.8% maturation to the 4-arm echinopluteus stage, assessed three days after thawing. Continued research could see cryopreservation added to the repertoire of artificial reproductive techniques for T. gratilla, thereby assisting in the preservation of this ecologically important urchin, all while augmenting aquaculture efforts that contribute to coral reef restoration.

Cystoseira compressa and Ericaria mediterranea: Effective Bioindicators for Heavy- and Semi-Metal Monitoring in Marine Environments with Rocky Substrates.

Marine environmental monitoring is essential to ensure that heavy-metal (HM) concentrations remain within safe limits. Most seawater analyses currently consider sediment or water samples, but this approach does not apply to rocky substrates, where water samples can only indicate immediate contamination. We used two common Mediterranean algae species, Cystoseira compressa and Ericaria mediterranea, as bioindicators living in the intertidal zone on rocky substrates along the seacoast. HM concentrations were assessed over a one-year period in the perennial base crust and in the seasonal frond, considering marine sites characterised by different contamination risks. Both algae showed that HMs accumulate mainly in the perennial base rather than in the seasonal frond. Furthermore, the algae species always showed a different order of bioaccumulation factors: Cd > Ni > Pb > Cr > Cu > Mn > Zn for the frond and Pb > Cr > Ni > Cd > Mn > Cu > Zn for the base. Our study shows that C. compressa and E. mediterranea accumulate HM consistently with the types of sites analysed and differentially with respect to the part of the thallus. These results demonstrate that these algae can be effectively used as reliable bioindicators to assess the presence of HM in marine environments with rocky substrates, providing both short- and long-term monitoring.

Investigation of alkyl, aryl, and chlorinated OPFRs in sediments from estuarine systems: Seasonal variation, spatial distribution and ecological risks assessment

Estuaries in South Africa are very important for biodiversity conservation and serve as focal points for leisure and tourism activities. The organophosphate flame retardants (OPFRs) levels in these aquatic systems haven't been documented in any studies as of yet. Due to the negative effects of persistent organic pollutants in South African estuaries, we examined the occurrence of eight OPFRs in sediments of two estuaries by studying their spatiotemporal distribution, season variation, and ecological risks. The Sundays Estuary (SDE), a semi-urbanized agricultural surrounding system, recorded an ∑8OPFR concentration in sediments that ranged from 0.71 to 22.5 ng/g dw, whereas Swartkops Estuary, a largely urbanized system, recorded a concentration that ranged from 0.61 to 119 ng/g dw. Alkyl-OPFRs were the prevalent homologue in both estuaries compared to the chlorinated and aryl groups. While TBP, TCPP, and TCrP were the most abundant compounds among the homologue groups. There was no distinct seasonal trend of ∑8OPFR concentration in either estuary, with summer and autumn seasons recording the highest concentrations in SDE and SWE, respectively. Ecological risks in the majority of the study sites for the detected compounds were at low (RQ < 0.1) and medium levels (0.1 ≤ RQ < 1) for certain species of fish, Daphnia magna and algae. However, the cumulative RQs for all the compounds had ∑RQs ≥1 for most sites in both estuaries, indicating that these organisms, if present in both estuaries, may be exposed to potential ecological concerns due to accumulated OPFR chemicals. The scope of future studies should be broadened to include research areas that are not only focus on the bioaccumulation patterns of these compounds but also find sustainable ways to reduce them from these estuarine environments.

Terrestrial algae: pioneer organisms of carbonate rock solutional weathering in South China karst.

The formation of soil in karst ecosystem has always been a scientific problem of great concern to human beings. Algae can grow on the exposed and non-nutrition carbonate surface, inducing and accelerating weathering of rock substrates, thus promoting soil formation. Yet the actual contribution of algae to solutional weathering intensity remains unclear. In this study, we performed weathering simulation experiment on two algae species (Klebsormidium dissectum (F.Gay) H.Ettl & G.Gärtner and Chlorella vulgaris Beijerinck), which were screened from carbonated rock surfaces from a typical karst region in South China. The results showed: (1) both algae have solutional weathering effect on carbonate rock, (2) there is no difference of solutional intensity observed, yet the solutional modes are different, suggesting different ecological adaptative strategies, (3) algae on carbonate rocks have higher carbonic anhydrase activity (CAA) and secrete more extracellular polysaccharide (EPS), accelerating rock weathering. (4) The absolute dissolution amount of carbonate rock with algae participation is 3 times of that of without algae. These results indicate the significant impact of terrestrial algae on carbonate rock solutional weathering and provides quantitative evidence that terrestrial algae are pioneer species. It also contributes to our further understanding of soil formation in karst ecosystems in South China.

Transcriptome analysis of the bloom-forming dinoflagellate Prorocentrum donghaiense exposed to Ginkgo biloba leaf extract, with an emphasis on photosynthesis.

Ginkgo biloba leaf extract (GBE) can effectively treat bloom-forming freshwater algae. However, there is limited information about the underlying suppression mechanism of the marine bloom-forming Prorocentrum donghaiense-the most dominant algal bloom species in the East China Sea. We investigated the effect of GBE on P. donghaiense in terms of its response to photosynthesis at the molecular/omic level. In total, 93,743 unigenes were annotated using six functional databases. Furthermore, 67,203 differentially expressed genes (DEGs) were identified in algae treated with 1.8 g∙L-1 GBE. Among these DEGs, we identified the genes involved in photosynthesis. PsbA, PsbB and PsbD in photosystem II, PsaA in photosystem I, and PetB and PetD in the cytochrome b6/f complex were downregulated. Other related genes, such as PsaC, PsaE, and PsaF in photosystem I; PetA in the cytochrome b6/f complex; and atpA, atpD, atpH, atpG, and atpE in the F-type H+-ATPase were upregulated. These results suggest that the structure and activity of the complexes were destroyed by GBE, thereby inhibiting the electron flow between the primary and secondary quinone electron acceptors, primary quinone electron acceptor, and oxygen-evolving complex in the PSII complex, and interrupting the electron flow between PSII and PSI, ultimately leading to a decline in algal cell photosynthesis. These findings provide a basis for understanding the molecular mechanisms underlying P. donghaiense exposure to GBE and a theoretical basis for the prevention and control of harmful algal blooms.

Catalytic pyrolysis of lignocellulosic and algal biomass using NaOH as a catalyst

AbstractIn this work, the pyrolysis of barley straw (BS) and brown algae (BA) mixed with NaOH as a catalyst was compared. Four different catalyst‐to‐biomass mass ratios (i.e., 6:100, 8:100, 10:100, and 12:100) and five pyrolysis heating rates were examined. The kinetic parameters (e.g., the activation energy and pre‐exponential factor) were evaluated using the Friedman method and kinetic models. For noncatalytic pyrolysis, the average activation energies for BS and BA samples were 139.71 and 183.19 kJ mol−1, respectively. However, the addition of catalyst generally increased the average activation energy of BS samples but decreased that of BA samples. The enthalpy change and Gibbs free energy change revealed that both catalytic and noncatalytic pyrolysis processes were nonspontaneous and endothermic, and the inclusion of catalyst increased the average entropy change of the BS samples but decreased that of the BA samples. Char and biochar yields after pyrolysis were also analyzed quantitatively. These observations provide insight into the differences in catalytic pyrolysis between lignocellulosic and algal biomass species.

INVESTIGATION OF ANTI-CANCER PROPERTIES OF COMPONENTS EXTRACTED FROM POLAR MICROALGAE

Cancer is irregular cell division that can be inherited or occur under environmental factors. Due to mutations in DNA, damage occurs in the cell division mechanism and cells divide uncontrollably [1]. Natural compounds are widely preferred in the treatment of cancer, which is the second leading cause of death. Microalgae have a great role in cancer treatment because they have rich bioactive components and high efficiency [2,3]. Microalgal biomass has many uses in a wide variety of fields, thanks to its potential for rich bioactive compounds and its ability to be used as a sustainable bio- product source. It provides benefits [3]. Therefore, research on microalgae is increasing as biotechnology advances. Bioactive compounds derived from microalgae are a natural, safe, and renewable resource and are research subjects for nutraceutical and pharmaceutical applications due to their potential therapeutic properties [4]. These bio-actives also have drug delivery, wound healing, and antioxidant, anti-oxidant, anti-inflammatory, neuroprotective, and anti-carcinogenic properties [5]. There is a lot of research done on microalgae. And these studies continue to increase. This study aims to determine the content of microalgae obtained from the polar regions and to investigate their anti-cancer properties, thus adding new information to the knowledge in the literature. Microalgae has been proven to have anti-cancer properties due to its bioactive properties. While microalgae exhibit natural killer cell activity against cancer cells, they also activate the immune system. There are no studies in the literature regarding the anticancer effects of polar microalgae. This project aims to extract the contents of various polar algae species and analyze these contents, then examine their anticancer properties through cancer lines and offer an alternative way to treat this disease. After investigating the properties of the produced polar microalgae, the substance obtained through extraction will be applied to cancer cells to study its anticancer activity. The primary field contribution of this project is to examine the anti-cancer activity of polar microalgae in various types of cancer and to pave the way for the production of polar algae-based biotechnological drugs. Therefore, one of our main goals is to fill the gaps in the literature and pioneer other studies. Keywords: Polar Microalgae, Biotechnology, Neuroprotective, Anti-inflammatory, Anti-carcinogenic.

CLAW: An automated Snakemake workflow for the assembly of chloroplast genomes from long-read data.

Chloroplasts are photosynthetic organelles in algal and plant cells that contain their own genome. Chloroplast genomes are commonly used in evolutionary studies and taxonomic identification and are increasingly becoming a target for crop improvement studies. As DNA sequencing becomes more affordable, researchers are collecting vast swathes of high-quality whole-genome sequence data from laboratory and field settings alike. Whole tissue read libraries sequenced with the primary goal of understanding the nuclear genome will inadvertently contain many reads derived from the chloroplast genome. These whole-genome, whole-tissue read libraries can additionally be used to assemble chloroplast genomes with little to no extra cost. While several tools exist that make use of short-read second generation and third-generation long-read sequencing data for chloroplast genome assembly, these tools may have complex installation steps, inadequate error reporting, poor expandability, and/or lack scalability. Here, we present CLAW (Chloroplast Long-read Assembly Workflow), an easy to install, customise, and use Snakemake tool to assemble chloroplast genomes from chloroplast long-reads found in whole-genome read libraries (https://github.com/aaronphillips7493/CLAW). Using 19 publicly available reference chloroplast genome assemblies and long-read libraries from algal, monocot and eudicot species, we show that CLAW can rapidly produce chloroplast genome assemblies with high similarity to the reference assemblies. CLAW was designed such that users have complete control over parameterisation, allowing individuals to optimise CLAW to their specific use cases. We expect that CLAW will provide researchers (with varying levels of bioinformatics expertise) with an additional resource useful for contributing to the growing number of publicly available chloroplast genome assemblies.

Occurrence of Trace-Level Antibiotics in the Msunduzi River: An Investigation into South African Environmental Pollution.

The presence of antibiotics in the environmental matrix has raised concerns regarding their risk to the aquatic ecosystem and human health. Surface water, such as rivers, plays a pivotal role in the dispersion and transport of antibiotic residues. The effective monitoring of these contaminants requires investigating their sources and distribution. While numerous studies have been conducted globally to comprehend the emergence, prevalence, and management of these substances, the investigation of therapeutic antibiotics in Africa remains notably underrepresented. Consequently, data regarding these emerging contaminants in the African aquatic environments are scarce, warranting further exploration. This study aims to investigate the occurrence of four specific therapeutic antibiotics-tetracycline, sulfathiazole, penicillin g, and erythromycin-across different seasons in the Msunduzi River, Eastern South Africa. Three sampling campaigns were conducted during spring, autumn, and winter to assess the presence of these antibiotics in the river. Analyte extraction from water samples was achieved through solid-phase extraction, and quantification was performed using liquid chromatography-mass spectrometry. The findings reveal notable concentrations of these antibiotics in the river at locations closest to a wastewater treatment discharge point. Among the antibiotics studied, tetracycline (158.42-1290.43 ng/L) and sulfathiazole (112.68-1151.25 ng/L) were the most frequently detected compounds across the majority of the sampling sites and tributaries of the river. Erythromycin was less frequently detected in the surface water and wastewater effluent but was found to be a risk to algal species within the river. While wastewater effluents represent a significant source of antibiotic contamination in the river, tributaries from industrial areas and informal settlements were identified as continuous sources of antibiotic pollution. Thus, it is imperative to implement appropriate monitoring protocols to mitigate antibiotic pollution in the aquatic environment.

UJI ORGANOLEPTIK dan DAYA HAMBAT EKSTRAK ALGA COKLAT (Sargassum Polycystum) TERHADAP JAMUR Candida albicans

Background: Candida albicans, a fungal normal flora that causes Denture stomatitis. Sargassum polycystum is a brown algae species (Phaeophyceae) which grows almost along the coasts of Indonesia islands, known to have antifungal and antibacterial activities. Purpose: To determine the inhibition of brown algae extract (Sargassum polycystum)’s on the growth of Candida albicans and determine whether Sargassum polycystum extract works as denture cleanser material through organoleptic test. Methods: The sample was Candida albicans equal to 0,5 McFarland (108 CFU/ml). The experiment groups comprises negative control group (K-) with 1% DMSO, positive control group (K+) with 0,2% chlorhexidine gluconate, and treatment groups 1-4 (P1;P2;P3;P4) consecutively with 2,5%; 5%; 10%; 20% Sargassum polycystum ethanol extract macerated for 15 minutes in 5 (Ø 6mm) paper discs. SDA medium was incubated for 24 hours and the visible transparent zone was calculated. Organoleptic test was conducted by asking 10 panelists about the observation on color, smell, and homogeneity level of brown algae extract (Sargassum polycystum) with the concentrations of 2,5%; 5%; 10%; and 20%. The experiment result was analyzed with the Kruskal-Wallis test and the Mann-Whitney test. Results: Experiment material’s inhibitory effect was undetectable as Sargassum polycystum ethanol extract against 1% DMSO solvent’s solubility was not homogeneous. The organoleptic test result showed that color, smell, and homogeneity level of brown algae extract (Sargassum polycystum) was not compliant with antiseptic standards. Conclusion: No inhibitory effect in brown algae extract (Sargassum polycystum) as the organoleptic test proved the antiseptic standards were not fulfilled.

The structure of fucoidan by linkage analysis tailored for fucose in four algae species: Fucus serratus, Fucus evanescens, Fucus vesiculosus and Laminaria hyperborea

Linkage analysis after permethylation allows the determination of the linkage patterns between monomers in complex polysaccharides. Fucoidan is a heteropolysaccharide found in algae that is derivatised with sulphate groups. We recently improved the methodology for the linkage analysis in fucoidan with a focus on fucose. Critical improvements were done in reaction conditions, reagents, isolation of the polymer, and the optimisation of the chromatographic separation. In this study, we employ this enhanced method to the fucoidans of Fucus serratus (FSR), Fucus evanescens (FE), Fucus vesiculosus (FV) and Laminaria hyperborea (LH). This shed new light on the diversity found in fucoidans and the capabilities of the method. The fucoidans were found to be very varied, with a degree of sulphation from 0.26 to 0.73. The sulphate content as determined by the linkage analysis agreed well with the barium sulphate method, which tended to underestimate higher sulphate contents. Sulphate groups were present in positions 3 and 4, 2 and 4, and exclusively 2, but never in all three possible positions. Glycosidic linkages were found in all possible positions, with 3 as the more common one. Branching occurs in all linkage-combinations, and only F. vesiculosus featured a sulphate substituent at a branching point.

Degradation of dyes using reactive species of atmospheric pressure dielectric barrier discharge formed by a pencil plasma jet

The dye degradation efficacy of the cold plasma pencil jet is presented in the present investigation. Dye degradation studies were performed using air plasma, six different types of selected dyes (erythrosine, metanil yellow, sudan I, crystal violet, rhodamine B, and Indigo). The degradation of dyes is analyzed using UV visible spectroscopy, total organic carbon, and chemical oxygen demand. The results showed complete degradation of all types of dyes in UV visible analysis with minimum time for indigo (3 min) and maximum time for erythrosine (45 min). Moreover, erythrosine (k = 1.08 mg l−1 min−1), sudan I (k = 3.46 mg l−1 min−1), rhodamine B (k = 3.955 mg l−1 min−1), and Indigo (k = 18.915 mg l−1 min−1) follows approximate zeroth-order degradation kinetic, and metanil yellow (k = 0.094 min−1) and crystal violet (k = 0.25 min−1), closer to first-order degradation kinetics. Additionally, a substantial enhancement in mineralization and reduction in chemical oxygen demand of all the dyes occurs after plasma treatment. In this study, air plasma is produced in the cylindrical coaxial dielectric barrier discharge configuration. Electrical characterization of plasma is performed and the plasma species are identified using optical emission spectroscopy. The toxicity of plasma degraded dyes solutions toward freshwater algae species (Chlorella Sorokiniana and Chlorella Pyrenoidosa) are significantly low compared to virgin dyes solutions. The study reveals that pencil plasma jet substantially degrades dyes as well as converts the dyes solutions non-toxic.