Cyanobacterial Research Articles

Prediction of Cyanobacteria Using Decision Tree Algorithm and Sensor Monitoring Data

A multifunctional weir was built on the Nakdong River. As a result, changes in the river environment occurred, such as an increase in river residence time. This causes changes in water quality, including green algae. The occurrence of green algae in the Nakdong River, which is used as a water source, also affects the purified water supply system. In particular, the mass spread of harmful algae is becoming a major problem as the frequency and intensity of occurrences increase. There are various causes of blue-green algae. We would like to examine the relationships between causal factors through a decision tree-based algorithm. Additionally, we would like to predict the occurrence of green algae based on the combination of these factors. For prediction, we studied categorical prediction based on the blue-green algae warning system used in Korea. RF, Catboost and XGBoost algorithms were used. Optimal hyperparameters were applied. We compared the prediction performance of each algorithm. In addition, the predictability of using sensor-based data was reviewed for a preemptive response to the occurrence of blue-green algae. By applying sensor-based data, the accuracy was over 80%. Prediction accuracy by category was also over 75%. It is believed that real-time prediction is possible through sensor-based factors. The optimal forecast period was analyzed to determine whether a preemptive response was possible and the possibility of improvement was examined through the segmentation of prediction categories. When there were three categories, 79% of predictions were possible by the 21st day. In seven categories, 75% prediction was possible up to 14 days. In this study, sensor-based categorical predictability was derived. In addition, real-time response and proactive response were determined. Such sensor-based algae prediction research is considered important for future blue-green algae management and river management.

Blue-green Algae: Diversity and Community Structure in Rice fields of Saran, Bihar

This study aimed to characterize the abundance of BGA in various rice ecologies of Saran (Bihar) with isolate identification and diversity indices in relation to species wise distribution. These investigations were under taken during cultivation cycle of rice in the years 2020 and 2021. The density and frequency of various BGA species was evaluated with standard methods. The study revealed occurrence of particular BGA with temporal and spatial variation, whereas abundance of BGA drastically reduced in preceding period of the study possibly due to effect of environmental constraints in the Saran district of Bihar.

Mechanism analysis of a novel natural cationic modified dextran flocculant and its application in the treatment of blue algal blooms

Blue algae, a type of harmful microalgae, are responsible for causing harmful algal blooms that result in severe environmental issues. To address this problem, a biopolysaccharide-based flocculant was developed for treating blue algae blooms. This flocculant was created by modifying high molecular weight dextran using the natural cationic monomer betaine (Dex-Bet), making it environmentally friendly. Various techniques were used to characterize the prepared Dex-Bet flocculant, including infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The effectiveness of the Dex-Bet flocculant was evaluated using kaolin-simulated wastewater. The results showed that the treated supernatant had a transmittance of up to 98.25 %. Zeta potential analysis revealed that the main mechanisms of flocculation were charge neutralization, charge patching, and adsorption bridging. The application of Dex-Bet in treating blue-green algae resulted in a maximum removal rate of 98.2 %. This study provides a potential flocculant for blue algae bloom treatment.

Preparation of Iron-improved Blue Algae Biochar and Its Co-adsorption Mechanism for Phosphorus in Surface Water

To alleviate the problems of eutrophication and blue algae accumulation in water, biochar was prepared from blue algae dehydrated using polymerized ferrous sulfate(PFS) to absorb phosphate in water, and the biochar was activated using steam to adjust the pore structure. The preparation conditions of blue algae biochar were optimized using the response surface method. The optimal results were as follows:the dosage of PFS was 458 mg·L-1, the carbonization temperature was 433℃, and the mass ratio of biochar precursor to steam was 1:11. Biochar without PFS(F0H11-433) and biochar with PFS(F458H11-433) were characterized using X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FTIR), zeta potential, and Raman spectra(Raman) were used to study whether blue algae biochar and PFS had a synergic effect on phosphate removal. The results showed that:compared with F0H11-433, iron oxide appeared on the surface, the zero point of charge(pHpzc) increased from 4.41 to 6.19, and the disorder and defect degree of biochar was increased in F458H11-433. The pseudo-second-order model and Langmuir model were suitable for describing the adsorption process of F458H11-433, and the saturated adsorption capacity was 31.97 mg·g-1. F458H11-433 had excellent phosphorus removal efficiency in actual lake water, and the residual phosphate content of effluent was less than 0.025 mg·L-1. In the presence of several common anions, it still showed excellent selective adsorption. After five cycles, the phosphate removal of F458H11-433 still reached 75.78%, indicating that F458H11-433 had the characteristic of being renewable. Combined with the material characterization results before and after adsorption, the phosphorus removal mechanism of F458H11-433 mainly involved electrostatic attraction and ligand exchange.

RETRACTED] Short-term dynamics and growth parameters of cyanobacteria and microcystins in freshwater from the Sidi-Yacoub dam, North-east of Algeria

Abstract. Boudjellab ZE, Ghannam M, Chaib N, Chekroud Z. 2023. Short-term dynamics and growth parameters of cyanobacteria and microcystins in freshwater from the Sidi-Yacoub dam, North-east of Algeria. Biodiversitas 24: 5598-5609. The study aimed to establish the inventory of the blue-green algae species and monitoring the monthly evolution of their specific and total cell biovolume in Sidi-Yacoub dam, located northwest of Algeria from February 2021 to January 2022. At the same time, a monthly assessment of particulate and dissolved microcystin concentrations, chlorophyll pigment concentrations, and certain physicochemical parameters has been conducted. Eight species were listed, cited in descending order of their average relative abundance are: Microcystis aeruginosa (54.05%); Oscillatoria limosa (23.68%); Merismopedia sp. (8.34%); Anabaena cylindrica (3.53%); Aphanizomenon sp. (2.41%); Microcystis botrys (2.66%); Woronichinia sp. (2.95%) and Chroococcus limneticus (2.34%). The maximum value of the total biovolume, was recorded during December (27.4x106 µm3.L-1). The maximum concentration of chlorophyll-a and phycocyanin were respectively 55.26 and 47.46 µg L-1, recorded in September 2021. The microcystins detected where mainly in the cell-bound form, reaching a maximum concentration of 0.134 µg L-1 in October 2021. The principal component analysis shows a strong positive correlation between the total monthly cell biovolume, particulate microcystin (MCP) and some physicochemical parameters. M. aeruginosa has been identified as the primary producer of microcystins found in the eutrophic waters of the dam, with these microcystins being predominantly maintained in an intracellular form throughout most of the year.

Preparation of high-yield carbon quantum dots and paper-based sensors from biomass wastes by mechano-chemical method

The synthesis of carbon quantum dots (CQDs) from biomass through a "bottom-up" method has attracted a great deal of interest because of its outstanding environmental and economic advantages. However, the yield of biomass-based CQDs is still low due to the high polymerization of biochar. In this study, we propose a new approach for harvesting high-yield biomass-based CQDs by integrating mechanochemistry and strong chemical oxidation. Ball milling can reduce the particle size and resistance of biochar and increase the contents of CC, while the powerful oxidant HOO- produced by alkaline hydrogen peroxide can break CC to generate biomass-based CQDs. Using this two-step process, the yields of biomass-based CQDs reached 57.75% for blue-green algae, 65.8% for straw, 47.9% for corn protein meal, and 45.35% for Typha angustifolia. Based on the excellent sensitivity and selectivity for Fe3+ of biomass-based CQDs, CQDs paper-based sensors were prepared for expedient and precise detection of Fe3+ in surface water, wastewater treatment plant effluent, and tap water. When the Fe3+ content is between 0 and 60 μM, the R2 of Fe3+ detection by blue-green algae CQDs can reach 0.9956. This work provides a new and reliable method for the large-scale preparation of biomass-based CQDs and expands their environmental applications.

Anticancer potential of blue-green algae extract (Spirulina plantesis) and Curcumin nanoparticles on Ehrlich ascites carcinoma–bearing mice

Anticancer potential of blue-green algae extract (Spirulina plantesis) and Curcumin nanoparticles on Ehrlich ascites carcinoma–bearing mice

Microcystin-LR-induced autophagy via miR-282–5p/PIK3R1 pathway in Eriocheir sinensis hepatopancreas

With the intensifying climate warming, blue-green algae blooms have become more frequent and severe, releasing environmental hazards such as microcystin that pose potential threats to human and animal health. Autophagy has been shown to play a crucial role in regulating immune responses induced by environmental hazards, enabling cells to adapt to stress and protect against damage. Although microcystin-LR (MC-LR) has been identified to affect autophagy in mammalian, its impact on aquatic animals has been poorly studied. To investigate the toxicological effects of MC-LR in aquatic ecosystems, we constructed a microRNA profile of acute MC-LR stress in the hepatopancreas of the Chinese mitten crab. Interestingly, we found the MC-LR exposure activated autophagy in the hepatopancreas based on the following evidence. Specifically, mRNA expression level of ATG7, Beclin1 and Gabarap was significantly up-regulated, autophagy regulatory pathways were significantly enriched, and numerous autolysosomes and autophagosomes were observed. Additionally, we found that miR-282–5p and its target gene PIK3R1 played important regulatory roles in autophagy by in vivo and in vitro experiments. Overexpression of miR-282–5p mimicked MC-LR-induced autophagy by inhibiting PIK3R1 expression, while miR-282–5p silencing inhibited autophagy by promoting PIK3R1 expression. Altogether, our findings suggest that MC-LR increases miR-282–5p, which then targets inhibition of PIK3R1 to stimulate autophagy. This study focused on the stress response regulatory mechanisms of juvenile crabs to toxic pollutants in water, offering a potential target for alleviating the toxicity of MC-LR. These findings lay a foundation for reducing the toxicity of MC-LR and environmental hazards in organisms.

Anti-Growth, Antioxidant, and Hepatoprotective Properties of Spirulina Platensis Extract

Spirulina platensis (S. platensis), a filamentous cyanobacterium often referred to as a blue-green alga, is recognized for its antioxidant, immunomodulatory, and anti-inflammatory properties. This study aimed to examine the growth-suppressing effects of S. platensis ethanolic extract on PANC-1 and MIA PaCa-2 human pancreatic cancer cells. Additionally, the in vivo hepatoprotective and antioxidant properties of S. platensis were explored. The ethanolic extract of S. platensis was lyophilized and dissolved in DMSO. Subsequently, PANC-1 and MIA PaCa-2 cell lines were exposed to concentrations ranging from 0.1-1000 µg/ml. Cell viability was assessed using sulforhodamine B viability assay. For in vivo evaluation of hepatoprotective and antioxidant properties, S. platensis was administered by gavage at a dose of 50 mg/kg/day over a four-week period. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured in the heart and liver of rats. The control group that received S. platensis showed a significant elevation in the activity of SOD and GSH-Px enzymes in the heart and liver tissues. There was a significant reduction in the ALT and AST enzyme levels. The extract notably hindered the growth of both the examined cell lines. Future research can focus on studying the effects of S. platensis extracts in conjunction with various chemotherapeutic agents or its effect on different cancer cell lines to better understand its anti-growth attributes.

Effect of methanol solvent concentration on the extraction of bioactive compounds using ultrasonic-assisted extraction (UAE) from Spirulina platensis

Spirulina platensis is a blue-green algae that contains bioactive compounds as a source of antioxidants. Methanol is a polar solvent; it has similarities to the content of the bioactive compound Spirulina platensis, which is polar. This study aimed to determine the effect of different concentrations of methanol solvent (50%, 70%, 96%) using UAE on the content of bioactive antioxidant compounds from Spirulina platensis. The parameters observed were yield, antioxidant activity, phytochemical screening, and GC-MS. The results showed that the difference in the concentration of methanol solvent using UAE significantly affected the antioxidant activity of the Spirulina platensis extract. The highest antioxidant activity was found in Spirulina platensis extract with 50% methanol solvent concentration using UAE with an average inhibition value of 91.81%. The yield value from the Spirulina platensis extract with a 50% methanol concentration was 9.3%. The qualitative phytochemical screening test carried out on Spirulina platensis extract with 50% methanol solvent using UAE showed positive results for flavonoid compounds, alkaloids, tannins and phenols. GC-MS analysis on Spirulina platensis with 50% methanol as a solvent using UAE resulted in 5 types of the most dominant compounds, pentadecanoic acid, 9-Ooctadecenoic acid, hexadecanoic acid, hexadecanal, and 1- nonadecene.

Biocatalyst Potential Candidate for Human Welfare

Biocatalysis is known since man knew about brewing which was known since 6000 years. Enzymes from microbial sources were then employed in industries such as production of beer, wine, cheese etc. Nearly 100 years down the lane biocatalysts have been used for chemical transformations. In order to access the repertoire of pharmacological and agrochemicals with high chemoselectivity, regioselectivity, and enantioselectivity, biocatalysis integrates microbiologists, enzymologists, and organic chemists. The usual chemical approach is challenged by the saturation of carbon-carbon double bonds by biocatalysts, as they avoid the usage of organocatalysts or precious metals (in combination with chiral ligands and molecular hydrogen). Since past 30 years they have been used for the synthesis of valuable fine chemicals especially pharmaceuticals. This review gives a brief about microbial biocatalyst including the photosynthetic blue-green algae.

Understanding the dynamics of Microcystis bloom: Unraveling the influence of suspended solids through proteomics and metabolomics approaches

Light plays a crucial role in blue-green algae bloom formation in lakes, while suspended solids (SS) influence underwater light intensity. This study investigates the integrated effects of SS concentrations (0–125 mg/L) on Microcystis aeruginosa in natural conditions. Results show that SS inhibits cyanobacterial growth above 100 mg/L, with 25–75 mg/L favoring bloom formation. Proteomic analysis reveals differential protein involvement in ribosomes, ABC transporters, cofactor biosynthesis, and photosynthesis pathways at 25 mg/L SS. SS concentrations within the range of 25–125 mg/L significantly impact the metabolism of algal cells, resulting in an increase in lipid metabolism and a decrease in the biosynthesis of secondary metabolites in cyanobacteria. These coordinated biochemical adaptations play a vital role in the survival of cyanobacteria in challenging environmental conditions. Employing a multi-omics approach enhances our comprehension of how M. aeruginosa responds to SS and the underlying molecular mechanisms, thereby contributing to our understanding of cyanobacteria outbreaks. This underscores the importance of monitoring SS concentrations in lakes as a proactive measure for future control of cyanobacteria dominance.

Effect of Methanol Extracts of Arthrospira platensis on Survival and Increased Disease Resistance in Litopenaeus vannamei against Vibriosis

Vibriosis is a common bacterial infection in shrimp that causes mortality in hatcheries and farms. Various steps have been initiated to increase the resistance against bacterial pathogens and decrease the mortality rate through improved culture conditions and feed. Arthrospira platensis (Spirulina), a blue-green alga, is a good source of protein and other nutrients and helps to improve digestion. The effects of the methanol extract of A. platensis on the survival rate and resistance against vibriosis were studied. The minimum inhibitory concentration of the extract for Vibrio species and in vivo antibacterial screening were investigated using Litopenaeus vannamei. Vibrio alginolyticus was inhibited with 2000 µg mL-1 extract and the other two species were inhibited by 1500 µg mL-1 extract. Furthermore, the mortality rate and antioxidant enzyme levels of shrimps injected with pathogens reduced and increased after treatment with the methanol extract, respectively. The survival rate of V. parahaemolyticus and V. harveyi-challenged shrimps were 33.3% and 50%, respectively, after 168 h. The survival rate of V. alginolyticus-infected shrimp reduced (16.6%) 168 h after injection. All surviving shrimp developed resistance to Vibrio pathogens. This study indicated that the bioactive compounds in A. platensis could not only effectively prevent bacterial infection, but also serve as eco-friendly and cost-effective immune stimulants.

Purification and characterization of thioredoxin reductase enzyme from commercial Spirulina platensis tablets by affinity chromatography and investigation of the effects of some chemicals and drugs on enzyme activity.

Thioredoxin reductase (TrxR, enzyme code [E.C.] 1.6.4.5) is a widely distributed flavoenzyme that catalyzes nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reduction of thioredoxin and many other physiologically important substrates. Spirulina platensis is a blue-green algae that is often used as a dietary supplement. S. platensis is rich in protein, lipid, polysaccharide, pigment, carotenoid, enzyme, vitamins and many other chemicals and exhibits a variety of pharmacological functions. In the present study, a simple and efficient method to purify TrxR from S. platensis tablets is reported. The extractions were carried out using two different methods: heat denaturation and 2',5'-adenosine diphosphate Sepharose 4B affinity chromatography. The enzyme was purified by 415.04-fold over the crude extract, with a 19% yield, and specific activity of 0.7640U/mg protein. Optimum pH, temperature and ionic strength of the enzyme activity, as well as the Michaelis constant (Km ) and maximum velocity of enzyme (Vmax ) values for NADPH and 5,5'-dithiobis(2-nitrobenzoic acid) were determined. Tested metal ions, vitamins, and drugs showed inhibition effects, except Se4+ ion, cefazolin sodium, teicoplanin, and tobramycin that increased the enzyme activity in vitro. Ag+ , Cu2+ , Mg2+ , Ni2+ , Pb2+ , Zn2+ , Al3+ , Cr3+ , Fe3+ , and V4+ ions; vitamin B3 , vitamin B6 , vitamin C, and vitamin U and aciclovir, azithromycin, benzyladenine, ceftriaxone sodium, clarithromycin, diclofenac, gibberellic acid, glurenorm, indole-3-butyric acid, ketorolac, metformin, mupirocin, mupirocin calcium, paracetamol, and tenofovir had inhibitory effects on TrxR. Ag+ exhibited stronger inhibition than 1-chloro-2,4-dinitrobenzene (a positive control).

In Situ Observation of Cellular Structure Changes in and Chain Segregations of Anabaena sp. PCC 7120 on TiO2 Films under a Photocatalytic Device.

Cyanobacteria outbreaks are serious water pollution events, causing water crises around the world. Photocatalytic disinfection, as an effective approach, has been widely used to inhibit blue algae growth. In this study, a tiny reaction room containing a TiO2 film was designed to fulfill in situ optical observation of the destruction process of a one-dimensional multicellular microorganism, Anabaena sp. PCC 7120, which is also a typical bacterial strain causing water blooms. It was found that the fragment number increased exponentially with the activation time. The fracture mechanics of the algae chains were hypothesized to be the combining functions of increased local tensile stress originated from the cell contracting as well as the oxidative attacks coming from reactive oxygen species (ROSs). It was assumed that the oxidative species were the root cause of cellular structure changes in and chain fractures of Anabaena sp. PCC 7120 in the photocatalytic inactivation activity.

INFLUENCE OF RIPARIAN FOREST AND TEMPERATURE ON PRIMARY PRODUCTION OF TROPICAL STREAMS

Primary production is a key feature for the functioning of aquatic ecosystems. The trophic state of the streams reflects this primary production and is influenced by local limnological variables and level of integrity of the watershed. Thus, in this study, habitat integrity index (HII) and physical, chemical, and biological parameters of tropical streams were sampled in two sub-basins to understand the functioning of these ecosystems. We hypothesized that the variables association to the environmental integrity should determine the primary production in the streams. Because of the similar land use in the sub-basins (ex.: agriculture and livestock) they will show similar limnological variables. To identify how the streams differed in relation to their limnological characterization and the HII, we performed a Principal Component Analysis (PCA). The association between variables was assessed by Pearson's correlation analysis. To identify the difference between the two basins, a Student's Test was performed. The best predictors of primary production were determined using a multiple regression analysis with the Akaike selection criteria. The concentration of chlorophyll-a in the surface water indicated that the tropical streams sampled have, in general, low concentrations of nutrients, except for some more urban points. The variables that most differed among streams were blue-green cells/ml, pH, conductivity, and width of the riparian forest. Only redox potential and pH differed between the two watersheds. Temperature, blue-green cells/ml and width of the riparian forest were the variables that best predicted the phytoplankton primary production of watercourses in both watersheds. In this study we reinforce the importance of temperature in aquatic productivity, even more present in the face of climate change, which, added to deforestation, increases the surface area of sunlight in water courses, increases primary productivity and the eutrophication process.Keywords: blue-green algae; chemical variables; chlorophyll-a; HII; phytoplankton.

Symptom frequency and exposure to a cyanobacteria bloom in Florida

This investigation was undertaken to characterize health effects associated with a major bloom of blue-green algae due to the proliferation Microcystis aeruginosa that occurred in Florida in 2018. Cyanobacteria produce multiple toxins, including the potent hepatotoxic microcystins (MCs), that have been reported to cause illness in exposed persons worldwide. Widespread exposure to toxins released by blue-green algae during the 2018 bloom was shown by the presence of MCs in the nasal passages of 95 percent of the individuals studied previously in south Florida (Schaefer et al., 2020). The current analyses were conducted to determine whether self-reported symptoms were associated with activity patterns, direct contact with water, residential, recreational, and occupational exposure. The 125 persons who participated in the initial study reported an average of 4.94 (± 4.87) symptoms. Those reported most commonly included rhinorrhea, sneezing, headache, sore throat and dry cough. Respiratory symptoms were reported by 74%, ocular symptoms by 62%, and gastrointestinal symptoms by 35% of respondents. Residential and recreational exposures were associated with increased risks of respiratory, gastrointestinal, or ocular symptoms in univariate and adjusted multivariable analyses. Residential exposure was significantly associated with increased reporting of dry cough (p = 0.03), dyspnea (p < 0.01) and wheezy respirations (p = 0.04). Among persons reporting gastrointestinal symptoms, nausea (p = 0.02) and abdominal pain (p < 0.01) were significantly associated with residential exposure. Recreational exposure was significantly associated with sore throat and eye irritation. The findings add to the evidence that exposure to cyanobacteria at concentrations encountered during an algal bloom is associated with a diverse array of symptoms and that inhalation of aerosols constitutes an important exposure pathway.

Management of the Risk of Blue-Green Algae Blooms in the Iskar Dam for Drinking Water Quality of Sofia City

The introduction of systems for ensuring quality and safe drinking water and risk management is the World Health Organization (WHO) good practice introduced as a legislative requirement for all water supply organizations (Directive EU 2020/2184) on the quality of water intended for human consumption. A specific object of this research is the implemented risk assessment and management system, part of the drinking water safety plan for Sofia city. The water supply system from the water source to the end user, operated by Sofiyska voda JSC and part of Veolia, was analyzed. The hazards and risk events were reviewed for each component of the system—the catchment, water source, supply water pipes, drinking water treatment plants (DWTPs) and distribution water network. The results of the risk evaluation show that the risk of an algal bloom falls from medium risk, with a value of 36 in 2018. This risk was new for the Iskar Dam—the main water source for Sofia city. The purpose of the current study is to analyze the risk of blue-green algae blooming and the potential release of toxins in the Iskar Dam. A data analysis of phytoplankton counts, temperature of the water in the dam, precipitation, algal diversity and quantity of microcystins for a period of three years shows that there is a low probability of algae blooming. The concentration of microcystin LR was below 0.6 µg/L and of microcystin YR was below 0.1 µg/L. The highest phytoplankton count was 70,000 cells/mL in 2018, and it decreased to 30,000 cells/mL in 2020. The impact of the risk of “blue-green algae blooms in the Iskar Dam” is assessed as moderate (3) and that has not changed between 2018 and 2022. The likelihood of occurrence of this risk decreased from possible (3) to unlikely (2) after risk reassessment, and the current control effectiveness changed from weakly controlled (4) in 2018 to well controlled (2) in 2022, because more risk management actions were included in Sofiyska voda JSC. The results of the risk evaluation show that the risk of an algal bloom falls into the low-risk category with a value of 12, after measures were considered and a reassessment. As a preventive measure for better management and risk minimization, it is necessary to continue monitoring the phytoplankton count, species composition, concentration of algae toxins (microcystin LR) and nutrients in raw water from the Iskar Dam. This research has added value to the global database for surface water sources intended for human consumption and is focuses on a potential problem, valid for agricultural as well as for urban territories rich in diffused sources of pollution. The specific risk evaluation and management steps could be used and adapted by other water supply companies.

Nicotinamide Riboside and Phycocyanin Oligopeptides Affect Stress Susceptibility in Chronic Corticosterone-Exposed Rats.

Nicotinamide riboside (NR) is an NAD+ precursor capable of regulating mammalian cellular metabolism. Phycocyanin oligopeptide (PC), a phytonutrient found in blue-green algae, has antioxidant and anti-inflammatory properties. This study explored the effects of NR, PC, and their combination on the telomere length as well as inflammatory and antioxidant status of rats under chronic stress conditions (CS). Forty-nine rats were allocated into seven groups: control, chronic stress (CS), CS with NR (26.44 mg/kg), a low dose of 2.64 mg/kg of PC (PC-LD), or a high dose of 26.44 mg/kg PC (PC-HD), NR + PC-LD, and NR + PC-HF. The rats were given daily corticosterone injections (40 mg/kg) to induce stress conditions, or NR and PC were orally administered for 21 days. NR and PC supplementation, particularly NR plus PC, increased the serum antioxidant enzyme activities, hepatic nicotinamide adenine (NAD+) content, and telomere length (p < 0.001 for all) compared to the CS group. The levels of serum malondialdehyde (MDA), liver interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), IL-1β, and IL-8 were reduced under the CS condition (p < 0.001). In addition, CS decreased the levels of hepatic telomere-related proteins and sirtuins (SIRT1 and 3), whereas administration of NR and PC or their combination to CS-exposed rats increased the levels of telomere-related proteins (e.g., POT1b, TRF1 and TRF2), SIRT3 and NAMPT (p < 0.05). In conclusion, NR and PC, especially their combination, can alleviate metabolic abnormalities by enhancing hepatic cytokines, SIRT3, NAMPT, and NAD+ levels in CS-exposed rats. More research is needed to further elucidate the potential health effects of the combination of NR and PC in humans.

Arthrospira platensis nanoparticle-based approach for efficient removal of methyl orange dye from aqueous solutions: isotherm, kinetic, and thermodynamic analysis

AbstractBlue-green algae Arthrospira platensis, strain NIOF 17/003, is an ecologically friendly were tested as adsorbents for the removal of methyl orange dye (MO) from aqueous solution. The surface deposition of A. platensis was investigated utilizing a variety of techniques, including Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM). FTIR analysis demonstrated the contribution of carbonyl and carboxylic groups to MO dye adsorption. Different initial concentrations of MO dye (5–30 mg L–1) at contact time (5–180 min.), adsorbent doses (0.05–0.4 g), temperature (20–60 °C), and pH (1–11) were conducted in batch conditions. The results revealed that MO sorption in aqueous solutions increased with contact time and concentration. Temperature also affects MO adsorption. The elimination of MO from the solution augmented as the mass of A. platensis increased. The maximum MO dye sorption onto A. platensis was achieved at 15 mg L−1, 20 °C, 0.4 g, pH 1, for 30 min. A significant quantity of dye can be removed with just 0.1 g of A. platensis, with a removal efficiency of 18.1% and 28.35% for seawater and real wastewater, respectively. Many isotherm equations were used to analyze the experimental results (including Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin models). The maximum adsorption capacity of MO onto A. platensis was 156.25 mg g−1. The fractionary-order kinetic model provided the best fit to experimental data compared with other models. Moreover, the thermodynamic parameters of ΔH° and ΔG° factors showed exothermic as well as spontaneous sorption processes. Additionally, A. platensis can be used more than once for economic gain, and it was found that the percent removal decreased to 89.28% of regeneration after three cycles for synthetic wastewater. These investigations indicate the effectiveness of the blue-green algae A. platensis, which may have significant potential for methyl orange dye applications in wastewater treatment.