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Chlorella vulgaris, a freshwater microalga, is gaining attention for its potential as a nutritious food source and dietary supplement. This review aims to provide a comprehensive discussion on C. vulgaris, evaluating its viability as a food substitute in the industry by exploring the nutritional value and application of C. vulgaris in the food industry. Rich in protein, lipids, carbohydrates, vitamins, and minerals, Chlorella offers substantial nutritional benefits, positioning it as a valuable food substitute. Its applications in the food industry include incorporation into smoothies, snacks, and supplements, enhancing the nutritional profile of various food products. The health benefits of Chlorella encompass antioxidant activity, immune system support, and detoxification, contributing to overall well‐being. Despite these advantages, the commercialization of Chlorella faces significant challenges. These include variability in antibacterial activity due to strain and growth conditions, high production costs, contamination risks, and sensory issues such as unpleasant taste and smell. Additionally, Chlorella can accumulate heavy metals from its environment, necessitating stringent quality control measures. Future prospects involve improving Chlorella strains through genetic manipulation to enhance nutrient content, developing cost‐effective culture systems, and exploring advanced processing techniques like pulsed electric fields for better digestibility. Addressing sensory issues through flavor‐masking strategies and employing environmental management practices will further support Chlorella's integration into the food industry. Although C. vulgaris shows great potential as a nutritious food ingredient, overcoming existing challenges and optimizing production methods would be crucial for its successful adoption and widespread use. [ABSTRACT FROM AUTHOR]

Allelopathy plays a crucial role in shaping phytoplankton community dynamics and diversity. It influences competition between photoautotrophs for resources and affects species succession in aquatic ecosystems. This article evaluates the allelopathic activity of cyanobacteria isolated from Lake Tuzkol, Kazakhstan. The allelopathic effects, including growth inhibition or stimulation, were assessed by adding cell‐free filtrates of the cyanobacteria Oscillatoria sp. SS‐9, Nostoc sp. CZS 2205, Synechococcus sp. SS‐5, or Anabaena sp. SS‐8 to the tested microalgae. The most pronounced effect was observed with Nostoc sp. CZS 2205, which reduced the cell counts of Chlorella vulgaris SP BB‐2 and Chlamydomonas reinhardtii CC‐124 by 60% and 57%, respectively, and Scenedesmus quadricauda CC‐1 and Ankistrodesmus falcatus CB‐2 by 55% and 53%, respectively. Synechococcus sp. SS‐5, in contrast, stimulated the growth of Chlorella vulgaris SP BB‐2 and Scenedesmus quadricauda CC‐1 by 11% and 8.8%, respectively. Filtrates from Oscillatoria sp. SS‐9 and Anabaena sp. SS‐8 had no significant impact on microalgal growth. Considering the significant allelopathic activity of Nostoc sp. CZS 2205, an agar diffusion test using biomass extracts confirmed a significant inhibitory effect, with the biomass extracts showing stronger activity than cell‐free filtrates. A detailed analysis of the cell‐free filtrates revealed eight compounds, including methyl heptadecanoate, methyl eicosanoate, tricosane, methyl octadeca‐9,12‐dienoate, methyl 13,16‐octadecadienoate, and 2,2‐dimethoxybutane. Additionally, nostocyclamide, a cyclic peptide, was identified in the biomass extract. The detection of nostocyclamide emphasizes its ecological importance and potential evolutionary role. These results enhance our understanding of the role of cyanobacteria in aquatic ecosystems and lay the groundwork for future research into their ecological applications. [ABSTRACT FROM AUTHOR]

Microalgae cultivation processes that recycle waste streams from biorefineries require the availability of flexible control strategies to avoid the rapid decline of the biomass. Unfortunately, the coupling with other processes constrains the possible control actions. We developed some data-driven nonlinear models to predict pH and growth of Chlorella vulgaris nurtured in mixothrophic conditions and fed with both flue gas and wastewater. NARX and Hammerstein-Wiener black-box models are identified for pH, showing a good capability to predict its dynamics, also when subject to pulse feeding. These models can be used to set-up control strategies for this important parameter, using only wastewater flow rate as the manipulated variable and leading to a great advantage in terms of costs, if compared to manipulation of flue gas flow rate or gas composition. A dynamic grey-box model to predict microalgae concentration using only some subsets of the online pH measures is also proposed and validated. Its possible application for optimizing microalgae harvesting is briefly discussed. In order to collect rich data to be used for the identification of the dynamic models, we designed and carried out proper open loop experimental campaigns. [ABSTRACT FROM AUTHOR]

Microalgae Chlorella vulgaris, Scenedesmus obliquus, and Monoraphidium sp were cultivated in effluent from the household appliance industry as an alternative medium for bioremediation due to the high variability of chemical and biological substances in wastewater. The experiments were carried out using biological effluent (BE), chemical effluent (CE), and a combination of the two (MIX). The results showed a maximum biomass yield of 1056 mg/L (± 0.216) in the BE cultivation of the microalga Scenedesmus obliquus, 969 mg/L (± 0.20) in the BE of the microalga Monoraphidium sp. and 468 mg/L (± 0.46) in the CE of Chlorella vulgaris. In addition, they showed N O 3 - removal (100%) in the CE and MIX for cultivation with Chlorella vulgaris and 100% BE and 75% MIX with Monoraphidium sp. For the P O 3 4 - (75.3%, 99% e 97.9%) in the cultures with C. vulgaris BE, CE, and MIX respectively, with Monoraphidium sp. 58% in BE and 42% in CE and MIX. With S. obliquus, 100% removal was observed in all 3 treatments. Metal removal was also observed. The C. vulgaris culture showed lipid contents of 16%, 12%, and 17% for BE, CE, and MIX, respectively. For Monoraphidium sp., 14.5% for BE, 16% for CE, and 14% for MIX. In the culture of S. obliquus, 17%, 15.5%, and 16.5% for BE, CE, and MIX, respectively. [ABSTRACT FROM AUTHOR]

There has been an emergence of a diversity of microalgal mixotrophic synergistic mechanisms due to substrate differences. In this study, the effects of the mixotrophic culture of Chlorella vulgaris were examined. The maximum values of cell density, specific growth rate, and cell dry weight of Chlorella vulgaris were 3.52*107 cells/mL, 0.75 d−1, and 3.48 g/L in the mixotrophic mode, respectively. These were higher than the corresponding values of photoautotrophic or heterotrophic modes. Moreover, it was found that the concentrations of sodium bicarbonate consumed by the Chlorella vulgaris under mixotrophic and photoautotrophic modes were 635 mg/L/d and 505 mg/L/d, respectively; the concentrations of sodium acetate consumed by the Chlorella vulgaris under mixotrophic and heterotrophic modes were 614 mg/L/d and 645 mg/L/d, respectively. The activity of Rubisco was 9.36 U/mL in the mixotrophic culture, which was 3.09 and 4.85 times higher than that of the photoautotrophic and heterotrophic modes, respectively. This indicated that the differences for the carbon source absorption efficiency of Chlorella vulgaris in the mixotrophy led to different internal metabolic efficiencies when compared to photoautotroph or heterotrophy. Additionally, Chlorella vulgaris exhibits a more rapid energy metabolism efficiency when operating in the mixotrophic mode. [ABSTRACT FROM AUTHOR]

Microalgae are susceptible to most pollutants in aquatic ecosystems and can be potentially damaged by silver nanoparticles (AgNPs). This study aims to clarify the potential consequences of Chlorella vulgaris internalizing AgNPs. The exposure of C. vulgaris to AgNPs stabilized with citrate led to the accumulation of NPs in the cell wall, increasing permeability, which allowed the entry of AgNPs and Ag + ions resulting from the dissolution of AgNPs. Ag + accumulated inside the cell could be converted into AgNPs (endogenous) due to the reducing potential of the cytoplasm. Both exogenous and endogenous AgNPs caused damage to all biological structures of the algae, as demonstrated by TEM images. This damage included the disorganization of chloroplasts, deposition of AgNPs on starch granules, and increased amounts of lipids, starch granules, exopolysaccharides, plastoglobuli, and cell diameters. These changes caused cell death by altering cell viability and interfering with organelle functions, possibly due to reactive oxygen species generated by nanoparticles, as shown in a lipid bilayer model. These findings highlight the importance of considering the exposure risks of AgNPs in a worldwide distributed chlorophyte. Highlights: Exposure to AgNPs increased the permeability of the cell wall to both AgNPs and Ag+. Cytoplasmic reducer potential can transform Ag + into endogenous AgNPs in the cell. FTIR spectra show AgNPs promote lipid oxidation, leading to membrane damage. TEM analysis shows exogenous and endogenous AgNPs damage all biological structures. AgNPs and Ag + produced cells death by altering membranes and organelles functions. [ABSTRACT FROM AUTHOR]

Plant pathogenic fungi are a major cause of plant diseases, contributing significantly to the global decline in food production. Their proliferation results in substantial crop losses, fruit and vegetable deterioration, reduced food accessibility, and billions of dollars in economic losses annually. While synthetic chemical fungicides are commonly used to combat fungal diseases, their environmental impact is concerning. Marine algae provide a sustainable alternative, offering diverse compounds with industrial applications and presenting an eco-friendly solution. Taphrina deformans is responsible for peach leaf curl, a widespread disease in peach trees that can severely impact crop productivity and tree lifespan. Seaweeds and algae, encountering various biological interactions and extreme abiotic conditions, have evolved defense mechanisms, including the production of biologically active substances. In our study, we investigated the efficacy of water extracts from six algae (Nannochloropsis sp., Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira weissflogii, Tisochrysis lutea, Chlorella vulgaris), four seaweeds (Palmaria palmata, Chondrus crispus, Ascophyllum nodosum), and one cyanobacterium (Arthrospira platensis) at two different concentrations (1% and 3%) in suppressing the outbreak of peach leaf curl disease in vivo on peach trees. The spray was applied twice in spring just before budbreak. Algae and seaweed extracts showed significant suppression of peach leaf curl outbreaks on peach trees compared to controls. Following the application of water extract of Chlorella vulgaris at both concentrations, the lowest incidences of symptomatic disease expression were observed (1.00 ±0.00% and 0.25 ±0.50%). Algae and seaweed extracts demonstrate potential in controlling leaf curl disease in peach trees. [ABSTRACT FROM AUTHOR]

Alkaline hydrolysate of chicken manure (HCM) containing artificially formed humic-like substances (HLSs) was investigated in combination with specially loaded cells (bacteria and microalgae) for oil degradation in soil. After 7 days in the laboratory experiment, the oil biodegradation efficiency in the polluted soil (50 g oil/kg soil) was 5–78% in 11 soil samples depending on the soil characteristics and used combination of additives. Higher level of oil-degradation corresponded to soil with high initial concentration of humic substances (HSs) (85–107 g/kg of dry matter). The best result in bioremediation (degradation of 82% of oil for 7 days) was achieved in experiment under field conditions with the similar initial oil pollution in the soil, when the HCM was used as additive (up to 220 mg HLSs/kg dry soil) in combination with an artificial symbionts composed of Rhodococcus erythropolis and Chlorella vulgaris cells. The introduction of HCM into oil-polluted soil with the mentioned cells led to an increase in all controlled enzymatic activities (peroxidase, dehydrogenase, phosphatase, protease, amylase, and urease) in the soil. The observed effects testified to activation of cell metabolic processes in the soil. As a result, the introduction of HCM in combination with artificial symbionts into the soil increased the rate of oil biodegradation under environmental conditions up to 1.8 times. [ABSTRACT FROM AUTHOR]

Microalgae have demonstrated biostimulant potential owing to their ability to produce various plant growth-promoting substances, such as amino acids, phytohormones, polysaccharides, and vitamins. Most previous studies have primarily focused on the effects of microalgal biostimulants on plant growth. While biomass extracts are commonly used as biostimulants, research on the use of culture supernatant, a byproduct of microalgal culture, is scarce. In this study, we aimed to evaluate the potential of Chlorella vulgaris culture as a biostimulant and assess its effects on the growth and drought tolerance of Arabidopsis thaliana, addressing the gap in current knowledge. Our results demonstrated that the Chlorella cell-free supernatant (CFS) significantly enhanced root growth and shoot development in both seedlings and mature Arabidopsis plants, suggesting the presence of specific growth-promoting compounds in CFS. Notably, CFS appeared to improve drought tolerance in Arabidopsis plants by increasing glucosinolate biosynthesis, inducing stomatal closure, and reducing water loss. Gene expression analysis revealed considerable changes in the expression of drought-responsive genes, such as IAA5, which is involved in auxin signaling, as well as glucosinolate biosynthetic genes, including WRKY63, MYB28, and MYB29. Overall, C. vulgaris culture-derived CFS could serve as a biostimulant alternative to chemical products, enhancing plant growth and drought tolerance. [ABSTRACT FROM AUTHOR]

To assess the potential of using the secondary treated wastewater for the production of algal biofuel, batch experiments were carried out in photobioreactors using indigenous Chlorella vulgaris isolated from the natural freshwater body. Secondary treated wastewater with partial nitrification was simulated using various proportions of NO3-N and NH4-N while keeping the total nitrogen the same. Experiments with similar concentrations of nitrate without the NH4-N were used for comparison. In the presence of only NO3-N in the concentration range of 9–37 mg/L, the growth and fatty acid methyl ester (FAME) production was similar to the literature reports. When NH4-N was present along with NO3-N, the biomass growth was adversely affected, indicating an impact on the metabolic activity. For the same initial concentrations of nitrate in the culture, the maximum biomass concentration was reduced by 50–60% in the presence of NH4-N. The FAME profile changed significantly and a new FAME was identified, suggesting an impact on the lipid synthesis pathway. Comparison and analysis with the help of existing literature indicated that the adverse effect due to NH4-N was a function of pH. The growth, biomass yield, and FAME production were unaffected by a wide range of phosphorus concentrations. Maximum fatty acid methyl ester (FAME) suitable for biodiesel production (fatty acid carbon chain length C16 to C18) was 381.01 mg/L (224.58 mg/g of dry biomass), produced at NO3-N concentration of 18.5 mg/L and initial nitrogen loading per unit biomass of 0.37 g NO3-N/g of dry biomass. [ABSTRACT FROM AUTHOR]

Chlorella, a single‐celled green algae rich in proteins, holds promise as a source of bioactive peptides. This research aimed to isolate an antioxidant peptide from Chlorella, examining its stability through digestion. Using Response Surface Methodology (RSM), we identified optimal hydrolysis conditions for Chlorella Protein Hydrolysate (CPH): 55°C, pH 8.75, and an enzyme‐to‐substrate ratio of 2.15%. These conditions led to CPH with notable radical scavenging activity against 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) (53.19 ± 0.99%), 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) (76.86 ± 0.28%), hydroxyl radical (53.39 ± 1.74%), and Fe2+ chelating rates of 22.56 ± 2.97%. Subsequently, peptides under 3 kDa isolated by ultrafication proved particularly stable and antioxidative after in vitro digestion. In addition, further purify to obtain component C1 with DPPH radical scavenging ability of 59.62 ± 1.29% and an Fe2+ chelating ability of 49.78 ± 1.55%. Subsequent LC‐MS/MS identification and virtual screening led to the discovery of a stable and antioxidative peptide, Ser‐Gly‐His‐His‐Lys‐Pro‐Leu (SGHHKPL). The study provides the theoretical basis for the development and utilization of chlorella. [ABSTRACT FROM AUTHOR]

In this study, the impact of exposure to a glyphosate-based herbicide (GBH) and a trifloxystrobin-based fungicide (TBF) on Daphnia magna in diverse feeding environments was assessed through the analysis of morphological and biochemical markers. The test organisms selected for analysis were Chlorella vulgaris and D. magna. First, the 48-hour median lethal concentrations (LC50) of GBH and TBF for D. magna were determined to be 253.1 mg/L and 20.7 µg/L, respectively. Secondly, the lethality, length, width, and spin length of D. magna were evaluated following exposure to sublethal pesticide concentrations, selected based on the LC50 values, in different feeding environments. Thirdly, the activities of glutathione S-transferase (GST), glutathione reductase, catalase (CAT), carboxylesterase, and acetylcholinesterase, as well as the levels of reduced glutathione, were measured in D. magna exposed to sublethal pesticide concentrations in different feeding environments. Both pesticides caused an increase in CAT activity, while GBH also caused an increase in GST activity in the unfed and mixed-fed groups. Conversely, it can be concluded that feeding with C. vulgaris reduces oxidative stress and toxic effects since there was a lesser increase in GST and CAT activities in the C. vulgaris-fed group for both pesticides, similar to the lethality. [ABSTRACT FROM AUTHOR]

Microalgae are emerging as functional feed ingredients in aquaculture due to their immune-stimulating and stress-modulating properties. We investigated the potential of the microalgae Chlorella vulgaris as a feed supplement to improve the health and modulate microbiota and stress responses of Atlantic salmon. Triplicate groups of Atlantic salmon (~ 126 g) were reared in a recirculating aquaculture system (RAS) at 15 °C and received diets supplemented with 2% (CV2) or 14% (CV14) spray-dried C. vulgaris daily, 14% once weekly (CV14w), or a control diet (CD) for 8 weeks. Subsequently, all groups were exposed to an acute one-hour peracetic acid (CH3CO3H; PAA) treatment, a commonly used disinfectant in RAS. While CV14 increased feed conversion (FCR) significantly, feeding the diets CV2 and CV14w improved protein retention efficiency. CV14 significantly modulated beta-diversity in the intestinal digesta and mucosa, but this effect was already visible in fish fed CV2. Feeding CV14 and, to a lesser degree, CV2 increased the relative abundances of Paenarthrobacter and Trichococcus in the digesta and mucosa, which are able to metabolize complex carbohydrates. However, the same diets reduced the abundance of the lactic acid bacteria Lactobacillus and Weissella in the digesta and Floricoccus in the mucosa. Peracetic acid exposure induced systemic stress (increase in plasma glucose and cortisol) and a local immune response in the gill, with the most prominent upregulation of several immune- and stress-regulated genes (clra, cebpb, marco, tnfrsf14, ikba, c1ql2, drtp1) 18 h after exposure in fish fed the control diet. Fish receiving CV14 once a week showed a reduced transcriptional response to PAA exposure. Catalase protein abundance in the liver increased following exposure to PAA, while superoxide dismutase abundance in the gill and liver was increased in response to C. vulgaris inclusion before stress. Overall, the results highlight that a high (14%) inclusion rate of C. vulgaris in feed for Atlantic salmon impairs feed conversion and shifts the intestinal microbiota composition in digesta and mucosa. Weekly feeding of C. vulgaris proves a viable approach in improving protein retention and improving transcriptional resilience towards oxidative stress in increasingly intensive production systems. Thereby this study may motivate future studies on optimizing temporal feeding schedules for health-promoting aquafeeds. [ABSTRACT FROM AUTHOR]

Synthesis of silver nanoparticles (Ag NPs) using microalgae is gaining recognition for its environmentally friendly and cost-effective nature while maintaining high activity of NPs. In the present study, Ag NPs were synthesized using a methanolic extract of Chlorella vulgaris and subjected to calcination. The X-ray diffraction (XRD) analysis showed a crystalline nature of the products with Ag2O and Ag phases with an average crystalline size of 16.07 nm before calcination and an Ag phase with 24.61 nm crystalline size after calcination. Fourier transform infrared spectroscopy (FTIR) revealed the capping functional groups on Ag NPs, while scanning electron microscopy (SEM) displayed their irregular morphology and agglomeration after calcination. The organic coating was examined by energy-dispersive X-ray spectroscopy (EDX) and thermogravimetric (TGA) analyses, confirming the involvement of the metabolites. The UV–Vis analysis showed a difference in optical properties due to calcination. Synthesized Ag NPs were applied for the photodegradation of hazardous dye Brilliant Blue R in visible light. Different values of light intensity, catalyst dose, initial dye concentration, and pH were tested to identify the optimal set of operating conditions. The highest degradation efficiency of 90.6% with an apparent rate constant of 0.04402 min−1 was achieved after 90 min of irradiation in the highest tested catalyst dosage. [ABSTRACT FROM AUTHOR]

The effect of added microalgae biomass to styrene–butadiene–styrene triblock composites (SBS) loaded with Chlorella vulgaris and Arthrospira platensis biomass was evaluated by nonisothermal chemiluminescence (CL), infrared spectroscopy, and differential scanning calorimetry (DSC) analysis. The high biomass content of up to 20% for Chlorella vulgaris and 30% for Arthrospira platensis create appropriate conditions for the propagation of oxidation, which is a convenient manner applicable to the degrading digestion of polymer matrix. The chemiluminescence spectra on these ecological formulations indicate the contribution of additives to the optimization of polymer waste disintegration. The degrading activities of the studied microalgal biomass added to the polymer matrix are influenced not only by concentration and source but also by the temperature evolution, which determines the proper thermal regime of material decay. The thermal aging of SBS/microalgal composites progresses peculiarly under the action of various pro-oxidant components. The amplitudes of oxidative conversion of SBS support are discussed with values of main kinetic parameters, onset, and intermediate oxidation temperatures. Although the addition of biomass to the polymer matrix introduces various transformations that affect its thermal behavior, the combined CL and DSC studies indicate that these changes ultimately enhance the polymer's stabilization. The control SBS composite was the most stable, likely due to its homogeneous structure compared to the heterogeneous mixture in the microalgae SBS composites. Prolonged heating at elevated temperatures (80 °C and 120 °C) can lead to thermal aging and degradation of the polymer matrix, causing changes such as chain scission or cross-linking, which alter the material's thermal properties. [ABSTRACT FROM AUTHOR]

This study assessed the possible pharmacological effects of Chlorella vulgaris (Cg), Spirulina platensis (St), and silymarin (Sl) against thioacetamide (TA)-induced cardiotoxicity in rats, with a focus on their antioxidant, cardioprotective, and anti-inflammatory properties. The following is the random grouping of sixty male rats into six groups of ten animals each: the control (negative control), TA-intoxicated group (positive control; 300 mg/kg body weight (BW)), Sl + TA group (100 mg Sl/kg BW + TA), St + TA group (400 mg St/kg BW + TA), Cg + TA (400 mg Cg/kg BW + TA), and St + Cg + TA group (400 St + 400 Cg mg/kg BW + TA) were all administered for 30 days. At the start of the study, groups 2 through 6 were administered TA intraperitoneally at a dosage of 300 mg/kg BW for two consecutive days, with a 24 h gap between each dose, to induce cardiac damage. Blood samples were obtained to measure hematological parameters and perform biochemical assays, including lipid profiles and cardiac enzymes. For histopathology and immunohistochemistry determination, tissue samples were acquired. The current findings showed that TA injection caused hematological alterations and cardiac injury, as evidenced by greater serum levels of troponin I, creatine kinase-MB, and total creatine kinase (p < 0.05), as well as significantly elevated serum malondialdehyde and decreased serum total antioxidant capacity (p < 0.05) concentrations. Moreover, an increase in blood low-density lipoprotein and total cholesterol concentration (p < 0.05) was recorded in the TA group. There were alterations in the heart tissue's histological structure of the TA group compared to the control ones. These alterations were characterized by vacuolar degeneration of myocytes, loss of cross striation, coagulative necrosis, and fibrosis of interstitial tissue, which was ameliorated by the supplementation of SI, St, and Cg. The TA-intoxicated group showed weak expression of B-cell lymphoma protein 2 (p < 0.05) and strong immunoreactivity of tumor necrosis factor-α and B-cell lymphoma protein 2-associated X (p < 0.05). However, the groups receiving Sl, St, and Cg experienced the opposite. The administration of Sl, St, Cg, and St + Cg along with TA significantly improved and restored (p < 0.05) erythrogram indices, including RBCs, hemoglobin, total leukocytic count, lymphocytes, and monocyte, to the normal control values. The administration of Sl, St, and Cg alleviated the cardiotoxicity caused by TA via reducing oxidative stress, inflammatory markers, and apoptosis in heart tissue. In summary, the current findings suggest that the treatment with Sl, St, and Cg was beneficial in ameliorating and reducing the cardiotoxicity induced by TA in rats. [ABSTRACT FROM AUTHOR]

A unique method for determining chlorophyll content in microalgae is devised employing a gold interdigitated electrode (G-IDE) with a 10-µm gap, augmented by a nano-molecularly imprinted polymer (nano-MIP) and a titanium dioxide/multiwalled carbon nanotube (TiO2/MWCNT) nanocomposite. The nano-MIP, produced using chlorophyll template voids, successfully trapped chlorophyll, while the TiO2/MWCNT nanocomposite, synthesized by the sol–gel technique, exhibited a consistent distribution and anatase crystalline structure. The rebinding of procured chlorophyll powder, which was used as a template for nano-MIP synthesis, was identified with a high determination coefficient (R2 = 0.9857). By combining the TiO2/MWCNT nanocomposite with nano-MIP, the G-IDE sensing method achieved a slightly better R2 value of 0.9892 for detecting chlorophyll in microalgae. The presented G-IDE sensor showed a significant threefold enhancement in chlorophyll detection compared with commercially available chlorophyll powder. It had a detection limit of 0.917 mL (v/v) and a linear range that spanned from 10-6 to 1 mL. The effectiveness of the sensor in detecting chlorophyll in microalgae was confirmed through validation of its repeatability and reusability. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the potential of upcycling Expanded Polystyrene (EPS) waste collected from food packaging into a membrane for microalgae harvesting, in which membrane filtration often challenges fouling and pore blocking. The target species is Spirulina platensis, with Chlorella vulgaris as a comparison agent. The membrane was fabricated from used Styrofoam, which typically ends up as single-use food packaging waste. In this study, PVP was used as an additive at varying concentrations, from 2 wt.% to 8 wt.%. The experimental results indicated that despite varying PVP concentrations, all EPS waste membranes exhibited near-complete recovery of Spirulina platensis biomass extraction. Despite the similar harvesting efficiency, EPS/PVP-8 exhibited the largest flux of 970.5 LMH/Bar, which is twice the value of the pristine EPS waste membrane. All membranes were hydrophilic; however, hydrophobicity increased with PVP concentration. SEM micrographs revealed that PVP enlarged the membrane surface pores and improved connectivity within the membrane's structure, ensuring efficient flow. The EPS waste membrane offers promising insights for sustainable materials and wastewater treatment. The upcycling of EPS waste into flat sheet membranes not only addresses the problem of Styrofoam waste accumulation but also paves the way to transform waste into valuable products. [ABSTRACT FROM AUTHOR]

This study investigates the potential of Chlorella vulgaris for nutrient removal and biomass production in synthetic wastewater. The experiments were conducted in 2 L photobioreactors under controlled aeration, agitation, and lighting conditions for 19 days. Despite a moderate growth rate (0.137 d−1), C. vulgaris achieved efficient pollutant removal, with 97% of nitrate, 90% of nitrite, and 90.6% of COD eliminated. Additionally, the biomass was processed to extract fatty acids, yielding a 20% extraction rate, indicating its potential as a biofuel feedstock. These results demonstrate C. vulgaris's dual function in wastewater remediation and biofuel production, presenting a sustainable and economically viable approach to addressing environmental challenges. [ABSTRACT FROM AUTHOR]

The stability of calcium alginate beads for microalgae immobilization in wastewater treatment has been a concern due to the potential exchange of Ca2+ ions from the bead surface with the environment. To overcome this constraint, adding biopolymers might improve the properties of alginate gel. The purpose of the study is to immobilize Chlorella vulgaris in blends of sodium alginate with carboxymethylcellulose (CMC) or pectin in different concentrations (1%, 1.5%, and 2%) to evaluate the microalgae growth and nutrient removal from culture media. The microalgae growth was assessed by cell counting and chlorophyll content using a fluorescent excitation–emission matrix. Nutrient removal was conducted by measuring the phosphate and nitrate concentration using ion chromatography. The characterization of beads, such as size, shrinkage degree, swelling ratio, water content, and dry weight, was also investigated. Compared to alginate-only beads, the results present better performance for cell growth and, similarly, for removing nutrients in the presence of pectin and CMC blends. Microalgae in alginate with 1.0% of pectin grew 26% more than in alginate-only beads on day 8. The blends with CMC showed faster removal of nutrients compared to pectin blends and alginate-only in only 3 days. For phosphate, the highest removal was by immobilized microalgae of 95% for 2.0% of CMC and 86% for 2.0% of pectin. For nitrate, the immobilized microalgae removed 100% in 1.0% and 1.5% of CMC and 98% in 1.0% of pectin. [ABSTRACT FROM AUTHOR]

In the scope of vegetarian diets, cobalamin (CBL or vitamin B12) remains a particular concern, as it is mostly absent from natural, vegetarian foods. As such, vegetarians must rely on supplementation or enriched food products, to fulfil their recommended daily intake of the vitamin. The potential of microalgae is of extreme importance in this context, given the fact that they may absorb exogenous CBL and display significant levels of the vitamin. Therefore, it is crucial to establish fast and reliable B12 determination methods, to accurately characterize these products or ingredients and conclude about their role as CBL sources. To that extent, this work presents the application of the AOAC's final action method 2014.02 on the determination of total CBL in selected, commercial, microalgae and cyanobacteria powder samples. Four variants of Chlorella vulgaris, namely organic, smooth, white and honey, as well as Spirulina (Arthrospira platensis) were investigated. High-performance liquid chromatography coupled with ultraviolet (UV), diode-array detection (HPLC-DAD) was implemented in the analysis of microalgal extracts. After slight adaptation and optimisation of the extraction and analysis procedures, namely to allow lower sample amounts, it was determined that the different commercial Chlorella products, organic, smooth, white and honey have total CBL concentrations of 1063 ± 158 μg (100 g)-1, 482 ± 55 μg (100 g)-1, 681 ± 87 μg (100 g)-1 and 660 ± 68 μg (100 g)-1, respectively. Analysis of Spirulina did not yield any measurable levels of CBL in any of the purified extracts. Despite the obtained results displaying the same order of magnitude previously determined in similar microalgal products, these CBL values are amongst the highest concentrations found. Therefore, even considering the known limitations in bioaccessibility and bioavailability of CBL in microalgae, it is possible to conclude that these results stand for the inclusion of these products in vegetarian foods or as food supplements, as good potential sources of CBL, which is generally lacking in vegetarian diets. [ABSTRACT FROM AUTHOR]

Crude oil spills imperil aquatic ecosystems globally, prompting innovative solutions such as microalgae-based bioremediation. This study explores the potential of Chlorella vulgaris and Scenedesmus quadricauda, for crude oil spill phycoremediation under mixotrophic conditions and varying crude oil concentrations (0.5–2%). C. vulgaris demonstrated notable resilience, thriving up to 1% crude oil exposure, while S. quadricauda adapted to lower concentrations. Optimal growth for both was observed at 0.5% exposure. Chlorophyll a content in C. vulgaris increases at 0.5% exposure but declines above 1%, while a decline was noticeable in chlorophyll b in treatment groups above 1%. Carotenoid levels varied, displaying the highest levels at higher concentrations above 1.5%. Similarly, S. quadricauda showed increased chlorophyll a content at 0.5% exposure, with stable carotenoid levels and a decline in chlorophyll b content at higher concentrations. GC/MS analyses indicated C. vulgaris efficiently degraded aliphatic compounds like decane and tridecane, surpassing S. quadricauda in degrading both aliphatic and aromatic hydrocarbons. Growth kinetics was best represented by the modified Gompertz and logistic models. These findings highlight the species-specific adaptability and optimal concentration for microalgae to degrade crude oil effectively, advancing phycoremediation processes and strategies critical for environmental restoration. NOVELTY STATEMENT: This study marks the first exploration of both Chlorella vulgaris and the previously unexplored Scenedesmus quadricauda for crude oil phycoremediation potential under mixotrophic conditions. Additionally, it pioneers the modeling and study of algae growth kinetics in response to crude oil exposure. Notably, this research demonstrated the adaptability and efficiency of C. vulgaris in degrading crude oil components under mixotrophic conditions up to a level of 1%, while S. quadricauda showed similar capabilities at a concentration of 0.5%. [ABSTRACT FROM AUTHOR]

• Assessing the effect of prebiotic on Lactobacillus casei. • Combining Spirulina platensis and L. casei. • Using molecular studies to confirm the mixture efficacy. • The present work elucidated the magnificent role of Spirulina as an immunomodulatory agent through being a prebiotic agent to mediate the antibacterial responses of L. casei. Microalgae are diminutive unicellular magnificent creatures that exist in the microscopic form. Within this classification, two notable subtypes, namely Spirulina platensis and Chlorella vulgaris , have garnered significant attention. S. platensis is mostly known for its therapeutic benefits due to proteins, vitamins, essential amino acids, minerals, and essential fatty acids abundance. The subsequent work aimed to investigate the prebiotic effect of S. platensis enhancing Lactobacillus casei microbiome growth rate and antibacterial effect. Different concentrations of S. platensis were prepared (0, 0.5, 5, and 50 mg/mL) then co-cultured with L. casei. Live probiotic enumeration, molecular characterization and scanning electron microscopy studies were performed. Data revealed that 5 mg/mL of S. platensis significantly enhanced the probiotic live count and consequently the antibacterial activity. The antibacterial and antibiofilm effects of L. casei / S. platensis mixture showed complete inhibition to the growth of bacterial cells after 4- and 8-h incubation with Staphylococcus epidermidis 12228 and Escherichia coli 25922, respectively. Moreover, minimal biofilm eradication concentration (MBEC) value of 16 µg/mL was recorded for L. casei / S. platensis mixture [ABSTRACT FROM AUTHOR]

Microalgae are one of the oldest inhabitants of the oceans and freshwaters. One of the most famous is the green seaweed Chlorella vulgaris. In this study, the antioxidant and functional properties of the hydrolyzed protein of Chlorella vulgaris were determined. For this purpose, the hydrolyzed protein of Chlorella vulgaris was produced by commercial enzymes alcalase and flavourzyme at intervals of 10, 20 and 30 minutes. The results related to the properties of hydrolyzed protein showed that the protein hydrolyzed by alcalase had a higher degree of hydrolysis than the enzyme flavourzyme. As well as, increasing the hydrolysis time had a positive effect on the mentioned parameters (p <0.05). The highest values of degree of hydrolysis and protein recovery were observed by alcalase at 30 minutes (37.63% and 18.44%, respectively). Chlorella vulgaris was high in essential amino acids. Then, the antioxidant and functional properties of proteins (by both enzymes at 30 minutes) were measured with molecular weights of 3, 5 and 10 kDa. The results showed that the protein hydrolyzed by alcalase enzyme with a molecular weight of 3 kDa had the highest antioxidant activity (p <0.05) and also had good functional properties. Therefore, the hydrolyzed protein derived from the alga Chlorella vulgaris (by the enzyme alcalase) can be used as a substitute for animal proteins in the diet as well as functional compounds in food formulations. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: The presence of heavy metals, specifically cadmium, in the environment poses significant threats to both ecological systems and human health. However, microalgae have shown potential in addressing this issue through their ability to absorb cadmium and produce valuable biomass, making them a promising solution for bioremediation. Among the various microalgae species, Chlorella vulgaris stands out as a suitable candidate due to its potential for biodiesel production and its capacity to effectively absorb cadmium. Therefore, the main objective of this study is to assess the toxicity of cadmium on Chlorella vulgaris cells using network meta-analysis as a methodology. METHODS: A comprehensive search was conducted on Scopus, Scilit, Google Scholar, and Web of Science to identify relevant studies published from 1 January 1990 to 16 January 2024. Only studies that reported the cell number of Chlorella vulgaris as a result of cadmium exposure were considered for inclusion. The collected data were then subjected to Bayesian frequentist network meta-analysis, utilizing standardized mean difference and a 95 percent confidence interval as measures of effect size. Additionally, a linear regression analysis was performed to examine the dose-dependent impact of cadmium toxicity. FINDINGS: Dose-dependent toxic effects of cadmium on Chlorella vulgaris were evident (R-square of more than 0.90), particularly at a concentration of 1 part per million, deemed as the maximum tolerable threshold. Prolonged exposure revealed a concentration-dependent reduction in cell viability, suggesting potential lifespan shortening. A comparison of growth stimulants, gibberellic acid and brassinolide (standard means differences of 1.7 and 3.8, respectively), in mitigating cadmium toxicity indicated the latter superior effectiveness in sustaining microalgal survivability. The presence of high nitrogen and low phosphorous levels was found to be significantly associated with a reduction in Chlorella vulgaris cells due to cadmium exposure. CONCLUSION: This research has provided conclusive proof of the harmful effects of cadmium on Chlorella vulgaris through the implementation of Bayesian frequentist network meta-analysis, offering valuable insights for environmental management practices. The findings reveal concentration-dependent effects of cadmium toxicity. The survivability of Chlorella vulgaris is determined by the compositions of macronutrients nitrogen and phosphorous. Comparative analyses highlight the superior protective effect of brassinolide over gibberellic acid in mitigating cadmium toxicity. Overall, the findings highlight the potential of Chlorella vulgaris in both bioremediation of heavy metals and biomass production. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: During this energy transition, research is being done to develop sustainable ways to support the shift to a decarbonized energy and production system. These ways include using renewable energy sources to promote circularity in products, green technologies, and safer procedures. Anaerobic digestion of palm oil mill effluent is a beneficial process for generating biogas, while the waste can also be utilized as fertilizer. The biogas can be further refined into biomethane, a valuable resource commonly used in transportation and power generation. The objective of this study is to examine the enhancement of biogas from Palm oil mill effluent and the elimination of sludge nutrients by utilizing microalgae Chlorella vulgaris. The microalgae will be cultivated in a modified photobioreactor to enhance the capture of carbon dioxide. METHODS: The study utilized anaerobic batch reactor digesters. A modified photobioreactor, consisting of two columns separated by a membrane, was developed for the technological advancement of biogas upgrading, specifically for carbon dioxide capture and biogas upgrading. A technological gap in biogas upgrade technology innovation is filled by the improved photobioreactor. To optimize the bio-fixation of carbon dioxide from flue gas, it is essential to carefully select a suitable strain of microalgae that possesses both a strong ability to absorb carbon dioxide and a high tolerance to varying concentrations of this gas. By choosing the right strain, the efficiency of carbon dioxide removal can be significantly enhanced. Since Chlorella vulgaris microalgae have demonstrated this potential, they were chosen for this investigation. Microalgae also play a role in removing nutrients contained in the sludge. FINDINGS: Numerous chemical and biological methods have been used to upgrade biogas. Results of biological upgrading of biogas from palm oil mill effluent have been reported, with carbon dioxide removal reaching 89 percent until the methane concentration of the biogas is upgraded to 84 percent. The highest biomass of 1,835 grams per liter was achieved by culturing the microalgae Chlorella vulgaris in laboratory-scale photobioreactors. In this study, the application of 15 percent volume per volume biogas with an optical density of 0.4 was found to be optimal for the growth of the microalgae. The cultivation period lasted for 14 days. The peak biomass production was observed due to the achievement of a remarkable 98 volume per volume efficiency in carbon dioxide removal, which subsequently led to a significant rise in methane content, reaching 60 percent. The enhanced biogas achieved a peak methane content of 98 percent, indicating a significant improvement in quality. CONCLUSION: The findings of this study, conducted using a modified photobioreactor, indicate that Chlorella vulgaris demonstrated high efficacy in the removal of carbon dioxide, with a rate of up to 90 percent. Additionally, it exhibited remarkable performance in upgrading biogas derived from palm oil mill effluent, achieving a conversion rate of up to 98 percent. The optical density of microalgae at 0.4 played a crucial role in these processes. Furthermore, Chlorella vulgaris showcased its ability to effectively eliminate nutrient nitrogen, reaching a removal rate of 90 percent at an optical density of 0.2. Moreover, it demonstrated a phosphate removal rate of 80 percent at an optical density of 0.4. [ABSTRACT FROM AUTHOR]

Microalgae are a promising protein source due to their high protein content; high reproductivity; and low carbon, water, and arable land footprints. In this study, the impact of adding 3 and 5% of four Chlorella vulgaris strains, namely Smooth (SCV), Honey (HCV), White (WCV), and New Honey C. vulgaris (NHCV), on the processing, cooking behavior, color, firmness, structure, and sensory properties of durum wheat semolina pasta was investigated. It was hypothesized that (1) changes in physical properties depend on strain and concentration, (2) acceptability varies by strain due to different colors, odors, and flavors, and (3) the absence of fishy odors and flavors is crucial for acceptance rather than color. The results show that high-quality pasta could be produced with all C. vulgaris strains and concentrations. Cooking time and water absorption of all samples decreased but only significantly for the samples with NHCV added. Also, the bite resistance (determined instrumentally and sensorially) increased for almost all samples due to increasing protein and fiber content. A clear concentration dependency could not be found. In terms of sensory acceptance, NHCV performed the best, and an unaltered typical odor was identified to be crucial rather than color or the absence of fishy odor. [ABSTRACT FROM AUTHOR]

Nicotine, a pervasive global environmental pollutant, is released throughout every phase of the tobacco's life cycle. This study examined the probable ameliorative role of Chlorella vulgaris (ChV) extract against nicotine (NIC)-induced hepatic injury in Ehrlich ascites carcinoma (EAC) bearing female Swiss mice. Sixty female Swiss mice were assigned to four equal groups orally gavaged 2% saccharin 0.2 mL/mouse (control group), orally intubated 100 mg ChV /kg (ChV group), orally intubated 100 µg/mL NIC in 2% saccharin (NIC group), and orally intubated NIC + ChV as in group 3 and 2 (NIC+ChV group). The dosing was daily for 4 weeks. Mice from all experimental groups were then inoculated intraperitoneally with viable tumor cells 2.5 × 106 (0.2 mL/mouse) in the fourth week, and the treatments were extended for another 2 weeks. The results have shown that NIC exposure significantly altered the serum levels of liver function indices, lipid profile, LDH, and ALP in the NIC-exposed group. NIC administration significantly increased hepatic inflammation, lipid peroxidation, and DNA damage-related biomarkers but reduced antioxidant enzyme activities. NIC exposure downregulated SOD1, SOD2, CAT, GPX1, and GPX2 but upregulated NF-κB hepatic gene expression. Notably, the presence of the EAC cells outside the liver was common in all mice groups. Liver tissue of the NIC-exposed group showed multifocal expansion of hepatic sinusoids by neoplastic cells. However, with no evidence of considerable infiltration of EAC cells inside the sinusoids or in periportal areas in the NIC + ChV groups. NIC significantly altered caspase-3, Bax, and BcL2 hepatic immune expression. Interestingly, ChV administration significantly mitigates NIC-induced alterations in hepatic function indices, lipid profile, and the mRNA expression of antioxidant and NF-κB genes and regulates the caspase-3, Bax, and BcL2 immunostaining. Finally, the in vivo protective outcomes of ChV against NIC-induced hepatic injury combined with EAC in female Swiss mice could suggest their helpful role for cancer patients who are directly or indirectly exposed to NIC daily. [ABSTRACT FROM AUTHOR]

The demand for safe and eco-friendly natural colourants has risen, leading to a growing interest in colors present in different flowers and vegetables. Different biotic sources have different coloring moieties but colors like red and green are always in great demand. This factor led to study colors present in beetroot, which not only have a vibrant red hue but also possess medicinal properties too. In this study, the focus was on extracting natural color from Beetroot (Beta vulgaris) and then studies were carried out to enhancing its shelf life by complexation with inorganic salts along with stability study of red pigment i.e. betalains present in them. Spectroscopic techniques like UV VIS and IR were used to observe changes after metal chelation. The study offers valuable insights into the extraction of betalains and its subsequent complexation with inorganic salts to enhance stability that may open opportunities for the development of functional food and beverage having stable natural color replacing their synthetic counterparts. [ABSTRACT FROM AUTHOR]

This study investigated the effect of co-culturing the photobiont and mycobiont in the microbial fuel cell (MFC) cathode on biomass production, lipid generation, and power output. Chlorella vulgaris provides oxygen and nutrients for the yeast Cystobasidium oligophagum JRC1, while the latter offers CO2 and quench oxygen for higher algal growth. The MFC with co-culture enhanced the lipid output of biomass by 28.33%, and the total yield and productivity were 1.47 ± 0.18 g/l and 0.123 g/l/day, respectively. Moreover, with co-culture, the open circuit voltage of 685 ± 11 mV was two times higher than algae alone. The specific growth rate (day−1) at the cathode was 0.367 ± 0.04 in co-culture and 0.288 ± 0.05 with C. vulgaris only. The power density of the system was 5.37 ± 0.21 mW/m2 with 75.88 ± 1.89% of COD removal. The co-culture thus proved beneficial at the MFC cathode in terms of total energy output as 11.5 ± 0.035 kWh/m3, which was 1.4-fold higher than algae alone. [ABSTRACT FROM AUTHOR]

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Addressing critical environmental challenges such as greenhouse gas emissions, global warming, and eutrophication demands urgent and innovative solutions. In recent years, microalgae have emerged as a promising avenue for addressing these pressing issues. In this study, the combination of dairy and municipal wastewater is proposed as a culture medium for cultivating microalgae strains capable of sequestering atmospheric CO2. Specifically, the growth of Chlorella vulgaris was investigated using Bold's basal medium, along with varying concentrations of municipal and dairy wastewater, both with and without CO2 supplementation, to assess their CO2 capture potential. Concurrently, the efficiency of chemical oxygen demand (COD), total nitrogen, potassium, and phosphate removal from the wastewater was evaluated. Additionally, the combination of wastewater media with CO2 supplementation yielded the highest CO2 uptake rates, indicating the feasibility of simultaneous CO2 capture during microalgae cultivation. Media composition with 25% municipal wastewater: 75% dairy wastewater supplemented with CO2 demonstrated superior COD elimination with a higher percentage of nutrient removal from wastewater compared to other wastewater proportions. The nutrient removal capacity of aforementioned media also comes in line with high CO2 sequestration rate (13.57 mg L−1 h−1). These findings underscore the potential of utilizing wastewater from diverse sources as a viable culture medium for microalgae cultivation, facilitating concurrent CO2 capture and wastewater treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Global food loss and waste have raised environmental concerns regarding the generation of greenhouse gases (e.g., carbon dioxide and methane gas), which directly contribute to climate change. To address these concerns, the present research aims to upcycle food waste into an alternative culture medium for the cultivation of microalgae. Various parameters including pretreatment of food waste (i.e., autoclave and non‐autoclave), concentration of food waste culture medium (i.e., 10%, 30%, 50%, 70%, 90% and 100%), harvesting efficiency and biochemical compounds of Chlorella sp. microalgae were carried out.Based on the preliminary findings, the highest biomass concentration obtained from 10% food waste culture medium in the autoclave for Chlorella sp., including strains FSP‐E, ESP‐31 and CY‐1, were 2.869 ± 0.022, 2.385 ± 0.018 and 0.985 ± 0.0026 g L−1, respectively. Since Chlorella vulgaris FSP‐E exhibited the highest biomass concentration, this microalgal strain was selected to examine the subsequent parameters. Cultivation of C. vulgaris FSP‐E in 100FW achieves a biomass concentration of 4.465 ± 0.008 g L−1 with biochemical compounds of 6.94 ± 1.396, 248.24 ± 0.976 and 406.23 ± 0.593 mg g−1 for lipids, carbohydrates and proteins, respectively.This study shows that using food waste as an alternative culture medium for C. vulgaris FSP‐E can achieve substantial biomass productivity and biochemical content. This research work would contribute to the concept of net zero emission and transitioning toward a circular bioeconomy by upcycling food waste as an alternative culture medium for the cultivation of microalgae. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION In recent decades the demand for freshwater has drastically increased as a consequence of population growth, economic development, climate change and pollution. Therefore, any strategy for wastewater treatment can play a role in alleviating the pressure on freshwater sources.In the present study an autochthonous microalgal pool (MP), isolated from a constructed wetland, was proposed as an alternative to the secondary treatment of an urban wastewater treatment system. The MP removal efficacy was compared to those obtained using Chlorella vulgaris and Scenedesmus quadricauda, against E. coli. Results exhibited a comparable removal efficacy and after 2 days, in samples inoculated with E. coli at lower density, S. quadricauda and C. vulgaris induced a decrease of 2.0 units Log and the autochthonous MP of 1.8 units Log, whereas in samples with E. coli at higher density the bacteria were reduced 2.8, 3.4 and 2.0 units Log by S. quadricauda, C. vulgaris and the autochthonous MP, respectively. Moreover, the identification of microalgal strains isolated from the MP revealed the presence of Klebsormidium sp. K39, C. vulgaris, Tetradesmus obliquus and S. quadricauda. Although the MP composition remained quite constant, at the end of the treatment, a different distribution among the microalgal species was observed with Klebsormidium sp. K39 found as dominant.The microalgal‐based wastewater treatment appears as a valuable alternative, although further investigations, based on ‘omics’ approaches, could be applied to better explore any fluctuation within the MP species composition in an in situ trial. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, the effects of combined stress factors involving light intensity and salinity (NaCl, MgCl2, CaCl2, and their combinations) on the two-stage cultivation of Chlorella vulgaris for simultaneous production of biomass and high-value products, were investigated. The two-stage strategies comprised a 25-day vegetative stage in BG11 medium, followed by a 15-day combined stress stage. During salt stress conditions, the addition of 15 g L−1 CaCl2 or 7.5 g L−1 MgCl2 / 7.5 g L−1 CaCl2 mixture with 140 µmol m−2 s−1 light intensity significantly promoted the growth of C. vulgaris achieving maximum biomass productivity of 50.50 ± 0.50 and 50.25 ± 3.25 mg L−1 d−1, respectively. Cultivation of C. vulgaris in a medium containing 7.5 g L−1 NaCl/ 7.5 g L−1 CaCl2 had remarkably increased the lipid content (31.15 ± 1.18%) and lipid productivity (14.55 ± 1.48 mg L−1 d−1). The saturated fatty acids (SFAs) at 39.52–59.29%, monounsaturated fatty acids (MUFAs) at 27.16–35.47%, and polyunsaturated fatty acids (PUFAs) at 7.18–29.97%, were obtained with palmitic (C16:0), oleic (C18:1), stearic (C18:0), and linolenic (C18:3) acids as predominant fatty acids. Cultures supplemented with 5 g L−1 NaCl / 5 g L−1 MgCl2 / 5 g L−1 CaCl2 and high light intensity exposure attained consistently high carbohydrate content (52.71 ± 2.50%). The combination of 7.5 g L−1 NaCl / 7.5 g L−1 MgCl2 also resulted in a marked increase in the protein content (35.32 ± 2.20%) and total carotenoids (0.31 ± 0.03 μg mL−1) as compared to the Controls. The highest antioxidant activity (86.16%) was achieved with a 7.5 g L−1 NaCl / 7.5 g L−1 CaCl2 combination in the growth stage. The antioxidant activities were attributed to the presence of phenolics, flavonoids, and tannins due to the stressed conditions. One of the key benefits of using a combined stress strategy in this study is that if one factor has a low impact on enhancing target metabolites, other factors can compensate. [ABSTRACT FROM AUTHOR]

Thorium biosorption by a green microalga, Chlorella Vulgaris, was studied in a stirred batch reactor to investigate the effect of initial solution pH, metal ion concentration, biomass dosage, contact time, kinetics, equilibrium and thermodynamics of uptake. The green microalgae showed the highest Th adsorption capacity at 45 °C for the solution with a thorium concentration of 350 mg L−1 and initial pH of 4. The amount of uptake raised from 84 to 104 mg g−1 as the temperature increased from 15 to 45 °C for an initial metal concentration of 75 mg L−1 at pH 4. Transformation Infrared Spectroscopy (FTIR) was employed to characterize the vibrational frequency changes for peaks related to surface functional groups. Also, the scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to determine the morphological changes and elemental analysis of the biosorbent before and after the sorption process. The Langmuir isotherm was in perfect agreement with the equilibrium empirical data of thorium biosorption and the highest sorption capacity of the Chlorella Vulgaris microalgae was determined as 185.19 mg g−1. Also, the results of kinetic studies show that the thorium biosorption process follows a pseudo-second-order kinetic model. The negative value of ΔG0 indicates spontaneity and the positive values of ΔH0 indicate the endothermic nature of the adsorption process. [ABSTRACT FROM AUTHOR]

Production of microalgae for biodiesel, one of the alternative renewable energy sources, is costly due to nutrient media. Industrial and domestic wastewater contains nitrogen, phosphorus and other nutrients that are the primary food source for algae. Releasing this environmentally harmful effluent into receiving bodies of water, such as the sea or a freshwater reservoir, without prior treatment causes serious problems. Combining microalgae cultivation with wastewater treatment is a promising strategy for improving wastewater and reducing the cost of nutrient media required for algae production. In this study, wastewater obtained from a wastewater treatment facility was diluted with clean water to 0.25%, 50%, and 75% concentrations, and Chlorella vulgaris and Scenedesmus obliquus were cultured in these nutrient media for 20 days. As a result, microalgae increased their biomass and lipid content, while consuming nitrite, nitrate, phosphate, and ammonium from the wastewater as nutrients. [ABSTRACT FROM AUTHOR]

Nematodes from the genus Meloidogyne are extremely harmful to agricultural crops due to their wide geographic distribution, variety of hosts, and strong reproductive capacity. The most used phytonematoid control method is the application of nematicides, which can also affect human health and the environment. Selenol ester derivatives have pharmaceutical applications, but little is known about their biological activities. We examined whether six selenol ester derivatives were nematicidal and ovicidal to the nematodes Caenorhabditis elegans and Meloidogyne incognita, and determined their toxicity to non-target organisms. The compound Se-p-methyl phenylselenobenzoate (2e) exhibited the lowest nematicidal and ovicidal Lethal concentration (LC50) to C. elegans (4.42 and 0.56 mg/L, respectively) and M. incognita (4.6 and 2.77 mg/L, respectively), which were similar or lower than the LC50 values for the control treatment with fluensulfone in C. elegans (4.07 and 6.05 mg/L, respectively) and M. incognita (43.07 and 49.63 mg/L, respectively). Compound 2e efficiently controlled the phytoparasite in greenhouse and reduced the number of galls and eggs present in tomato roots. Compared with the negative control, compound 2e was not toxic to other organisms such as Chlorella vulgaris algae, Galleria mellonella and Aedes aegypti larvae, and the aquatic protozoan Tetrahymena pyriformis. Our findings indicate that the selenol ester derivatives are potent and effective nematicides with no toxicity to the non-target organisms tested. [ABSTRACT FROM AUTHOR]

Simple Summary: The use of alternative feed sources such as Chlorella vulgaris in diets for birds, particularly for laying hens, has been gaining attention due to its potential benefits. This study evaluates how different dietary levels of Chlorella vulgaris affect the productive performance and physical quality of eggs from laying hens. The results indicated that the incorporation of Chlorella vulgaris in the diets of the hens had a limited impact on performance parameters and positively influenced egg quality and yolk color. Chlorella vulgaris (CV) is a microalga with considerable nutritional value, containing high levels of protein, carotenoids, and polyunsaturated fatty acids, which have the potential to positively influence the productive performance and egg quality of laying hens. CV emerges as a more sustainable ingredient than soybean meal (SBM) as it can be produced locally and with fewer inputs. In this regard, a study was conducted with 48 H&N Brown Nick strain laying hens, at 19 weeks of age, over a period of 16 weeks. The hens were divided into four treatments, with 12 replicates each. The treatments consisted of providing four different diets: a control diet based on corn and SBM without the inclusion of CV, and three other diets with partial substitution of SBM by 2.5, 5, and 10% of CV. The results showed that the inclusion of CV in the diets did not significantly affect feed intake, feed conversion ratio, or egg production (p > 0.05). In addition, moderate CV levels increased egg weight, while higher levels reduced it. Haugh units, yolk index, albumen index, egg surface area, specific density, and translucency were not affected (p > 0.05), while shell index and shell thickness were lower in the groups that received the CV (p < 0.0001). Yolk color improved significantly with increasing CV levels (p < 0.0001), with darker, more intensely colored yolks at higher CV concentrations. The results of this study suggest that the incorporation of CV in the diet of laying hens had a limited impact on performance parameters. In addition, CV supplementation can positively influence egg quality and yolk color, although careful consideration of optimal levels is necessary to avoid negative effects on other parameters. [ABSTRACT FROM AUTHOR]

The three-chamber septic tank has become essential in the middle rural areas of China, although its drainage serves as a potential source of groundwater contamination. A photosynthetic electrochemical system using Chlorella vulgaris was developed to treat synthetic sewage, and the impact of environmental factors on treatment performance was investigated. The results showed that the removal efficiencies of chemical oxygen demand (COD), NH4+-N and PO43−-P reached maximum value under 1.00 times/day−1 hydraulic circulation, 0.3·g L−1 initial algae dosage and 4,350 Lux light intensity. When the optimal condition were applied to treat the effluent of three-chamber septic tank, the removal efficiencies of COD, NH4+-N , and PO43−-P were 61.95%, 88.32%, and 95.36%, respectively. This study provided an optional treatment technology of rural sewage, and future research should focus on the algae separation and recovery in practical applications. [ABSTRACT FROM AUTHOR]

Microalgal biomass for biofuel production, integration into functional food, and feed supplementation has generated substantial interest worldwide due to its high growth rate, non-competitiveness for agronomic land, ease of cultivation in containments, and presence of several bioactive molecules. In this study, genetic engineering tools were employed to develop transgenic lines of freshwater microalga Chlorella vulgaris with a higher starch content, by up-regulating ADP-glucose pyrophosphorylase (AGPase), which is a rate-limiting enzyme in starch biosynthesis. Expression of the Escherichia coli glgC (AGPase homolog) gene in C. vulgaris led to an increase in total carbohydrate content up to 45.1% (dry cell weight, DCW) in the transgenic line as compared to 34.2% (DCW) in the untransformed control. The starch content improved up to 16% (DCW) in the transgenic alga compared to 10% (DCW) in the control. However, the content of total lipid, carotenoid, and chlorophyll decreased differentially in the transgenic lines. The carbohydrate-rich biomass from the transgenic algal line was used to produce bioethanol via yeast fermentation, which resulted in a higher ethanol yield of 82.82 mg/L as compared to 54.41 mg/L from the untransformed control. The in vitro digestibility of the transgenic algal starch revealed a resistant starch content of up to 7% of total starch. Faster growth of four probiotic bacterial species along with a lowering of the pH of the growth medium indicated transgenic alga to exert a positive prebiotic effect. Taken together, the study documents the utilization of genetically engineered C. vulgaris with enriched carbohydrates as bioethanol feedstock and functional food ingredients. [ABSTRACT FROM AUTHOR]

In the face of current challenges related to climate change, maintaining the appropriate quality of freshwater becomes crucial. This study examined the effectiveness of removing heavy metals (Cu(II) and Co(II)) using Chlorella vulgaris biosorbents (dietary supplements in the form of powder). This study determined the parameters of the biosorbent (point of zero charge (PZC) analysis using scanning electron microscopy with back-scattered electron (SEM-BSE) and Fourier transform infrared spectroscopy (FT-IR) analysis). Batch tests were also performed to determine the kinetic constants and adsorption equilibrium of Cu(II) and Co(II) ions. Based on the conducted research, it was found that a pseudo-second-order equation describes the kinetics of the biosorption process. Among the studied adsorption isotherms, the Langmuir and Freundlich models fit best. The results indicate that single-layer adsorption took place and Chlorella vulgaris is a microporous adsorbent. The maximum sorption capacity in the single-component system for Cu(II) and Co(II) was 30.3 mg·g−1 and 9.0 mg·g−1, respectively. In contrast, in the binary system, it was 20.8 mg·g−1 and 19.6 mg·g−1 (extended Langmuir model) and 23.5 mg·g−1 and 19.6 mg·g−1 (Jain-Snoeyinka model). Chlorella vulgaris is an effective biosorbent for removing heavy metals from freshwater. This technology offers an ecological and economical solution for improving water quality, making it a promising alternative to traditional purification methods. [ABSTRACT FROM AUTHOR]

The current study explored the influence of dietary supplementation of Chlorella vulgaris dried powder (CV) with zinc-oxide-nanoparticles (ZnO-NPs), and/or selenium-nanoparticles (Se-NPs) on broilers’ growth, antioxidant capacity, immune status, histological responses, and gene expression of some related genes. Several 200 one-day-old Cobb-500 male chicks were distributed into 5 groups with four replicates each. In the 1st group, birds were fed the basal diet (BD). In the 2nd, 3rd, 4th, and 5th groups, birds received the BD supplemented with CV only, CV + ZnO-NPs, CV + Se-NPs, and CV + ZnO-NPs + Se-NPs, respectively. The CV dried powder, ZnO-NPs, and Se-NPs were added to the BD at a rate of 1 g, 40 mg, and 0.3 mg/kg diet, respectively. After 6 weeks of feeding, increases in final body weights (P < 0.05), body weight gain (P < 0.05), and feed intake (P < 0.05) were linked with improvements in FCR (P < 0.05) and intestinal morphometric indices (P < 0.05), and marked up-regulations of MYOS (P < 0.05), GHR (P < 0.05), and IGF (P < 0.05) genes were established. Additionally, distinct increases in antioxidant enzyme activities of SOD (P < 0.05), and GPX (P < 0.05) with increases in the mRNA copies of their genes were measured. Moreover, slight improvement in immunity indices, WBCs count (P > 0.05), and phagocytic and lysozyme activities (P > 0.05) were found. However, distinct increases in phagocytic index (P < 0.05) and up-regulations of IL-1β and TNF, and down-regulation of IL-10 mRNA levels were reported (P < 0.05). These findings were prominent in the case of the separate supplementation of CV with ZnO-NPs or Se-NPs confirming the synergistic mechanisms of CV with ZnO-NPs or Se-NPs. Thus, the synergetic supplementation of CV with ZnO-NPs, or Se-NPs in the broiler’s diet could augment their growth and antioxidant response. [ABSTRACT FROM AUTHOR]

The study investigates the influence of various catalysts (Ni/TiO2, Co/TiO2, and Zeolite) on the hydrothermal liquefaction of microalgae and explores the effect of co-solvents (acetone, methanol, and toluene) on biocrude yield from different microalgae three species namely Nannochloropsis oculata, Chlorella vulgaris, and Spirulina maxima. Catalyst characterization using FESEM, XRD, and BET analysis revealed distinct properties. Under Co-TiO2, Nannochloropsis oculata and Chlorella vulgaris yield 56.21% and 57.6% biocrude at 5% loading; Spirulina maxima yields 45.3% at 2.5% loading. With Ni-TiO2, Nannochloropsis oculata yields 52.4% at 2.5% loading; Chlorella vulgaris yields 44.7% at 5%; Spirulina maxima yields 44% at 2.5% loading. Zeolite yields: Spirulina maxima and Chlorella vulgaris yield 53.8% and 52.1% at 2.5%; Nannochloropsis oculata yields 48.3% at 7.5% loading. Co-solvent addition significantly boosts biocrude yield; methanol and toluene yield 53.7% and 49.2% for Chlorella vulgaris and Spirulina maxima, respectively, while acetone yields 57.6% for Nannochloropsis oculata. Different solvents extract diverse functional groups such as alkanes, halides, aromatics, and aldehydes which has wide industrial applications. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is an environmental pollutant known as endocrine disruptor. Cd has been reported to induce perturbations of the testicular functions and the subsequent decline of the male fertility of both animals and humans. Chlorella vulgaris (ChV) a species of green microalga has been reported to have multiple beneficial activities such as anti-inflammatory, antioxidant, and antiapoptotic effects. Thus, this work was conducted to declare the benefits of Chlorella vulgaris (ChV) (500 mg/kg doses) against cadmium chloride CdCl2 (2 mg/kg doses) toxicity on the main and accessory reproductive organs' weight, structure, and function of male rats. Briefly, 40 adult male rats in 4 groups (n = 10) were used as follows; control, ChV, CdCl2, and CdCl2+ChV. (i) The 1st group was kept as control fed on pellet chow and water ad libitum. (ii) The second group is Chlorella vulgaris (ChV) group fed with C. vulgaris alga for 10 days (500 mg/kg BW). (iii) The third group was administrated CdCl2 (2mg/kg BW) via subcutaneous injection (S/C) daily for 10 days. (iv) The fourth group administered both CdCl2 and ChV with the abovementioned doses daily for successive 10 days. Our observations declared that cadmium exhibited an adverse influence on the testes and prostate gland architecture indicated by seminiferous tubule destruction, testicular edema, degeneration of Leydig cells, and prostate acini damage. All together affect the epididymal semen quality and quantity including sperm viability, motility, and count. Interestingly, ChV could restore the testicular architecture and spermatozoa regeneration accompanied by semen quality improvement and increased reproductive hormones including testosterone. On the other side, ChV suppresses reactive oxygen species (ROS) formation via enhancement the antioxidant-related genes in the testicular tissue including SOD, CAT, GSH, and MDA and maintaining spermatocyte survival via suppression of apoptotic related genes including caspase3 and activating steroidogenic related genes including StAR and HSD17β3 in the cadmium-treated testes. In this study, ChV could enhance male fertility under normal or stressful conditions and ameliorate the adverse effects of hazardous heavy metals that are widely distributed in our environment. [ABSTRACT FROM AUTHOR]

The impacts of cumulative Chlorella vulgaris intake (proportion of microalga in the diet multiplied by the total feed consumed by each bird) on broiler carcass traits, meat quality and oxidative stability were reviewed to identify the optimal intake levels for maximising benefits. Our findings indicate that a cumulative intake of 8.73 g/bird significantly enhances thigh yield, while levels ranging from 8.73 to 401 g/bird optimise carcass weight and overall meat quality. However, higher cumulative levels may reduce carcass dressing percentage due to metabolic inefficiencies. Furthermore, C. vulgaris intake improves the oxidative stability of broiler meat by increasing antioxidant levels and balancing pro- and antioxidants. Including C. vulgaris in broiler diets boosts total carotenoid content, and antioxidant assays confirm that it enhances meat oxidative stability, with low to moderate cumulative intake levels (8.73 to 401 g/bird) providing the best balance of benefits. Optimal oxidative stability and antioxidant properties were observed at a cumulative intake level of 401 g/bird, showing significant improvements in meat antioxidant capacity. Higher levels may lead to diminishing returns or potential negative effects due to the digestibility issues of the microalga. Future research should refine intake models, understand the bioavailability of C. vulgaris nutrients and explore cost-effective methods to enhance its digestibility, to ensure its viability and sustainability as a feed additive. [ABSTRACT FROM AUTHOR]

Polymers and biopolymers have gained significance due to their applicability and use in industry reducing the negative impact of polymers based on petroleum. A possible solution for the conventional polymer's biodegradability is bio‐composites, which contain natural fibers or aggregates such as microalgae. Hence, microalgae biomass has a promising application to address the biodegradability issue of conventional polymers. In this study, Chlorella vulgaris biomass was mixed with pectin for control samples with glycerol as plasticizer. The mixture microalgae‐pectin‐glycerol, and the addition of pine needles was used to evaluate the tensile strength and compression of the bio‐composite. This bio‐composite showed a higher Young's modulus of 95.66 MPa for blend C2 and a higher strength with 20% of pectin concentration in the mixture. Additionally, the pine needle addition did not have a low effect between the compression results. On the other hand, analysis on elasticity showed that the full recovery of the bio‐composite happened after 10 min in all the blends. Also, the bio‐composite showed a slow release of nitrogen and phosphorous after 5 days of water addition, indicating an effective slow release for blend B for both nutrients. Water uptake capacity and loss of soluble material was studied using pullulan, chitosan, and cetyltrimethylammonium bromide additives. These cationic surfactants demonstrated their potential for reduction of water solubility of the bio‐composite. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: The presence of heavy metals, specifically cadmium, in the environment poses significant threats to both ecological systems and human health. However, microalgae have shown potential in addressing this issue through their ability to absorb cadmium and produce valuable biomass, making them a promising solution for bioremediation. Among the various microalgae species, Chlorella vulgaris stands out as a suitable candidate due to its potential for biodiesel production and its capacity to effectively absorb cadmium. Therefore, the main objective of this study is to assess the toxicity of cadmium on Chlorella vulgaris cells using network meta-analysis as a methodology.METHODS: A comprehensive search was conducted on Scopus, Scilit, Google Scholar, and Web of Science to identify relevant studies published from 1 January 1990 to 16 January 2024. Only studies that reported the cell number of Chlorella vulgaris as a result of cadmium exposure were considered for inclusion. The collected data were then subjected to Bayesian frequentist network meta-analysis, utilizing standardized mean difference and a 95 percent confidence interval as measures of effect size. Additionally, a linear regression analysis was performed to examine the dose-dependent impact of cadmium toxicity.FINDINGS: Dose-dependent toxic effects of cadmium on Chlorella vulgaris were evident (R-square of more than 0.90), particularly at a concentration of 1 part per million, deemed as the maximum tolerable threshold. Prolonged exposure revealed a concentration-dependent reduction in cell viability, suggesting potential lifespan shortening. A comparison of growth stimulants, gibberellic acid and brassinolide (standard means differences of 1.7 and 3.8, respectively), in mitigating cadmium toxicity indicated the latter superior effectiveness in sustaining microalgal survivability. The presence of high nitrogen and low phosphorous levels was found to be significantly associated with a reduction in Chlorella vulgaris cells due to cadmium exposure.CONCLUSION: This research has provided conclusive proof of the harmful effects of cadmium on Chlorella vulgaris through the implementation of Bayesian frequentist network meta-analysis, offering valuable insights for environmental management practices. The findings reveal concentration-dependent effects of cadmium toxicity. The survivability of Chlorella vulgaris is determined by the compositions of macronutrients nitrogen and phosphorous. Comparative analyses highlight the superior protective effect of brassinolide over gibberellic acid in mitigating cadmium toxicity. Overall, the findings highlight the potential of Chlorella vulgaris in both bioremediation of heavy metals and biomass production.

BACKGROUND AND OBJECTIVES: During this energy transition, research is being done to develop sustainable ways to support the shift to a decarbonized energy and production system. These ways include using renewable energy sources to promote circularity in products, green technologies, and safer procedures. Anaerobic digestion of palm oil mill effluent is a beneficial process for generating biogas, while the waste can also be utilized as fertilizer. The biogas can be further refined into biomethane, a valuable resource commonly used in transportation and power generation. The objective of this study is to examine the enhancement of biogas from Palm oil mill effluent and the elimination of sludge nutrients by utilizing microalgae Chlorella vulgaris. The microalgae will be cultivated in a modified photobioreactor to enhance the capture of carbon dioxide.METHODS: The study utilized anaerobic batch reactor digesters. A modified photobioreactor, consisting of two columns separated by a membrane, was developed for the technological advancement of biogas upgrading, specifically for carbon dioxide capture and biogas upgrading. A technological gap in biogas upgrade technology innovation is filled by the improved photobioreactor. To optimize the bio-fixation of carbon dioxide from flue gas, it is essential to carefully select a suitable strain of microalgae that possesses both a strong ability to absorb carbon dioxide and a high tolerance to varying concentrations of this gas. By choosing the right strain, the efficiency of carbon dioxide removal can be significantly enhanced. Since Chlorella vulgaris microalgae have demonstrated this potential, they were chosen for this investigation. Microalgae also play a role in removing nutrients contained in the sludge. FINDINGS: Numerous chemical and biological methods have been used to upgrade biogas. Results of biological upgrading of biogas from palm oil mill effluent have been reported, with carbon dioxide removal reaching 89 percent until the methane concentration of the biogas is upgraded to 84 percent. The highest biomass of 1,835 grams per liter was achieved by culturing the microalgae Chlorella vulgaris in laboratory-scale photobioreactors. In this study, the application of 15 percent volume per volume biogas with an optical density of 0.4 was found to be optimal for the growth of the microalgae. The cultivation period lasted for 14 days. The peak biomass production was observed due to the achievement of a remarkable 98 volume per volume efficiency in carbon dioxide removal, which subsequently led to a significant rise in methane content, reaching 60 percent. The enhanced biogas achieved a peak methane content of 98 percent, indicating a significant improvement in quality.CONCLUSION: The findings of this study, conducted using a modified photobioreactor, indicate that Chlorella vulgaris demonstrated high efficacy in the removal of carbon dioxide, with a rate of up to 90 percent. Additionally, it exhibited remarkable performance in upgrading biogas derived from palm oil mill effluent, achieving a conversion rate of up to 98 percent. The optical density of microalgae at 0.4 played a crucial role in these processes. Furthermore, Chlorella vulgaris showcased its ability to effectively eliminate nutrient nitrogen, reaching a removal rate of 90 percent at an optical density of 0.2. Moreover, it demonstrated a phosphate removal rate of 80 percent at an optical density of 0.4.