Search Results (89)

Phytoene is a colourless carotenoid widely available from dietary sources and a precursor for the synthesis of other carotenoids. Although present at high concentrations across different tissues, phytoene is largely viewed as not having physiological activity. Here, we utilize the model organism C. elegans to show that phytoene is bioactive and has anti-ageing properties. Supplementation with phytoene protects against oxidative damage and amyloid-β₄₂ proteotoxicity (a major pathology of Alzheimer’s disease), and extends lifespan. We also examine extracts from two microalgae, Chlorella sorokiniana and Dunaliella bardawil. We show that the extracts contain high levels of phytoene, and find that these phytoene-rich extracts have protective effects similar to pure phytoene. Our findings show that phytoene is a bioactive molecule with positive effects on ageing and longevity. Our work also suggests that phytoene-rich microalgae extracts can utilized to produce foods or supplements that promote healthy ageing and prevent the development of chronic age-related diseases. Full article

Chlorella sorokiniana, isolated from a pond adjacent to a cement plant, was cultured using flue gas collected directly from kiln emissions using 20 L and 25000 L photobioreactors. Lipids, proteins, and polysaccharides were analyzed to understand their overall composition for potential applications. The lipid content ranged from 17.97% to 21.54% of the dry biomass, with carotenoid concentrations between 8.4 and 9.2 mg/g. Lutein accounted for 55% of the total carotenoids. LC/MS analysis led to the identification of 71 intact triacylglycerols, 8 lysophosphatidylcholines, 10 phosphatidylcholines, 9 monogalactosyldiacylglycerols, 12 digalactosyldiacylglycerols, and 1 sulfoquinovosyl diacylglycerol. Palmitic acid, oleic acid, linoleic acid, and α-linolenic acid were the main fatty acids. Polyunsaturated fatty acid covers ≥ 56% of total fatty acids. Protein isolates and polysaccharides were also extracted. Protein purity was determined to be ≥75% by amino acid analysis, with all essential amino acids present. Monomer analysis of polysaccharides suggested that they are composed of mainly D-(+)-mannose, D-(+)-galactose, and D-(+)-glucose. The results demonstrate that there is no adverse effect on the metabolite profile of C. sorokiniana biomass cultured using flue gas as the primary carbon source, revealing the possibility of utilizing such algal biomass in industrial applications such as animal feed, sources of cosmeceuticals, and as biofuel. Full article

Chlorich^®EnergyBoost, a water extract obtained from Chlorella sorokiniana, has been proposed to enhance physical performance and provide anti-fatigue effects. This study assessed the impact of Chlorich^®EnergyBoost supplementation on physical performance and its anti-fatigue properties. Twenty-four mice were allocated into four groups: (1) the control group receiving only water,;(2) the 1X group (49.2 mg/kg/day); (3) the 2X group (98.4 g/kg/day); and (4) the 5X group (246 g/kg/day). All groups were orally administered the supplements for four consecutive weeks. The evaluation included grip strength, swimming endurance, an exhaustion test, and serum biochemistry analysis. Additionally, the study examined the bioactive peptides through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) and conducted bacterial reverse mutation and acute oral toxicity tests for safety assessment. The findings indicated that Chlorich^®EnergyBoost supplementation led to a significant reduction in serum lactate levels by 14.08% to 22.54% and blood urea nitrogen levels by 12.23% to 16.76%, an increase in the lactate clearance rate by 0.28 to 0.35, an enhancement of muscle glycogen storage by 1.10 to 1.44-fold, and hepatic glycogen storage by 1.41 to 1.47-fold. These results demonstrated dose-dependent effects. MALDI-TOF analysis revealed the expression of dihydrolipoamide dehydrogenase and superoxide dismutase. Both the bacterial reverse mutation and acute oral toxicity tests showed no adverse effects. Full article

Microalgae-based water treatments for the removal of different types of pollution have been gaining considerable attention during the last few decades. However, information about microalgae potential in the removal of pharmaceuticals and personal care products (PPCPs) and the ecotoxicological outcomes is still limited. Therefore, in this work, we aimed at investigating salicylic acid removal from water by three different microalgae strains, namely Chlorella sorokiniana, Chlorella vulgaris and Scenedesmus obliquus. For such a purpose, photobioreactors were operated under batch and semi-continuous mode. Apart from determining the reduction in the concentration of salicylic acid attained by each strain, we used zebrafish embryo bioassays to assess the efficiency of microalgae to reduce its toxicity effects. S. obliquus was the strain that achieved the most significant decrease in the concentration and toxic effects of salicylic acid. Indeed, S. obliquus was able to rescue mortality and reduce abnormalities at practically 100%. The efficiency of C. sorokiniana and, especially, that of C. vulgaris were not so remarkable, indicating that the removal of SA and its toxic effects from water by microalgae is markedly strain dependent. The obtained results proved the importance of considering toxic effects for a more comprehensive evaluation of microalgae efficiency in the removal of PPCPs in view of an adequate selection for water treatment. Full article

Marine and extreme environments harbor a huge diversity of microorganisms able to produce new bioactive metabolites with beneficial health effects. In this study, ethanol, aqueous, methanol, and acetone extracts and protein hydrolysates were obtained from five different microalgae species and two haloarchaea. An in vitro study of cytotoxicity, migration, angiogenic effect, antioxidant capacity, and modulation of detoxifying enzyme expression was carried out using resistant (HCT-15) and non-resistant (T84) colon cancer tumor lines. Our results showed that the aqueous extract of the microalga Chlorella sorokiniana induced the greatest cytotoxic effect in both cell lines, while the ethanolic extracts of the archaea Haloarcula hispanica and Halobacterium salinarum caused the greatest inhibition on the migratory capacity. Meanwhile, the protein hydrolyzate and the aqueous extract of the microalga Chlorella sorokiniana significantly protected cells against hydrogen peroxide damage. Moreover, the aqueous extracts of Haloarcula hispanica and Halobacterium salinarum resulted in inducing the greatest increase in the activity of the detoxifying enzymes enzyme quinone oxidoreductase and glutathione S-transferase. These preliminary results suggest that aqueous extracts of some microalgae and haloarchaea may be promising candidates for an adjuvant therapy against colorectal cancer. However, additional research is required to identify the active principles and elucidate the mechanisms of action involved. Full article

Rotavirus is the main cause of acute diarrhea in children up to five years of age. In this regard, probiotics are commonly used to treat or prevent gastroenteritis including viral infections. The anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana, by reducing viral infectivity and improving IFN-type I response, has been previously reported. The present study aimed to study the effect of B. longum and/or C. sorokiniana on modulating the antiviral cellular immune response mediated by IFN-γ, IL-10, SOCS3, STAT1, and STAT2 genes in rotavirus-infected cells. To determine the mRNA relative expression of these genes, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection. In addition, infected cells were treated with B. longum and/or C. sorokiniana. Cellular RNA was purified, used for cDNA synthesis, and amplified by qPCR. Our results demonstrated that the combination of B. longum and C. sorokiniana stimulates the antiviral cellular immune response by upregulating IFN-γ and may block pro-inflammatory cytokines by upregulating IL-10 and SOCS3. The results of our study indicated that B. longum, C. sorokiniana, or their combination improve antiviral cellular immune response and might modulate pro-inflammatory responses. Full article

Four strains of green microalgae (Scenedesmus acutus, Scenedesmus vacuolatus, Chlorella sorokiniana, and Chlamydomonas reinhardtii) were compared to determine growth and pigment composition under photoautotrophic or heterotrophic conditions. Batch growth experiments were performed in multicultivators with online monitoring of optical density. For photoautotrophic growth, light-limited (CO₂-sufficient) growth was analyzed under different light intensities during the exponential and deceleration growth phases. The specific growth rate, measured during the exponential phase, and the maximal biomass productivity, measured during the deceleration phase, were not related to each other when different light intensities and different species were considered. This indicates species-dependent photoacclimation effects during cultivation time, which was confirmed by light-dependent changes in pigment content and composition when exponential and deceleration phases were compared. Except for C. reinhardtii, which does not grow on glucose, heterotrophic growth was promoted to similar extents by acetate and by glucose; however, these two substrates led to different pigment compositions. Weak light increased the pigment content during heterotrophy in the four species but was efficient in promoting growth only in S. acutus. C. sorokiniana, and S. vacuolatus exhibited the best potential for heterotrophic biomass productivities, both on glucose and acetate, with carotenoid (lutein) content being the highest in the former. Full article

Prymnesium parvum is a harmful alga found in brackish waters worldwide whose toxins can be lethal to aquatic organisms. Established field methods to control blooms of this species, however, are unavailable. Earlier studies showed that various extracts of giant reed (Arundo donax) can suppress P. parvum growth and that ellipticine, an allelochemical present in giant reed, is a potent algicide against this species. The unintended effects of giant reed products on nontarget organisms, however, are not fully understood. This study determined the effects of giant reed leachate (aqueous extract of dried chips) and ellipticine on growth of P. parvum and the green microalga Chlorella sorokiniana; survival and reproduction of the planktonic crustacean Daphnia pulex; and hatching success, larval survival, and larval swimming behavior of the teleost fish Danio rerio. Leachate made with 3 g chips L⁻¹ was lethally toxic to P. parvum and D. pulex, stimulated C. sorokiniana growth, and impaired D. rerio behavior. Leachate at 1 g L⁻¹ fully suppressed P. parvum growth, had moderate effects on D. pulex reproductive output, and had no effects on D. rerio. Ellipticine at 0.01 mg L⁻¹ irreversibly inhibited P. parvum growth, acutely but reversibly inhibited C. sorokiniana growth, slightly delayed D. pulex reproduction, and had no effects on D. rerio. These observations suggest that when applied at appropriate concentrations, natural products derived from giant reed can be used as tools to specifically control P. parvum growth with minimal effects on nontarget species. Full article

Microalgae offer a promising solution for efficiently treating high-nitrogen wastewater and recovering valuable nutrients. To optimize microalgae growth and nutrient assimilation, case-dependent studies are essential to demonstrate the process’s potential. This study aimed to evaluate the treatment capacity of high-nitrogen anaerobic digestion effluent as a nutrient source for a C. sorokiniana microalgal culture in a tubular photobioreactor. The study had two primary objectives: to assess how the concentration and composition of the digestate influence microalgae growth, and to identify the preferred nitrogen forms assimilated by the microalgae during long-term, continuous operation. A 20 L tubular airlift bioreactor was constructed and used in batch mode; various digestate concentrations were examined with ammonia nitrogen levels reaching to 160 mg/L. These experiments revealed a biomass growth rate of up to 130 mg/L/d and an ammonia nitrogen assimilation rate ranging from 8.3 to 12.5 mg/L/d. The presence of phosphorous proved essential for microalgae growth, and the growth entered a stationary phase when the initial phosphorous was fully assimilated. A nitrogen-to-phosphorous (N/P) ratio of 10 supported efficient species growth. While ammonia was the preferred nitrogen form for microalgae, they could also utilize alternative forms such as organic and nitrate nitrogen, depending on the specific digestate properties. The results from the continuous photobioreactor operation confirmed the findings from the batch mode, especially regarding the initial nitrogen and phosphorous content. An important condition for nearly complete ammonia removal was the influent dilution rate, to balance the nitrogen assimilation rate. Moreover, treated effluent was employed as dilution medium, contributing to a more environmentally sustainable water management approach for the entire process, at no cost to the culture growth rate. Full article

The residual antibiotics in livestock excreta (LE) have been regarded as a potential threat to the ecosystem and human society. Some photoautotrophic microalgae, however, were found to metabolize them during active biomass photosynthesis. This study investigates how the strength of the antibiotics impacts the overall biodiesel yield and composition of the harvested microalgal biomass grown from LE. The microalgal growth results demonstrate that increasing the concentration of residual antibiotics suppresses the microalgal growth rate from 0.87 d⁻¹ to 0.34 d⁻¹. This 61% lower biomass production rate supports the proposition that the kinetic impact of antibiotics may slow lipid synthesis. Moreover, the analytical results of fatty acid methyl ester (FAME) demonstrate that amoxicillin substantially reduces the C16:0 content by over 96%. This study evidences that the functional group similarity of amoxicillin may competitively inhibit the esterification reaction by consuming methanol. This explanation further highlights that residual antibiotics interfere with microalgal lipid synthesis and its transesterification. Moreover, it was confirmed that the presence of residual antibiotics may not affect the major nutrient removal (total nitrogen: 74.5~78.0%, total phosphorus: 95.6~96.8%). This indicates that residual antibiotics inhibit the metabolism associated with carbon rather than those associated with nitrogen and phosphorus, which is connected to the decrease in the biodiesel yield. Overall, these results reveal that the frequent abuse of antibiotics in livestock may harm the eco-friendly conversion of waste-into-bioenergy strategy. Full article

Unnecessary discharge of nutrient-rich aquaculture wastewater is a significant threat to the environment, exacerbating massive resource wasting worldwide. Microalgae-based circular economy strategies utilize atmospheric CO₂ and aquaculture wastewater nutrients and convert them into valuable compounds. Lutein, a natural pigment, is a nutritional supplement for eye protection, anti-cancer and anti-inflammatory effects, and other health benefits. It is widely utilized in the food and pharmaceutical industries. The primary purpose of this study is to reuse aquaculture wastewater to grow microalgae and optimize conditions to achieve a high yield of lutein as well as the removal of nutrients from wastewater. When cultured in 1.0× BG11 nutrient-added aquaculture wastewater and aerated using 2% CO₂, the biomass concentration and lutein content of Chlorella sorokiniana NIES-2168 increased to 1.78 g L⁻¹ and 7.43 mg g⁻¹, respectively. A two-stage culture strategy further increased the lutein content and yield of microalgae. The highest lutein content of 13.95 mg g⁻¹ and lutein productivity of 3.63 mg L⁻¹ d⁻¹ in the second stage aligned with other phototrophic microalgae currently used for lutein production. C. sorokiniana NIES-2168 also showed exceptional nitrogen and phosphorus removal efficiency, with nitrate and phosphate removal rates reaching 96.07% and 96.75% during the two-stage culture process. Full article

Microalgae cultivation is a promising approach for sustainable CO₂ fixation. This work describes the optimization of a laboratory-scale experimental model for microalgae cultivation under CO₂ supplementation. The experimental model was developed using a stirred clear glass reactor, white LED strips, connection system caps with three ports, tubes, valves, regulators, and N₂-CO₂ compressed gas cylinder. Three microalgae strains were used: Raphidocelis subcapitata ATCC22662, Desmodesmus communis NIVA-CHL 7, and Chlorella sorokiniana NIVA-CHL 176. The appropriate medium for cultivation of each of these strains was selected. The optimized experimental model demonstrated the positive influence of CO₂ supplementation on microalgae growth, particularly for Chlorella sorokiniana. Full article

In terrestrial plants, strigolactones act as multifunctional endo- and exo-signals. On microalgae, the strigolactones determine akin effects: induce symbiosis formation with fungi and bacteria and enhance photosynthesis efficiency and accumulation of biomass. This work aims to synthesize and identify strigolactone mimics that promote photosynthesis and biomass accumulation in microalgae with biotechnological potential. Novel strigolactone mimics easily accessible in significant amounts were prepared and fully characterized. The first two novel compounds contain 3,5-disubstituted aryloxy moieties connected to the bioactive furan-2-one ring. In the second group of compounds, a benzothiazole ring is connected directly through the cyclic nitrogen atom to the bioactive furan-2-one ring. The novel strigolactone mimics were tested on Chlorella sorokiniana NIVA-CHL 176. All tested strigolactones increased the accumulation of chlorophyll b in microalgae biomass. The SL-F3 mimic, 3-(4-methyl-5-oxo-2,5-dihydrofuran-2-yl)-3H-benzothiazol-2-one (7), proved the most efficient. This compound, applied at a concentration of 10⁻⁷ M, determined a significant biomass accumulation, higher by more than 15% compared to untreated control, and improved the quantum yield efficiency of photosystem II. SL-F2 mimic, 5-(3,5-dibromophenoxy)-3-methyl-5H-furan-2-one (4), applied at a concentration of 10⁻⁹ M, improved protein production and slightly stimulated biomass accumulation. Potential utilization of the new strigolactone mimics as microalgae biostimulants is discussed. Full article

This study investigated the effect of dietary protein levels on Litopenaeus vannamei. Five isolipid diets with protein levels of 32%, 36%, 40%, 44% and 48% were prepared using C. sorokiniana as the main protein source. L. vannamei (initial body weight 0.83 ± 0.02 g) were fed these five diets for 8 weeks and referred to as the CHL32, CHL36, CHL40, CHL44 and CHL48 groups, respectively. When the feeding trial was finished, the growth performance, body composition, intestinal digestion and microbiota of L. vannamei were studied. The results showed that the maximum weight gain rate (WGR) of L. vannamei was in the CHL40 group while the lowest feed conversion ratio (FCR) was in the CHL48 group. According to the regression analysis using WGR as the evaluation index, the best growth performance of L. vannamei was obtained when the dietary protein level was 40.81%. The crude protein content of whole shrimp showed an increasing and then decreasing trend with increasing dietary protein levels. Furthermore, the L. vannamei muscle amino acid composition was relatively stable and, to some extent, independent of dietary protein levels. Trypsin, lipase and amylase (AMS) activity increased and then decreased with increasing dietary protein levels and, significantly, peaked in the CHL44 group. Analysis of the alpha diversity of the intestinal microbiota showed that the Chao1 index peaked in the CHL40 group and was significantly lower in the CHL48 group. Additionally, the relative abundance of pathogenic bacteria decreased significantly while the relative abundance of beneficial bacteria increased significantly in the intestine of L. vannamei as the dietary protein levels increased. The functional prediction of the intestinal microbiota revealed that dietary protein levels may influence the growth of L. vannamei by regulating various metabolic activities, and the highest WGR in the CHL40 group may have been related to the significant enrichment of nicotinate and nicotinamide metabolism and biotin metabolism functions. In summary, the optimal protein requirement for L. vannamei was around 40% when C. sorokiniana was used as the primary protein source. Too high or too low dietary protein levels could adversely affect shrimp body composition, intestinal digestion and microbiota. Full article

The type of protein source in diets has many effects on shrimp. In this study, Litopenaeus vannamei with an initial body weight of 3.68 ± 0.002 g were fed for 8 weeks on three experimental diets (isoproteic: 41.00%; isolipidic: 7.61%) that were formulated using fish meal (FM), Chlorella sorokiniana (CHL), and Clostridium autoethanogenum protein (CAP) as the primary protein sources, respectively. This study examined the growth, non-specific immunity, intestinal digestion, and microbiota of L. vannamei after the feeding experiment concluded. Compared to the FM group, the findings indicate that the weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) of L. vannamei were notably enhanced via dietary CAP. The CHL group exhibited the highest levels of catalase (CAT), phenoloxidase (PO), and superoxide dismutase (SOD) activities in the gills of L. vannamei, whereas the FM group had the lowest levels. Conversely, the malondialdehyde (MDA) content showed the opposite trend. Both dietary CHL and CAP promoted the digestive enzyme activities of L. vannamei, with dietary CAP having a more pronounced promotional effect. An analysis of alpha diversity indicated that the consumption of dietary CHL substantially enhanced the abundance and diversity of microbiota in the intestinal tract of L. vannamei. Furthermore, the dietary CHL significantly increased the colonization of immune-associated beneficial bacteria and inhibited the colonization of pathogenic bacteria in the intestinal tract of L. vannamei, whereas dietary CAP mainly increased the colonization of growth-associated beneficial bacteria. Functional predictions showed that different dietary protein sources affect various metabolic activities and signaling pathways of L. vannamei, and some functions, including signal transduction, cell motility, and the immune system, were significantly enhanced in the CHL group. In summary, both dietary CHL and dietary CAP promoted growth and immunity in L. vannamei compared to dietary FM. The results of this study could be helpful for the sustainable development of shrimp farming. Full article