Effect of spirulina on risk of hospitalization among patients with COVID-19: the TOGETHER randomized trial.

BACKGROUND: Algae-derived nutraceuticals, such as spirulina, have been reported to have biological activities that may minimize clinical consequences to COVID-19 infections. OBJECTIVES: This study aimed to determine whether spirulina is an effective treatment for high-risk patients with early COVID-19 in an outpatient setting. METHODS: The TOGETHER trial is a placebo-controlled, randomized, platform trial conducted in Brazil. Eligible participants were symptomatic adults with a positive rapid test for SARS-CoV-2 older than 50 y or with a known risk factor for disease severity. Patients were randomly assigned to receive placebo or spirulina (1 g twice daily for 14 d). The primary end point was hospitalization defined as either retention in a COVID-19 emergency setting for >6 h or transfer to tertiary hospital owing to COVID-19 at 28 d. Secondary outcomes included time-to-hospitalization, mortality, and adverse drug reactions. We used a Bayesian framework to compare spirulina with placebo. RESULTS: We recruited 1126 participants, 569 randomly assigned to spirulina and 557 to placebo. The median age was 49.0 y, and 65.3% were female. The primary outcome occurred in 11.2% in the spirulina group and 8.1% in the placebo group (odds ratio [OR]: 1.24; 95% credible interval: 0.84, 1.86). There were no differences in emergency department visit (OR: 1.21; 95% credible interval: 0.81, 1.83), nor time to symptom relief (hazard ratio: 0.90; 95% credible interval: 0.79, 1.03). Spirulina also not demonstrate important treatment effects in the prespecified subgroups defined by age, sex, BMI, days since symptom onset, or vaccination status. CONCLUSIONS: Spirulina has no any clinical benefits as an outpatient therapy for COVID-19 compared with placebo with respect to reducing the retention in an emergency setting or COVID-19-related hospitalization. There are no differences between spirulina and placebo for other secondary outcomes. This trial was registered at clinicaltrials.gov as NCT04727424.

Impact of ambient conditions on the minor nutrients content in spirulina "Arthrospira platensis" (AP) extracted from Lake Chad revealed by fluorescence spectroscopy coupled with chemometric methods.

In this study, the technique of fluorescence spectroscopy coupled with chemometric methods is used to analyse samples of Lake Chad Spirulina "Arthrospira platensis" (AP), either harvested and conditioned by using the traditional method at different seasons or industrially processed. The content of minor fluorescent nutrients is investigated. To this end, fluorescence excitation-emission matrices (EEMs) of 46 AP samples are recorded in aqueous solution. Synchronous fluorescence (SF) spectra are extracted from these EEMs and their important features are compared to those of PARAFAC methods. Synchronous fluorescence scanning allows different AP samples to be characterized in a single scan. The SF and PARAFAC methods yielded two groups of fluorescent compounds; the first group, consisting of vitamin-like molecules, shows excitation/emission (ex/em) peaks at 340/460, 390/462, 370/440 and 450/526 nm, attributed to caffeic acid, vitamin K, E and riboflavins respectively, while the second group, consisting of pigments, shows ex/em peaks at 610/654, 590/630 and 570/644 nm, attributed to phycocyanins, C-phycocyanin and allophycocyanin. Our fluorescence data showed that while both vitamins and pigments are present in AP during the rainy season, only fluorescent components of vitamin-like compounds are present during the dry season. PCA methods allowed classifying different AP samples according to their geographic origin and harvesting season. Fluorescence spectroscopy therefore appears to be a powerful technique for rapidly assessing the chemical composition of AP.

Stress-resilient effect of Spirulina platensis on zebrafish chronic unpredictable stress model.

Spirulina platensis is rich in nutritional profile and a great source of prebiotic with neuro-protective properties. Stress is an inevitable part of today's lives, affecting people differently, and individuals with resilient adaptations are less vulnerable to it. The present study aims at evaluating Spirulina as a prebiotic supplement in the early life of zebrafish to cope with chronic unpredictable stress (CUS) in its later stage of life. Zebrafish 5dpf larvae were fed with 1% Spirulina formulated diet for 90 days, and then adult zebrafish were subjected to CUS for 15 days to evaluate the diet's response to chronic stress. The observations were compared by studying the anxiety level through behavioural test, gut microbiota composition analysis, and the effect on the myelin sheath at the ultrastructural and molecular levels. In zebrafish given the Spirulina supplemented diet, CUS did not induce anxiety-like behaviour, Spirulina supplementation lowered the Firmicutes to Bacteroidetes ratio and helped in myelin protection, with a significant decrease in the myelin g-ratio and upregulation of myelin-related genes bdnf, mpz, olig2 and sox10 which resulted in mitigating the effect of stress as compared to fish fed with a normal diet. To conclude, Spirulina supplementation in the early life of zebrafish helps to reduce the effects of a chronic unpredictable stress. However, Spirulina's protective effect against overall stress needs to be evaluated further.

Microalgae realizes self N-doped biochar for heavy metal polluted sediment remediation.

Heavy metal contamination in sediment has become a significant global environmental challenge. Numerous studies have demonstrated the effectiveness of modified biochar to solve heavy metal contamination in sediment. However, the modification process with complex methods and expensive modifiers prevented its large-scale application. In this study, an N self-doped biochar was obtained by pyrolysis of Spirulina sp. (SBC). Meanwhile, the K2CO3 impregnation method was utilized to prepare Spirulina sp. biochar (KSBC), which demonstrated a higher specific surface area (874 m2/g) and richer O, N functional groups. The adsorption capacity of KSBC550-120 for Cu (Ⅱ), Zn (Ⅱ), and Cd (Ⅱ) was 57.9 ± 0.3 mg/g, 43.6 ± 0.7 mg/g, and 63.9 ± 0.6 mg/g, respectively. The adsorption process is primarily governed by chemical processes, mainly through ion exchange, surface complexation, dissolution-precipitation, electrostatic interactions, adsorption-reduction, and cation-π interactions. Moreover, utilizing KSBC550-120 for mixing or capping effectively reduced heavy metal concentrations in both the overlying and pore water of the sediments. 1.0 wt% KSBC550-120 with capping treatment significantly reduced the release of heavy metals from the sediment by 80.3-91.9%. This study provides effective theoretical support for re-utilizing waste algal residues and remediation of the heavy metal-contaminated river and lake sediments using microalgae biochar.

Spirulina supplementation and circuit resistance training (CRT) reduce serum asprosin and appetite and improve energy balance in men with obesity and overweight.

PURPOSE: The present study aimed to investigate the effects of 8 weeks spirulina supplementation and circuit resistance training (CRT) on asprosin, appetite, and energy balance in men with obesity and overweight. METHODS: The study comprised a single-blind randomized controlled trial. Sixty men with obesity and overweight (BMI > 25) were selected and randomly divided into four equal groups (n = 15 each) of training plus spirulina, training plus placebo, spirulina, and placebo. The participants of the training groups performed 12 movements with 40-90% maximal repetition (three sessions per week) and the supplemental groups consumed 1000 mg of spirulina per day for 8 weeks. Asprosin, appetite using visual analog scales, calorie intake, energy expenditure, and body composition were measured before and after the intervention. To analyze the data, the paired sample t-test, analysis of covariance, Bonferroni post-hoc, and Pearson correlation tests were employed using SPSS (version 20) at a significance level of p < 0.05. RESULTS: After the intervention, asprosin level (P = 0.015, P = 0.015, and P = 0.020, respectively), weight (P < 0.001, P < 0.001, and P < 0.001, respectively), calorie intake (P = 0.015, P = 0.011, and P = 0.004, respectively), and hunger (P = 0.011, P = 0.015, and P = 0.015, respectively) declined in the training plus spirulina, training plus placebo, and spirulina groups (p < 0.05). In addition, energy expenditure (P = 0.012 and P = 0.015, respectively) and fullness (P = 0.015 and P = 0.011, respectively) increased in the training plus spirulina and training plus placebo groups. The mean changes of the research indicators in the training plus spirulina group were significantly more than those of the other groups (p < 0.001). CONCLUSION: It was shown that 8 weeks of CRT and spirulina supplementation decreases the level of asprosin and improves appetite and energy balance in men with obesity and overweight.

Impact of long-term feeding a high level of Spirulina combined with enzymes on growth performance, carcass traits and meat quality in broiler chickens.

This study evaluates the effect of prolonged feeding with a high inclusion level of Spirulina, combined with peptidases, on broiler chicken's growth performance, digesta viscosity, carcass attributes and meat quality. The experiment involved 120 male broilers divided into 40 battery brooders, each housing 3 birds. Post 7-day acclimatisation with a corn and soybean-based diet, the birds were provided with one of four diets: a corn and soybean meal-based diet (CON), a mix incorporating 15% Spirulina (SP), a Spirulina-rich mix supplemented with 0.025% of commercial VemoZyme® P (SPV), or a Spirulina-rich mix supplemented with 0.10% of porcine pancreatin (SPP). The CON group had higher body weight and weight gain (p < 0.001) and a lower feed conversion ratio (p < 0.001) from day 7-21, compared to the Spirulina-fed groups. Spirulina-fed chickens significantly increased ileum viscosity (p < 0.05). Spirulina also elevated the weight (p < 0.05) of the duodenum and the length (p < 0.001) of the entire gastrointestinal tract compared to CON. Breast and thigh muscles from Spirulina-fed broilers displayed higher values of yellowness (b*) (p < 0.001), pigments (p < 0.05), and n-3 PUFA (p < 0.01), while n-6/n-3 ratio (p < 0.001) and α-tocopherol (p < 0.001) decreased relative to the CON. In conclusion, the introduction of a high level of Spirulina into broiler diets for an extended duration, has the potential to diminish birds' growth performance, possibly due to increased digesta viscosity. However, it does enhance the nutritional quality of the meat.

Design and development of multibiocomponent hybrid alginate hydrogels and lipid nanodispersion as new materials for medical and cosmetic applications.

The multibiocomponent hybrid alginate hydrogels based on brown and sea algae, containing 100 % ingredients of natural origin were prepared by ionic crosslinking reaction of a polymeric matrix with lipid nanodispersion. To the best of the Authors' knowledge such multicomponent biobased hydrogel of promising medical and cosmetical applications for the first time was obtained in the environment of flower water, received earlier as a waste by-product from various chemical processes. An innovative hybrid alginate hydrogel that is completely biodegradable and eco-friendly was obtained following waterless and upcycling trends that are in line with the principles of sustainable development. The optimal composition of the lipid nanodispersion and the polymeric matrix was selected using the statistical method of design of the experiment. Based on obtained results, multibiocomponent hybrid alginate hydrogels with various ratios of lipid nanodispersion were obtained. Subsequently, the porous structure and elasticity of the hybrid hydrogels were analyzed. Moreover, to confirm the safety of the multibiocomponent alginate hybrid hydrogels the cytotoxic tests were carried out using human fibroblasts and keratinocytes cell lines. As the final product hybrid of hydrolate-swollen alginate hydrogel and lipid nanodispersion containing several active ingredients (silymarin, bakuchiol, spirulina) was obtained.

Trends in extracting protein from microalgae Spirulina platensis, using innovative extraction techniques: mechanisms, potentials, and limitations.

Microalgal, species are recognized for their high protein content, positioning them as a promising source of this macronutrient. Spirulina platensis, in particular, is noteworthy for its rich protein levels (70 g/100 g dw), which are higher than those of meat and legumes. Incorporating this microalgae into food can provide various benefits to human health due to its diverse chemical composition, encompassing high amount of protein and elevated levels of minerals, phenolics, essential fatty acids, and pigments. Conventional techniques employed for protein extraction from S. platensis have several drawbacks, prompting the exploration of innovative extraction techniques (IETs) to overcome these limitations. Recent advancements in extraction methods include ultrasound-assisted extraction, microwave-assisted extraction, high-pressure-assisted extraction, supercritical fluid extraction, pulse-electric field assisted extraction, ionic liquids assisted extraction, and pressurized liquid extraction. These IETs have demonstrated efficiency in enhancing protein yield of high quality while maximizing biomass utilization. This comprehensive review delves into the mechanisms, applications, and drawbacks associated with implementing IETs in protein extraction from S. platensis. Notably, these innovative methods offer advantages such as increased extractability, minimized protein denaturation, reduced solvent consumption, and lower energy consumption. However, safety considerations and the synergistic effects of combined extraction methods warrant further exploration and investigation of their underlying mechanisms.

Sustainability in the Development of Natural Pigment-Based Colour Masterbatches and Their Application in Biopolymers.

This article is focused on the development and characterization of a series of biodegradable and eco-friendly colour masterbatches (MBs), based on natural pigments and biodegradable polylactic acid (PLA) and polybutylene succinate (PBS). Four commercial natural pigments were used, spirulina, curcumin, beetroot and chlorophyllin, to develop the colour masterbatches using a twin-screw extruder. The natural pigment-based MBs were added at 2, 4 and 6 wt%, as additives to study the effect on the properties of injected biodegradable parts (PLA and PBS). The injected samples were characterized in terms of their mechanical (tensile and Charpy impact tests) and visual properties (according to CieLab). In addition, the ageing of the coloured material was followed by colorimetric analysis after its exposure under a Xenon lamp. The mechanical results showed that the addition of coloured masterbatches in different percentages (2-6 wt%) did not significantly change the properties of the materials with respect to the as-received ones. A noticeable colour difference in the injected samples was observed after the first 50 h of artificial light exposure. Regarding environmental concerns, the study showed that the carbon footprint of natural pigments and electricity consumption during extrusion and pelletizing were lower.

Phytochemical Evaluation of Lepidium meyenii, Trigonella foenum-graecum, Spirulina platensis, and Tribulus arabica, and Their Potential Effect on Monosodium Glutamate Induced Male Reproductive Dysfunction in Adult Wistar Rats.

Monosodium glutamate (MSG), a sodium salt derived from glutamic acid, is widely used in commercial food products to improve taste, quality, and preservation. However, its consumption may have detrimental effects on male reproductive function. Nevertheless, plant extracts, such as Lepidium meyenii (Maca), Trigonella foenum-graecum (Fenugreek), Spirulina platensis (Spirulina), and Tribulus arabica (Tribulus), may ameliorate these adverse effects. To this effect, the phytochemical properties of Lepidium meyenii, Trigonella foenum-graecum, Spirulina platensis, and Tribulus arabica were assessed, and their potential impact on MSG-induced impairment of reproductive parameters was examined. The phytochemical composition (steroids, terpenes, phenols, flavonoids) of the plants was profiled through spectrophotometry and the antioxidant activity was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Thirty-six male Wistar rats were divided into six groups at random: a control group receiving distilled water, and five experimental groups (MSG, Maca, Fenugreek, Spirulina, and Tribulus) receiving 900 mg/kg/day of MSG dissolved in water for 45 days. Subsequently, the animals in the experimental groups were administered 500 mg/kg/day of the respective plant extract via oral gavage for an additional 35 days, while the MSG group continued to receive water only. Following the treatment period, the animals were sacrificed, and their reproductive tract organs were collected, weighed, and subjected to further analysis. Phytochemical analysis revealed the presence of diverse bioactive elements in the plant extracts, including phenolic and flavonoid compounds. Exposure to MSG negatively impacted total and progressive sperm motility, which was ameliorated by Lepidium meyenii treatment. Sperm morphology showed no significant differences among groups. Treatment of the phytochemical agents diminished histomorphometric alternations of the testicular length, germinal epithelium height, and number of cells in seminiferous tubules, which were caused by the initial administration of MSG. Testosterone and LH levels were reduced in the MSG group but improved in extract-treated groups. The study suggests Lepidium meyenii as a potential remedy for reproductive dysfunction. However, further investigation into its mechanisms and human safety and efficacy is warranted.

Interventional clinical trial on mitigating endemic fluorosis in pregnant and lactating ewes with Spirulina platensis and its impact on lamb production traits.

This interventional clinical trial aimed to assess the potential impact of Spirulina platensis supplementation on pregnant and lactating ewes living in a Moroccan endemic fluorosis area. Forty-eight ewes were divided into four equal groups: Groups I and II served as controls belonging respectively to fluorosis-free and endemic fluorosis areas, Groups III and IV received respectively 250 and 500 mg*kg-1 BW/day of S. platensis, during late pregnancy and early lactation. The results revealed that ewes reared in fluorosis-free areas exhibited significantly lower plasma fluoride and significantly higher haemoglobin levels compared to endemic fluorosis areas (P < 0.0001). However, supplementation with 500 mg*kg-1 BW*day-1 of S. platensis significantly improved these two parameters compared to Group II (P < 0.0001). Ewes in the endemic area also displayed increased oxidative stress (P < 0.05), characterized by decreased ascorbic acid levels and catalase activity, as well as elevated levels of reduced glutathione and malondialdehyde. Supplementation with 500 mg*kg-1 BW*day-1 of S. platensis enhanced the antioxidant status (P < 0.05) by increasing ascorbic acid levels and catalase activity and decreasing levels of reduced glutathione and malondialdehyde. Moreover, this dose yielded similar average daily gains compared to lambs of ewes living in fluorosis-free area. In conclusion, S. platensis may serve as a promising solution for addressing endemic fluorosis in pregnant and lactating ewes.

Self-flocculating Spirulina platensis CMB-02 to efficiently treat ammonia nitrogen of rare earth elements wastewater.

The study aimed to evaluate the cyanobacteria Spirulina platensis CMB-02 (S. platensis CMB-02) with self-flocculation properties to treat the ammonia nitrogen of rare earth elements (REEs) wastewater. The results demonstrated that S. platensis CMB-02 could effectively remove total ammonia nitrogen (TAN) and total inorganic nitrogen within 5 days. Simultaneously, a self-flocculation efficiency of 82.59 % was achieved by microalga in 30 min after wastewater treatment. The pH, tightly bound extracellular polymeric substances (TB-EPS), and cell morphology of S. platensis CMB-02 were identified as key factors influencing its self-flocculation capabilities. Moreover, the established semi-continuous process with a 20 % renewal rate showed a stable treatment effect, representing a TAN degradation rate of 10.9 mg/(L·d). These obtained findings could conclude that the developed approach mediated with self-flocculating S. platensis CMB-02 was a promising way for REEs wastewater treatment.

The biochar derived from Spirulina platensis for the adsorption of Pb and Zn and enhancing the soil physicochemical properties.

Microalgae can be collected in large quantities and hold significant potential for environmental remediation, offering a cost-effective solution. This study explores the use of Spirulina platensis (SP) as feedstock for biochar production. SP contains abundant nitrogen-rich components, such as proteins, which can serve as nitrogen sources. We prepared SP-derived biochar through pyrolysis for the adsorption of Pb and Zn from aqueous solutions and used it as an amending agent to remediate heavy metal-contaminated agricultural soil. Pyrolysis of proteins in SP introduces nitrogen-functional groups, resulting in nitrogen-doped biochar. We investigated the surface chemical behavior of thermally treated SP using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Surface analysis revealed the presence of pyridine-N and pyrrole-N from protein pyrolysis products. The study also demonstrated that these functional groups affect interactions with heavy metals. Batch experiments examined the effects of pH and initial concentration on the adsorption of Pb and Zn using SP400 and SP600. Both types of biochar showed satisfactory performance in adsorbing Pb and Zn. The effect of SP400 and SP600 on the removal of Pb and Zn through the physicochemical properties and surface functional groups was investigated. Analysis of SP400 and SP600 highlighted that electrostatic interactions, cation exchange, complexation, and mineral precipitation contributed to Pb and Zn adsorption. The study concludes that SP-derived biochar, particularly SP600, is effective for immobilizing Pb and Zn in contaminated agricultural soil, with SP600 showing superior performance.

Utilizing Mixed Cultures of Microalgae to Up-Cycle and Remove Nutrients from Dairy Wastewater.

This study explores the novel use of mixed cultures of microalgae-Spirulina platensis, Micractinium, and Chlorella-for nutrient removal from dairy wastewater (DW). Microalgae were isolated from a local wastewater treatment plant and cultivated under various light conditions. The results showed significant biomass production, with mixed cultures achieving the highest biomass (2.51 g/L), followed by Spirulina (1.98 g/L) and Chlorella (1.92 g/L). Supplementing DW (75%) with BG medium (25%) significantly enhanced biomass and pH levels, improving pathogenic bacteria removal. Spirulina and mixed cultures exhibited high nitrogen removal efficiencies of 92.56% and 93.34%, respectively, while Chlorella achieved 86.85% nitrogen and 83.45% phosphorus removal. Although growth rates were lower under phosphorus-limited conditions, the microalgae adapted well to real DW, which is essential for effective algal harvesting. Phosphorus removal efficiencies ranged from 69.56% to 86.67%, with mixed cultures achieving the highest removal. Microbial and coliform removal efficiencies reached 97.81%, with elevated pH levels contributing to significant reductions in fecal E. coli and coliform levels. These findings suggest that integrating microalgae cultivation into DW treatment systems can significantly enhance nutrient and pathogen removal, providing a sustainable solution for wastewater management.

Spirulina platensis shields the submandibular gland from cadmium toxicity by bolstering antioxidant defenses and maintaining its structural integrity.

Cadmium (Cd), an element categorized as a non-essential transitional metal, has potential hazards to the health of both human beings and animals. Spirulina platensis (SP), a type of blue-green algae, possesses a high concentration of essential antioxidants. The present study aimed to explore the possible defensive role of SP against Cd-induced submandibular gland injury in rats by assessment of biomarkers related to both oxidative stress and inflammatory processes, which were further explored through histopathological examination of submandibular gland tissue. Consequently, the study included 32 mature rats, subdivided into four different groups as follows: control, SP, Cadmium chloride (CdCl2), and CdCl2/SP. The duration of the study was 24days. The results revealed that CdCl2 induced submandibular gland injury as shown by the oxidant/antioxidant imbalance and increased inflammatory reactions, in addition to, histopathological changes and overexpression of BAX immunostaining. Concurrent SP administration to CdCl2-treated rats significantly improved all these effects. We concluded that concurrent SP supplement improved the submandibular gland injury provoked by CdCl2.

Combining In Vitro, In Vivo, and Network Pharmacology Assays to Identify Targets and Molecular Mechanisms of Spirulina-Derived Biomolecules against Breast Cancer.

The current research employed an animal model of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary gland carcinogenesis. The estrogen receptor-positive human breast adenocarcinoma cell line (MCF-7) was used for in vitro analysis. This was combined with a network pharmacology-based approach to assess the anticancer properties of Spirulina (SP) extract and understand its molecular mechanisms. The results showed that the administration of 1 g/kg of SP increased the antioxidant activity by raising levels of catalase (CAT) and superoxide dismutase (SOD), while decreasing the levels of malonaldehyde (MDA) and protein carbonyl. A histological examination revealed reduced tumor occurrence, decreased estrogen receptor expression, suppressed cell proliferation, and promoted apoptosis in SP protected animals. In addition, SP disrupted the G2/M phase of the MCF-7 cell cycle, inducing apoptosis and reactive oxygen species (ROS) accumulation. It also enhanced intrinsic apoptosis in MCF-7 cells by upregulating cytochrome c, Bax, caspase-8, caspase-9, and caspase-7 proteins, while downregulating Bcl-2 production. The main compounds identified in the LC-MS/MS study of SP were 7-hydroxycoumarin derivatives of cinnamic acid, hinokinin, valeric acid, and α-linolenic acid. These substances specifically targeted three important proteins: ERK1/2 MAPK, PI3K-protein kinase B (AKT), and the epidermal growth factor receptor (EGFR). Network analysis and molecular docking indicated a significant binding affinity between SP and these proteins. This was verified by Western blot analysis that revealed decreased protein levels of p-EGFR, p-ERK1/2, and p-AKT following SP administration. SP was finally reported to suppress MCF-7 cell growth and induce apoptosis by modulating the PI3K/AKT/EGFR and MAPK signaling pathways suggesting EGFR as a potential target of SP in breast cancer (BC) treatment.

Viromic and Metagenomic Analyses of Commercial Spirulina Fermentations Reveal Remarkable Microbial Diversity.

Commercially produced cyanobacteria preparations sold under the name spirulina are widely consumed, due to their traditional use as a nutrient-rich foodstuff and subsequent marketing as a superfood. Despite their popularity, the microbial composition of ponds used to cultivate these bacteria is understudied. A total of 19 pond samples were obtained from small-scale spirulina farms and subjected to metagenome and/or virome sequencing, and the results were analysed. A remarkable level of prokaryotic and viral diversity was found to be present in the ponds, with Limnospira sp. and Arthrospira sp. sometimes being notably scarce. A detailed breakdown of prokaryotic and viral components of 15 samples is presented. Twenty putative Limnospira sp.-infecting bacteriophage contigs were identified, though no correlation between the performance of these cultures and the presence of phages was found. The high diversity of these samples prevented the identification of clear trends in sample performance over time, between ponds or when comparing successful and failed fermentations.

Dietary Spirulina effects in Eimeria-challenged broiler chickens: growth performance, nutrient digestibility, intestinal morphology, serum biomarkers, and gene expression.

This study investigated the growth performance, nutrient utilization, and intestinal health responses of Eimeria-challenged broiler chickens to dietary Spirulina (Arthrospira platensis). On day 1, birds were assigned to 2 diets supplemented with Spirulina (0 or 5 g/kg) in a randomized complete block design. The birds within each diet were divided into 2 Eimeria-challenge groups (challenge or no-challenge) and that resulted in a 2 × 2 factorial arrangement with 2 levels each of Spirulina and challenge on day 14. On day 15, the birds in the challenge or no-challenge groups were orally gavaged with a solution containing Eimeria oocysts or 1% PBS, respectively. Samples were collected on days 21 and 26 (6- and 11-d post-infection; dpi). Data collected from days 1 to 26 were analyzed using the MIXED procedure of SAS. Birds that were fed Spirulina-supplemented diets had increased (P < 0.05) BW gain, gain-to-feed ratio, and total tract retention nitrogen from days 14 to 21. The ileal villus perimeter and area, serum catalase, HMOX1 and SOD1 jejunal abundance were all increased (P < 0.05) in birds fed Spirulina-supplemented diets on day 21 (6 dpi). However, there was no effect on bone ash or oocyst count. From days 21 to 26, there was a tendency (P = 0.059) for a Spirulina × Challenge interaction on the BW gain of birds. Moreover, dietary Spirulina addition increased (P < 0.05) serum catalase, total antioxidant capacity, ileal villus perimeter, tibia bone ash, and the relative mRNA expression of HMOX1, SOD1, claudin 1, and TNFα in the jejunal mucosa of birds on day 26 (11 dpi). On both 6 and 11 dpi, the Eimeria challenge negatively (P < 0.05) impacted growth performance, gut morphology, and the relative mRNA expression of genes. Overall, assessing the impact of Spirulina in broilers revealed its positive antioxidant, immune-modulating, and health benefits. However, its dietary addition did not completely reverse the Eimeria-induced effects in these birds. Ultimately, this study outlines the positive properties of dietary Spirulina beyond its use in the diet of healthy broiler chickens.

In recent years, nutritional strategies for managing coccidiosis in broiler chickens have focused on feed additives, amino acids, and minerals. Spirulina, a cyanobacterium, is a feed additive rich in bioactive compounds like phycocyanin, polysaccharides, B vitamins, minerals, polyunsaturated fatty acids, and carotenoids. These compounds confer antioxidant, anti-inflammatory, and immunomodulatory properties to Spirulina. While Spirulina has been extensively explored as a health supplement in humans, its dietary application in broiler chickens and pigs is now gaining attention. Additionally, its potential to combat the Eimeria-induced effects on growth performance, nutrient digestibility, and health in birds has not been adequately addressed. Hence, the aim of this study was to investigate the effect of Spirulina on growth performance, nutrient digestibility, immune response, bone mineral deposition, and serum phosphorus in Eimeria-challenged broiler chickens. Results from this study showed that the positive properties of dietary Spirulina extend beyond its use in the diet of healthy broiler chickens as it reduced some of the negative impact of an Eimeria infection in birds.

Green and sustainable extraction of phycocyanin from Spirulina platensis by temperature-sensitive polymer-based aqueous two-phase system and mechanism study.

In this study, a sustainable and environmentally friendly method was developed for the enrichment and purification of phycocyanin from Spirulina platensis. This was achieved by utilizing a temperature-sensitive polymer, Pluronic F68, in an aqueous two-phase solvent system. The phase behavior of the temperature-sensitive polymer-based biphasic system was evaluated. The extraction conditions were optimized by both single-factor experiments and response surface methodology. Under the optimal conditions, the upper polymer-rich phase was recycled for sustainable phycocyanin extraction, resulting in a grade of 3.23 during the third extraction cycle. Pluronic F68 could be efficiently recovered and reused during the extraction process. The interaction mechanism between Pluronic F68 and phycocyanin was systematically studied using FT-IR and fluorescence analysis. This was further complemented by static and dynamic calculation of molecular motion through molecular docking and molecular dynamics simulation, indicating that hydrophobic segment of Pluronic F68 played a key role in the binding process with phycocyanin.

Unveiling drastic influence of cross-interactions in hydrothermal carbonization of spirulina with cellulose, lignin or poplar on nature of hydrochar and activated carbon.

Spirulina platensis contains abundant nitrogen-containing organics, which might react with derivatives of cellulose/lignin during hydrothermal carbonization (HTC), probably affecting yield, property of hydrochar, and pore development in activation of hydrochar. This was investigated herein by conducting co-HTC of spirulina platensis with cellulose, lignin, and sawdust at 260 °C and subsequent activation of the resulting hydrochars with K2C2O4 at 800 °C. The results showed that cross-condensation of spirulina platensis-derived proteins with cellulose/lignin-derived ketones and phenolics did take place in the co-HTC, forming more π-conjugated heavier organics, retaining more nitrogen species in hydrochar, reducing yields of hydrochar, making the hydrochar more aromatic and increasing the thermal stability and resistivity towards activation. This enhanced the yield of activated carbon (AC) by 7 %-20 % and significantly increased specific surface area of the AC from activation of hydrochar of spirulina platensis + lignin to 2074.5 m2/g (859.3 m2/g from spirulina platensis only and 1170.1 m2/g from lignin only). Furthermore, more mesopores from activation of hydrochar of spirulina platensis + cellulose (47 %) and more micropores from activation of hydrochar of spirulina + sawdust (93 %) was generated. The AC from spirulina platensis + lignin with the developed pore structures generated sufficient sites for adsorption of tetracycline from aqueous phase and minimized steric hindrance for mass transfer with the abundant mesopores (43 %).