16 results
Search Results
2. Examining the diet quality of Canadian adults and the alignment of Canadian front-of-pack labelling regulations with other front-of-pack labelling systems and dietary guidelines.
- Author
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Lee, Jennifer J., Ahmed, Mavra, Julia, Chantal, Ng, Alena Praneet, Paper, Laura, Lou, Wendy Y., and L'Abbé, Mary R.
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- 2024
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3. Ethical AI and Global Cultural Coherence: Issues and Challenges
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Groumpos, Peter P. and PAPER, PLENARY
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- 2022
- Full Text
- View/download PDF
4. SARS-CoV-2 seroprevalence among Beninese pregnant women in the third year of the pandemic.
- Author
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Figueroa-Romero, Antía, Atchadé, Aurore, Yadouleton, Anges, Fiogbe, Marc, Bonnet, Emmanuel, Yovo, Emmanuel, Accrombessi, Manfred, Hounsa, Sandrine, Paper, Thierry, Dupont, Raphael, Gaudart, Jean, Le Hesran, Jean-Yves, Massougbodji, Achille, Cottrell, Gilles, and González, Raquel
- Subjects
PREGNANT women ,RAPID diagnostic tests ,SARS-CoV-2 ,THIRD trimester of pregnancy ,COVID-19 pandemic - Abstract
Background: Pregnant women are a vulnerable population to COVID-19 given an increased susceptibility to severe SARS-CoV-2 infection and pregnancy complications. However, few SARS-CoV-2 serological surveys have been performed among this population to assess the extent of the infection in sub-Saharan countries. The objectives of this study were to determine SARS-CoV-2 seroprevalence among Beninese pregnant women, to identify spatial seropositivity clusters and to analyse factors associated with the infection. Methods: A cross-sectional study including women in their third trimester of pregnancy attending the antenatal care (ANC) clinics at Allada (south Benin) and Natitingou (north Benin) was conducted. Rapid diagnostic tests (RDT) for detection of IgG/IgM against the SARS-CoV-2 spike protein were performed using capillary blood. Seroprevalence of SARS-CoV-2 antibodies and associations between SARS-CoV-2 serostatus and maternal characteristics were analyzed by multivariate logistic regression. Spatial analyses were performed using the spatial scan statistics to identify spatial clusters of SARS-CoV-2 infection. Results: A total of 861 pregnant women were enrolled between May 4 and June 29, 2022. 58/861 (6.7%) participants reported having received COVID-19 vaccine. None of the participants had been diagnosed with COVID-19 during their pregnancy. SARS-CoV-2 antibodies were detected in 607/802 (75.7%; 95% CI 72.56%–78.62%) of unvaccinated participants. Several urban and rural spatial clusters of SARS-CoV-2 cases were identified in Allada and one urban spatial cluster was identified in Natitingou. Unvaccinated participants from Allada with at least one previous morbidity were at a three-times higher risk of presenting SARS-CoV-2 antibodies (OR = 2.89; 95%CI 1.19%-7.00%). Conclusion: Three out of four pregnant women had SARS-CoV-2 antibodies, suggesting a high virus circulation among pregnant women in Benin, while COVID-19 vaccination coverage was low. Pregnant women with comorbidities may be at increased risk of SARS-CoV-2 infection. This population should be prioritized for COVID-19 diagnosis and vaccination in order to prevent its deleterious effects. Trial registration: NCT06170320 (retrospectively registered on December 21, 2023). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Performances of two rapid LAMP-based techniques for the intrapartum detection of Group B Streptococcus vaginal colonization.
- Author
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Charfi, Rym, Guyonnet, Cécile, Untrau, Meiggie, Giacometti, Gaëlle, Paper, Thierry, Poyart, Claire, Plainvert, Céline, and Tazi, Asmaa
- Subjects
STREPTOCOCCUS agalactiae ,LOOP-mediated isothermal amplification ,SONICATION ,NEONATAL diseases - Abstract
Purpose: Group B Streptococcus (GBS) is the leading cause of invasive infections in newborns. The prevention of GBS neonatal disease relies on the administration of an intrapartum antibiotic prophylaxis to GBS-colonized women. In recent years, rapid intrapartum detection of GBS vaginal colonization using real-time nucleic acid amplification tests (NAATs) emerged as an alternative to antenatal culture screening methods. Methods: We compared the performances of two loop-mediated isothermal amplification (LAMP) tests, the Ampliflash® GBS and the PlusLife® GBS tests, to standard culture for GBS detection in vaginal specimens from pregnant women. The study was conducted from April to July 2023 in a French hospital of the Paris area. Results: A total of 303 samples were analyzed, including 85 culture-positive samples (28.1%). The Ampliflash® GBS test and the PlusLife® GBS tests gave a result for 100% and 96.3% tests, respectively. The performances of the tests were as follows: sensitivity 87.1% (95% confidence interval (CI) 78.3–92.6) and 98.7% (95% CI 93.0-99.8), specificity 99.1% (95% CI 96.7–99.8), and 91.9% (95% CI 87.3–95.0), respectively. False negative results of the Ampliflash® GBS test correlated with low-density GBS cultures. Time-to-results correlated with GBS culture density only for the PlusLife® GBS test (p < 0.001). Conclusion: Both techniques provide excellent analytical performances with high sensitivity and specificity together with a short turnaround time and results available in 10 to 35 min. Their potential to further reduce the burden of GBS neonatal disease compared with antenatal culture screening needs to be assessed in future clinical studies. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Can individual fatty acids be used as functional biomarkers of dairy fat consumption in relation to cardiometabolic health? A narrative review.
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Sellem, Laury, Jackson, Kim G., Paper, Laura, Givens, Ian D., and Lovegrove, Julie A.
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CARDIOVASCULAR disease related mortality ,BIOMARKERS ,CARDIOVASCULAR diseases risk factors ,NUTRITIONAL assessment ,SERUM ,BLOOD plasma ,GLYCEMIC control ,GUT microbiome ,HEALTH status indicators ,DAIRY products ,TYPE 2 diabetes ,METABOLIC disorders ,RISK assessment ,METABOLIC syndrome ,MOLECULAR structure ,FATTY acids ,DIETARY fats ,SHORT-chain fatty acids - Abstract
In epidemiological studies, dairy food consumption has been associated with minimal effect or decreased risk of some cardiometabolic diseases (CMD). However, current methods of dietary assessment do not provide objective and accurate measures of food intakes. Thus, the identification of valid and reliable biomarkers of dairy product intake is an important challenge to best determine the relationship between dairy consumption and health status. This review investigated potential biomarkers of dairy fat consumption, such as odd-chain, trans- and branched-chain fatty acids (FA), which may improve the assessment of full-fat dairy product consumption. Overall, the current use of serum/plasma FA as biomarkers of dairy fat consumption is mostly based on observational evidence, with a lack of well-controlled, dose–response intervention studies to accurately assess the strength of the relationship. Circulating odd-chain SFA and trans-palmitoleic acid are increasingly studied in relation to CMD risk and seem to be consistently associated with a reduced risk of type 2 diabetes in prospective cohort studies. However, associations with CVD are less clear. Overall, adding less studied FA such as vaccenic and phytanic acids to the current available evidence may provide a more complete assessment of dairy fat intake and minimise potential confounding from endogenous synthesis. Finally, the current evidence base on the direct effect of dairy fatty acids on established biomarkers of CMD risk (e.g. fasting lipid profiles and markers of glycaemic control) mostly derives from cross-sectional, animal and in vitro studies and should be strengthened by well-controlled human intervention studies. [ABSTRACT FROM AUTHOR]
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- 2022
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7. Into Africa: Salvinia minima Baker (Salviniaceae) invades South Africa.
- Author
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Coetzee, Julie A., Paper, Matthew K., Miller, Benjamin E., Kinsler, David, Cilliers, Carina J., and Hill, Martin P.
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INDIGENOUS peoples of South America ,BODIES of water - Abstract
Salvinia minima Baker (Salviniaceae) has been recorded for the first time in Africa. This South American native macrophyte is highly invasive and damaging, costing millions of dollars to control in the USA, and has the potential to invade many of southern Africa's waterbodies. Field surveys have confirmed the presence of S. minima from four sites in South Africa, with the largest invasion occurring on the highly polluted Hartbeespoort Dam, north east of the country's capital. Salvinia minima has been targeted for biological control in South Africa, using the weevil, Cyrtobagous salviniae, which is undergoing host specificity testing under quarantine conditions. [ABSTRACT FROM AUTHOR]
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- 2022
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8. SARS-CoV-2 seroprevalence among Beninese pregnant women in the third year of the pandemic
- Author
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Antía Figueroa-Romero, Aurore Atchadé, Anges Yadouleton, Marc Fiogbe, Emmanuel Bonnet, Emmanuel Yovo, Manfred Accrombessi, Sandrine Hounsa, Thierry Paper, Raphael Dupont, Jean Gaudart, Jean-Yves Le Hesran, Achille Massougbodji, Gilles Cottrell, and Raquel González
- Subjects
Pregnancy ,SARS-CoV-2 ,Sub-saharan Africa ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Pregnant women are a vulnerable population to COVID-19 given an increased susceptibility to severe SARS-CoV-2 infection and pregnancy complications. However, few SARS-CoV-2 serological surveys have been performed among this population to assess the extent of the infection in sub-Saharan countries. The objectives of this study were to determine SARS-CoV-2 seroprevalence among Beninese pregnant women, to identify spatial seropositivity clusters and to analyse factors associated with the infection. Methods A cross-sectional study including women in their third trimester of pregnancy attending the antenatal care (ANC) clinics at Allada (south Benin) and Natitingou (north Benin) was conducted. Rapid diagnostic tests (RDT) for detection of IgG/IgM against the SARS-CoV-2 spike protein were performed using capillary blood. Seroprevalence of SARS-CoV-2 antibodies and associations between SARS-CoV-2 serostatus and maternal characteristics were analyzed by multivariate logistic regression. Spatial analyses were performed using the spatial scan statistics to identify spatial clusters of SARS-CoV-2 infection. Results A total of 861 pregnant women were enrolled between May 4 and June 29, 2022. 58/861 (6.7%) participants reported having received COVID-19 vaccine. None of the participants had been diagnosed with COVID-19 during their pregnancy. SARS-CoV-2 antibodies were detected in 607/802 (75.7%; 95% CI 72.56%–78.62%) of unvaccinated participants. Several urban and rural spatial clusters of SARS-CoV-2 cases were identified in Allada and one urban spatial cluster was identified in Natitingou. Unvaccinated participants from Allada with at least one previous morbidity were at a three-times higher risk of presenting SARS-CoV-2 antibodies (OR = 2.89; 95%CI 1.19%-7.00%). Conclusion Three out of four pregnant women had SARS-CoV-2 antibodies, suggesting a high virus circulation among pregnant women in Benin, while COVID-19 vaccination coverage was low. Pregnant women with comorbidities may be at increased risk of SARS-CoV-2 infection. This population should be prioritized for COVID-19 diagnosis and vaccination in order to prevent its deleterious effects. Trial registration NCT06170320 (retrospectively registered on December 21, 2023).
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- 2024
- Full Text
- View/download PDF
9. Corrigendum: Examining the diet quality of Canadian adults and the alignment of Canadian front-of-pack labelling regulations with other front-of-pack labelling systems and dietary guidelines
- Author
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Jennifer J. Lee, Mavra Ahmed, Chantal Julia, Alena Praneet Ng, Laura Paper, Wendy Y. Lou, and Mary R. L'Abbé
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front-of-pack ,FOPL ,dietary patterns ,nutrient profiling ,HEFI ,Nutri-score ,Public aspects of medicine ,RA1-1270 - Published
- 2024
- Full Text
- View/download PDF
10. Performances of two rapid LAMP-based techniques for the intrapartum detection of Group B Streptococcus vaginal colonization
- Author
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Rym Charfi, Cécile Guyonnet, Meiggie Untrau, Gaëlle Giacometti, Thierry Paper, Claire Poyart, Céline Plainvert, and Asmaa Tazi
- Subjects
Group B Streptococcus ,Intrapartum screening ,NAAT ,Neonatal infection ,LAMP ,Therapeutics. Pharmacology ,RM1-950 ,Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Abstract Purpose Group B Streptococcus (GBS) is the leading cause of invasive infections in newborns. The prevention of GBS neonatal disease relies on the administration of an intrapartum antibiotic prophylaxis to GBS-colonized women. In recent years, rapid intrapartum detection of GBS vaginal colonization using real-time nucleic acid amplification tests (NAATs) emerged as an alternative to antenatal culture screening methods. Methods We compared the performances of two loop-mediated isothermal amplification (LAMP) tests, the Ampliflash® GBS and the PlusLife® GBS tests, to standard culture for GBS detection in vaginal specimens from pregnant women. The study was conducted from April to July 2023 in a French hospital of the Paris area. Results A total of 303 samples were analyzed, including 85 culture-positive samples (28.1%). The Ampliflash® GBS test and the PlusLife® GBS tests gave a result for 100% and 96.3% tests, respectively. The performances of the tests were as follows: sensitivity 87.1% (95% confidence interval (CI) 78.3–92.6) and 98.7% (95% CI 93.0-99.8), specificity 99.1% (95% CI 96.7–99.8), and 91.9% (95% CI 87.3–95.0), respectively. False negative results of the Ampliflash® GBS test correlated with low-density GBS cultures. Time-to-results correlated with GBS culture density only for the PlusLife® GBS test (p
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- 2024
- Full Text
- View/download PDF
11. Stripped: contribution of cyanobacterial extracellular polymeric substances to the adsorption of rare earth elements from aqueous solutions
- Author
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Michael Paper, Patrick Jung, Max Koch, Michael Lakatos, Tom Nilges, and Thomas B. Brück
- Subjects
extracellular polymeric substances ,polysaccharides ,Komarekiella ,Nostoc ,Desmonostoc ,biosorption ,Biotechnology ,TP248.13-248.65 - Abstract
The transformation of modern industries towards enhanced sustainability is facilitated by green technologies that rely extensively on rare earth elements (REEs) such as cerium (Ce), neodymium (Nd), terbium (Tb), and lanthanum (La). The occurrence of productive mining sites, e.g., is limited, and production is often costly and environmentally harmful. As a consequence of increased utilization, REEs enter our ecosystem as industrial process water or wastewater and become highly diluted. Once diluted, they can hardly be recovered by conventional techniques, but using cyanobacterial biomass in a biosorption-based process is a promising eco-friendly approach. Cyanobacteria can produce extracellular polymeric substances (EPS) that show high affinity to metal cations. However, the adsorption of REEs by EPS has not been part of extensive research. Thus, we evaluated the role of EPS in the biosorption of Ce, Nd, Tb, and La for three terrestrial, heterocystous cyanobacterial strains. We cultivated them under N-limited and non-limited conditions and extracted their EPS for compositional analyses. Subsequently, we investigated the metal uptake of a) the extracted EPS, b) the biomass extracted from EPS, and c) the intact biomass with EPS by comparing the amount of sorbed REEs. Maximum adsorption capacities for the tested REEs of extracted EPS were 123.9–138.2 mg g−1 for Komarekiella sp. 89.12, 133.1–137.4 mg g−1 for Desmonostoc muscorum 90.03, and 103.5–129.3 mg g−1 for Nostoc sp. 20.02. A comparison of extracted biomass with intact biomass showed that 16% (Komarekiella sp. 89.12), 28% (Desmonostoc muscorum 90.03), and 41% (Nostoc sp. 20.02) of REE adsorption was due to the biosorption of the extracellular EPS. The glucose- rich EPS (15%–43% relative concentration) of all three strains grown under nitrogen-limited conditions showed significantly higher biosorption rates for all REEs. We also found a significantly higher maximum adsorption capacity of all REEs for the extracted EPS compared to cells without EPS and untreated biomass, highlighting the important role of the EPS as a binding site for REEs in the biosorption process. EPS from cyanobacteria could thus be used as efficient biosorbents in future applications for REE recycling, e.g., industrial process water and wastewater streams.
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- 2023
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12. Particularities of wooden carved iconostases in selected post-Byzantine churches of Albania
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This paper presents the data and study results of the post-Byzantine wood carved iconostases of different churches in Albania, which notwithstanding the circumstances of the communistic period have preserved to a considerable extent their typical characteristics. The paper aims to examine the stylistic and morphological aspects of the iconostasis in selected churches in relation to the architecture and tries to identify the relationships, sequences and reasons for such phenomena. The presence of iconostases in the Eastern Orthodox Church is based on the carried rituals and services that are expressed through ecclesiastical sculptures and other works. In these contexts, the iconostasis is the most dominating screen, related to the rood screen of English mediaeval churches, but contrary to them it is a closed and solid structure. In the iconostasis, architecture and wood carving workers collaborate on a large scale in order to create a solid and well-integrated frame. The analysis includes St Mary’s Monastery, also known as the Monastery of Dormition of Theotokos Mary, a medieval Byzantine church on Zvërnec island in the Narta Lagoon, southwest of the city of Vlora, southwestern Albania (SMZ); the Church of Apostles in Hoshtevë, Gjirokastra, with its spectacular interior completely covered with frescoes that became a cultural monument of Albania in 1948 (SA); and the Church of the Dormition of the Theotokos, simply known as Koimissi or St Mary, in the village of Labovë e Kryqit, Gjirokastër County, southern Albania (SM).
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cultural heritage ,post-byzantine ,churches ,albanian ,iconostasis ,Museums. Collectors and collecting ,AM1-501 - Abstract
This paper presents the data and study results of the post-Byzantine wood carved iconostases of different churches in Albania, which notwithstanding the circumstances of the communistic period have preserved to a considerable extent their typical characteristics. The paper aims to examine the stylistic and morphological aspects of the iconostasis in selected churches in relation to the architecture and tries to identify the relationships, sequences and reasons for such phenomena. The presence of iconostases in the Eastern Orthodox Church is based on the carried rituals and services that are expressed through ecclesiastical sculptures and other works. In these contexts, the iconostasis is the most dominating screen, related to the rood screen of English mediaeval churches, but contrary to them it is a closed and solid structure. In the iconostasis, architecture and wood carving workers collaborate on a large scale in order to create a solid and well-integrated frame. The analysis includes St Mary’s Monastery, also known as the Monastery of Dormition of Theotokos Mary, a medieval Byzantine church on Zvërnec island in the Narta Lagoon, southwest of the city of Vlora, southwestern Albania (SMZ); the Church of Apostles in Hoshtevë, Gjirokastra, with its spectacular interior completely covered with frescoes that became a cultural monument of Albania in 1948 (SA); and the Church of the Dormition of the Theotokos, simply known as Koimissi or St Mary, in the village of Labovë e Kryqit, Gjirokastër County, southern Albania (SM)
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- 2022
- Full Text
- View/download PDF
13. Examining the diet quality of Canadian adults and the alignment of Canadian front-of-pack labelling regulations with other front-of-pack labelling systems and dietary guidelines
- Author
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Jennifer J. Lee, Mavra Ahmed, Chantal Julia, Alena Praneet Ng, Laura Paper, Wendy Y. Lou, and Mary R. L’Abbé
- Subjects
front-of-pack ,FOPL ,dietary patterns ,nutrient profiling ,HEFI ,Nutri-score ,Public aspects of medicine ,RA1-1270 - Abstract
IntroductionCanada promulgated mandatory front-of-pack labelling (FOPL) regulations in 2022, requiring pre-packaged foods meeting and/or exceeding recommended thresholds for nutrients-of-concern (i.e., saturated fat, sodium, sugars) to display a “high-in” nutrition symbol. However, there is limited evidence on how Canadian FOPL (CAN-FOPL) regulations compare to other FOPL systems and dietary guidelines. Therefore, the objectives of the study were to examine the diet quality of Canadians using the CAN-FOPL dietary index system and its alignment with other FOPL systems and dietary guidelines.MethodsNationally representative dietary data from the 2015 Canadian Community Health Survey-Nutrition survey (n = 13,495) was assigned dietary index scores that underpin CAN-FOPL, Diabetes Canada Clinical Practice (DCCP) Guidelines, Nutri-score, Dietary Approaches to Stop Hypertension (DASH) and Canada’s Food Guide (Healthy Eating Food Index-2019 [HEFI-2019]). Diet quality was examined by assessing linear trends of nutrient intakes across quintile groups of CAN-FOPL dietary index scores. The alignment of CAN-FOPL dietary index system compared with other dietary index systems, with HEFI as the reference standard, was examined using Pearson’s correlations and к statistics.ResultsThe mean [95% CI] dietary index scores (range: 0–100) for CAN-FOPL, DCCP, Nutri-score, DASH, and HEFI-2019 were 73.0 [72.8, 73.2], 64.2 [64.0, 64.3], 54.9 [54.7, 55.1], 51.7 [51.4, 51.9], and 54.3 [54.1, 54.6], respectively. Moving from the “least healthy” to the “most healthy” quintile in the CAN-FOPL dietary index system, intakes of protein, fiber, vitamin A, vitamin C, and potassium increased, while intakes of energy, saturated fat, total and free sugars, and sodium decreased. CAN-FOPL showed moderate association with DCCP (r = 0.545, p
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- 2023
- Full Text
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14. Rare earths stick to rare cyanobacteria: Future potential for bioremediation and recovery of rare earth elements
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Michael Paper, Max Koch, Patrick Jung, Michael Lakatos, Tom Nilges, and Thomas B. Brück
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cyanobacteria ,biosorption ,mechanism ,rare earth elements ,ion exchange ,Biotechnology ,TP248.13-248.65 - Abstract
Biosorption of metal ions by phototrophic microorganisms is regarded as a sustainable and alternative method for bioremediation and metal recovery. In this study, 12 cyanobacterial strains, including 7 terrestrial and 5 aquatic cyanobacteria, covering a broad phylogenetic diversity were investigated for their potential application in the enrichment of rare earth elements through biosorption. A screening for the maximum adsorption capacity of cerium, neodymium, terbium, and lanthanum was conducted in which Nostoc sp. 20.02 showed the highest adsorption capacity with 84.2–91.5 mg g-1. Additionally, Synechococcus elongatus UTEX 2973, Calothrix brevissima SAG 34.79, Desmonostoc muscorum 90.03, and Komarekiella sp. 89.12 were promising candidate strains, with maximum adsorption capacities of 69.5–83.4 mg g-1, 68.6–83.5 mg g-1, 44.7–70.6 mg g-1, and 47.2–67.1 mg g-1 respectively. Experiments with cerium on adsorption properties of the five highest metal adsorbing strains displayed fast adsorption kinetics and a strong influence of the pH value on metal uptake, with an optimum at pH 5 to 6. Studies on binding specificity with mixed-metal solutions strongly indicated an ion-exchange mechanism in which Na+, K+, Mg2+, and Ca2+ ions are replaced by other metal cations during the biosorption process. Depending on the cyanobacterial strain, FT-IR analysis indicated the involvement different functional groups like hydroxyl and carboxyl groups during the adsorption process. Overall, the application of cyanobacteria as biosorbent in bioremediation and recovery of rare earth elements is a promising method for the development of an industrial process and has to be further optimized and adjusted regarding metal-containing wastewater and adsorption efficiency by cyanobacterial biomass.
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- 2023
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15. Efficient Green Light Acclimation of the Green Algae Picochlorum sp. Triggering Geranylgeranylated Chlorophylls
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Michael Paper, Matthias Glemser, Martina Haack, Jan Lorenzen, Norbert Mehlmer, Tobias Fuchs, Gerhard Schenk, Daniel Garbe, Dirk Weuster-Botz, Wolfgang Eisenreich, Michael Lakatos, and Thomas B. Brück
- Subjects
green light ,photosynthesis ,chlorophyll derivatives ,light adaption mechanism ,geranylgeranylated ,eukaryotic microalgae ,Biotechnology ,TP248.13-248.65 - Abstract
In analogy to higher plants, eukaryotic microalgae are thought to be incapable of utilizing green light for growth, due to the “green gap” in the absorbance profiles of their photosynthetic pigments. This study demonstrates, that the marine chlorophyte Picochlorum sp. is able to grow efficiently under green light emitting diode (LED) illumination. Picochlorum sp. growth and pigment profiles under blue, red, green and white LED illumination (light intensity: 50–200 μmol m−2 s−1) in bottom-lightened shake flask cultures were evaluated. Green light-treated cultures showed a prolonged initial growth lag phase of one to 2 days, which was subsequently compensated to obtain comparable biomass yields to red and white light controls (approx. 0.8 gDW L−1). Interestingly, growth and final biomass yields of the green light-treated sample were higher than under blue light with equivalent illumination energies. Further, pigment analysis indicated, that during green light illumination, Picochlorum sp. formed unknown pigments (X1-X4). Pigment concentrations increased with illumination intensity and were most abundant during the exponential growth phase. Mass spectrometry and nuclear magnetic resonance data indicated, that pigments X1-X2 and X3-X4 are derivatives of chlorophyll b and a, which harbor C=C bonds in the phytol side chain similar to geranylgeranylated chlorophylls. Thus, for the first time, the natural accumulation of large pools (approx. 12 mg gDW−1) of chlorophyll intermediates with incomplete hydrogenation of their phytyl chains is demonstrated for algae under monochromatic green light (Peak λ 510 nm, full width at half maximum 91 nm). The ability to utilize green light offers competitive advantages for enhancing biomass production, particularly under conditions of dense cultures, long light pathways and high light intensity. Green light acclimation for an eukaryotic microalgae in conjunction with the formation of new aberrant geranylgeranylated chlorophylls and high efficiency of growth rates are novel for eukaryotic microalgae. Illumination with green light could enhance productivity in industrial processes and trigger the formation of new metabolites–thus, underlying mechanisms require further investigation.
- Published
- 2022
- Full Text
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16. Isolation and Investigation of Natural Rare Earth Metal Chelating Agents From Calothrix brevissima - A Step Towards Unraveling the Mechanisms of Metal Biosorption
- Author
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Wojciech Jurkowski, Michael Paper, and Thomas B. Brück
- Subjects
biosorption ,cyanobacteria ,rare earth elements ,mechanism ,calothrix ,complexation ,Biotechnology ,TP248.13-248.65 - Abstract
In this study water soluble compounds that form complexes with Rare Earth Elements (REE) and other metals were isolated from Calothrix brevissima biomass with chromatographic methods for the first time. Molecular characterization showed that the isolated compounds are most likely polysaccharides comprised of arabinose, xylose, mannose, galactose and glucose. FT-IR analysis revealed functional groups involved in the binding mechanism of Tb are likely sulfate- and to a lesser extend hydroxyl-groups. The binding specificity of the isolated compounds was investigated with different metal solutions. Here, ions of the alkali and alkaline earth metals Na, K, Mg and Ca showed no competition for Tb-binding even at 10-fold excess concentration. Ions of the elements Co and Pb on the other hand replaced Tb at higher concentrations. Addition of the isolated compounds significantly reduced the precipitation of Eu at pH-values between 6.7 and 9.5, indicating that the interaction between the isolated chelators and Rare Earth Metals is stable even at high pH-values.
- Published
- 2022
- Full Text
- View/download PDF
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