Recycling of cellulases in lignocellulosic hydrolysates using alkaline elution

The recovery of cellulases from lignin, lignocellulosic hydrolysates and cellulose by alkaline washes at pH 9 and 10 was examined. The effect of the pH on the structural stability of purified Cel7A was analyzed by circular dichroism. Purified Cel7A showed conformational changes at pH 9 and 10 that were reversible at pH 4.8. Temperature influenced the enzymatic hydrolysis of wheat straw and may be critical for the efficiency of cellulase recycling from wheat straw hydrolysates. Operation at moderate temperatures (37 °C) resulted in a rate of saccharification 19% higher than that obtained at 50° C, improving cellulase recycling by 49%. Over 60% of the enzyme activity on the synthetic substrate 4-methylumbelliferyl-β-d-cellobioside (MUC) may be recovered by using a simple alkaline wash. This is thus a promising strategy for enzyme recycling that is simple to implement at industrial scale, economical and effective.The authors acknowledge funding through FP7 KACELLE (Kalundborg Cellulosic Ethanol) project for supporting his work. We also thank Dr. Mai Ostergaard Haven for critical reviewing of the manuscript and Dr. Jane Lindedam for supplying the lignin

Tracking bacterial nanocellulose in animal tissues by fluorescence microscopy

The potential of nanomaterials in food technology is nowadays well-established. However, their commercial use requires a careful risk assessment, in particular concerning the fate of nanomaterials in the human body. Bacterial nanocellulose (BNC), a nanofibrillar polysaccharide, has been used as a food product for many years in Asia. However, given its nano-character, several toxicological studies must be performed, according to the European Food Safety Agency’s guidance. Those should especially answer the question of whether nanoparticulate cellulose is absorbed in the gastrointestinal tract. This raises the need to develop a screening technique capable of detecting isolated nanosized particles in biological tissues. Herein, the potential of a cellulose-binding module fused to a green fluorescent protein (GFP–CBM) to detect single bacterial cellulose nanocrystals (BCNC) obtained by acid hydrolysis was assessed. Adsorption studies were performed to characterize the interaction of GFP–CBM with BNC and BCNC. Correlative electron light microscopy was used to demonstrate that isolated BCNC may be detected by fluorescence microscopy. The uptake of BCNC by macrophages was also assessed. Finally, an exploratory 21-day repeated-dose study was performed, wherein Wistar rats were fed daily with BNC. The presence of BNC or BCNC throughout the GIT was observed only in the intestinal lumen, suggesting that cellulose particles were not absorbed. While a more comprehensive toxicological study is necessary, these results strengthen the idea that BNC can be considered a safe food additive.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI‐01‐0145‐FEDER‐006684) and BioTecNorte operation (NORTE‐01‐0145‐FEDER‐000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Development of bacterial cellulose wound dressings with controlled delivery of vitamin D3

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Wounds, in particular traumatic (e.g. burns) and chronic ones, are a major cause of morbidity and impaired life quality. They often result in long hospitalization stays, taking up substantial health resources in developed countries. This proposal aims at developing a safe, easy-to-use and nonexpensive approach to efficiently address this problem, by attaining faster and proper wound healing. Recent studies showed that an antimicrobial peptide (AMP), LLKKK18, released from conjugates with dextrin embedded in a Carbopol hydrogel significantly improved burn wound healing. In addition to antimicrobial activity, this peptide stimulates vascularization, thus supporting a faster healing and tissue regeneration[1]. As such, one can hypothesize that a hydrogel comprising drugs that stimulate the expression of LL37 will improve wound healing while keeping the wound area infection-free. This work comprised the approach towards the development of a novel bacterial nanocellulose (BNC) dressing. BNC, already used clinically for the treatment of burn wounds due to the unique properties like high water holding capacity, high crystallinity, ultrafine fiber network, high resistance, high moldability and biocompatibility[2]. In this work BNC will be used as drug carriers for the controlled release of drugs, namely of vitamin D3, an inducer of an endogenous expression of AMP LL37, known for accelerating the wound healing process, and as a protective barrier against exogenous agents (dust, microorganism) that can impair wound healing. [...]info:eu-repo/semantics/publishedVersio

Overcoming the regulatory hurdles on nanocelluloses is bacterial cellulose absorbed at the intestine?

The potential of nanomaterials in food technology is nowadays well-established. However, their commercial use requires a careful risk assessment, in particular concerning the fate of nanomaterials in the human body. Bacterial NanoCellulose (BNC), a nanofibrillar polysaccharide, has been used as a food product for many years in Asia. However, given its nano-character, several toxicological studies must be performed, according to the European Food Safety Agencys Guidance. Those should especially answer the question on whether nanoparticulate cellulose is absorbed in the Gastrointestinal Tract. This raises the need to develop a screening technique capable of detecting isolated nanosized particles in biological tissues. Here, the potential of a Cellulose Binding Module fused to a Green Fluorescent Protein (GFP-CBM) to detect single bacterial cellulose nanocrystals (BCNC) obtained by acid hydrolysis was assessed. Adsorption studies were performed to characterize the interaction of GFP-CBM with BNC and BCNC. Correlative Electron Light Microscopy was used to demonstrate that isolated BCNC may be detected by fluorescence microscopy. The uptake of BCNC by macrophages was also assessed. Finally, an exploratory 21-day repeated dose study was performed where Wistar rats were daily fed with BNC. The presence of BNC or BCNC throughout the GIT was observed only in the intestinal lumen, suggesting that cellulose particles were not absorbed. While a more comprehensive toxicological study is necessary, these results strengthen the idea that BNC can be considered a safe food additive.info:eu-repo/semantics/publishedVersio

Association between circulating exhausted CD4+ T cells with poor meningococcal C conjugate vaccine antibody response in HIV-infected children and adolescents

OBJECTIVES: To investigate the expression levels of surface markers of activation (CD38 and HLA-DR), inhibition (PD-1, TIGIT and CD57) and co-stimulation (CD28 and CD127) on CD4+ T cells of children/adolescents with vertical HIV infection (HI patients) and HIV-uninfected (HU) controls vaccinated with the meningococcal C conjugate vaccine (MCC). METHODS: HI patients (n=12), aged 8–17 years, were immunized with two MCC injections, while HU controls (n=9), aged 5.3–10.7 years, received a single MCC dose (as per national recommendation at the time of this study, a single MCC vaccine dose should be given for healthy children and youth aged 1–18 years). The HI patients were categorized according to the combined antiretroviral therapy (cART) treatment. Blood samples were obtained before vaccination, after priming, and after the administration of a booster dose of vaccine to determine the serum bactericidal antibody (SBA) titers and the expression levels of surface markers on CD4+ T cells by flow cytometry. The levels of serum cytokines, IL-4 and CXCL-13 were also measured using Luminex kits. RESULTS: The co-expression of the TIGIT-HLA-DR-CD38 molecules increased in the CD4+ T cells of HI patients/ no-cART who also showed a lower frequency of CD127+CD28+ CD4+ T cells than HI patients/cART and HU group subjects. There were significant negative correlations between the frequency of exhausted CD4+ T cells and the SBA response. IL-4 levels were higher in HI patients/cART and positively correlated with SBA titers but negatively associated with the expression of exhaustion markers. Moreover, the CXCL-13 levels were positively correlated with the exhausted CD4+ T cells. CONCLUSION: The results of our study suggest that the co-expression of exhaustion markers and/or loss of co-stimulatory molecules influence the SBA response in HI patients

Bioactivity of Ionic Liquids Based on Valproate in SH-SY5Y Human Neuroblastoma Cell Line

This work received financial support from the PT national funds (FCT-MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project UIDB/50006/2020 | UIDP/50006/2020. A.F.M.S. and Ž.P. also acknowledge FCT-MCTES for the PhD grant (SFRH/BD/132551/2017) and Norma Transitória DL 57/2016 program contract, respectivelyThe search for alternative and effective therapies to fight cancer is one of the main goals of the pharmaceutical industry. Recently, ionic liquids (ILs) have emerged as potential therapeutic agents with antitumor properties. The goal of this study was to synthesize and evaluate the bioactivity of different ILs coupled with the active pharmaceutical ingredient (API) valproate (VPA) as an antitumor agent. The toxicity of the prepared ionic liquids was evaluated by the MTT cell metabolic assay in human neuroblastoma SH-SY5Y and human primary Gingival Fibroblast (GF) cell lines, in which they showed inhibitory effects during the study period. In addition, low cytotoxicity against GF cell lines was observed, suggesting that these compounds are not toxic to human cell lines. [C2OHDMiM][VPA] demonstrated an outstanding antitumor activity against SH-SY5Y and lower activity against the non-neoplastic GF line. The herein assessed compounds played an important role in the modulation of the signaling pathways involved in the cellular behavior. This work also highlights the potential of these ILs-API as possible antitumor agentspublishersversionpublishe

Active regulatory T-cells contribute to broadened T-cell repertoire diversity in ivIg-treated SLE patients

Octapharma

Investigation of the level of knowledge in different countries about edible insects : cluster segmentation

This study aimed to investigate the level of knowledge about edible insects (EIs) in a sample of people from thirteen countries (Croatia, Greece, Latvia, Lebanon, Lithuania, Mexico, Poland, Portugal, Romania, Serbia, Slovenia, Spain, and Turkey). Data collection was based on a questionnaire survey applied through online tools between July and November 2021. For data analysis, techniques such as factor analysis, cluster analysis, and chi-square tests were used, with a significance level of 5%. A total of 27 items were used to measure knowledge on a five-point Likert scale. Applying factor analysis with principal components and Varimax rotation, a solution that explains about 55% of variance was obtained. This accounts for four factors that retained 22 of the 27 initial items: F1 = Sustainability (8 items), F2 = Nutrition (8 items), F3 = Production Factors (2 items), and F4 = Health Concerns (4 items). Internal consistency was evaluated through Cronbach’s alpha. The cluster analysis consisted of the application of hierarchical methods followed by k-means and produced three clusters (1—‘fearful’, 2—‘farming,’ and 3—‘ecological’ individuals). The characterisation of the clusters revealed that age did not influence cluster membership, while sex, education, country, living environment, professional area, and income all influenced the composition of the clusters. While participants from Mexico and Spain were fewer in the ‘fearful’ cluster, in those from Greece, Latvia, Lebanon, and Turkey, the situation was opposed. Participants from rural areas were mostly in cluster 2, which also included a higher percentage of participants with lower income. Participants from professional areas linked with biology, food, and nutrition were mostly in cluster 3. In this way, we concluded that the level of knowledge about EIs is highly variable according to the individual characteristics, namely that the social and cultural influences of the different countries lead to distinct levels of knowledge and interpretation of information, thus producing divergent approaches to the consumption of insects—some more reluctant and measuring possible risks. In contrast, others consider EIs a good and sustainable protein-food alternative.info:eu-repo/semantics/publishedVersio

Investigation of the Level of Knowledge in Different Countries about Edible Insects: Cluster Segmentation

This study aimed to investigate the level of knowledge about edible insects (EIs) in a sample of people from thirteen countries (Croatia, Greece, Latvia, Lebanon, Lithuania, Mexico, Poland, Portugal, Romania, Serbia, Slovenia, Spain, and Turkey). Data collection was based on a questionnaire survey applied through online tools between July and November 2021. For data analysis, techniques such as factor analysis, cluster analysis, and chi-square tests were used, with a significance level of 5%. A total of 27 items were used to measure knowledge on a five-point Likert scale. Applying factor analysis with principal components and Varimax rotation, a solution that explains about 55% of variance was obtained. This accounts for four factors that retained 22 of the 27 initial items: F1 = Sustainability (8 items), F2 = Nutrition (8 items), F3 = Production Factors (2 items), and F4 = Health Concerns (4 items). Internal consistency was evaluated through Cronbach’s alpha. The cluster analysis consisted of the application of hierarchical methods followed by k-means and produced three clusters (1—‘fearful’, 2—‘farming,’ and 3—‘ecological’ individuals). The characterisation of the clusters revealed that age did not influence cluster membership, while sex, education, country, living environment, professional area, and income all influenced the composition of the clusters. While participants from Mexico and Spain were fewer in the ‘fearful’ cluster, in those from Greece, Latvia, Lebanon, and Turkey, the situation was opposed. Participants from rural areas were mostly in cluster 2, which also included a higher percentage of participants with lower income. Participants from professional areas linked with biology, food, and nutrition were mostly in cluster 3. In this way, we concluded that the level of knowledge about EIs is highly variable according to the individual characteristics, namely that the social and cultural influences of the different countries lead to distinct levels of knowledge and interpretation of information, thus producing divergent approaches to the consumption of insects—some more reluctant and measuring possible risks. In contrast, others consider EIs a good and sustainable protein-food alternative.info:eu-repo/semantics/publishedVersio

Setting performance indicators for coastal marine protected areas: An expert-based methodology

Marine Protected Areas (MPAs) require effective indicators to assess their performance, in compliance with the goals of relevant national and international commitments. Achieving and prioritizing shortlists of multidisciplinary indicators demands a significant effort from specialists to depict the multiple conservation and socioeconomic interests, and the large complexity of natural systems. The present paper describes a structured expert-based methodology (process and outputs) to co-define a list of multidisciplinary MPA performance indicators. This work was promoted by the management authority of coastal MPAs in mainland Portugal to gather a consensual and feasible list of indicators that would guide the design of a future national monitoring program. Hence, Portuguese coastal MPAs served as a case study to develop such a process between 2019 and 2020. In the end, participants (1) agreed on a shortlist of prioritized indicators (i.e., environmental, governance, and socioeconomic indicators) and (2) defined minimum monitoring frequencies for the indicators in this list, compatible with the potential replicability of the associated survey methods. The present approach recommends that management plans incorporate monitoring procedures and survey methods, with a validated list of indicators and associated monitoring periodicity, agreed among researchers, MPA managers and governance experts. The proposed methodology, and the lessons learned from it, can support future processes aiming to define and prioritize MPA performance indicatorsFundação para a Ciência e Tecnologia - FCT, European Maritime and Fisheries Fund (EMFF)info:eu-repo/semantics/publishedVersio