Bioreactor and bioprocess design issues in enzymatic hydrolysis of lignocellulosic biomass

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Butanol production by clostridium acetobutylicum in a series of packed biofilm bed reactors

The reactor design plays a key role in the fermentative production of biobutanol. The high cell concentration that may be reached in confined – biofilm, membrane, recycling - cell reactors offers high conversion rates. To the authors knowledge, the concentration of solvents in the broth from biofilm reactors reported in literature is not particularly high and it negatively affects the successive stages for butanol recovery. The low concentration of solvents in the produced stream is typically due to the inhibitory effect of solvents on the fermentation. Therefore, the butanol bioreactor productivity is as low as the bioreactor behaviour approaches the CSTR limit. The aim of this contribution is to report recent results on the design of a continuous biofilm reactor to optimize the process performances. Clostridium acetobutylicum DSM 792 was adopted for the fermentation process. The conversion was carried out in 4 packed bed reactors (PBRs) connected in series: the first reactor of the series was kept under acidogenesis and the successive reactors were kept under solventogenesis. Tests were carried out feeding the reactor system with solutions bearing glucose. Please click Additional Files below to see the full abstract

Life-course vaccinations for migrants and refugees. Drawing lessons from the COVID-19 vaccination campaigns

Covid-19 showed once more, and very evidently, that some disadvantaged subgroups, including mi- grants and refugees (M&Rs), are at higher risk of contracting a disease or suffering from its severe con- sequences in areas with high transmission [1,2]. This may be due to their living conditions, which make physical distancing difficult, and/or to their legal status, which may exclude them from health care services. Additionally, COVID-19 reminded us that M&Rs tend to also have suboptimal vaccination coverage compared to the general population due to several concurrent factors [3,4]: – exclusion from health and vaccination plans and systems, often due to a lack of legal entitlements to health care or due to administrative/residence barriers; – health system barriers due to language, lack of cultural sensitivity, lack of outreach and community engagement capacity, lack of collaboration with civil society organisations, barriers to primary care, and vaccination services access, including vaccination costs; – high mobility of M&Rs; – lack of confidence in the health system and misconceptions about the vaccine. We propose some elements useful for orienting the research agenda and generating debate based on the experience of the COVID-19 pandemic. While M&Rs experienced exclusion due to the pandemic in many contexts, in others, it has been an opportunity not just to maximise coverage, but also to set up, test, and implement new, effective, and replicable approaches in vaccination services

Serum concentrations of perfluorinated alkyl substances in farmers living in areas affected by water contamination in the Veneto Region (Northern Italy)

Abstract Human exposure to per- and polyfluorinated alkyl substances (PFASs) is a major public health concern because in the last decades several cases of overexposure of people to PFASs, in particular through contaminated water, occurred worldwide. In 2013–2017 a PFAS drinking water contamination was discovered and investigated in northern Italy (Veneto region) and high PFAS serum levels were detected in exposed people. 629 subjects were enrolled: 257 residing in municipalities in the areas under impact, 250 residing in municipalities in areas at presumed background exposure and 122 farmers living in contaminated rural areas producing and consuming own livestock and vegetables and frequently using well water. The highest PFAS serum concentrations (median PFOA concentrations 40 ng/g) were found in the subgroup of farmers. The main factors influencing PFAS serum levels of farmers were residence area and the related extent of drinking water contamination, gender, years of residence in the municipalities, well water consumption and consumption of own produced food. PFOA serum concentrations in farmers residing in the areas of the Veneto region impacted by PFAS contamination are among the highest found worldwide

Biobutanol production from high sugar content wastewaters

Over the last decade, the depletion of oil resources and concerns regarding both economic and environmental issues associated with petroleum-based fuels have renewed interests in biofuel production from renewable resources . Industrial and academic researches have paid attention to the development of (bio)sustainable processes and to the produce biofuels by conversion of renewable feedstoks. The spectrum of biofuels includes the butanol, a simple four carbon alcohol characterized by interesting features. A biotechnological route to produce butanol is based on the fermentation of clostridia: saccharolytic butyric acid-producing bacteria able to produce acetone-butanol-ethanol (ABE) by fermentation adopting a wide spectrum of carbohydrates, typically present in renewable unexpensive feedstocks. This contribution reports about a study on the feasibility of bio-butanol production by fermentation of high-sugar content beverages (HSCBs). The anaerobic solventogenic bacterium Clostridium acetobutylicum DSM 792 was adopted for the fermentation process. Commercial pineapple juice, lemon syrup and tonic water were tested as substrate for the fermentation. Preliminary tests pointed out that: i) the microorganism did not grow on any of the HSBCs investigated without complex medium supplementation; ii) the conversion degree of sucrose was quite low. Therefore, tests were carried out with broth made of the complex medium and HSCB pre-idrolized (sucrose idrolized to glucose and fructose)

Social capital and willingness to participate in COVID-19 vaccine trials: an Italian case-control study

Background: What leads healthy people to enter in a volunteer register for clinical trials? This study aimed to investigate the relationship between the decision to volunteer in clinical trials for a COVID-19 vaccine and social capital, in a sample of healthy volunteers in Italy. Since social capital is characterized by trust, reciprocity, and social and political participation, we claim that it is key in leading individuals to actively take action to protect public health, and to take a risk for the (potential) beneft not only of themselves but for the entire community. Methods: This study was conducted through the administration of a questionnaire to healthy volunteers registered for a phase 1 clinical trial for a COVID-19 vaccine in the Unit Research Centre of ASST-Monza, in September 2020. The primary purpose of a phase 1 study is to evaluate the safety of a new drug candidate before it proceeds to further clinical studies. To approximate a case–control study, we randomly matched the 318 respondents to healthy volunteers (cases) with 318 people randomly selected by Round 9 of the European Social Survey (controls), using three variables, which we considered to be associated with the decision to volunteer: gender, age, and education level. To execute this matching procedure, we used the “ccmatch” module in STATA. Results: The fndings highlight the positive impact of social capital in the choice of healthy individuals to volunteer in COVID-19 vaccine clinical trials. Controlling for possible confounding factors, some exemplary results show that people with a high level of general trust have a greater likelihood of volunteering compared to people with low trust (OR=2.75, CI=1.58–4.77); we also found that it is more probable that volunteers are people who have actively taken action to improve things compared with people who have not (for individuals who did three or more actions: OR=7.54, CI=4.10–13.86). People who reported voting (OR=3.91, CI=1.70–8.99) and participating in social activities more than other people of their age (OR=2.89, CI=1.82–4.60) showed a higher probability to volunteer. Conclusions: Together with the adoption of urgent health measures in response to COVID-19, government policymakers should also promote social capital initiatives to encourage individuals to actively engage in actions aimed at protecting collective health. Our fndings make an empirical contribution to the research on vaccines and its intersection with social behaviour, and they provide useful insights for policymakers to manage current and future disease outbreaks and to enhance the enrolment in vaccine trials

Excess TPX2 Interferes with Microtubule Disassembly and Nuclei Reformation at Mitotic Exit.

The microtubule-associated protein TPX2 is a key mitotic regulator that contributes through distinct pathways to spindle assembly. A well-characterised function of TPX2 is the activation, stabilisation and spindle localisation of the Aurora-A kinase. High levels of TPX2 are reported in tumours and the effects of its overexpression have been investigated in cancer cell lines, while little is known in non-transformed cells. Here we studied TPX2 overexpression in hTERT RPE-1 cells, using either the full length TPX2 or a truncated form unable to bind Aurora-A, to identify effects that are dependent-or independent-on its interaction with the kinase. We observe significant defects in mitotic spindle assembly and progression through mitosis that are more severe when overexpressed TPX2 is able to interact with Aurora-A. Furthermore, we describe a peculiar, and Aurora-A-interaction-independent, phenotype in telophase cells, with aberrantly stable microtubules interfering with nuclear reconstitution and the assembly of a continuous lamin B1 network, resulting in daughter cells displaying doughnut-shaped nuclei. Our results using non-transformed cells thus reveal a previously uncharacterised consequence of abnormally high TPX2 levels on the correct microtubule cytoskeleton remodelling and G1 nuclei reformation, at the mitosis-to-interphase transition

Glycosylation tunes neuroserpin physiological and pathological properties

Neuroserpin (NS) is a member of the serine protease inhibitors superfamily. Specific point mutations are responsible for its accumulation in the endoplasmic reticulum of neurons that leads to a pathological condition named familial encephalopathy with neuroserpin inclusion bodies (FENIB). Wild-type NS presents two N-glycosylation chains and does not form polymers in vivo, while non-glycosylated NS causes aberrant polymer accumulation in cell models. To date, all in vitro studies have been conducted on bacterially expressed NS, de facto neglecting the role of glycosylation in the biochemical properties of NS. Here, we report the expression and purification of human glycosylated NS (gNS) using a novel eukaryotic expression system, LEXSY. Our results confirm the correct N-glycosylation of wild-type gNS. The fold and stability of gNS are not altered compared to bacterially expressed NS, as demonstrated by the circular dichroism and intrinsic tryptophan fluorescence assays. Intriguingly, gNS displays a remarkably reduced polymerisation propensity compared to non-glycosylated NS, in keeping with what was previously observed for wild-type NS in vivo and in cell models. Thus, our results support the relevance of gNS as a new in vitro tool to study the molecular bases of FENIB

Gut bacteriome analysis of Anastrepha fraterculus sp. 1 during the early steps of laboratory colonization

Microbial communities associated to insect species are involved in essential biological functions such as host nutrition, reproduction and survivability. Main factors have been described as modulators of gut bacterial community, such as diet, habit, developmental stage and taxonomy of the host. The present work focuses on the complex changes that gut microbial communities go through when wild insects are introduced to artificial rearing conditions. Specifically, we analyzed the effect of the laboratory colonization on the richness and diversity of the gut bacteriome hosted by the fruit fly pest Anastrepha fraterculus sp. 1. Bacterial profiles were studied by amplicon sequencing of the 16S rRNA V3–V4 hypervariable region in gut samples of males and females, in teneral (1-day-old, unfed) and post-teneral (15-day-old, fed) flies. A total of 3,147,665 sequence reads were obtained and 32 bacterial operational taxonomic units (OTUs) were identified. Proteobacteria was the most abundant phylum (93.3% of the total reads) and, Wolbachia and Enterobacter were the most represented taxa at the genus level (29.9% and 27.7%, respectively, of the total read counts). Wild and laboratory flies showed highly significant differences in the relative abundances of bacteria. The analysis of the core bacteriome showed the presence of five OTUs in all samples grouped by origin, while nine and five OTUs were exclusively detected in laboratory and wild flies, respectively. Irrespective of fly origin or sex, a dominant presence of Wolbachia was observed in teneral flies, whereas Enterobacter was highly abundant in post-teneral individuals. We evidenced significant differences in bacterial richness and diversity among generations under laboratory colonization (F0, F1, F3 and F6) and compared to laboratory and wild flies, displaying also differential patterns between teneral and post-teneral flies. Laboratory and wild A. fraterculus sp. 1 harbor different gut bacterial communities. Laboratory colonization has an important effect on the microbiota, most likely associated to the combined effects of insect physiology and environmental conditions (e.g., diet and colony management).Instituto de GenéticaFil: Salgueiro, Julieta. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pimper, Lidia Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Milla, Fabian Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Russo, Romina María. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Asimakis, Elias D. University of Patras. Department of Environmental Engineering; GreciaFil: Stathopoulou, Panagiota. University of Patras. Department of Environmental Engineering; GreciaFil: Bourtzis, Kostas. Vienna International Centre. Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. Insect Pest Control Laboratory; AustriaFil: Cladera, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tsiamis, George. University of Patras. Department of Environmental Engineering; GreciaFil: Lanzavecchia, Silvia Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética "Ewald A. Favret". Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Differential Responses of Colorectal Cancer Cell Lines to Enterococcus faecalis' Strains Isolated from Healthy Donors and Colorectal Cancer Patients

The metabolites produced by the host’s gut microbiota have an important role in the maintenance of intestinal homeostasis, but can also act as toxins and induce DNA damage in colorectal epithelial cells increasing the colorectal cancer (CRC) chance. In this scenario, the impact of some of the components of the natural human gastrointestinal microbiota, such as Enterococcus faecalis (E. faecalis), at the onset of CRC progression remains controversial. Since under dysbiotic conditions it could turn into a pathogen, the aim of this study was to compare the effect of E. faecalis’ strains (isolated from CRC patients and healthy subjects’ stools) on the proliferation of different colorectal cells lines. First, we isolated and genotyping characterized the Enterococcus faecalis’ strains. Then, we analyzed the proliferation index (by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay) of three tumor and one normal intestinal cell lines, previously exposed to E. faecalis strains pre-cultured medium. Stool samples of CRC patients demonstrated a reduced frequency of E. faecalis compared to healthy subjects. In addition, the secreted metabolites of E. faecalis’ strains, isolated from healthy donors, decreased the human ileocecal adenocarcinoma cell line HCT-8 and human colon carcinoma cell line HCT-116 cell proliferation without effects on human colorectal adenocarcinoma cell line SW620 and on normal human diploid cell line CLR-1790. Notably, the metabolites of the strains isolated from CRC patients did not influence the cell growth of CRC cell lines. Our results demonstrated a new point of view in the investigation of E. faecalis’ role in CRC development, which raises awareness of the importance of not only associating the presence/absence of a unique microorganism, but also in defining the specific characteristics of the different investigated strains