Simplified Reactor Design for Mixed Culture-Based Electrofermentation toward Butyric Acid Production

Mixed microbial culture (MMC) electrofermentation (EF) represents a promising tool to drive metabolic pathways toward the production of a specific compound. Here, the MMC-EF process has been exploited to obtain butyric acid in simplified membrane-less reactors operated by applying a difference of potential between two low-cost graphite electrodes. Ten values of voltage difference, from -0.60 V to -1.5 V, have been tested and compared with the experiment under open circuit potential (OCP). In all the tested conditions, an enhancement in the production rate of butyric acid (from a synthetic mixture of glucose, acetate, and ethanol) was observed, ranging from 1.3- to 2.7-fold relative to the OCP. Smaller enhancements in the production rate resulted in higher values of the calculated specific energy consumption. However, at all applied voltages, a low flow of current was detected in the one-chamber reactors, accounting for an average value of approximately -100 µA. These results hold a substantial potential with respect to the scalability of the electrofermentation technology, since they pinpoint the possibility to control MMC-based bioprocesses by simply inserting polarized electrodes into traditional fermenters

Protection against pertussis in humans correlates to elevated serum antibodies and memory B cells

Pertussis is a respiratory infection caused by Bordetella pertussis that may be particularly severe and even lethal in the first months of life when infants are still too young to be vaccinated. Adults and adolescents experience mild symptoms and are the source of infection for neonates. Adoptive maternal immunity does not prevent pertussis in the neonate. We compared the specific immune response of mothers of neonates diagnosed with pertussis and mothers of control children. We show that women have pre-existing pertussis-specific antibodies and memory B cells and react against the infection with a recall response increasing the levels specific serum IgG, milk IgA, and the frequency of memory B cells of all isotypes. Thus, the maternal immune system is activated in response to pertussis and effectively prevents the disease indicating that the low levels of pre-formed serum antibodies are insufficient for protection. For this reason, memory B cells play a major role in the adult defense. The results of this study suggest that new strategies for vaccine design should aim at increasing long-lived plasma cells and their antibodies

Biocorrosion of speleothems driven by lampenflora: preliminary observations in Bossea show cave (NW-Italy)

Speleothems in show caves are often subjected to tourism-driven alterations, including corrosion due to CO2 increase, undersaturated water and photosynthetic biofilms (e.g. Piano et al., 2015; Pulido-Bosch et al., 1997; White et al., 2021). In particular, the growth of the so-called “lampenflora” causes physical, chemical and aesthetic damage to speleothems (Piano et al., 2015). In this work we investigated for the first time the biocorrosion of speleothems at microscopic level due to lampenflora in Bossea Show cave (NW-Italy). In this cave, the presence of lampenflora was previously documented in Piano et al. (2015) and biocorrosion on speleothems can be observed in different areas along the touristic path. In this work, a first tentative to describe the possible related biocorrosion from a geo-mineralogical point of view was made. Four superficial samples of 1x1 cm of 0.5 maximum thickness were collected on speleothems along the tourist path, in close proximity of halogen lamps. During in situ sampling, the concentration of the main photosynthetic groups composing lampenflora (cyanobacteria, diatoms, and green algae) was measured with Benthotorch®, a portable fluorimeter. The substrate samples were analysed in laboratory by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), in order to assess the alteration degree and the presence of lampenflora possibly responsible of biocorrosion. SEM images of some speleothem samples show high abundance of diatom frustules and the presence of bacteria, algae and fungi. Fluorimeter measures of cyanobacteria, diatoms and green algae amount were then compared to SEM images and EDX results showing in some cases a relation between the speleothems features visible to the naked eyes, the in situ measurements, the degree of alteration of calcite and the presence of bacteria and diatoms frustules at microscope. Moreover, in light of a long-term study aiming at evaluating changes in calcite crystal habits over time, a homogenous speleothem was collected and divided into several parts, observed and photographed with SEM and placed along the tourist path in areas colonized by lampenflora, near the new LED lamps, where they will remain for about a year. The samples will then be collected and re-examined at SEM to verify and eventually quantify the degree of biocorrosion due to the flashlight after at least one year of exposition

An Italian functional genomic resource for Medicago truncatula

Background: Medicago truncatula is a model species for legumes. Its functional genomics have been considerably boosted in recent years due to initiatives based both in Europe and US. Collections of mutants are becoming increasingly available and this will help unravel the genetic control of important traits for many species of legumes. Findings: Our report is on the production of three complementary mutant collections of the model species Medicago truncatula produced in Italy in the frame of a national genomic initiative. Well established strategies were used: Tnt1 mutagenesis, TILLING and activation tagging. Both forward and reverse genetics screenings proved the efficiency of the mutagenesis approaches adopted, enabling the isolation of interesting mutants which are in course of characterization. We anticipate that the reported collections will be complementary to the recently established functional genomics tools developed for Medicago truncatula both in Europe and in the United States

The Citrus Flavonoid Naringenin Protects the Myocardium from Ageing-Dependent Dysfunction: Potential Role of SIRT1

Sirtuin 1 (SIRT1) enzyme plays a pivotal role in the regulation of many physiological functions. In particular, it is implicated in ageing-related diseases, such as cardiac hypertrophy, myocardial infarct, and endothelial dysfunction; moreover, its expression decreases with age. Therefore, an effective strategy to extend the lifespan and improve cardiovascular function is the enhancement of the expression/activity of SIRT1 with exogenous agents. The Citrus flavonoid naringenin (NAR) presents structural similarity with the natural SIRT1 activator resveratrol. In this study, we demonstrate through in vitro assays that NAR significantly activates SIRT1 enzyme and shows antisenescence effects. The binding mode of NAR into SIRT1 was detailed investigated through in silico studies. Moreover, chronic administration (for six months) of NAR (100 mg/kg/day) to 6-month-old mice leads to an enhancement of SIRT1 expression and a marked reduction of reactive oxygen species production in myocardial tissue. Furthermore, at the end of the treatment, the plasma levels of two well-known markers of cardiovascular inflammation, TNF-α and IL6, are significantly reduced in 12-month-old mice treated with NAR, as well as the cardiovascular risk (total cholesterol/HDL ratio) compared to control mice. Finally, the age-associated fibrotic remodeling, which is well detected through a Mallory trichrome staining in the vehicle-treated 12-month-old mice, is significantly reduced by the chronic treatment with NAR. Moreover, an improvement of myocardium functionality is highlighted by the enhancement of citrate synthase activity and stabilization of the mitochondrial membrane potential after NAR treatment. Taken together, these results suggest that a nutraceutical approach with NAR may have positive impacts on many critical hallmarks of myocardial senescence, contributing to improve the cardiac performance in aged subjects

Partial T cell defects and expanded CD56bright NK cells in an SCID patient carrying hypomorphic mutation in the IL2RG gene

X-linked severe combined immunodeficiency (X-SCID) caused by full mutation of the IL2RG gene leads to T- B+ NK- phenotype and is usually associated with severe opportunistic infections, diarrhea, and failure to thrive. When IL2RG hypomorphic mutation occurs, diagnosis could be delayed and challenging since only moderate reduction of T and NK cells may be present. Here, we explored phenotypic insights and the impact of the p.R222C hypomorphic mutation (IL2RGR222C ) in distinct cell subsets in an 8-month-old patient with atypical X-SCID. We found reduced CD4+ T cell counts, a decreased frequency of naïve CD4+ and CD8+ T cells, and an expansion of B cells. Ex vivo STAT5 phosphorylation was impaired in CD4+ CD45RO+ T cells, yet compensated by supraphysiological doses of IL-2. Sanger sequencing on purified cell subsets showed a partial reversion of the mutation in total CD3+ cells, specifically in recent thymic emigrants (RTE), effector memory (EM), and CD45RA+ terminally differentiated EM (EMRA) CD4+ T cells. Of note, patient's NK cells had a normal frequency compared to age-matched healthy subjects, but displayed an expansion of CD56bright cells with higher perforin content and cytotoxic potential, associated with accumulation of NK-cell stimulatory cytokines (IL-2, IL-7, IL-15). Overall, this report highlights an alteration in the NK-cell compartment that, together with the high disease-phenotype variability, should be considered in the suspicion of X-SCID with hypomorphic IL2RG mutation

The bnt162b2 vaccine induces humoral and cellular immune memory to sars-cov-2 Wuhan strain and the Omicron variant in children 5 to 11 years of age

SARS-CoV-2 mRNA vaccines prevent severe COVID-19 by generating immune memory, comprising specific antibodies and memory B and T cells. Although children are at low risk of severe COVID-19, the spreading of highly transmissible variants has led to increasing in COVID-19 cases and hospitalizations also in the youngest, but vaccine coverage remains low. Immunogenicity to mRNA vaccines has not been extensively studied in children 5 to 11 years old. In particular, cellular immunity to the wild-type strain (Wuhan) and the cross-reactive response to the Omicron variant of concern has not been investigated. We assessed the humoral and cellular immune response to the SARS-CoV-2 BNT162b2 vaccine in 27 healthy children. We demonstrated that vaccination induced a potent humoral and cellular immune response in all vaccinees. By using spike-specific memory B cells as a measurable imprint of a previous infection, we found that 50% of the children had signs of a past, undiagnosed infection before vaccination. Children with pre-existent immune memory generated significantly increased levels of specific antibodies, and memory T and B cells, directed against not only the wild type virus but also the omicron variant

Induction of immune response after SARS-CoV-2 mRNA BNT162b2 vaccination in healthcare workers

[no abstract available

Evaluation of humoral and cellular response to four vaccines against COVID-19 in different age groups: A longitudinal study

To date there has been limited head-to-head evaluation of immune responses to different types of COVID-19 vaccines. A real-world population-based longitudinal study was designed with the aim to define the magnitude and duration of immunity induced by each of four different COVID-19 vaccines available in Italy at the time of this study. Overall, 2497 individuals were enrolled at time of their first vaccination (T0). Vaccine-specific antibody responses induced over time by Comirnaty, Spikevax, Vaxzevria, Janssen Ad26.COV2.S and heterologous vaccination were compared up to six months after immunization. On a subset of Comirnaty vaccinees, serology data were correlated with the ability to neutralize a reference SARS-CoV-2 B strain, as well as Delta AY.4 and Omicron BA.1. The frequency of SARS-CoV-2-specific CD4+ T cells, CD8+ T cells, and memory B cells induced by the four different vaccines was assessed six months after the immunization. We found that mRNA vaccines are stronger inducer of anti-Spike IgG and B-memory cell responses. Humoral immune responses are lower in frail elderly subjects. Neutralization of the Delta AY.4 and Omicron BA.1 variants is severely impaired, especially in older individuals. Most vaccinees display a vaccine-specific T-cell memory six months after the vaccination. By describing the immunological response during the first phase of COVID-19 vaccination campaign in different cohorts and considering several aspects of the immunological response, this study allowed to collect key information that could facilitate the implementation of effective prevention and control measures against SARS-CoV-2