How organic matter quality influences dark fermentation effectiveness

Summary In next generation bio-based refineries, hydrolysis and primary (or extractive) fermentations by undefined microbial cultures (UMC) are precursors of secondary bio-transformations, in which H2, CO2 and mixed carboxylates are used as substrate for achieving added-value target products (e.g. bio-based chemicals, bio-plastics and pigments). Dark fermentation (DF) is the most simple UMC-driven hydrolysis and primary fermentations to extract gaseous and soluble mixtures of compounds from raw biomass. Which solid fractions (types of macro-molecules) of mixed raw organic matter (OM) are efficiently hydrolyzed + fermented during DF is an aspect that was rarely considered in depth. Here, a first attempt was made to propose a new approach for understanding the effects of DF on different fractions of biomass. A set of seven different biomasses underwent optimized DF tests and, for simplicity, only the gaseous main product, i.e. bio-hydrogen potential (BHP) production, was used as parameter to assess DF efficacy. BHP was studied in relation with OM characteristics: on one side, chemical composition (macro-molecular fractions) and, on the other side, bioavailability to UMC attack (using two different biological assays). BHP was found significantly correlated (Pearson's test for p   0.05, n = 7). A statistical model (partial least square regression) was proposed for predicting BHP from OM characteristics, with interesting predictability. In the next future, the proposed approach should be widened to better understand the DF effectiveness not only referred to its gaseous products, but especially focusing on the wide range of soluble products (carboxylates), thought as substrates for secondary biorefinery. Copyright © 2015 John Wiley & Sons, Ltd

A Storable Mediatorless Electrochemical Biosensor for Herbicide Detection.

A novel mediatorless photo-bioelectrochemical sensor operated with a biofilm of the cyanobacterium Synechocystis PCC6803 wt. for herbicide detection with long term stability (>20 days) was successfully developed and tested. Photoanodic current generation was obtained in the absence of artificial mediators. The inhibitory effect on photocurrent of three commonly used herbicides (i.e., atrazine, diuron, and paraquat) was used as a means of measuring their concentrations in aqueous solution. The injection of atrazine and diuron into the algal medium caused an immediate photocurrent drop due to the inhibition of photosynthetic electron transport. The detected concentrations were suitable for environmental analysis, as revealed by a comparison with the freshwater quality benchmarks set by the Environmental Protection Agency of the United States (US EPA). In contrast, paraquat caused an initial increase (~2 h) of the photocurrent effect of about 200%, as this compound can act as a redox mediator between the cells and the anode. A relatively long-term stability of the biosensor was demonstrated, by keeping anodes colonized with cyanobacterial biofilm in the dark at 4 °C. After 22 days of storage, the performance in terms of the photocurrent was comparable with the freshly prepared biosensor. This result was confirmed by the measurement of chlorophyll content, which demonstrated preservation of the cyanobacterial biofilm. The capacity of this biosensor to recover after a cold season or other prolonged environmental stresses could be a key advantage in field applications, such as in water bodies and agriculture. This study is a step forward in the biotechnological development and implementation of storable mediatorless electrochemical biosensors for herbicide detection

Compost Heat Recovery Systems: An alternative to produce renewable heat and promoting ecosystem services

Abstract Aerobic biodegradation of biomass can release considerable heat, reaching temperatures of up to 65 °C. This heat can be recovered and used for domestic purposes through the implementation of Compost Heat Recovery System (CHRS). In this study, data were collected from a full-scale CHRS, fed with tree-pruning residues, installed in a farmhouse located in Northern Italy. The CHRS (2.75 kW average heating power) worked in conjunction with a pellet combustor for one year. Energy and carbon balances were analyzed and compared (over a 15-year life-time) with combinations of alternative heating systems (both traditional and green ones). The real case study provided a heat supply at a competitive cost (0.087 € kWh−1). A scenario with two CHRSs would further decrease costs (0.074 € kWh−1). In terms of the carbon balance, a CHRS can save up to 0.252 kgCO2-eq kWh−1 of energy produced, compared to a fossil-fuel alternative (natural-gas), while promoting carbon storage for around 0.05 kgCO2-eq kWh−1 in agricultural soils by compost amendment. Over a 15-year period, each module can potentially substitute fossil-derived heat for around 264 MgCO2-eq, while increasing soil carbon pool by around 20 MgCO2-eq, as C-stock calculated on a medium-term scenario (100-years). CHRSs have great potential to furnish renewable heat at competitive prices, while providing other ecosystem services, such as carbon storage and nutrients cycling to soil. Economic valorization of tree-pruning residues could also be an incentive for the implementation of agroforestry practices and landscape features. Further studies are needed in this relatively unexplored field, which might be of interest in the context of EU regulatory frameworks such as the EU Directive 2018/2001 and the upcoming Common Agricultural Policy (CAP) 2021 – 2027

Fetal face shape analysis from prenatal 3D ultrasound images

3D ultrasound imaging of fetal faces has been predominantly confined to qualitative assessment. Many genetic conditions evade diagnosis and identification could assist with parental counselling, pregnancy management and neonatal care planning. We describe a methodology to build a shape model of the third trimester fetal face from 3D ultrasound and show how it can objectively describe morphological features and gestational-age related changes of normal fetal faces. 135 fetal face 3D ultrasound volumes (117 appropriately grown, 18 growth-restricted) of 24-34 weeks gestation were included. A 3D surface model of each face was obtained using a semi-automatic segmentation workflow. Size normalisation and rescaling was performed using a growth model giving the average size at every gestation. The model demonstrated a similar growth rate to standard head circumference reference charts. A landmark-free morphometry model was estimated to characterize shape differences using non-linear deformations of an idealized template face. Advancing gestation is associated with widening/fullness of the cheeks, contraction of the chin and deepening of the eyes. Fetal growth restriction is associated with a smaller average facial size but no morphological differences. This model may eventually be used as a reference to assist in the prenatal diagnosis of congenital anomalies with characteristic facial dysmorphisms

Electroactive Biochar for Large-Scale Environmental Applications of Microbial Electrochemistry

Large-scale environmental applications of microbial electrochemical technologies (MET), such as wastewater treatment, bioremediation, or soil improvement, would be more feasible if bioelectrodes could be fabricated with simpler materials. Biochar with potentially improved electroactive properties (e-biochar) can be an ideal candidate for this scope, being at the same time widely available, biocompatible, and fully recyclable at its end-of-life as a soil amendment. Here we review the application of biochar to MET, to set benchmarks aimed at tuning the electroactive properties of such materials from the point of view of MET. The precursor biomass, thermochemical process conditions, and pre-, in situ-, and/or post-treatments should tailor optimized combinations of electrical conductivity, capacitance, superficial redox-active and electroactive functional groups, porosity distribution, and capacity to host electroactive microbial communities. We also discuss methods to rigorously characterize e-biochar properties and the most relevant multidisciplinary research challenges toward its application in large-scale MET.This work has been financed by the Italian Ministry of University and Research (MIUR), within the SIR2014 Grant, project RBSI14JKU3. Dr. R. Berenguer also thanks the Spanish Ministerio de Economía y Competitividad and FEDER funds (RYC-2017-23618 and CTM2015-71520-C2-1-R) for financial support. Ricardo Louro and Catarina Paquete thank Fundação para a Ciência e a Tecnologia (FCT) Portugal [PTDC/BBBBQB/4178/2014 and PTDC/BIA-BQM/30176/2017], by Project LISBOA-01-0145-FEDER-007660 (Microbiologia Molecular, Estrutural e Celular) funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI), and by ITQB research unit GREEN-it “Bioresources for sustainability” (UID/Multi/04551/2013). This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 810856. This investigation has also received funding from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No. 642190 (Project “iMETLAND”; http://www.imetland.eu)

Biochar addition to compost heat recovery systems improves heat conversion yields

Introduction: Compost heat recovery systems (CHRS) represent an emerging technology to recover residual woody biomass from agroforestry and forestry activities and use the heat that is naturally produced during aerobic biodegradation (composting). However, a low oxygen concentration in the gas phase and self-drying and compaction of the compost body often limit efficient oxidation by microbial communities. Woodchip-derived biochar has often been proposed as a bulking agent and improver of water retention and of oxygen accessibility in the composting process, but the literature reporting its effects in the CHRS is scarce.Methods: Here, biochar (average particle size of 10 mm) was added at 10% (on weight basis) to chipped pruning residues into two bench-scale-controlled reactors (0.2 m3), operated in parallel for 57 days.Results and Discussion: The addition of 10% (w/w) biochar to the composting body increased biodegradation yields by approximately 50% and improved oxidation rates over readily biodegradable organic fractions (addition of cheese whey). Temperatures were on average 1.34°C higher, and heat extraction flux was also improved in the presence of biochar (0.3 kW/m3) versus in its absence (0.1 kW/m3). The organic matter mass balance resulted in approximately 50% higher biodegradation yield and improved oxidation rates over readily biodegradable organic fractions. Microbial analysis highlighted a higher concentration of thermophilic species and a lower concentration of well-known pathogenic and antibiotic-resistant genera in the presence of biochar

Performance Assessment in Fingerprinting and Multi Component Quantitative NMR Analyses

An interlaboratory comparison (ILC) was organized with the aim to set up quality control indicators suitable for multicomponent quantitative analysis by nuclear magnetic resonance (NMR) spectroscopy. A total of 36 NMR data sets (corresponding to 1260 NMR spectra) were produced by 30 participants using 34 NMR spectrometers. The calibration line method was chosen for the quantification of a five-component model mixture. Results show that quantitative NMR is a robust quantification tool and that 26 out of 36 data sets resulted in statistically equivalent calibration lines for all considered NMR signals. The performance of each laboratory was assessed by means of a new performance index (named Qp-score) which is related to the difference between the experimental and the consensus values of the slope of the calibration lines. Laboratories endowed with a Qp-score falling within the suitable acceptability range are qualified to produce NMR spectra that can be considered statistically equivalent in terms of relative intensities of the signals. In addition, the specific response of nuclei to the experimental excitation/relaxation conditions was addressed by means of the parameter named NR. NR is related to the difference between the theoretical and the consensus slopes of the calibration lines and is specific for each signal produced by a well-defined set of acquisition parameters

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt