-12/5/2016
(Coord.) Politecnico di Torino

SCIENTIFIC PUBLICATIONS

2016, August: When Shakespeare inspires the scientific research

An interesting review around bioplastic from CSIC

"To be, or not to be biodegradable… that is the question for the bio-based plastics"

Auxiliadora Prieto


Abstract

Summary Global warming, market and production capacity are being the key drivers for selecting the main players for the next decades in the market of bio‐based plastics. The drop‐in bio‐based polymers such as the bio‐based polyethylene terephtalate (PET) or polyethylene (PE), chemically identical to their petrochemical counterparts but having a component of biological origin, are in the top of the list. They are followed by new polymers such as PHA and PLA with a significant market growth rate since 2014 with projections to 2020. Research will provide improved strains designed through synthetic and systems biology approaches; furthermore, the use of low‐cost substrates will contribute to the widespread application of these bio‐ based polymers. The durability of plastics is not considered anymore as a virtue, and interesting bioprospecting strategies to isolate microorganisms for assimilating the recalcitrant plastics will pave the way for in vivo strategies for plastic mineralization. In this context, waste management of bio‐based plastic will be one of the most important issues in the near future in terms of the circular economy. There is a clear need for standardized labelling and sorting instructions, which should be regulated in a coordinated way by policymakers and material producers.



2016, October: A new CELBICON publication is out!

Follow the new work of POLITO

 "Electro-oxidation of phenol over electrodeposited MnOx nanostructures and the role of a TiO2 nanotubes interlayer" 

 Massa A., Hernández S., Lamberti A., Galletti C., Russo N., Fino D.


Abstract

More and more attention has recently been paid to the electrochemical treatment of wastewater for the degradation of refractory organics, such as phenol and its derivatives. The electrodeposition of different types of manganese oxides (MnOx) over two substrates, namely metallic titanium and titania nanotubes (TiO2-NTs), is reported herein. X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) analyses have confirmed the formation of different oxidation states of the manganese, while Field Emission Scanning Electronic Microscopy (FESEM) analysis has helped to point out the evolutions in the morphology of the samples, which depends on the electrodeposition parameters and calcination conditions.

Moreover, cross section FESEM images have demonstrated the penetration of manganese oxides inside the NTs for anodically deposited samples. The electrochemical properties of the electrodes have been investigated by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV), both of which have shown that both calcination and electrodeposition over TiO2-NTs lead to more stable electrodes that exhibited a marked increase in the current density. The activity of the proposed nanostructured samples toward phenol degradation has been investigated. The cathodically electrodeposited manganese oxides (α-MnO2) have been found to be the most active phase, with a phenol conversion of 26.8%. The anodically electrodeposited manganese oxides (α-Mn2O3), instead, have shown higher stability, with a final working potential of 2.9 V vs. RHE. The TiO2-NTs interlayer has contributed, in all cases, to a decrease of about 1–1.5 V in the final (reached) potential, after a reaction time of 5 h. Electrochemical impedance spectroscopy (EIS) and accelerated life time tests have confirmed the beneficial effect of TiO2-NTs, which contributes by improving both the charge transfer properties (kinetics of reaction) and the adhesion of MnOx films.




2017: Discover PHA production!

Follow the book chapter of CSIC

"Biogenesis of medium-chain-length polyhydroxyalkanoates"

Ryan Kniewel, Olga Revelles Lopez, M. Auxiliadora Prieto


Abstract

Medium-chain-length polyhydroxyalkanoates (mcl-PHA) are biotechnologically useful natural products found in many bacteria. This biopolymer functions as a carbon and energy storage reservoir in cells but has physical and mechanical properties that make it a promising bioplastic with applications ranging from adhesives to medical implants. Therefore, there is much interest in understanding the biology of mcl-PHA synthesis and metabolism. Increased knowledge of PHA biology serves as a foundation for the bioengineering of PHA and its eventual use as a biologically derived product. This chapter covers the state of knowledge on mcl-PHA, including its synthesis and its central role in cellular metabolism. Moreover, this chapter discusses methods for bioengineering mcl-PHA production in bacteria as well as synthetic biology methods for its study and production in the natural mcl-PHA producer, Pseudomonas putida.





2017: New publication is out!

Follow new perspectives of CO2 conversion proposed by POLITO and TU Delft


"Syngas production from electrochemical reduction of CO2: current status and prospective implementation"

Hernández S., Farkhondehfal M.A., Sastre F., Makkee M., Saracco G. and Russo N.


 Abstract

The CO2 that comes from the use of fossil fuels accounts for about 65% of the global greenhouse gas emission, and it plays a critical role in global climate changes. Among the different strategies that have been considered to address the storage and reutilization of CO2, the transformation of CO2 into chemicals or fuels with a high added-value has been considered a winning approach. This transformation is able to reduce the carbon emission and induce a “fuel switching” that exploits renewable energy sources. The aim of this brief review is to gather and critically analyse the main efforts that have been made and achievements that have been made in the electrochemical reduction of CO2 for the production of CO. The main focus is on the prospective of exploiting the intrinsic nature of the electrolysis process, in which COreduction and H2 evolution reactions can be combined, into a competitive approach, to produce syngas. Several well-established processes already exist for the generation of fuels and fine-chemicals from H2/CO mixtures of different ratios. Hence, the different kinds of electrocatalysts and electrochemical reactors that have been used for the CO and H2 evolution reactions have been analysed, as well as the main factors that influence the performance of the system from the thermodynamic, kinetic and mass transport points of view.


2017: New publication is out!

Follow the new article from POLITO in collaboration with Universität Wien


"The physiology of trace elements in biological methane production"

Abdel Azim A., Pruckner C, Kolar PTaubner RSFino D,  Saracco G, Sousa FLRittmann SKR

Abstract


Trace element (TE) requirements of Methanothermobacter okinawensis and Methanothermobacter marburgensis were examined in silico, and using closed batch and fed-batch cultivation experiments. In silico analysis revealed genomic differences among the transport systems and enzymes related to the archaeal Wood-Ljungdahl pathway of these two methanogens. M. okinawensis responded to rising concentrations of TE by increasing specific growth rate (µ) and volumetric productivity (MER) during closed batch cultivation, and can grow and produce methane (CH4) during fed-batch cultivation. M. marburgensis showed higher µ and MER during fed-batch cultivation and was therefore prioritized for subsequent optimization of CO2-based biological CH4 production. Multiple-parameter cultivation dependency on growth and productivity of M. marburgensis was finally examined using exponential fed-batch cultivation at different medium-, TE- and sulphide dilution rates, and different gas inflow rates. MER of 476 mmolL-1h-1 and µ of 0.69h-1 were eventually obtained during exponential fed-batch cultivations employing M. marburgensis.





2017: New review is out!

Follow the new article from CSIC and POLITO

"About how to capture and exploit the CO2 surplus that nature, per se, is not capable of fixing"

Godoy M.S., Mongili B., Fino D., Prieto M.A.


Abstract


Human activity has been altering many ecological cycles for decades, disturbing the natural mechanisms which are responsible for re‐establishing  the normal environmental balances. Probably, the most disrupted of these cycles is the cycle of carbon. In this context, many technologies have been developed for an efficient CO2 removal from the atmosphere. Once captured, it could be stored in large geological formations and other reservoirs like oceans. This strategy could present some environmental and economic problems. Alternately, CO2 can be transformed into carbonates or different added‐value products, such as biofuels and bioplastics, recycling CO2 from fossil fuel. Currently different methods are being studied in this field. We classified them into biological, inorganic and hybrid systems for CO2 transformation. To be environmentally compatible, they should be powered by renewable energy sources. Although hybrid systems are still incipient technologies, they have made great advances in the recent years. In this scenario, biotechnology is the spearhead of ambitious strategies to capture CO2 and reduce global warming.



2018: New article is out!

Follow new perspectives of CO2 conversion proposed by POLITO


"Enhanced electrochemical oxidation of phenol over manganese oxides under mild wet air oxidation conditions"

Massa A., Hernández S., Ansaloni S., Castellino M., Russo N., Fino D.

Abstract

Low-cost manganese oxide, MnOx-based electrocatalysts, containing α-MnO2 and mixed α-Mn2O3/α-MnO2 phases, were synthesized by scalable anodic and cathodic electrodeposition methods, respectively. Their morphological and chemical composition were characterized by means of Field Emission Scanning Electronic Microscopy (FESEM), X-Ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). These electrodes were tested for the electro-oxidation of a recalcitrant molecule (i.e. phenol) in a lab-scale high temperature and high pressure (HTHP) batch electrocatalytic reactor. Their electrocatalytic activity was compared with that of state-of-the-art anodes for phenol electro-oxidation: antimony-doped tin oxide (SnO2–Sb5+) and ruthenium oxide (RuO2): first, under standard ambient conditions, and then, under the conditions of a Polymeric Electrolyte Membrane (PEM) electrolyzer (i.e. 85 °C and 30 bar) and of mild Catalytic Wet Air Oxidation (CWAO, i.e. 150 °C and 30 bar). Both reaction time and current density were varied to investigate their effect in the performances of the system as well as on the reaction mechanism. Both MnOx electrodes reported enhanced conversion efficiencies, up to ∼75%, at the highest pressure and temperature, and at the lowest applied current density, which influenced the process by improving dissolution of the O2 evolved, the reaction kinetics and thermodynamics, and by minimizing irreversibilities, respectively. The here reported MnOx films achieved conversion and mineralization efficiencies comparable to Sb-SnO2 (that is the more toxic) and RuO2 (that is more expensive) materials, operating under mild CWAO operation conditions, which demonstrate the potential of the electrocatalytic HTHP process as a sustainable advanced oxidation technology for wastewater treatment or electrosynthesis applications. 



2018: New article is out!

Follow the new article written by KJT

"Physiology and methane productivity of Methanobacterium thermaggregans"

Mauerhofer L.-M., Reischl B., Schmider T., Schupp B., Nagy K., Pappenreiter P., … Rittmann S. K.-M. R.


Abstract

Accumulation of carbon dioxide (CO2), associated with global temperature rise, and drastically decreasing fossil fuels necessitate the development of improved renewable and sustainable energy production processes. A possible route for CO2 recycling is to employ autotrophic and hydrogenotrophic methanogens for CO2-based biological methane (CH4) production (CO2-BMP). In this study, the physiology and productivity of Methanobacterium thermaggregans was investigated in fed-batch cultivation mode. It is shown that M. thermaggregans can be reproducibly adapted to high agitation speeds for an improved CH4 productivity. Moreover, inoculum size, sulfide feeding, pH, and temperature were optimized. Optimization of growth and CH4 productivity revealed that M. thermaggregans is a slightly alkaliphilic and thermophilic methanogen. Hitherto, it was only possible to grow seven autotrophic, hydrogenotrophic methanogenic strains in fed-batch cultivation mode. Here, we show that after a series of optimization and growth improvement attempts another methanogen, M. thermaggregas could be adapted to be grown in fed-batch cultivation mode to cell densities of up to 1.56 g L-1. Moreover, the CH4 evolution rate (MER) of M. thermaggregans was compared to Methanothermobacter marburgensis, the CO2-BMP model organism. Under optimized cultivation conditions, a maximum MER of 96.1 ± 10.9 mmol L-1 h-1 was obtained with M. thermaggregans-97% of the maximum MER that was obtained utilizing M. marburgensis in a reference experiment. Therefore, M. thermaggregans can be regarded as a CH4 cell factory highly suited to be applicable for CO2-BMP.




2018, September: A new CELBICON publication is out!

Follow the new work of F-IGB


Csepei L. I. , Gärtner T.,  Schmid J.,  V. Sieber

https://doi.org/10.1002/cite.201855022





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