Search

Bioplastics are emerging as a promising solution to reduce pollution caused by petroleum-based plastics. Among them, polyhydroxyalkanoates (PHAs) stand out as viable biotechnological alternatives, though their commercialization is limited by expensive downstream processes. Traditional PHA extraction methods often involve toxic solvents and high energy consumption, underscoring the need for more sustainable approaches. This study evaluated physical and chemical methods to extract PHAs from Pseudomonas putida U, a bacterium known to produce poly-3-hydroxyoctanoate P(3HO). Lyophilized cells underwent six extraction methods, including the use of the following: boiling, sonication, sodium hypochlorite (NaClO), sodium dodecyl sulfate (SDS), sodium hydroxide (NaOH), and chloroform. Physical methods such as boiling and sonication achieved yields of 70% and 60%, respectively, but P(3HO) recovery remained low (30–40%). NaClO extraction provided higher yields (80%) but resulted in significant impurities (70%). NaOH methods offered moderate yields (50–80%), with P(3HO) purities between 50% and 70%, depending on the conditions. Spectroscopic and analytical techniques (FTIR, TGA, NMR, GPC) identified 0.05 M NaOH at 60 °C as the optimal extraction condition, delivering high P(3HO) purity while minimizing environmental impact. This positions NaOH as a sustainable alternative to traditional halogenated solvents, paving the way for more eco-friendly PHA production processes. [ABSTRACT FROM AUTHOR]

This study explores the impact of incorporating conductive materials and bioelectrochemical systems (BES) on the efficiency of anaerobic digestion (AD) of sewage sludge. The research consists of two phases: biodegradability tests using 3D-printed polylactic acid-based conductive fillers (PLA/Carbon Black and PLA/Graphene) and semi-continuous assays integrating an external BES into the AD process. Results from biodegradability tests indicate that conductive fillers enhance around 50% methane production during the start-up phase, with microbial communities adapting over time to reduce variability in methane yields. Moreover, as the experiment progressed, the methane yields of the digesters with and without fillers became equal. Semi-continuous experiments demonstrate that BES integration improves process stability and methane production by achieving a 5–10% improvement in the amount of methane in the biogas throughout the entire operation, even under high organic loads, by facilitating diverse electron transfer pathways. The challenges of BES operation highlight the need for optimized designs to ensure scalability. Microbial analyses reveal that BES application shifts methanogenic pathways, favouring acetoclastic methanogenesis. Overall, the findings underscore the potential of conductive materials and BES to improve biogas quality and production, contributing to sustainable wastewater management and renewable energy generation. [ABSTRACT FROM AUTHOR]

Despite over two decades of intense research into bioelectrochemical systems (BESs), their practical implementation remains unrealized, partly due to the low performance of bioelectrodes. With the introduction of additive manufacturing techniques, the development of a new generation of bioelectrodes with custom-shaped geometries using conductive composites has become feasible. This study examines the potential of using two conductive composites, Poly-lactic acid (PLA) and thermoplastic polyurethane (TPU), for 3D-printed electrodes. Electrochemical characterization reveals that TPU has a charge transfer resistance approximately two orders of magnitude higher than PLA, rendering it unsuitable for bioelectrodes. The presence of triangular patterns enhances the performance of planar electrodes, with optimal results observed for PLA-based electrodes with surface pattern depths between 0.6 and 1.4 mm. Additionally, electrodeposition (ED) of graphene oxide (GO) further improves performance across all cases. During the subsequent biotic start-up, patterned PLA electrodes with a depth of 1.4 mm exhibit higher current. However, these 3D-printed electrodes exhibit degradation after 56 days of operation. [ABSTRACT FROM AUTHOR]

Electromethanogenesis is a process of microbial electrosynthesis (MES) in which electroactive microorganisms reduce carbon dioxide (CO2) to produce methane (CH4), using a cathode as an electron donor. The efficiency of this reaction is greatly determined by the establishment of a robust microbial community on the biocathodes, which eventually affects the global performance of the bioreactor. Moreover, the development of the biofilm depends on several characteristics of the electrodes, more specifically their material and geometry. Since electrode geometry is a crucial parameter, this study aims at evaluating the sole influence of the electrode shape by installing carbon‐based electrodes with two different constructions (brush and carbon felt) of biocathodes in an electromethanogenic reactor for CO2 capture. The overall performance of the reactors showed coulombic efficiencies around 100%, with high‐quality biogas reaching methane concentrations above 90%. The results reveal that the electrode geometry affects the individual biocathode performance, and the carbon brush showed a bigger contribution to current generation and electrical capacitance, exhibiting higher peak hydrogen production compared to the carbon felt, which could be reflected in higher CO2 capture and methane generation. Both geometries showed a greater proliferation of archaea over bacteria (between 53 and 85%), which was more significant on the brush than on the carbon felt. Archaea community was dominated by Methanobacterium in carbon felt electrodes and codominated with Methanobrevibacter in brush electrodes, while bacteria analyses showed a very similar community for both geometries. © 2022 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Esophageal squamous cell carcinoma (ESCC) is the predominant type of esophageal cancer in the Asian region, including Japan. A previous study reported mutational landscape of Japanese ESCCs by using exome sequencing. However, somatic structural alterations were yet to be explored. To provide a comprehensive mutational landscape, we performed whole genome sequencing (WGS) analysis of biopsy specimens from 20 ESCC patients in a Japanese population. WGS analysis identified non-silent coding mutations of TP53, ZNF750 and FAT1 in ESCC. We detected six mutational signatures in ESCC, one of which showed significant association with smoking status. Recurrent structural variations, many of which were chromosomal deletions, affected genes such as LRP1B, TTC28, CSMD1, PDE4D, SDK1 and WWOX in 25%·30% of tumors. Somatic copy number amplifications at 11q13.3 (CCND1), 3q26.33 (TP63/SOX2), and 8p11.23 (FGFR1) and deletions at 9p21.3 (CDKN2A) were identified. Overall, these multi-dimensional view of genomic alterations improve the understanding of the ESCC development at molecular level and provides future prognosis and therapeutic implications for ESCC in Japan. [ABSTRACT FROM AUTHOR]

New energy concepts such as distributed power generation systems (DPGSs) are changing the face of electric distribution and transmission. Power electronics researchers try to apply new electronic controller solutions with the capacity of implementing new and more complex control algorithms combined with internal high-speed communication interfaces. Thus, it is possible to monitor, store, and transfer a large number of internal variables that can be sent online to local or remote hosts in order to take new set points of different generation units. With this objective, this paper presents the design, implementation, and test of an industrial multiprocessor controller based on a floating-point digital signal processor (DSP) and a field-programmable gate array, which operate cooperatively. The communication architecture, which has been added to the proposed electronic solution, consists of a universal serial bus (USB), implemented with a minimum use of the DSP core, and a controller area network (CAN) bus that permits distributed control. Although the proposed system can be readily applied to any DPGS, in this paper, it is focused on a 150-kVA back-to-back three-level neutral-point-clamped voltage source converter for wind turbine applications. [ABSTRACT FROM AUTHOR]