The "Oil-Spill Snorkel": an innovative bioelectrochemical approach to accelerate hydrocarbons biodegradation in marine sediments

This study presents the proof-of-concept of the "Oil-Spill Snorkel": a novel bioelectrochemical approach to stimulate the oxidative biodegradation of petroleum hydrocarbons in sediments. The "Oil-Spill Snorkel" consists of a single conductive material (the snorkel) positioned suitably to create an electrochemical connection between the anoxic zone (the contaminated sediment) and the oxic zone (the overlying O-2-containing water). The segment of the electrode buried within the sediment plays a role of anode, accepting electrons deriving from the oxidation of contaminants. Electrons flow through the snorkel up to the part exposed to the aerobic environment (the cathode), where they reduce oxygen to form water. Here we report the results of lab-scale microcosms setup with marine sediments and spiked with crude oil. Microcosms containing one or three graphite snorkels and controls (snorkel-free and autoclaved) were monitored for over 400 days. Collectively, the results of this study confirmed that the snorkels accelerate oxidative reactions taking place within the sediment, as documented by a significant 1.7-fold increase (p = 0.023, two-tailed t-test) in the cumulative oxygen uptake and 1.4-fold increase (p = 0.040) in the cumulative CO2 evolution in the microcosms containing three snorkels compared to snorkel-free controls. Accordingly, the initial rate of total petroleum hydrocarbons (TPH) degradation was also substantially enhanced. Indeed, while after 200 days of incubation a negligible degradation of TPH was noticed in snorkel-free controls, a significant reduction of 12 1% (p = 0.004) and 21 1% (p = 0.001) was observed in microcosms containing one and three snorkels, respectively. Although, the "Oil-Spill Snorkel" potentially represents a groundbreaking alternative to more expensive remediation options, further research efforts are needed to clarify factors and conditions affecting the snorkel-driven biodegradation processes and to identify suitable configurations for field applications

Enhancing methane production from food waste fermentate using biochar. The added value of electrochemical testing in pre-selecting the most effective type of biochar

Background: Recent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying fundamentals of the process are still largely speculative and, therefore, a priori identification, screening, and even design of suitable biochar materials for a given biotechnological process are not yet possible. Results: Here, three charcoal-like products (i.e., biochars) obtained from the pyrolysis of different lignocellulosic materials, (i.e., wheat bran pellets, coppiced woodlands, and orchard pruning) were tested for their capacity to enhance methane production from a food waste fermentate. In all biochar-supplemented (25 g/L) batch experiments, the complete methanogenic conversion of fermentate volatile fatty acids proceeded at a rate that was up to 5 times higher than that observed in the unamended (or sand-supplemented) controls. Fluorescent in situ hybridization analysis coupled with confocal laser scanning microscopy revealed an intimate association between archaea and bacteria around the biochar particles and provided a clear indication that biochar also shaped the composition of the microbial consortium. Based on the application of a suite of physico-chemical and electrochemical characterization techniques, we demonstrated that the positive effect of biochar is directly related to the electron-donating capacity (EDC) of the material, but is independent of its bulk electrical conductivity and specific surface area. The latter properties were all previously hypothesized to play a major role in the biochar-mediated interspecies electron transfer process in methanogenic consortia. Conclusions: Collectively, these results of this study suggest that for biochar addition in anaerobic digester operation, the screening and identification of the most suitable biochar material should be based on EDC determination, via simple electrochemical tests. © 2017 The Author(s)

Enhancing methane production from food waste fermentate using biochar. The added value of electrochemical testing in pre-selecting the most effective type of biochar

Background: Recent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying fundamentals of the process are still largely speculative and, therefore, a priori identification, screening, and even design of suitable biochar materials for a given biotechnological process are not yet possible. Results: Here, three charcoal-like products (i.e., biochars) obtained from the pyrolysis of different lignocellulosic materials, (i.e., wheat bran pellets, coppiced woodlands, and orchard pruning) were tested for their capacity to enhance methane production from a food waste fermentate. In all biochar-supplemented (25 g/L) batch experiments, the complete methanogenic conversion of fermentate volatile fatty acids proceeded at a rate that was up to 5 times higher than that observed in the unamended (or sand-supplemented) controls. Fluorescent in situ hybridization analysis coupled with confocal laser scanning microscopy revealed an intimate association between archaea and bacteria around the biochar particles and provided a clear indication that biochar also shaped the composition of the microbial consortium. Based on the application of a suite of physico-chemical and electrochemical characterization techniques, we demonstrated that the positive effect of biochar is directly related to the electron-donating capacity (EDC) of the material, but is independent of its bulk electrical conductivity and specific surface area. The latter properties were all previously hypothesized to play a major role in the biochar-mediated interspecies electron transfer process in methanogenic consortia. Conclusions: Collectively, these results of this study suggest that for biochar addition in anaerobic digester operation, the screening and identification of the most suitable biochar material should be based on EDC determination, via simple electrochemical tests. © 2017 The Author(s)

How to access and exploit natural resources sustainably: petroleum biotechnology

As we transition from fossil fuel reliance to a new energy future, innovative microbial biotechnologies may offer new routes to maximize recovery from conventional and unconventional energy assets; as well as contributing to reduced emission pathways and new technologies for carbon capture and utilization. Here we discuss the role of microbiology in petroleum biotechnologies in relation to addressing UN Sustainable Development Goal 12 (ensure sustainable consumption and production patterns), with a focus on microbially-mediated energy recovery from unconventionals (heavy oil to methane), shale gas and fracking, bioelectrochemical systems for the production of electricity from fossil fuel resources, and innovations in synthetic biology. Furthermore, using wastes to support a more sustainable approach to fossil fuel extraction processes is considered as we undertake the move towards a more circular global economy

PENGARUH WAKTU PEMANGKASAN PUCUK TERHADAP PERTUMBUHAN DAN HASIL TANAMAN KENTANG (Solanum tuberosum L.) G0

Penelitian ini telah dilaksanakan pada bulan Maret sampai Juni 2019 di Pusat Alih Teknologi dan Pengembangan Kawasan Penelitian Universitas Andalas yang berlokasi di Jorong Galagah Kenagarian Alahan Panjang Kecamatan Lembah Gumanti, Kabupaten Solok, Sumatera Barat, dengan ketinggian ±1616 m dpl. Tujuan penelitian ini yaitu untuk melihat pengaruh pemangkasan pucuk umbi G0 terhadap pertumbuhan dan hasil kentang G1. Perlakuan disusun dalam Rancangan Acak Lengkap (RAL) yang terdiri 4 perlakuan yaitu tanpa pemangkasan pucuk, pemangkasan pucuk 10 HST, pemangkasan pucuk 15 HST dan pemangkasan pucuk 20 HST serta 3 ulangan. Data di analisis secara statistik dengan uji F pada taraf nyata 5% apabila uji F lebih besar dari F tabel maka dilanjutkan dengan Uji Duncan Multiple Range Tes (DMRT) pada taraf 5%. Hasil penelitian perlakuan pemangkasan pucuk tanaman kentang melihatkan pengaruh yang sama pada parameter tinggi tanaman, bobot umbi, diameter umbi, jumlah umbi pertanaman, bobot umbi per petak dan memberikan pengaruh pada perlakuan ketiga 15 HST yaitu jumlah cabang batang serta jumlah daun. Kata kunci : umbi, Kentang, Pemangkasan pucu

Carbon nanotubes accelerate methane production in pure cultures of methanogens and in a syntrophic coculture

Carbon materials have been reported to facilitate direct interspecies electron transfer (DIET) between bacteria and methanogens improving methane production in anaerobic processes. In this work, the effect of increasing concentrations of carbon nanotubes (CNT) on the activity of pure cultures of methanogens and on typical fatty acid-degrading syntrophic methanogenic coculture was evaluated. CNT affected methane production by methanogenic cultures, although acceleration was higher for hydrogenotrophic methanogens than for acetoclastic methanogens or syntrophic coculture. Interestingly, the initial methane production rate (IMPR) by Methanobacterium formicicum cultures increased 17 times with 5 g·L1 CNT. Butyrate conversion to methane by Syntrophomonas wolfei and Methanospirillum hungatei was enhanced (1.5 times) in the presence of CNT (5 g·L1), but indications of DIET were not obtained. Increasing CNT concentrations resulted in more negative redox potentials in the anaerobic microcosms. Remarkably, without a reducing agent but in the presence of CNT, the IMPR was higher than in incubations with reducing agent. No growth was observed without reducing agent and without CNT. This finding is important to re-frame discussions and re-interpret data on the role of conductive materials as mediators of DIET in anaerobic communities. It also opens new challenges to improve methane production in engineered methanogenic processes. This article is protected by copyright. All rights reserved.This study was supported by the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 323009 and by the Portuguese Foundation for Science and Technology (FCT) under the scope of the following programs: strategic funding of UID/BIO/04469/2013 unit, funded by COMPETE 2020 (POCI-01-0145-FEDER-006684), Project RECI/BBBEBI/0179/2012 (FCOMP-01-0124-FEDER-027462), Project UID/CTM/50011/2013 (POCI-01-0145-FEDER-007679), fellowship awarded to Gilberto Martins (SFRH/BPD/80528/ 2011) under the scope of the program POPH/ESF and the sabbatical FCT fellowship reference SFRH/BSAB/113660/ 2015 attributed to Madalena Alves.The authors thank also the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, BioTecNorte operation (NORTE-01-0145-FEDER-000004). Finally, the authors thank to Luciana Pereira (Centre of Biological Engineering, University of Minho) and Fernando Pereira (Laboratory of Catalysis and Materials, Universidade do Porto) for providing the CNT for this study. Also a special acknowledgement is due to Orianna Bretschger from J Craig Venter Institute, for the interesting scientific discussions. All authors disclose anypotentialsources of conflict ofinterest.info:eu-repo/semantics/publishedVersio

Membrane-less bioelectrochemical reactor for the treatment of groundwater contaminated by toluene and trichloroethene

To address the ever-growing environmental problem of groundwater contamination, microbial electrochemical technologies (METs) are being studied as promising substitutes for traditional remediation techniques. Among their many advantages, they possess the capability of providing a virtually inexhaustible electron acceptor (or donor) directly in the aquifer without addition of air, oxygen or other chemicals. In this way, they can promote microbially-driven oxidation and/or reduction of contaminants in-situ, in a more sustainable and cost-effective way

Como poderemos fazer psiquiatria preventiva?

Pithon Rémy, Viggi Bruno, Taillibert Christel. 17e Giornate del Cinema Muto, Pordenone, octobre 1998. In: 1895, revue d'histoire du cinéma, n°26, 1998. pp. 182-205

Natural Magnetite Minerals Enhance 1,2-Dichloroethane Reductive Dechlorination

Contamination of soil and groundwater by chlorinated solvents is an environmental issue of primary concern. Recently, electrically conductive iron particles have been proposed as a novel approach to accelerate anaerobic bioremediation processes. In fact, it was demonstrated that conductive particles facilitate the exchange of electrons between microorganisms via Direct Interspecies Electron Transfer (DIET) processes, thus enhancing the pollutant-degrading potential of the microbial community. However, the use of natural minerals in this context has not been reported so far. In this study, we applied, for the first time, natural magnetite and hematite to accelerate the reductive dechlorination of 1,2-dichloroethane by an enrichment culture in lab-scale anaerobic microcosms. After four feeding cycles, low magnetite-amended microcosms (13 mg/L) yielded the highest rate of 1,2-DCA reductive dechlorination and reduced methanogenic activity. By contrast, hematite did not display any apparent stimulatory effect. Surprisingly, in the presence of higher amounts of iron oxides, a weaker effect was obtained, probably because iron(III) present in the minerals competed for the electrons necessary for reductive dechlorination. For all microcosms, the concentration of the toxic byproduct vinyl chloride was negligible throughout the whole study. The SEM/EDS analysis confirmed the close interaction between the conductive iron oxide particles and the dechlorinating bacteria. This work opens the possibility of using natural conductive minerals for bioremediation applications as well as shedding light on the previously unrecognized role of such minerals in contaminated ecosystemsThe authors would like to thank FCT (Portuguese Foundation for Science and Technology) for the financial support of Patrícia Leitão through the Ph.D. grant SFRH/BD/87312/2012info:eu-repo/semantics/publishedVersio