Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: New metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes

Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD-coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation-were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria-Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step

Development of a continuous-flow anaerobic co-digestion process of olive mill wastewater and municipal sewage sludge

BACKGROUND: Olive mill wastewater (OMW) represents an environmental problem due to its high organic load and relevant concentration of phenolic compounds (PCs). OMW treatment and disposal represents a relevant challenge and cost for olive mills and multi-utilities in charge of waste management in Mediterranean countries. The goal of this study was to develop an anaerobic co-digestion (co-AD) process of OMW and sewage sludge (SwS) from municipal wastewater treatment. RESULTS: Different volumetric OMW:SwS ratios up to 100% OMW were fed in continuous 1.7-L bioreactors. The reactors fed with raw OMW (rOMW) performed better than those fed with OMW dephenolized by adsorption (dOMW). At a 23-day hydraulic retention time, the best performances were obtained in the reactor fed with 25% rOMW, with a 105% increase in methane yield in comparison to the 100% SwS test. At a 40-day hydraulic retention time, the reactor fed with 40% rOMW attained a 268 NLCH4/kgvolatile solids methane yield. The conversion of phenolic compoundsreached 70% when the hydraulic retention time was increased from 23 to 40 days. A cost\u2013benefit analysis indicated that both rOMW co-AD in existing digesters and phenolic compounds recovery from OMW followed by co-AD of dOMW can lead to relevant additional revenues for the multi-utilities in charge of wastewater management. CONCLUSION: This work proves that, using the existing network of SwS anaerobic digesters, it is feasible to co-digest the entire OMW production in regions characterized by intense olive oil production, thus attaining a relevant increase in methane production yield (a 144% increase in comparison to 100% SwS)

Executive functions in children with specific learning disorders: Shedding light on a complex profile through teleassessment

Executive Functions (EFs) are high-order cognitive processes relevant to learning and adaptation and frequently impaired in children with specific learning disorders (SLDs). This study aimed to investigate EFs in children with SLD and explore the role of specific EF-related subprocesses, such as stimuli processing and processing speed. Fifty-seven SLD and 114 typically developing (TD) children, matched for gender and age, completed four tasks measuring response inhibition, interference control, shifting, and updating on a web-based teleassessment platform. The results show that SLD children performed lower in all EF tasks than TD children, regardless of stimulus type and condition. Mediation analyses suggested that differences between the SLD and TD groups are mediated by EF-related subprocesses, offering an interpretative model of EF deficits in children with SLD

Negotiated matter: a robotic exploration of craft-driven innovation

This paper introduces a novel approach to craft-driven robotic innovation in architectural research. Here craft is not portrayed as a source of ornamental or historical inspiration, but instead as an open-ended process described by a framework involving material properties, diverging modes of knowledge production and representation, emergent tectonic configurations and embodied interaction with technology. To do so, this paper firstly contrasts a definition of craft (Pye 1968) with practices of robotic architectural production. Additionally, the notion of emergent tectonics resulting from negotiated material and technological processes is addressed by critically situating the theories of architectural tectonics by Kenneth Frampton (2001) and digital tectonics by Leach, Turnbull and Williams (2004) in the context of robotic fabrication in architecture. Finally, the ongoing project “Computing Craft” is presented as a case study illustrating a proposed framework for robotic craft-driven innovation

Biogeochemistry, grain size and mineralogy of the Central and Southern Adriatic Sea sediments: a review.

Volume 26 Supplement 1, January 2010

Investigation of the effect of specific operational parameters on a process of chloroform cometabolic biodegradation by butane-grown biomasses

An aerobic cometabolic CF degradation process by butane-grown biomasses was studied by means of slurry microcosm tests. The lag-phase for the onset of butane utilization by the indigenous biomass of the studied sandy soil was lower than 2 weeks in all the experimental conditions tested. The lag-time for the onset of CF depletion was strongly affected by temperature, with no CF degradation after several weeks in the tests conducted at 15\ub0C. Bioaugmentation treatments performed with 2 types of microbial inocula led, even at the smallest dose tested (0.15 grams of dry cell / m^3 of aq. phase), to a marked decrease of the butane lag-time. Both the initial CF degradation rate and the amount of CF depleted in the absence of butane proved to depend on the type of inoculum utilized, rather than on its dose. The minimum butane/CF molar ratio required to carry out a sustainable CF degradation process proved to be comprised between 1.6 and 14

Biodegradazione aerobica cometabolica di 1,1,2,2-tetracloroetano: prove di bioaugmentation in microcosmi

L\u2019obiettivo di questo lavoro \ue8 stato lo studio del processo di biodegradazione aerobica cometabolica dell\u20191,1,2,2-tetracloroetano (TeCA) ad opera di biomasse metanotrofe e propanotrofe. La sperimentazione \ue8 stata condotta in microcosmi allestiti sia in condizioni slurry che, limitatamente alla biomassa propanotrofa, liquido/gas. I risultati indicano che il TeCA pu\uf2 essere biodegradato tramite cometabolismo aerobico ad opera sia di biomasse metano-utilizzatrici che propano-utilizzatrici nell\u2019intervallo 0-600 mg/l aq., e che tale processo pu\uf2 essere protratto per parecchi mesi senza che si verifichino fenomeni di inattivazione o danneggiamento delle biomasse oggetto di studio. Il trattamento di bioaugmentation ha consentito di ridurre drasticamente il lag-time per l\u2019avvio del processo degradativo cometabolico. I risultati positivi ottenuti nei microcosmi liquido/gas dimostrano che, a partire da pochi ml di biomassa propano-utilizzatrice sviluppata nei microcosmi slurry, \ue8 possibile produrre elevati quantitativi di inoculo tramite un processo di crescita in bioreattori non contenenti terreno, senza che si verifichino significative diminuzioni dell\u2019efficacia dell\u2019inoculo nella degradazione del TeCA

Utilization of static mixers in the oil transesterification reaction for biodiesel production

In this study, the utilization of Sulzer Chemtech 15 mm SMV\uae static mixers for the KOH-catalysed transesterification of sunflower oil was studied by means of batch tests conducted in an experimental ring equipped with a 22 L reactor. Oil and methanol (containing the dissolved KOH) were initially loaded into two tanks, whose headspace was connected to a line of compressed gas. The two streams were mixed in a tee connection and then fed to the reactor by gas displacement. The methanol:oil molar ratio was set to 6, the temperature to 60 \ub0C, and the KOH concentration to 0.8% of the initial oil mass. The effect of SM number (0-5) and superficial velocity (0.4-2.5 m/s) was investigated; the results were compared to those of analogous tests performed in batch conditions with only mechanical agitation, at different rotational speeds. The test conducted with one single SM at a 1.3 m/s superficial velocity (Re = 1490) resulted in a profile of sunflower oil conversion versus time equivalent to that obtained in the best-performing tests with mechanical agitation, characterized by the presence of two Rushton turbines operated at a rotational speed ≥ 400 rpm (Remixing ≥ 2870). In these tests, the equilibrium conversion was equal to 93-96%, and the time for the attainment of a conversion equal to 90% of the equilibrium value (t90) was equal to about 2.5 minutes. The tests conducted, with 1 SM, at superficial velocities higher than 1.3 m/s provided the same reaction profile as the test at 1.3 m/s. This observation, in agreement with an evaluation of the reaction and transport characteristic times, indicates that the test at 1.3 m/s was affected by a negligible mass transfer limitations (kinetically controlled condition). Conversely, a test conducted with 1 SM at a superficial velocity of 0.4 m/s resulted to be characterized by a significant mass-transfer resistance. In order to evaluate the actual contribution of the SM section in the generation of the methanol/oil dispersion, a further group of tests was conducted, with the same system for loading oil and methanol, in the absence of SM. The test conducted at a velocity in the empty SM section equal to 1.3 m/s (corresponding to 2.9 m/s in the piping) led to a 65% increase of t90. This result indicates on the one hand that the single SM provides a relevant contribution to the generation of the dispersion, but on the other that contribution of the simple \u201cT\u201d junction of the loading system is not negligible. Lastly, the mixing energy required for the generation of the methanol/oil dispersion with SM and with mechanical agitation was evaluated. In the SM test at 1.3 m/s, the specific energy requirement evaluated at an oil conversion equal to 90% of the equilibrium value (e90) resulted equal to 15 J/kgbiodiesel. In the batch tests with mechanical agitation with two Rushton turbines, in order to attain a similar energetic performance it was necessary to reduce the rotational speed to 250 rpm, which led to a 15-20 % increase of t90. These results show that, with both mechanical agitation and static mixing, the mixing energy for biodiesel production can be reduced to very low values by means of a careful evaluation of the optimal rotational speed or SM superficial velocity. On the whole, this study suggest that static mixing can be effectively applied to oil transesterification processes for biodiesel production