A sustainable production of natural hydraulic lime mortars through bio-amendment

.This article examined the effect of a bioproduct suspension obtained from fermentation of biodiesel’s crude glycerol when used to formulate natural hydraulic lime mortars, as a fluid replacing the mixing water. The bioproduct was used either sonicated or non-sonicated and two volumes of mixing fluid were tested. The aim was to assess the advantages and drawbacks that could be achieved with a waste-based bioproduct, instead of petrochemical-based additions. The investigation revealed a positive effect on workability, producing mortars with a lower mixing fluid content, improving the mechanical performance. Finally, the bioproducts reduced the mortar water absorption by gravity and capillary.S

NMR assignment of the apo-form of a Desulfovibrio gigas protein containing a novel Mo–Cu cluster

Biomol NMR Assign (2007) 1:81–83 DOI 10.1007/s12104-007-9022-3We report the 98% assignment of the apo-form of an orange protein, containing a novel Mo–Cu cluster isolated from Desulfovibrio gigas. This protein presents a region where backbone amide protons exchange fast with bulk solvent becoming undetectable. These residues were assigned using 13C-detection experiments

Electron transfer complex between nitrous oxide reductase and cytochrome c552 from Pseudomonas nautica: kinetic, nuclear magnetic resonance, and docking studies

Biochemistry. 2008 Oct 14;47(41):10852-62. doi: 10.1021/bi801375qThe multicopper enzyme nitrous oxide reductase (N 2OR) catalyzes the final step of denitrification, the two-electron reduction of N 2O to N 2. This enzyme is a functional homodimer containing two different multicopper sites: CuA and CuZ. CuA is a binuclear copper site that transfers electrons to the tetranuclear copper sulfide CuZ, the catalytic site. In this study, Pseudomonas nautica cytochrome c 552 was identified as the physiological electron donor. The kinetic data show differences when physiological and artificial electron donors are compared [cytochrome vs methylviologen (MV)]. In the presence of cytochrome c 552, the reaction rate is dependent on the ET reaction and independent of the N 2O concentration. With MV, electron donation is faster than substrate reduction. From the study of cytochrome c 552 concentration dependence, we estimate the following kinetic parameters: K m c 552 = 50.2 +/- 9.0 muM and V max c 552 = 1.8 +/- 0.6 units/mg. The N 2O concentration dependence indicates a K mN 2 O of 14.0 +/- 2.9 muM using MV as the electron donor. The pH effect on the kinetic parameters is different when MV or cytochrome c 552 is used as the electron donor (p K a = 6.6 or 8.3, respectively). The kinetic study also revealed the hydrophobic nature of the interaction, and direct electron transfer studies showed that CuA is the center that receives electrons from the physiological electron donor. The formation of the electron transfer complex was observed by (1)H NMR protein-protein titrations and was modeled with a molecular docking program (BiGGER). The proposed docked complexes corroborated the ET studies giving a large number of solutions in which cytochrome c 552 is placed near a hydrophobic patch located around the CuA center

New spectroscopic and electrochemical insights on a class I superoxide reductase: evidence for an intramolecular electron-transfer pathway

Biochem. J. (2011) 438,485–494 doi:10.1042/BJ2011083

Effect of surface biotreatments on construction materials

STSM Grant from the COST Action CA15202. Spanish Ministry of Economy - project BIA2017-83526-R. project DB-Heritage – Database of building materials with historical and heritage interest (PTDC/EPH-PAT/4684/2014). IF/01054/2014/CP1224/CT0005. FCT/MCTES (UID/QUI/50006/2019; UID/Multi/04378/2019). POCI-01-0145-FEDER-007728. Nídia Almeida is supported by the Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT-PD/00193/2012; UCIBIO-UID/Multi/04378/2019 and by a PhD fellowship from FCT/MCTES (PD/BD/106034/2015).Surface treatment technology is instrumental to construction material conservation and more specifically to preventing decay and improving durability. Surface treatments help protect and consolidate the built heritage against material damage, reducing repair and replacement costs. This study assessed the effect of two eco-friendly healing agents, one generated by iron-enriched Escherichia coli and the other by mixed microbial cultures that metabolise glycerol, a biodiesel processing by-product, to produce polyhydroxyalkanoates. Healing was monitored by measuring the water drop absorption rate in cement mortar, air lime mortar, ceramic brick, limestone, adobe and compressed earth block. The agents tested lengthened water absorption times in all the materials studied, confirming their efficacy as external repair treatments for construction materials.authorsversionpublishe

Molybdenum Induces the expression of a protein containing a new heterometallic Mo-Fe cluster in desulfoVibrio alaskensis

Biochemistry. 2009 Feb 10;48(5):873-82. doi: 10.1021/bi801773t.The characterization of a novel Mo-Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis is reported. Biochemical characterization shows that MorP is a periplasmic homomultimer of high molecular weight (260 +/- 13 kDa) consisting of 16-18 monomers of 15321.1 +/- 0.5 Da. The UV/visible absorption spectrum of the as-isolated protein shows absorption peaks around 280, 320, and 570 nm with extinction coefficients of 18700, 12800, and 5000 M(-1) cm(-1), respectively. Metal content, EXAFS data and DFT calculations support the presence of a Mo-2S-[2Fe-2S]-2S-Mo cluster never reported before. Analysis of the available genomes from Desulfovibrio species shows that the MorP encoding gene is located downstream of a sensor and a regulator gene. This type of gene arrangement, called two component system, is used by the cell to regulate diverse physiological processes in response to changes in environmental conditions. Increase of both gene expression and protein production was observed when cells were cultured in the presence of 45 microM molybdenum. Involvement of this system in Mo tolerance of sulfate reducing bacteria is proposed

A Novel Function

Funding Information: This work was supported by Fundação para a Ciência e Tecnologia, Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES), through the grant number PTDC/QUI/64248/2006 (to A.S.P.), the Radiation Biology and Biophysics Doctoral Training Programme—RaBBiT (PD/00193/2012), Applied Molecular Biosciences Unit—UCIBIO (UIDP/04378/2020, i4HB—Institute for Health and Bioeconomy (LA/P/0140/2020) and CEFITEC (UIDB/00068/2020). A.V.A. (PD/BD/135477/2017 and COVID/BD/152498/2022) is supported by the RaBBiT programme. This work benefited from STSM funding by COST Action (CA15126 MOBIEU) and by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. Publisher Copyright: © 2022 by the authors.Encapsulins are protein nanocages capable of harboring smaller proteins (cargo proteins) within their cavity. The function of the encapsulin systems is related to the encapsulated cargo proteins. The Myxococcus xanthus encapsulin (EncA) naturally encapsulates ferritin-like proteins EncB and EncC as cargo, resulting in a large iron storage nanocompartment, able to accommodate up to 30,000 iron atoms per shell. In the present manuscript we describe the binding and protection of circular double stranded DNA (pUC19) by EncA using electrophoretic mobility shift assays (EMSA), atomic force microscopy (AFM), and DNase protection assays. EncA binds pUC19 with an apparent dissociation constant of 0.3 ± 0.1 µM and a Hill coefficient of 1.4 ± 0.1, while EncC alone showed no interaction with DNA. Accordingly, the EncAC complex displayed a similar DNA binding capacity as the EncA protein. The data suggest that initially, EncA converts the plasmid DNA from a supercoiled to a more relaxed form with a beads-on-a-string morphology. At higher concentrations, EncA self-aggregates, condensing the DNA. This process physically protects DNA from enzymatic digestion by DNase I. The secondary structure and thermal stability of EncA and the EncA−pUC19 complex were evaluated using synchrotron radiation circular dichroism (SRCD) spectroscopy. The overall secondary structure of EncA is maintained upon interaction with pUC19 while the melting temperature of the protein (Tm) slightly increased from 76 ± 1 °C to 79 ± 1 °C. Our work reports, for the first time, the in vitro capacity of an encapsulin shell to interact and protect plasmid DNA similarly to other protein nanocages that may be relevant in vivo.publishersversionpublishe

Biodegradable Polymers on Cementitious Materials

[EN] Nowadays the sustainability and safety requirements of structures inspire the study of new self-healing materials and preventive repair methods on cementitious elements. To achieve this undertaking, this research replaces widely employed synthetic polymers by biodegradable ones as consolidants and water-repellents, and assesses the protection and consolidation effect of biopolymers (obtained by using waste biomass of mixed microbial cultures from polyhydroxyalkanoates production processes) as eco-friendly healing agents by analysing the water absorption of two kind of materials. The first group of samples are cement mortar specimens whose external surface has been treated with biopolymer products and subsequently evaluated by water drop absorption test. The second group of samples are cement mortar specimens formulated with biopolymer products included in its mixing water and later the waterproofing efficiency is analysed by capillary water absorption tests. The water absorption behaviour of both kind of samples shows a potential improvement of cementitious elements durability, since water absorption results have decreased for treated samples in comparison with untreated one

Dietary restriction, caloric value and the accumulation of hepatic fat

<p>Abstract</p> <p>Background</p> <p>Studies using laboratory animals under what are considered to be "standard" conditions normally offer unrestricted amounts of food to the animals, which can lead to metabolic disorders. Moreover, standard diets have different compositions.</p> <p>Aim</p> <p>Therefore, the aim of the present study was to assess the effects of two non-isocaloric diets (commercial Purina^®and AIN-93M), which are considered standard diets, on the accumulation of fat in the liver of rats when offered ad libitum or in a restricted amount.</p> <p>Methods</p> <p>Thus, 40 Wistar rats (90 days old) were separated into 4 groups according to the amount of food offered (ad libitum or dietary restriction) and the type of diet (commercial diet, 3,028.0 kcal/g or AIN-93M, 3,802.7 kcal/g): animals fed the commercial Purina^®diet ad libitum (AP), animals fed restricted amounts of the commercial Purina^®diet (RP), animals fed the AIN-93M diet ad libitum (AD), and animals fed restricted amounts of the AIN-93M diet (RD). Dietary restriction consisted of pair-feeding the RP and RD groups with 60% of the total food consumed by the corresponding ad libitum groups.</p> <p>Results</p> <p>Because of its higher carbohydrate and calorie content, AIN-93M was found to accelerate weight gain, reduce glucose tolerance and peripheral insulin sensitivity, and increase the amount of fat in the liver when compared to the commercial diet. Conversely, a 40% dietary restriction assisted in weight loss without causing malnutrition, contributing to an improved glucose tolerance and higher levels of HDL cholesterol.</p> <p>Conclusion</p> <p>Therefore, differences in the amount of carbohydrates and calories provided by the diet can lead to important metabolic disorders, such as impaired tolerance and accumulation of hepatic fat, and dietary restriction improves serum and tissue lipid profiles in laboratory animals.</p

Biodegradable Polymers on Cementitious Materials

[EN] Nowadays the sustainability and safety requirements of structures inspire the study of new self-healing materials and preventive repair methods on cementitious elements. To achieve this undertaking, this research replaces widely employed synthetic polymers by biodegradable ones as consolidants and water-repellents, and assesses the protection and consolidation effect of biopolymers (obtained by using waste biomass of mixed microbial cultures from polyhydroxyalkanoates production processes) as eco-friendly healing agents by analysing the water absorption of two kind of materials. The first group of samples are cement mortar specimens whose external surface has been treated with biopolymer products and subsequently evaluated by water drop absorption test. The second group of samples are cement mortar specimens formulated with biopolymer products included in its mixing water and later the waterproofing efficiency is analysed by capillary water absorption tests. The water absorption behaviour of both kind of samples shows a potential improvement of cementitious elements durability, since water absorption results have decreased for treated samples in comparison with untreated one