• Synthesis and characterisation of novel nopyl-derived phosphonium ionic liquids

      Yu, Jiangou; Wheelhouse, Richard T; Honey, Mark A; Karodia, Nazira (Elsevier, 2020-07-18)
      A series of novel nopyl-derived chiral phosphonium ionic liquids have been successfully synthesised and characterised. Analysis of each novel ionic liquid was conducted in order to confirm structure, purity and thermal stability.

      Williams, Craig D.; Roberts, Clive L.; Rios Reyes, Carlos (Universidad Nacional de Colombia, 2011)
      low-silica zeolitic materials like sod, can and jbw crystallized after hydrothermal transformation of kaolinite in the system na2o-al2o3-sio2-h2o at 200°c, with or without the addition of a structure-directing agent. the synthesis products were characterized by xrd, sem, ftir, 29si and 27al mas-nmr and tga. after dissolution of kaolinite in alkaline medium, co-crystallization of sod and can, likely via a metastable lta intermediate, was followed by a transformation to jbw-type structure.
    • Synthesis and characterization of zeotype ANA framework by hydrothermal reaction of natural clinker.

      Sandoval, M.V.; Henao, J.A.; Rios, Carlos A.; Williams, Craig D.; Apperley, David C. (Amsterdam: Elsevier, 2009)
      The zeotype ANA framework was successfully synthesized for the first time by conventional hydrothermal alkaline activation of natural clinker. The synthesis process was investigated as a function of the starting material, reaction temperature, reaction time and mineralizer concentration. The as-synthesized products were characterized by X-ray powder diffraction (XRPD) analysis, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, magic-angle spinning nuclear magnetic resonance (MAS NMR) and thermogravimetric analyses (TGA). The results of this study indicate that ANA with a low quantity of impurities can be synthesized using natural clinker as starting material.
    • Synthesis and evaluation of selected benzimidazole derivatives as potential antimicrobial agents

      Alasmary, FAS; Snelling, AM; Zain, ME; Alafeefy, AM; Awaad, AS; Karodia, N; Chemistry Department, College of Science, King Saud University, Riyadh 11362, Saudi Arabia. fasmari@ksu.edu.sa. (MDPI, 2015-08-20)
      © 2015 by the authors. A library of 53 benzimidazole derivatives, with substituents at positions 1, 2 and 5, were synthesized and screened against a series of reference strains of bacteria and fungi of medical relevance. The SAR analyses of the most promising results showed that the antimicrobial activity of the compounds depended on the substituents attached to the bicyclic heterocycle. In particular, some compounds displayed antibacterial activity against two methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentrations (MICs) comparable to the widely-used drug ciprofloxacin. The compounds have some common features; three possess 5-halo substituents; two are derivatives of (S)-2-ethanaminebenzimidazole; and the others are derivatives of one 2-(chloromethyl)-1Hbenzo[ d]imidazole and (1H-benzo[d]imidazol-2-yl)methanethiol. The results from the antifungal screening were also very interesting: 23 compounds exhibited potent fungicidal activity against the selected fungal strains. They displayed equivalent or greater potency in their MIC values than amphotericin B. The 5-halobenzimidazole derivatives could be considered promising broad-spectrum antimicrobial candidates that deserve further study for potential therapeutic applications.
    • Synthesis and structural characterization of bioactive PHA and γ-PGA oligomers for potential applications as a delivery system

      Kwiecień, Iwona; Kwiecień, Michał; Adamus, Grażyna; Radecka, Iza (MDPI - Open Access Publishing, 2016-04-25)
      The (trans)esterification reaction of bacterial biopolymers with a selected bioactive compound with a hydroxyl group was applied as a convenient method for obtaining conjugates of such compound. Tyrosol, a naturally occurring phenolic compound, was selected as a model of a bioactive compound with a hydroxyl group. Selected biodegradable polyester and polyamide, poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) and poly-γ-glutamic acid (γ-PGA), respectively, were used. The (trans)esterification reactions were carried out in melt mediated by 4-toluenesulfonic acid monohydrate. The structures of (trans)esterification products were established at the molecular level with the aid of ESI-MS2 (electrospray ionization tandem mass spectrometry) and/or 1H NMR (nuclear magnetic resonance) techniques. Performed analyses confirmed that the developed method leads to the formation of conjugates in which bioactive compounds are covalently bonded to biopolymer chains. The amount of covalently bonded bioactive compounds in the resulting conjugates depends on the type of biopolymers applied in synthesis.
    • Synthesis of an orthogonally protected polyhydroxylated cyclopentene from l-Sorbose

      Lo Re, D; Jones, L; Giralt, E; Murphy, P; School of Chemistry, National University of Ireland, Galway, University Road, Galway, Ireland. daniele.lore@irbbarcelona.org. (Wiley, 2016-07-06)
      © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The use of l-sorbose in the synthesis of functionalized cyclopentene derivatives was accomplished. These cyclopentene derivatives are related to those found in naturally occurring jatrophane frameworks and in other bioactive compounds. The formation of allyl α-l-sorbopyranoside was a key synthetic step. Regioselective introduction of protecting groups was followed by the hydrolysis of the allyl glycoside to furnish a fully protected acyclic l-sorbose derivative. This acyclic intermediate was subsequently used to give an orthogonally protected polyhydroxylated cyclopentene, which has potential for further synthesis of bioactive compounds. The protected cyclopentene itself showed a clear cytotoxic activity when tested against a panel of human cancer cell lines (HT29, LS174T, SW620, A549, and HeLa cells).
    • Synthesis of electroneutralized amphiphilic copolymers with peptide dendrons for intramuscular gene delivery

      Pu, Linyu; Wang, Jiali; Li, Na; Chai, Qiuxia; Irache, Juan M; Wang, Gang; Tang, James Z; Gu, Zhongwei (ACS Publications, 2016-06-08)
      Intramuscular gene delivery materials are of great importance in plasmid-based gene therapy system, but there is limited information so far on how to design and synthesize them. A previous study showed that the peptide dendron-based triblock copolymer with its components arranged in a reversed biomembrane architecture could significantly increase intramuscular gene delivery and expression. Herein, we wonder whether copolymers with biomembrane-mimicking arrangement may have similar function on intramuscular gene delivery. Meanwhile, it is of great significance to uncover the influence of electric charge and molecular structure on the function of the copolymers. To address the issues, amphiphilic triblock copolymers arranged in hydrophilic-hydrophobic-hydrophilic structure were constructed despite the paradoxical characteristics and difficulties in synthesizing such hydrophilic but electroneutral molecules. The as-prepared two copolymers, dendronG2(l-lysine-OH)-poly propylene glycol2k(PPG2k)-dendronG2(l-lysine-OH) (rL2PL2) and dendronG3(l-lysine-OH)-PPG2k-dendronG3(l-lysine-OH) (rL3PL3), were in similar structure but had different hydrophilic components and surface charges, thus leading to different capabilities in gene delivery and expression in skeletal muscle. rL2PL2 was more efficient than Pluronic L64 and rL3PL3 when mediating luciferase, β-galactosidase, and fluorescent protein expressions. Furthermore, rL2PL2-mediated growth-hormone-releasing hormone expression could significantly induce mouse body weight increase in the first 21 days after injection. In addition, both rL2PL2 and rL3PL3 showed good in vivo biosafety in local and systemic administration. Altogether, rL2PL2-mediated gene expression in skeletal muscle exhibited applicable potential for gene therapy. The study revealed that the molecular structure and electric charge were critical factors governing the function of the copolymers for intramuscular gene delivery. It can be concluded that, combined with the previous study, both structural arrangements either reverse or similar to the biomembrane are effective in designing such copolymers. It also provides an innovative way in designing and synthesizing new electroneutralized triblock copolymers, which could be used safely and efficiently for intramuscular gene delivery.
    • Synthesis of high silicon content SAPO(4)-5 using anionic surfactants in a hexanol/aqueous two phase media.

      Han, Xue S.; Williams, Craig D.; Lee, Darren F.; Round, Catherine I. (Royal Society of Chemistry, 2002)
      High silicon content SAPO(4)-5 (up to 0.511 atoms per unit cell) has been synthesised, using sodium 3-bromopropanesulfonate, sodium 1-butanesulfonate, sodium naphthalene-1-sulfonate or sodium n-decyl sulfate as surfactants; the SiO2 in the reaction gels ranged up to 3.0 (molar ratio), silicon incorporation was confirmed by XRD, XRF, TG-DTA, FT-IR and SEM techniques.
    • Synthesis of hydrogels made of poly-γ-glutamic acid (γ-PGA) for potential applications as probiotic-delivery vehicles

      Kwiecien, Iwona; Niewolik, Daria; Gupta, Abhishek; Itohowo Ekere, Anabel; Radecka, Izabela (MDPI, 2020-04-17)
      Numerous hydrogels made of poly-γ-glutamic acid (γ-PGA) and various cross-linkers have been explored, but only limited data on hydrogels made of γ-PGA and poly(ethylene glycol) (PEG) are available. In this study, γ-PGA, a biodegradable and edible biopolyamide, was successfully cross-linked with selected PEGs to obtain a series of hydrogels. The swelling behaviour of these hydrogels was investigated under various pH conditions. It was also found that the structure of the cross-linker (linear or branched) affected the hydrogels’ swelling behaviour. In addition, in disc diffusion assay, hydrogel discs loaded with antibiotic were tested against Staphylococcus aureus and Escherichia coli. Prolonged activity of hydrogels loaded with antibiotics in comparison to paper discs containing antibiotics was observed. Moreover, the protective effect of hydrogels on entrapped probiotic cells subjected to low pH was investigated. The hydrogel swelling ratio and amount influenced the survival rate of the protected bacteria. Considering potential biomedical applications of hydrogels, cytotoxicity was evaluated towards two cell lines, MSTO and PANC 1.
    • Synthesis of migrastatin analogues as inhibitors of tumour cell migration: exploring structural change in and on the macrocyclic ring

      LoRe, D; Zhou, Y; Mucha, J; Jones, LF; Leahy, L; Santocanale, C; Krol, M; Murphy, PV (Wiley, 2015-11-04)
      © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Migrastatin and isomigrastatin analogues have been synthesised in order to contribute to structure-activity studies on tumour cell migration inhibitors. These include macrocycles varying in ring size, functionality and alkene stereochemistry, as well as glucuronides. The synthesis work included application of the Saegusa-Ito reaction for regio- and stereoselective unsaturated macroketone formation, diastereoselective Brown allylation to generate 9-methylmigrastatin analogues and chelation-induced anomerisation to vary glucuronide configuration. Compounds were tested in vitro against both breast and pancreatic cancer cell lines and inhibition of tumour cell migration was observed in both wound-healing (scratch) and Boyden chamber assays. One unsaturated macroketone showed low affinity for a range of secondary drug targets, indicating it is at low risk of displaying adverse side effects.
    • Synthesis of silver nanoparticles using curcumin-cyclodextrins loaded into bacterial cellulose based hydrogels for wound dressing applications

      Gupta, Abhishek; Briffa, Sophie M; Swingler, Sam; Gibson, Hazel; Kannappan, Vinodh; Adamus, Grazyna; Kowalczuk, Marek M; Martin, Claire; Radecka, Iza (American Chemical Society (ACS), 2020-01-22)
      Chronic wounds are often recalcitrant to treatment due to high microbial bioburden and the problem of microbial resistance. Silver is a broad spectrum natural antimicrobial agent with wide applications extending to proprietary wound dressings. Recently silver nanoparticles have attracted attention in wound management. In the current study, the green synthesis of nanoparticles was accomplished using a natural reducing agent, curcumin which is a natural polyphenolic compound, well known as a wound healing agent. The hydrophobicity of curcumin was overcome by its microencapsulation in cyclodextrins. This prediction study demonstrates the production, characterisation of silver nanoparticles using aqueous curcumin:hydroxypropyl-β-cyclodextrin complex and loading them into bacterial cellulose hydrogel with moist wound healing properties. These silver nanoparticle-loaded bacterial cellulose hydrogels were characterised for wound management applications. In addition to high cytocompatibility, these novel dressings exhibited antimicrobial activity against three representative wound infecting pathogenic microbes Staphylococcus aureus, Pseudomonas. aeruginosa and Candida auris.
    • Synthesis of Sodalite from Sepiolite by Alkali Fusion Method and Its Application to Remove Fe3+, Cr3+, and Cd2+ from Aqueous Solutions

      Kamyab, Seyedeh Mahsa; Modabberi, Soroush; Williams, Craig D; Badiei, Alireza (Mary Ann Liebert Inc, 2020-06-16)
      The aim of this article is to study the sodalite synthesis from sepiolite through an alkali fusion method followed by hydrothermal process, and to investigate its application in heavy metal removal. The fused precursors were prepared through mixing sepiolite with sodium hydroxide (NaOH) and potassium hydroxide (KOH) activators, at 650°C. Hydrothermal reactions were performed at 100°C, 140°C, 180°C, and 220°C. Under the hydrothermal treatment at 140°C, pure sodalite 1 was formed from fused precursor of sepiolite-NaOH, for 48 h, while pure sodalite 2 was synthesized from fused mixture of sepiolite and KOH, at 180°C for 72 h. Pure sodalites and raw material were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) analyses. The potential of two sodalites for removal of Fe3+, Cr3+, and Cd2+ cations from 0.001, 0.01, and 0.1 M aqueous solutions was evaluated through a series of batch experiments. The optimum adsorption of Fe3+ and Cr3+ was achieved from 0.001 to 0.01 M solutions. In contrast, Cd2+ was removed most efficiently from 0.1 M solution. In terms of contact time, the maximum adsorption amount from 0.001 M solutions was achieved between 1 and 2 h for pure sodalite 1 and between 30 min and 1 h for pure sodalite 2. The highest adsorption rate from 0.01 to 0.1 M solutions was observed between 30 min and 1 h, for both pure sodalite 1 and pure sodalite 2. Sepiolite was shown to be successfully used as raw material for formation of pure sodalite, and subsequently, pure sodalite has considerable capability to be used for environmental cleanups.
    • Synthesis of triazole-linked morpholino oligonucleotides via Cu<sup>I</sup> catalysed cycloaddition

      Palframan, MJ; Alharthy, RD; Powalowska, PK; Hayes, CJ; School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK. chris.hayes@nottingham.ac.uk. (Royal Society of Chemistry (RSC), 2016-02-16)
      © The Royal Society of Chemistry 2016. Triazole-linked morpholino (TLMO) oligonucleic acids were synthesised using the CuI catalysed (3 + 2) azide-alkyne cycloaddition (CuAAC) reaction. The modified DNA analogues were incorporated into 13-mer sequences via solid phase synthesis. UV melting experiments showed that the TLMO modification gives higher Tm values than the corresponding TLDNA modification.
    • Synthesis of Zeolites and Zeotypes by Hydrothermal transformation of Kaolinite and Metakaolinite.

      Rios, Carlos A.; Williams, Craig D.; Maple, Martin J. (Bucaramanga, Colombia: Universidad de Pamplona, 2007)
      The synthesis of zeolitic materials by hydrothermal transformation of kaolinite and metakaolinite in NaOH solutions of various concentrations was investigated between 100 and 200 degrees C, over different reaction times, using in some cases precipitated SiO2 or organic templates. Materials were obtained, including clathrasils: cancrinite (CAN), sodalite (SOD), and Linde Type A (LTA), faujasite (FAU), NaP1 (GIS), analcime (ANA) and nepheline hydrate I (JBW) zeolites. In general, co-crystallization of CAN and SOD, likely via an unstable LTA zeolite intermediate, was observed after dissolution of kaolinite at low temperature; although the feldspathoids tend to be unstable at high temperature. LTA zeolite was synthesized after metakaolinite reaction, with minor amount of FAU zeolite, ANA and SOD. Solids were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA).
    • Synthesis of zeolitic materials from natural clinker: A new alternative for recycling coal combustion by-products.

      Rios, Carlos A.; Williams, Craig D. (Amsterdam: Elsevier, 2008)
      In this study, we report an innovative process of zeolite synthesis through transforming of natural raw clinker (NRC) via (1) conventional hydrothermal alkaline activation and (2) alkaline fusion prior to hydrothermal reaction. Both methods were evaluated at 100 °C as a function of the alkaline agent, although in the first method other variables such as concentration of the activation solution and reaction time were selected, whereas in the second method similar ratios of alkaline activator/NRC and H2O/alkali fused product during different reaction times were used. Experimental results indicate that the method, alkali activator, concentration and time have a strong effect on the type and degree of crystallinity of the synthesized zeolite. Low-silica sodium or potassium zeolitic materials were synthesized, which include Na-phillipsite, hydroxysodalite and hydroxycancrinite, K-chabazite, zeolite K-F, faujasite and zeolite Linde Type A. The use of a recycling process of NRC in zeolite synthesis could become an area of important interest and research, playing an active role in encouraging and promoting technological advances, research and technology transfer related to the use and disposal of mining wastes, remaining after the natural and spontaneous combustion of coal seams. NRC-based zeolites (NRCZs) synthesized under well-optimized experimental conditions could be used in applications for environmental waste treatment.
    • Synthetic faujasite based on coal by-products for the treatment of acid mine drainage (AMD).

      Rios, Carlos A.; Williams, Craig D.; Roberts, Clive L.; Fullen, Michael A. (Greece: University of Patras, 2008)
      Acid mine drainage (AMD) has long been a significant environmental problem associated to mining operations at the Parys Mountain copper-lead-zinc deposit of Anglesey (North Wales), a volcanogenic massive sulphide district of major metallogenic importance. AMD is a natural occurrence resulting from the microbial oxidation of sulphide minerals, especially pyrite (FeS2), pyrite in presence of water and air, which produces polluted waters strongly acidic containing high concentrations of Fe, sulphate and toxic metals. The treatment of AMD has traditionally been conducted by neutralization with lime or similar materials. However, liming is often temporary and produces secondary wastes, such as metal hydroxide sludges and gypsum, which are highly regulated and have costly disposal requirements. Several methods for AMD treatment have been developed, although adsorption being the preferred method for heavy metal removal due to its effectiveness. AMD remediation can be very costly and difficult, due to the high costs of activated carbon production and regeneration for water treatment. Therefore, alternative low-cost liming materials are constantly sought. Such adsorbents should be readily available, economically viable and easily regenerated. The aim of this study is to investigate the efficiency of synthetic faujasite obtained from coal by-products as adsorbent in removing heavy metals from AMD generated at the Parys Mountain copper-lead-zinc deposit.
    • Systematic literature research of the current implementation of Unmanned Aerial System (UAS) in the construction industry

      Vanderhorst, Hamlet Reynoso; Suresh, Subashini; Renukappa, Suresh (Blue Eyes Intelligence Engineering & Sciences, 2019-10-10)
      The implementation of UAS is bringing easiness and time saving activities into the currently construction site task. In the construction industry, diverse and relevant benefits of the technology have been identified through the project life cycle, such as monitoring project progress report, faster and low-cost land measurements and 3D modelling. Currently, the most valuable benefits of the UAS in the construction industry are related to automation the construction process, low cost, greater speed and safer real-time data collection compare with the traditional methods, and a reliable replacement over satellites and manned vehicles in terms of high-resolution images. However, there is a lack of exemplification and clarity of the actual implementation of the UAS in the construction industry in terms of adoption process and impacted usage. Therefore, a systematic literature review was carried out in order to explore the literature available of the topic related to implementation of unmanned aerial system in the construction industry, the most relevant tasks, cases, areas of usage and the reasons of applying it. The finding of this paper is providing exemplification models of current usage such as visualisation and disaster management, evolution map of the UAS according to the publication numbers and construction project stages when to use the UAS.
    • A Systematic Review and Meta-Analysis Evaluating Antibiotic Prophylaxis in Dental Implants and Extraction Procedures

      Singh Gill, A; Morrissey, H; Rahman, A; School of Pharmacy, University of Wolverhampton, Wolverhampton WV1 1LY, UK. a.s.gill2@wlv.ac.uk. (MDPI, 2018-12-01)
      Background and objectives: The use of antibiotic prophylaxis in extraction and implant dentistry is still controversial, with varying opinions regarding their necessity. The overuse of antibiotics has led to widespread antimicrobial resistance and the emergence of multi drug resistant strains of bacteria. The main aim of this work was to determine whether there is a genuine need for antibiotic prophylaxis in two common dental procedures; dental implants and tooth extractions. Methods: Electronic searches were conducted across databases such as Cochrane Register of Controlled Trials, the UK National Health Service, Centre for reviews, Science Direct, PubMed and the British Dental Journal to identify clinical trials of either dental implants or tooth extractions, whereby the independent variable was systemic prophylactic antibiotics used as part of treatment in order to prevent postoperative complications such as implant failure or infection. Primary outcomes of interest were implant failure, and postoperative infections which include systemic bacteraemia and localised infections. The secondary outcome of interest was adverse events due to antibiotics. The Critical Appraisal Skills Programme tool was used to assess the risk of bias, extract outcomes of interest and to identify studies for inclusion in the meta-analysis. Results: Seven randomised clinical trials (RCTs) were included in the final review comprising n = 1368 patients requiring either tooth extraction(s) or dental implant(s). No statistically significant evidence was found to support the routine use of prophylactic antibiotics in reducing the risk of implant failure (p = 0.09, RR 0.43; 95% CI 0.16⁻1.14) or post-operative complications (p = 0.47, RR: 0.74; 95% CI 0.34⁻1.65) under normal conditions. Approximately 33 patients undergoing dental implant surgery need to receive antibiotics in order to prevent one implant failure from occurring. Conclusions: There is little conclusive evidence to suggest the routine use of antibiotic prophylaxis for third molar extractive surgery in healthy young adults. There was no statistical evidence for adverse events experienced for antibiotics vs. placebo. Based on our analysis, even if financially feasible, clinicians must carefully consider the appropriate use of antibiotics in dental implants and extraction procedures due to the risk of allergic reactions and the development of microbial drug resistance.
    • Systematic review of the efficacy of pharmacological treatment alone vs. psychotherapy alone or the combination of both in the treatment of depressive disorders

      Bashir, Aqib; Morrissey, Hana; Ball, Patrick (International Journal of Current Medical and Pharmaceutical Research, 2018-04-28)
      Depression is a challenging condition to treat especially where the efficacy of the current types of treatments has been in debate for decades. The aim of this review was to compare the effectiveness of medications to psychotherapy interventions and the combination of both interventions in the treatment of depression. This was conducted by evaluating the evidence from studies that investigated the efficacy of alone interventions and dual therapy to identify the best course of treatment for depression. Twenty studies were selected of which ten were directly compared pharmacotherapy with psychotherapy and a further ten compared the combination of both to either of the two monotherapies. The results showed that in either of monotherapies cohorts, the rates of response, remission and changes in symptom severity were near equivalent for both but dropout rates were higher for the medications groups. Comparing dual therapy to the monotherapies showed higher efficacy in terms of response, remission and reduction of symptom severity for combination. The difference however seen less with pharmacotherapy and showed psychotherapy being least effective but the difference was in efficacy is small in the majority of the studies, to a point in which the question of‘is the difference clinically significant’ remained unanswered which require more definitive future research.
    • A systems biology approach sheds new light on Escherichia coli acid resistance

      Stincone, A; Daudi, N; Rahman, AS; Antczak, P; Henderson, I; Cole, J; Johnson, MD; Lund, P; Falciani, F; The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. (Oxford University Press (OUP), 2011-06-17)
      In order to develop an infection, diarrhogenic Escherichia coli has to pass through the stomach, where the pH can be as low as 1. Mechanisms that enable E. coli to survive in low pH are thus potentially relevant for pathogenicity. Four acid response systems involved in reducing the concentration of intracellular protons have been identified so far. However, it is still unclear to what extent the regulation of other important cellular functions may be required for survival in acid conditions. Here, we have combined molecular and phenotypic analysis of wild-type and mutant strains with computational network inference to identify molecular pathways underlying E. coli response to mild and strong acid conditions. The interpretative model we have developed led to the hypothesis that a complex transcriptional programme, dependent on the two-component system regulator OmpR and involving a switch between aerobic and anaerobic metabolism, may be key for survival. Experimental validation has shown that the OmpR is responsible for controlling a sizeable component of the transcriptional programme to acid exposure. Moreover, we found that a ΔompR strain was unable to mount any transcriptional response to acid exposure and had one of the strongest acid sensitive phenotype observed. © 2011 The Author(s).