Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

Several model plants are known to respond to bacterial quorum sensing molecules with altered root growth and gene expression patterns and induced resistance to plant pathogens. These compounds may represent novel elicitors that could be applied as seed primers to enhance cereal crop resistance to pathogens and abiotic stress and to improve yields. We investigated whether the acyl-homoserine lactone N-hexanoyl-L-homoserine lactone (C6-HSL) impacted winter wheat (Triticum aestivum L.) seed germination, plant development and productivity, using two Ukrainian varieties, Volodarka and Yatran 60, in both in vitro experiments and field trials. In vitro germination experiments indicated that C6-HSL seed priming had a small but significant positive impact on germination levels (1.2x increase, p < 0.0001), coleoptile and radicle development (1.4x increase, p < 0.0001). Field trials over two growing seasons (2015-16 and 2016-17) also demonstrated significant improvements in biomass at the tillering stage (1.4x increase, p < 0.0001), and crop structure and productivity at maturity including grain yield (1.4 – 1.5x increase, p < 0.0007) and quality (1.3x increase in good grain, p < 0.0001). In some cases variety effects were observed (p ≤ 0.05) suggesting that the effect of C6-HSL seed priming might depend on plant genetics, and some benefits of priming were also evident in F1 plants grown from seeds collected the previous season (p ≤ 0.05). These field-scale findings suggest that bacterial acyl-homoserine lactones such as C6-HSL could be used to improve cereal crop growth and yield and reduce reliance on fungicides and fertilisers to combat pathogens and stress

eDNA inactivation and biofilm inhibition by the polymeric biocide polyhexamethylene guanidine hydrochloride (PHMG-Cl)

The choice of effective biocides used for routine hospital practice should consider the role of disinfectants in the maintenance and development of local resistome and how they might affect antibiotic resistance gene transfer within the hospital microbial population. Currently, there is little understanding of how different biocides contribute to eDNA release that may contribute to gene transfer and subsequent environmental retention. Here, we investigated how different biocides affect the release of eDNA from mature biofilms of two opportunistic model strains Pseudomonas aeruginosa ATCC 27853 (PA) and Staphylococcus aureus ATCC 25923 (SA) and contribute to the hospital resistome in the form of surface and water contaminants and dust particles. The effect of four groups of biocides, alcohols, hydrogen peroxide, quaternary ammonium compounds, and the polymeric biocide polyhexamethylene guanidine hydrochloride (PHMG-Cl), was evaluated using PA and SA biofilms. Most biocides, except for PHMG-Cl and 70% ethanol, caused substantial eDNA release, and PHMG-Cl was found to block biofilm development when used at concentrations of 0.5% and 0.1%. This might be associated with the formation of DNA–PHMG-Cl complexes as PHMG-Cl is predicted to bind to AT base pairs by molecular docking assays. PHMG-Cl was found to bind high-molecular DNA and plasmid DNA and continued to inactivate DNA on surfaces even after 4 weeks. PHMG-Cl also effectively inactivated biofilm-associated antibiotic resistance gene eDNA released by a pan-drug-resistant Klebsiella strain, which demonstrates the potential of a polymeric biocide as a new surface-active agent to combat the spread of antibiotic resistance in hospital settings

Полімер-електролітна мембрана для паливних елементів на основі зшитого полііміду і протонної іонної рідини

The aim of this research was to develop polymer-electrolyte membrane on the base of commercial polyimide Matrimid which has high proton conductivity at elevated temperatures above 100 °C. Hydrophobic ionic liquid 1-butylimidazolium bis(trifluoromethylsulfonyl)imide (BIM-TFSI) has been synthesized and used as proton conducting electrolyte. The electrical conductivity of the ionic liquid determined by electrochemical impedance method was found to have a value of 10–3 S/cm in the temperature range from 100 to 180 °С. The composite film based on Matrimid polyimide containing 70 wt % of protic ionic liquid has been prepared by casting from methylene chloride solution. Polyetheramine Jeffamine® D-2000 was used as a cross-linking agent for polyimide. According to mechanical and thermal analysis data, Matrimid/BIM-TFSI composite has tensile strength of 18 MPa and thermal degradation point of 306 °С. Electrophysical properties of polyimide film impregnated with ionic liquid was studied by two-probe technique at the frequencies of 0.1, 1.0 and 10 kHz by using immitance meter in the temperature range from 25 to 180 °С. The electrical conductivity was found to be 2.7∙10–4 S/cm at room temperature and reached the value of 1.5∙10–3 S/cm at 180 °С. Thus, in this work proton conducting membrane based on commercial polyimide has been obtained for the first time by simple method without additional sulfonation stage. Matrimid/BIM-TFSI composite membrane is promising for applications in fuel cells operating at elevated temperature without external humidification.Целью работы было получение полимер-электролитной мембраны на основе промышленного полиимида Matrimid с высоким уровнем протонной проводимости при температурах выше 100 °С. Синтезирована гидрофобная протонная ионная жидкость бис(трифторметилсульфонил)имид 1-бутилимидазолия (БИМ-ТФСИ), которая была использована в качестве протонпроводящего электролита. Удельная электропроводность ионной жидкости, измеренная методом электрохимического импеданса, имеет значение порядка 10–3 См/см в интервале температур 100–180 °С. Получена композитная пленка на основе полиимида Matrimid, содержащая 70 % ионной жидкости, поливом из раствора в метиленхлориде. Полиэфир Jeffamine® D-2000 использован в качестве сшивающего агента для полиимида. Согласно результатам механических и термических исследований, прочность на разрыв композита Matrimid/БИМ-ТФСИ составляет 18 мПа, а температура начала деструкции – 306 °С. Электрофизические свойства полиимидной пленки, насыщенной протонной ионной жидкостью, исследовали двухконтактным методом с помощью измерителя иммитанса на частотах 0.1, 1.0 и 10 кГц в температурном интервале 25–180 °С. Установлено, что удельная электропроводность материала составляет 2.7∙10–4 См/см при комнатной температуре, возрастая до величины 1.5∙10–3 См/см при 180 °С.  Таким образом, в данной работе впервые получена протонобменная мембрана на основе коммерческого полиимида технологически простым методом, без дополнительной стадии сульфирования полимера. Композитная мембрана Matrimid/БІМ-ТФСІ перспективна для использования в топливных элементах, которые эксплуатируются при температурах выше 100 °С при отсутствии увлажнения.Метою роботи було отримання полімер-електролітної мембрани на основі промислового полііміду Matrimid з високим рівнем протонної провідності при температурі вище 100 °С. Синтезовано гідрофобну іонну рідину біс(трифторметилсульфоніл)імід 1-бутилімідазолію (БІМ-ТФСІ), яку використано в якості протонпровідного електроліту. Питома електропровідність іонної рідини, визначена методом електрохімічного імпедансу, має значення порядку 10-3 См/см в інтервалі температур  100-180 °С. Отримано композитну плівку на основі полііміду Matrimid із вмістом протонної іонної рідини 70 % поливом з розчину в метиленхлориді. Поліетерамін Jeffamine® D-2000 використано в якості зшиваючого агенту для полііміду. Згідно з результатами механічних і термічних досліджень, міцність на розрив композиту Matrimid/БІМ-ЕФСІ становить 18 мПа, а температура початку деструкції – 306 °С. Електрофізичні властивості поліімідної плівки, насиченої протонною іонною рідиною, досліджували двоконтактним методом за допомогою вимірювача іммітансу на частотах 0.1, 1.0 і 10 кГц в температурному інтервалі 25-180 °С. Встановлено, що питома електропровідність матеріалу становить 2.7 ∙ 10-4 См/см при кімнатній температурі, досягаючи величини 1.5 ∙ 10-3 См/см при 180 °С. Таким чином, в даній роботі вперше отримано протонобмінну мембрану на основі комерційного полііміду технологічно простим методом, без додаткової стадії сульфування полімеру. Композитна мембрана Matrimid/БІМ-ТФСІ перспективна для використання в паливних елементах, які експлуатуються при підвищених температурах за відсутності зволоження.

POLYMER-ELECTROLYTE MEMBRANE FOR FUEL CELLS BASED ON CROSS-LINKED POLYIMIDE AND PROTIC IONIC LIQUID

The aim of this research was to develop polymer-electrolyte membrane on the base of commercial polyimide Matrimid which has high proton conductivity at elevated temperatures above 100 °C. Hydrophobic ionic liquid 1-butylimidazolium bis(trifluoromethylsulfonyl)imide (BIM-TFSI) has been synthesized and used as proton conducting electrolyte. The electrical conductivity of the ionic liquid determined by electrochemical impedance method was found to have a value of 10–3 S/cm in the temperature range from 100 to 180 °С. The composite film based on Matrimid polyimide containing 70 wt % of protic ionic liquid has been prepared by casting from methylene chloride solution. Polyetheramine Jeffamine® D-2000 was used as a cross-linking agent for polyimide. According to mechanical and thermal analysis data, Matrimid/BIM-TFSI composite has tensile strength of 18 MPa and thermal degradation point of 306 °С. Electrophysical properties of polyimide film impregnated with ionic liquid was studied by two-probe technique at the frequencies of 0.1, 1.0 and 10 kHz by using immitance meter in the temperature range from 25 to 180 °С. The electrical conductivity was found to be 2.7∙10–4 S/cm at room temperature and reached the value of 1.5∙10–3 S/cm at 180 °С. Thus, in this work proton conducting membrane based on commercial polyimide has been obtained for the first time by simple method without additional sulfonation stage. Matrimid/BIM-TFSI composite membrane is promising for applications in fuel cells operating at elevated temperature without external humidification

Theoretical and Experimental Studies of Phosphonium Ionic Liquids as Potential Antibacterials of MDR <i>Acinetobacter baumannii</i>

A previously developed model to predict antibacterial activity of ionic liquids against a resistant A. baumannii strain was used to assess activity of phosphonium ionic liquids. Their antioxidant potential was additionally evaluated with newly developed models, which were based on public data. The accuracy of the models was rigorously evaluated using cross-validation as well as test set prediction. Six alkyl triphenylphosphonium and alkyl tributylphosphonium bromides with the C8, C10, and C12 alkyl chain length were synthesized and tested in vitro. Experimental studies confirmed their activity against A. baumannii as well as showed pronounced antioxidant properties. These results suggest that phosphonium ionic liquids could be promising lead structures against A. baumannii

Theoretical and Experimental Studies of Phosphonium Ionic Liquids as Potential Antibacterials of MDR Acinetobacter baumannii

A previously developed model to predict antibacterial activity of ionic liquids against a resistant A. baumannii strain was used to assess activity of phosphonium ionic liquids. Their antioxidant potential was additionally evaluated with newly developed models, which were based on public data. The accuracy of the models was rigorously evaluated using cross-validation as well as test set prediction. Six alkyl triphenylphosphonium and alkyl tributylphosphonium bromides with the C8, C10, and C12 alkyl chain length were synthesized and tested in vitro. Experimental studies confirmed their activity against A. baumannii as well as showed pronounced antioxidant properties. These results suggest that phosphonium ionic liquids could be promising lead structures against A. baumannii