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Korza G, DePratti S, Fairchild D, Wicander J, Kanaan J, Shames H, Nichols FC, Cowan A, Brul S, Setlow P. Expression of the 2Duf protein in wild-type Bacillus subtilis spores stabilizes inner membrane proteins and increases spore resistance to wet heat and hydrogen peroxide. J Appl Microbiol 2023; 134:lxad040. [PMID: 36841229 PMCID: PMC10035073 DOI: 10.1093/jambio/lxad040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/09/2023] [Accepted: 02/24/2023] [Indexed: 02/27/2023]
Abstract
AIMS This work aimed to characterize spore inner membrane (IM) properties and the mechanism of spore killing by wet heat and H2O2 with spores overexpressing the 2Duf protein, which is naturally encoded from a transposon found only in some Bacillus strains with much higher spore resistance than wild-type spores. METHODS AND RESULTS Killing of Bacillus subtilis spores by wet heat or hydrogen peroxide (H2O2) was slower when 2Duf was present, and Ca-dipicolinic acid release was slower than killing. Viabilities on rich plates of wet heat- or H2O2 -treated spores +/- 2Duf were lower when NaCl was added, but higher with glucose. Addition of glucose but not Casamino acids addition increased treated spores' viability on minimal medium plates. Spores with 2Duf required higher heat activation for germination, and their germination was more wet-heat resistant than that of wild-type spores, processes that involve IM proteins. IM permeability and lipid mobility were lower in spores with 2Duf, although IM phospholipid composition was similar in spores +/- 2Duf. CONCLUSIONS These results and previous work suggests that wet heat and H2O2 kill spores by damaging an IM enzyme or enzymes involved in oxidative phosphorylation.
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Affiliation(s)
- George Korza
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Sarah DePratti
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Daniel Fairchild
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - James Wicander
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Julia Kanaan
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Hannah Shames
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Frank C Nichols
- Division of Periodontology, UConn Health, Farmington, CT 06030-3305, USA
| | - Ann Cowan
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
| | - Stanley Brul
- Molecular Biology & Microbial Food Safety, Swammerdam Institute for Life Science, University of Amsterdam, 1098XH Amsterdam, UK
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, Farmington, CT 06030-3305, USA
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Adamoczky A, Nagy T, Fehér PP, Pardi-Tóth V, Kuki Á, Nagy L, Zsuga M, Kéki S. Isocyanonaphthol Derivatives: Excited-State Proton Transfer and Solvatochromic Properties. Int J Mol Sci 2022; 23:7250. [PMID: 35806254 PMCID: PMC9266744 DOI: 10.3390/ijms23137250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 02/04/2023] Open
Abstract
Fluorescent probes that exhibit solvatochromic or excited-state proton-transfer (ESPT) properties are essential tools for the study of complex biological or chemical systems. Herein, the synthesis and characterization of a novel fluorophore that reveals both features, 5-isocyanonaphthalene-1-ol (ICOL), are reported. Various solvatochromic methods, such as Lippert−Mataga and Bilot−Kawski, together with time-dependent density functional theory (TD-DFT) and time-resolved emission spectroscopy (TRES), were applied to gain insights into its excited-state behavior. To make comparisons, the octyloxy derivative of ICOL, 5-isocyano-1-(octyloxy)naphthalene (ICON), was also prepared. We found that internal charge transfer (ICT) takes place between the isocyano and −OH groups of ICOL, and we determined the values of the dipole moments for the ground and excited states of both ICOL and ICON. Furthermore, in the emission spectra of ICOL, a second band at higher wavelengths (green emission) in solvents of higher polarities (dual emission), in addition to the band present at lower wavelengths (blue emission), were observed. The extent of this dual emission increases in the order of 2-propanol < methanol < N,N-dimethylformamide (DMF) < dimethyl sulfoxide (DMSO). The presence of the dual fluorescence of ICOL in these solvents can be ascribed to ESPT. For ICOL, we also determined ground- and excited-state pKa values of 8.4 ± 0.3 and 0.9 ± 0.7, respectively, which indicates a considerable increase in acidity upon excitation. The TRES experiments showed that the excited-state lifetimes of the ICOL and ICON spanned from 10.1 ns to 5.0 ns and from 5.7 ns to 3.8 ns, respectively. In addition, we demonstrated that ICOL can be used as an effective indicator of not only the critical micelle concentration (cmc) of ionic (sodium lauryl sulfate (SLS)) and nonionic surfactants (Tween 80), but also other micellar parameters, such as partition coefficients, as well as to map the microenvironments in the cavities of biomacromolecules (e.g., BSA). It is also pointed out that fluorescence quenching by pyridine can effectively be utilized for the determination of the fractions of ICOL molecules that reside at the water−micelle interface and in the interior spaces of micelles.
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Affiliation(s)
- Anita Adamoczky
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary
| | - Tibor Nagy
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
| | - Péter Pál Fehér
- Research Centre for Natural Sciences, Magyar Tudósok Körútja 2., H-1117 Budapest, Hungary;
| | - Veronika Pardi-Tóth
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1., H-4032 Debrecen, Hungary
| | - Ákos Kuki
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
| | - Lajos Nagy
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
| | - Miklos Zsuga
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
| | - Sándor Kéki
- Department of Applied Chemistry, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (A.A.); (T.N.); (V.P.-T.); (Á.K.); (L.N.); (M.Z.)
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3
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Liang D, Wang X, Wu X, Liao X, Chen F, Hu X. The effect of high pressure combined with moderate temperature and peptidoglycan fragments on spore inactivation. Food Res Int 2021; 148:110615. [PMID: 34507759 DOI: 10.1016/j.foodres.2021.110615] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 11/26/2022]
Abstract
High pressure processing (HPP) is a promising non-thermal processing method for food production. However, extremely high pressure and temperature are often required to achieve spores inactivation and commercial sterilization using HPP. In this study, the combined treatment of HPP, moderate temperature, and peptidoglycan fragments (PGF) for spore inactivation was investigated. The combined treatment of 200 MPa and 1 mg/mL PGF at 80 °C for 20 min resulted in 8.6 log inactivation of Bacillus subtilis 168 and more than 5 log reductions of Clostridium sporogenes PA3679 spores, respectively. A strong synergistic effect on spore inactivation among HPP, PGF, and temperature was observed. By comparing the effect of the treatment on the fluidity of the inner membrane and structural change of spores using fluorescence assay, a probable inactivation mechanism was proposed. It was concluded that the spores were firstly triggered to enter the Stage I of the germination process by HPP and PGF, and then immediately inactivated by the mild heat. This novel processing method could be an alternative to ensure commercial sterilization in the food industry.
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Affiliation(s)
- Dong Liang
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, China
| | - Xu Wang
- College of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Xiaomeng Wu
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetable Processing, Ministry of Agriculture, Beijing 100083, China
| | - Xiaojun Liao
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetable Processing, Ministry of Agriculture, Beijing 100083, China
| | - Fang Chen
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetable Processing, Ministry of Agriculture, Beijing 100083, China
| | - Xiaosong Hu
- College of Food Science and Nutritional Engineering, National Engineering Research Centre for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetable Processing, Ministry of Agriculture, Beijing 100083, China.
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Stolarek P, Bernat P, Szczerbiec D, Różalski A. Phospholipids and Fatty Acids Affect the Colonization of Urological Catheters by Proteus mirabilis. Int J Mol Sci 2021; 22:ijms22168452. [PMID: 34445157 PMCID: PMC8395112 DOI: 10.3390/ijms22168452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 01/10/2023] Open
Abstract
Proteus mirabilis-mediated CAUTIs are usually initiated by the adherence of bacteria to a urinary catheter surface. In this paper, three isolates of different origin and exhibiting different adhesion abilities were investigated in search of any changes in lipidome components which might contribute to P. mirabilis adhesion to catheters. Using GC-MS and LC-MS/MS techniques, 21 fatty acids and 27 phospholipids were identified in the examined cells. The comparison of the profiles of phospholipids and fatty acids obtained for catheter-attached cells and planktonic cells of the pathogens indicated C11:0 and PE 37:2 levels as values which could be related to P. mirabilis adhesion to a catheter, as well as cis C16:1, PE 32:0, PE 33:0, PE 38:2, PG 33:1, PG 34:0, PE 30:1, PE 32:1 and PG 30:2 levels as values which could be associated with cell hydrophobicity. Based on DiBAC4 (3) fluorescence intensity and an affinity to p-xylene, it was found that the inner membrane depolarization, as well as strong cell-surface hydrophobicity, were important for P. mirabilis adhesion to a silicone catheter. A generalized polarization of Laurdan showed lower values for P. mirabilis cells attached to the catheter surface than for planktonic cells, suggesting lower packing density of membrane components of the adherent cells compared with tightly packed, stiffened membranes of the planktonic cells. Taken together, these data indicate that high surface hydrophobicity, fluidization and depolarization of P. mirabilis cell membranes enable colonization of a silicone urinary catheter surface.
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Affiliation(s)
- Paulina Stolarek
- Department of Biology of Bacteria, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (D.S.); (A.R.)
- Correspondence: ; Tel.: +48-42-635-43-24; Fax: +48-42-665-58-18
| | - Przemysław Bernat
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland;
| | - Dominika Szczerbiec
- Department of Biology of Bacteria, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (D.S.); (A.R.)
| | - Antoni Różalski
- Department of Biology of Bacteria, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (D.S.); (A.R.)
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5
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Delbrück AI, Zhang Y, Heydenreich R, Mathys A. Bacillus spore germination at moderate high pressure: A review on underlying mechanisms, influencing factors, and its comparison with nutrient germination. Compr Rev Food Sci Food Saf 2021; 20:4159-4181. [PMID: 34147040 DOI: 10.1111/1541-4337.12789] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 02/05/2023]
Abstract
Spore-forming bacteria are resistant to stress conditions owing to their ability to form highly resistant dormant spores. These spores can survive adverse environmental conditions in nature, as well as decontamination processes in the food and related industries. Bacterial spores may return to their vegetative state through a process called germination. As spore germination is critical for the loss of resistance, outgrowth, and development of pathogenicity and spoilage potential, the germination pathway has piqued the interest of the scientific community. The inhibition and induction of germination have critical applications in the food industry. Targeted germination can aid in decreasing the resistance of spores and allow the application of milder inactivation procedures. This germination-inactivation strategy allows better maintenance of important food quality attributes. Different stimuli are reported to trigger germination. Among those, isostatic high pressure (HP) has gained increasing attention due to its potential applications in industrial processes. However, pressure-mediated spore germination is extremely heterogeneous as some spores germinate rapidly, while others exhibit slow germination or do not undergo germination at all. The successful and safe implementation of the germination-inactivation strategy, however, depends on the germination of all spores. Therefore, there is a need to elucidate the mechanisms of HP-mediated germination. This work aimed to critically review the current state of knowledge on Bacillus spore germination at a moderate HP of 50-300 MPa. In this review, the germination mechanism, heterogeneity, and influencing factors have been outlined along with knowledge gaps.
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Affiliation(s)
- Alessia I Delbrück
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
| | - Yifan Zhang
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
| | - Rosa Heydenreich
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
| | - Alexander Mathys
- Sustainable Food Processing Laboratory, Institute of Food, Nutrition and Health, Department of Health Science and Technology, ETH Zürich, Zurich, Switzerland
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6
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Lipidomic adaptations of the Metarhizium robertsii strain in response to the presence of butyltin compounds. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:316-326. [DOI: 10.1016/j.bbamem.2018.06.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/06/2018] [Accepted: 06/11/2018] [Indexed: 02/07/2023]
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7
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Drücker P, Rühling A, Grill D, Wang D, Draeger A, Gerke V, Glorius F, Galla HJ. Imidazolium Salts Mimicking the Structure of Natural Lipids Exploit Remarkable Properties Forming Lamellar Phases and Giant Vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1333-1342. [PMID: 27935708 DOI: 10.1021/acs.langmuir.6b03182] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Tailor-made ionic liquids based on imidazolium salts have recently attracted a large amount of attention because of their extraordinary properties and versatile functionality. An intriguing ability to interact with and stabilize membranes has already been reported for 1,3-dialkylimidazolium compounds. We now reveal further insights into the field by investigating 1,3-dimethyl-4,5-dialkylimidazolium (Cn-IMe·HI, n = 7, 11, 15) and 1,3-dibenzyl-4,5-dialkylimidazolium (Cn-IBn·HBr, n = 7, 11, 15) salts. Diverse alkyl chain lengths and headgroups differing in their steric demand were employed for the membrane interface interaction with bilayer membranes imitating the cellular plasma membrane. Membrane hydration properties and domain fluidization were analyzed by fluorescent bilayer probes in direct comparison to established model membranes in a buffered aqueous environment, which resembles the salt content and pH of the cytosol of living cells. Membrane binding and insertion was analyzed via a quartz crystal microbalance and confocal laser scanning microscopy. We show that short-chain 4,5-dialkylimidazolium salts with a bulky headgroup were able to disintegrate membranes. Long-chain imidazolium salts form bilayer membrane vesicles spontaneously and autonomously without the addition of other lipids. These 4,5-dialkylimidazolium salts are highly eligible for further biochemical engineering and drug delivery.
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Affiliation(s)
- Patrick Drücker
- Institute of Biochemistry, University of Münster , Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
- Department of Cell Biology, Institute of Anatomy, University of Bern , Baltzerstrasse 2, 3000 Bern 9, Switzerland
| | - Andreas Rühling
- Organic Chemistry Institute, University of Münster , Corrensstrasse 40, D-48149 Münster, Germany
| | - David Grill
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster , Von-Esmarch-Str. 56, D-48149 Münster, Germany
| | - Da Wang
- Institute of Biochemistry, University of Münster , Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Annette Draeger
- Department of Cell Biology, Institute of Anatomy, University of Bern , Baltzerstrasse 2, 3000 Bern 9, Switzerland
| | - Volker Gerke
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster , Von-Esmarch-Str. 56, D-48149 Münster, Germany
| | - Frank Glorius
- Organic Chemistry Institute, University of Münster , Corrensstrasse 40, D-48149 Münster, Germany
| | - Hans-Joachim Galla
- Institute of Biochemistry, University of Münster , Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
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8
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Sánchez-Maldonado AF, Schieber A, Gänzle MG. Antifungal activity of secondary plant metabolites from potatoes (Solanum tuberosum L.): Glycoalkaloids and phenolic acids show synergistic effects. J Appl Microbiol 2016; 120:955-65. [PMID: 26786886 DOI: 10.1111/jam.13056] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/20/2015] [Accepted: 12/26/2015] [Indexed: 12/29/2022]
Abstract
AIMS To study the antifungal effects of the potato secondary metabolites α-solanine, α-chaconine, solanidine and caffeic acid, alone or combined. METHODS AND RESULTS Resistance to glycoalkaloids varied among the fungal species tested, as derived from minimum inhibitory concentrations assays. Synergistic antifungal activity between glycoalkaloids and phenolic compounds was found. Changes in the fluidity of fungal membranes caused by potato secondary plant metabolites were determined by calculation of the generalized polarization values. The results partially explained the synergistic effect between caffeic acid and α-chaconine and supported findings on membrane disruption mechanisms from previous studies on artificial membranes. LC/MS analysis was used to determine variability and relative amounts of sterols in the different fungal species. Results suggested that the sterol pattern of fungi is related to their resistance to potato glycoalkaloids and to their taxonomy. CONCLUSION Fungal resistance to α-chaconine and possibly other glycoalkaloids is species dependent. α-Chaconine and caffeic acid show synergistic antifungal activity. The taxonomic classification and the sterol pattern play a role in fungal resistance to glycoalkaloids. SIGNIFICANCE AND IMPACT OF THE STUDY Results improve the understanding of the antifungal mode of action of potato secondary metabolites, which is essential for their potential utilization as antifungal agents in nonfood systems.
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Affiliation(s)
- A F Sánchez-Maldonado
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - A Schieber
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.,Institute of Nutritional and Food Sciences, Chair of Food Technology and Food Biotechnology, University of Bonn, Bonn, Germany
| | - M G Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
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9
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Assessment of Membrane Fluidity Fluctuations during Cellular Development Reveals Time and Cell Type Specificity. PLoS One 2016; 11:e0158313. [PMID: 27362860 PMCID: PMC4928918 DOI: 10.1371/journal.pone.0158313] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/14/2016] [Indexed: 01/11/2023] Open
Abstract
Cell membrane is made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as differentiation cell membranes undergo dramatic fluidity changes induced by proteins such as ARC and Cofilin among others. In this study we used the generalized polarization (GP) property of fluorescent probe Laurdan using two-photon microscopy to determine membrane fluidity as a function of time and for various cell lines. A low GP value corresponds to a higher fluidity and a higher GP value is associated with a more rigid membrane. Four different cell lines were monitored such as hN2, NIH3T3, HEK293 and L6 cells. Membrane fluidity was measured at 12h, 72h and 92 h. Our results show significant changes in membrane fluidity among all cell types at different time points. GP values tend to increase significantly within 92 h in hN2 cells and 72 h in NIH3T3 cells and only at 92 h in HEK293 cells. L6 showed a marked decrease in membrane fluidity at 72 h and starts to increase at 92 h. As expected, NIH3T3 cells have more rigid membrane at earlier time points. On the other hand, neurons tend to have the highest membrane fluidity at early time points emphasizing its correlation with plasticity and the need for this malleability during differentiation. This study sheds light on the involvement of membrane fluidity during neuronal differentiation and development of other cell lines.
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10
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Loison P, Gervais P, Perrier-Cornet JM, Kuimova MK. Effect of ethanol perturbation on viscosity and permeability of an inner membrane in Bacillus subtilis spores. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2060-2069. [PMID: 27267704 DOI: 10.1016/j.bbamem.2016.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 05/30/2016] [Accepted: 06/02/2016] [Indexed: 02/02/2023]
Abstract
In this work, we investigated how a combination of ethanol and high temperature (70°C), affect the properties of the inner membrane of Bacillus subtilis spores. We observed membrane permeabilization for ethanol concentrations ≥50%, as indicated by the staining of the spores' DNA by the cell impermeable dye Propidium Iodide. The loss of membrane integrity was also confirmed by a decrease in the peak corresponding to dipicolinic acid using infrared spectroscopy. Finally, the spore refractivity (as measured by phase contrast microscopy) was decreased after the ethanol-heat treatment, suggesting a partial rehydration of the protoplast. Previously we have used fluorescent lifetime imaging microscopy (FLIM) combined with the fluorescent molecular rotor Bodipy-C12 to study the microscopic viscosity in the inner membrane of B. subtilis spores, and showed that at normal conditions it is characterized by a very high viscosity. Here we demonstrate that the ethanol/high temperature treatment led to a decrease of the viscosity of the inner membrane, from 1000cP to 860cP for wild type spores at 50% of ethanol. Altogether, our present work confirms the deleterious effect of ethanol on the structure of B. subtilis spores, as well as demonstrates the ability of FLIM - Bodipy-C12 to measure changes in the microviscosity of the spores upon perturbation.
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Affiliation(s)
- Pauline Loison
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, PMB, F-21000 Dijon, France
| | - Patrick Gervais
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, PMB, F-21000 Dijon, France
| | - Jean-Marie Perrier-Cornet
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, PMB, F-21000 Dijon, France; Dimacell Imaging Resource Center, Univ. Bourgogne Franche-Comté, AgroSup Dijon, F-21000 Dijon, France.
| | - Marina K Kuimova
- Department of Chemistry, Imperial College London, Exhibition Road, SW7 2AZ, UK.
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Membrane fluidity-related adaptive response mechanisms of foodborne bacterial pathogens under environmental stresses. Food Res Int 2015. [DOI: 10.1016/j.foodres.2015.03.016] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Geobacillus stearothermophilus ATCC 7953 spore chemical germination mechanisms in model systems. Food Control 2015. [DOI: 10.1016/j.foodcont.2014.08.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Bonaventura G, Barcellona ML, Golfetto O, Nourse JL, Flanagan LA, Gratton E. Laurdan monitors different lipids content in eukaryotic membrane during embryonic neural development. Cell Biochem Biophys 2014; 70:785-94. [PMID: 24839062 PMCID: PMC4228983 DOI: 10.1007/s12013-014-9982-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We describe a method based on fluorescence-lifetime imaging microscopy (FLIM) to assess the fluidity of various membranes in neuronal cells at different stages of development [day 12 (E12) and day 16 (E16) of gestation]. For the FLIM measurements, we use the Laurdan probe which is commonly used to assess membrane water penetration in model and in biological membranes using spectral information. Using the FLIM approach, we build a fluidity scale based on calibration with model systems of different lipid compositions. In neuronal cells, we found a marked difference in fluidity between the internal membranes and the plasma membrane, being the plasma membrane the less fluid. However, we found no significant differences between the two cell groups, E12 and E16. Comparison with NIH3T3 cells shows that the plasma membranes of E12 and E16 cells are significantly more fluid than the plasma membrane of the cancer cells.
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Affiliation(s)
- Gabriele Bonaventura
- Department of Drug Science, Section of Biochemistry, University of Catania, Catania, Italy,
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Zhou C, Ontiveros-Valencia A, Cornette de Saint Cyr L, Zevin AS, Carey SE, Krajmalnik-Brown R, Rittmann BE. Uranium removal and microbial community in a H2-based membrane biofilm reactor. WATER RESEARCH 2014; 64:255-264. [PMID: 25073000 DOI: 10.1016/j.watres.2014.07.013] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 07/06/2014] [Accepted: 07/07/2014] [Indexed: 05/26/2023]
Abstract
We evaluated a hydrogen-based membrane biofilm reactor (MBfR) for its capacity to reduce and remove hexavalent uranium [U(VI)] from water. After a startup period that allowed slow-growing U(VI) reducers to form biofilms, the MBfR successfully achieved and maintained 94-95% U(VI) removal over 8 months when the U surface loading was 6-11 e(-) mEq/m(2)-day. The MBfR biofilm was capable of self-recovery after a disturbance due to oxygen exposure. Nanocrystalline UO2 aggregates and amorphous U precipitates were associated with vegetative cells and apparently mature spores that accumulated in the biofilm matrix. Despite inoculation with a concentrated suspension of Desulfovibrio vulgaris, this bacterium was not present in the U(VI)-reducing biofilm. Instead, the most abundant group in the biofilm community contained U(VI) reducers in the Rhodocyclaceae family when U(VI) was the only electron acceptor. When sulfate was present, the community dramatically shifted to the Clostridiaceae family, which included spores that were potentially involved in U(VI) reduction.
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Affiliation(s)
- Chen Zhou
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Aura Ontiveros-Valencia
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
| | - Louis Cornette de Saint Cyr
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA; Institut Sup'Biotech de Paris, France
| | - Alexander S Zevin
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Sara E Carey
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Rosa Krajmalnik-Brown
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Bruce E Rittmann
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
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15
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In situ investigation of Geobacillus stearothermophilus spore germination and inactivation mechanisms under moderate high pressure. Food Microbiol 2014; 41:8-18. [DOI: 10.1016/j.fm.2014.01.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 11/21/2013] [Accepted: 01/10/2014] [Indexed: 01/18/2023]
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16
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1,6-Diphenyl-1,3,5-hexatrine as a reporter of inner spore membrane fluidity in Bacillus subtilis and Alicyclobacillus acidoterrestris. J Microbiol Methods 2013; 96:101-3. [PMID: 24280194 DOI: 10.1016/j.mimet.2013.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/18/2013] [Accepted: 11/18/2013] [Indexed: 11/23/2022]
Abstract
A method to determine the inner membrane fluidity of spore populations was developed using the hydrophobic probe 1,6-diphenyl-1,3,5-hexatriene (DPH). DPH incorporated into the inner spore membrane of Bacillus subtilis ATCC 6633 and Alicyclobacillus acidoterrestris N1100, during static and dynamic fluidity experiments. The membrane fluidity of A. acidoterrestris spores stripped of the outer spore coats was the same as that of native spores. In addition, laser scanning confocal microscopy confirmed the presence of DPH in the spore membrane. This is the first report of spores containing fluid regions of their inner membranes.
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17
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Rácz D, Nagy M, Mándi A, Zsuga M, Kéki S. Solvatochromic properties of a new isocyanonaphthalene based fluorophore. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2013.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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18
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Loison P, Hosny NA, Gervais P, Champion D, Kuimova MK, Perrier-Cornet JM. Direct investigation of viscosity of an atypical inner membrane of Bacillus spores: a molecular rotor/FLIM study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2436-43. [PMID: 23831602 DOI: 10.1016/j.bbamem.2013.06.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/05/2013] [Accepted: 06/25/2013] [Indexed: 10/26/2022]
Abstract
We utilize the fluorescent molecular rotor Bodipy-C12 to investigate the viscoelastic properties of hydrophobic layers of bacterial spores Bacillus subtilis. The molecular rotor shows a marked increase in fluorescence lifetime, from 0.3 to 4ns, upon viscosity increase from 1 to 1500cP and can be incorporated into the hydrophobic layers within the spores from dormant state through to germination. We use fluorescence lifetime imaging microscopy to visualize the viscosity inside different compartments of the bacterial spore in order to investigate the inner membrane and relate its compaction to the extreme resistance observed during exposure of spores to toxic chemicals. We demonstrate that the bacterial spores possess an inner membrane that is characterized by a very high viscosity, exceeding 1000cP, where the lipid bilayer is likely in a gel state. We also show that this membrane evolves during germination to reach a viscosity value close to that of a vegetative cell membrane, ca. 600cP. The present study demonstrates quantitative imaging of the microscopic viscosity in hydrophobic layers of bacterial spores Bacillus subtilis and shows the potential for further investigation of spore membranes under environmental stress.
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Affiliation(s)
- Pauline Loison
- UMR PAM/Equipe PMB Université de Bourgogne/Agrosup Dijon Nord, 1 Esplanade Erasme 21000 Dijon, France
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Hofstetter S, Gebhardt D, Ho L, Gänzle M, McMullen LM. Effects of nisin and reutericyclin on resistance of endospores of Clostridium spp. to heat and high pressure. Food Microbiol 2013; 34:46-51. [DOI: 10.1016/j.fm.2012.11.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 09/18/2012] [Accepted: 11/08/2012] [Indexed: 11/29/2022]
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20
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In situ determination of Clostridium endospore membrane fluidity during pressure-assisted thermal processing in combination with nisin or reutericyclin. Appl Environ Microbiol 2013; 79:2103-6. [PMID: 23335780 DOI: 10.1128/aem.03755-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study determined the membrane fluidity of clostridial endospores during treatment with heat and pressure with nisin or reutericyclin. Heating (90°C) reduced laurdan (6-dodecanoyl-2-dimethylaminonaphthalene) general polarization, corresponding to membrane fluidization. Pressure (200 MPa) stabilized membrane order. Reutericyclin and nisin exhibit divergent effects on heat- and pressure-induced spore inactivation and membrane fluidity.
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