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Isik B, Bilgi M. Investigation of Physicochemical Characteristics of Aspergillus niger Biomass and Examination of Its Ability to Separate Butyl Acetate Isomers. Appl Biochem Biotechnol 2024:10.1007/s12010-024-04881-y. [PMID: 38411937 DOI: 10.1007/s12010-024-04881-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2024] [Indexed: 02/28/2024]
Abstract
Aspergillus niger is a species of fungus that is widely found in natural ecosystems and has an important role in various industrial fields and is readily available. To study the adhesion of microbial cells to solid substrates and to improve their properties, physicochemical characterization of microorganisms is extremely important. For this purpose, in this study, the surface properties of A. niger biomass were determined at low cost and with high accuracy by inverse gas chromatography (IGC), a physicochemical characterization technique. IGC experiments were conducted between 303.2 and 328.2 K at infinite dilution. Among these temperatures, various organic solvent vapors were passed over the A. niger biomass considered as stationary phase and their retention behavior was studied. Using the raw data, net retention volumes were calculated and retention diagrams were drawn. From the linear retention diagrams, the dispersive surface energy was calculated according to Dorris-Gray (48.73-46.09 mJ/m2), Donnet-Park (47.12-44.50 mJ/m2), Schultz (46.88-42.45 mJ/m2), and Hamieh (76.42-64.06 mJ/m2) methods. With the IGC method, the acidity-basicity parameters of A. niger biomass were determined and it was found that the surface was basic (K D / K A = 4.871 ). In the second part of this study, the butyl acetate isomer series, which are difficult to be separated by conventional methods, were effectively separated by the IGC method using A. niger stationary phase.
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Affiliation(s)
- Birol Isik
- Department of Chemistry, Faculty of Arts & Sciences, Yildiz Technical University, Esenler, Istanbul, 34220, Turkey.
| | - Mesut Bilgi
- Department of Chemistry, Faculty of Arts & Sciences, Yildiz Technical University, Esenler, Istanbul, 34220, Turkey
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2
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Fontes AM, Oliveira C, Bargiela P, da Rocha MDGC, Geris R, da Silva AF, Gangishetty MK, Scott RWJ, Malta M. Unveiling the Surface and the Ultrastructure of Palladized Fungal Biotemplates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12961-12971. [PMID: 34714089 DOI: 10.1021/acs.langmuir.1c02023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this paper, two biosystems based on filamentous fungi and Pd nanoparticles (NPs) were synthesized and structurally characterized. In the first case, results concerning the integration and distribution of Pd-NPs on Phialomyces macrosporus revealed that nanoparticles are accumulated on the cell wall, keeping the cytoplasm isolated from abiotic particles. However, the Penicillium sp. species showed an unexpected internalization of Pd-NPs in the fungal cytosol, becoming a promising biosystem to further studies of in vivo catalytic reactions. Next, we report a new solution-based strategy to prepare palladized biohybrids through sequential reduction of Pd2+ ions over previously harvested fungus/Au-NP composites. The chemical composition and the morphology of the biohybrid surface were characterized using a combination of scanning electron microscopy, transmission electron microscopy, and photoelectron spectroscopy. The deposition of Pd0 over the fungal surface produced biohybrids with a combination of Au and Pd in the NPs. Interestingly, other chemical species such as Au+ and Pd2+ are also observed on the outermost wall of microorganisms. Finally, the application of A. niger/AuPd-NP biohybrids in the 3-methyl-2-buten-1-ol hydrogenation reaction is presented for the first time. Biohybrids with a high fraction of Pd0 are active for this catalytic reaction.
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Affiliation(s)
- Adriana M Fontes
- Institute of Chemistry, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
| | - Camila Oliveira
- Institute of Chemistry, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
| | - Pascal Bargiela
- Institute of Chemistry, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
| | - Maria da G C da Rocha
- Institute of Chemistry, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
| | - Regina Geris
- Institute of Chemistry, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
| | - Antonio F da Silva
- Institute of Physics, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
| | - Mahesh K Gangishetty
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
- Department of Chemistry and Physics, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Robert W J Scott
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Marcos Malta
- Institute of Chemistry, Federal University of Bahia, Campus Ondina, Salvador, Bahia 40170-115, Brazil
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3
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Rowley MC, Grand S, Spangenberg JE, Verrecchia EP. Evidence linking calcium to increased organo-mineral association in soils. BIOGEOCHEMISTRY 2021; 153:223-241. [PMID: 34776566 PMCID: PMC8550578 DOI: 10.1007/s10533-021-00779-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/19/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED Geochemical indicators are emerging as important predictors of soil organic carbon (SOC) dynamics, but evidence concerning the role of calcium (Ca) is scarce. This study investigates the role of Ca prevalence in SOC accumulation by comparing otherwise similar sites with (CaCO3-bearing) or without carbonates (CaCO3-free). We measured the SOC content and indicators of organic matter quality (C stable isotope composition, expressed as δ 13C values, and thermal stability) in bulk soil samples. We then used sequential sonication and density fractionation (DF) to separate two occluded pools from free and mineral-associated SOC. The SOC content, mass, and δ 13C values were determined in all the fractions. X-ray photoelectron spectroscopy was used to investigate the surface chemistry of selected fractions. Our hypothesis was that occlusion would be more prevalent at the CaCO3-bearing site due to the influence of Ca on aggregation, inhibiting oxidative transformation, and preserving lower δ 13C values. Bulk SOC content was twice as high in the CaCO3-bearing profiles, which also had lower bulk δ 13C values, and more occluded SOC. Yet, contrary to our hypothesis, occlusion only accounted for a small proportion of total SOC (< 10%). Instead, it was the heavy fraction (HF), containing mineral-associated organic C, which accounted for the majority of total SOC and for the lower bulk δ 13C values. Overall, an increased Ca prevalence was associated with a near-doubling of mineral-associated SOC content. Future investigations should now aim to isolate Ca-mediated complexation processes that increase organo-mineral association and preserve organic matter with lower δ 13C values. SUPPLEMENTARY INFORMATION The online version of this article (10.1007/s10533-021-00779-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mike C. Rowley
- Institut des dynamiques de la surface terrestre (IDYST), Université de Lausanne, Lausanne, Switzerland
- Energy and Geosciences Division, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Stephanie Grand
- Institut des dynamiques de la surface terrestre (IDYST), Université de Lausanne, Lausanne, Switzerland
| | - Jorge E. Spangenberg
- Institut des dynamiques de la surface terrestre (IDYST), Université de Lausanne, Lausanne, Switzerland
| | - Eric P. Verrecchia
- Institut des dynamiques de la surface terrestre (IDYST), Université de Lausanne, Lausanne, Switzerland
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Maliszewska I, Tylus W, Chęcmanowski J, Szczygieł B, Pawlaczyk-Graja I, Pusz W, Baturo-Cieśniewska A. Biomineralization of gold by Mucor plumbeus: The progress in understanding the mechanism of nanoparticles' formation. Biotechnol Prog 2017; 33:1381-1392. [PMID: 28726315 DOI: 10.1002/btpr.2531] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 05/17/2017] [Indexed: 12/23/2022]
Abstract
This contribution describes the deposition of gold nanoparticles by microbial reduction of Au(III) ions using the mycelium of Mucor plumbeus. Biosorption as the major mechanism of Au(III) ions binding by the fungal cells and the reduction of them to the form of Au(0) on/in the cell wall, followed by the transportation of the synthesized gold nanoparticles to the cytoplasm, is postulated. The probable mechanism behind the reduction of Au(III) ions is discussed, leading to the conclusion that this process is nonenzymatic one. Chitosan of the fungal cell wall is most likely to be the major molecule involved in biomineralization of gold by the mycelium of M. plumbeus. Separation of gold nanoparticles from the cells has been carried out by the ultrasonic disintegration and the obtained nanostructures were characterized by UV-vis spectroscopy and transmission electron micrograph analysis. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1381-1392, 2017.
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Affiliation(s)
- Irena Maliszewska
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, 50-370, Poland
| | - Włodzimierz Tylus
- Faculty of Chemistry, Division of Advanced Material Technologies, Wrocław University of Science and Technology, WybrzeżeWyspiańskiego 27, Wrocław, 50-370, Poland
| | - Jacek Chęcmanowski
- Faculty of Chemistry, Division of Advanced Material Technologies, Wrocław University of Science and Technology, WybrzeżeWyspiańskiego 27, Wrocław, 50-370, Poland
| | - Bogdan Szczygieł
- Faculty of Chemistry, Division of Advanced Material Technologies, Wrocław University of Science and Technology, WybrzeżeWyspiańskiego 27, Wrocław, 50-370, Poland
| | - Izabela Pawlaczyk-Graja
- Faculty of Chemistry, Department of Organic and Pharmaceutical Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, 50-370, Poland
| | - Wojciech Pusz
- Department of Plant Protection, Division of Phytopathology and Mycology, Wrocław University of Environmental and Life Sciences, Grunwaldzki Sq 24a, Wrocław, 50-363, Poland
| | - Anna Baturo-Cieśniewska
- Department of Molecular Phytopathology, University of Technology and Life Sciences, Kordeckiego Str 20, Bydgoszcz, 85-225, Poland
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Wang Z, Chen Z, Yang L, Tan F, Wang Y, Li Q, Chang YI, Zhong CJ, He N. Effect of surface physicochemical properties on the flocculation behavior of Bacillus licheniformis. RSC Adv 2017. [DOI: 10.1039/c6ra28057a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Flocculation model ofB. licheniformisCGMCC 2876 deduced by XDLVO and surface thermodynamic characterization.
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Affiliation(s)
- Zhi Wang
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
| | - Zhen Chen
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
| | - Lijie Yang
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
| | - Fen Tan
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
| | - Qingbiao Li
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
| | - You-Im Chang
- Department of Chemical and Material Engineering
- Tunghai University
- Taichung 40704
- Taiwan
| | - Chuan-Jian Zhong
- Department of Chemistry
- State University of New York at Binghamton
- Binghamton
- USA
| | - Ning He
- Department of Chemical and Biochemical Engineering
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- P. R. China
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6
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Baalousha M, Ju-Nam Y, Cole PA, Hriljac JA, Jones IP, Tyler CR, Stone V, Fernandes TF, Jepson MA, Lead JR. Characterization of cerium oxide nanoparticles-part 2: nonsize measurements. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2012; 31:994-1003. [PMID: 22368072 DOI: 10.1002/etc.1786] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 07/26/2011] [Accepted: 12/05/2011] [Indexed: 05/31/2023]
Abstract
Part 1 (see companion paper) of the present study discussed the application of a multimethod approach in characterizing the size of cerium oxide nanoparticles (NPs). However, other properties less routinely investigated, such as shape and morphology, structure, chemical composition, and surface properties, are likely to play an important role in determining the behavior, reactivity, and potential toxicity of these NPs. The present study describes the measurement of the aforementioned physicochemical properties of NPs (applied also to nanomaterials [NMs]) compared with micrometer particles (MPs). The authors use a wide range of techniques, including high resolution-transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray energy dispersive spectroscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and electrophoresis, and compare these techniques, their advantages, and their limitations, along with recommendations about how best to approach NM characterization, using an application to commercial cerium oxide NPs and MPs. Results show that both cerium oxide NPs and MPs are formed of single polyhedron or truncated polyhedron crystals. Cerium oxide NPs contain a mixture of Ce(3+) and Ce(4+) cations, whereas the MPs contain mainly Ce(4+) , which is potentially important in understanding the toxicity of cerium oxide NPs. The isoelectric point of cerium oxide NPs was approximately pH 8, which explains their propensity to aggregate in aqueous media (see companion paper).
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Affiliation(s)
- Mohammed Baalousha
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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Saad M, Gaiani C, Mullet M, Scher J, Cuq B. X-ray photoelectron spectroscopy for wheat powders: measurement of surface chemical composition. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:1527-40. [PMID: 21294508 DOI: 10.1021/jf102315h] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The functional properties of wheat powders depend largely on the surface characteristics of their particles. X-ray photoelectron spectroscopy (XPS) has been considered to investigate the surface composition of wheat powders. The objective of the present study is to evaluate the ability of XPS to discriminate wheat components and to calculate the surface composition of wheat powders. First, XPS surveys for the main wheat isolated components (starch, proteins, arabinoxylans, and lipids) were determined. XPS results demonstrate that it is able to distinguish wheat proteins, polysaccharides, and lipids, but it is not able to distinguish starch and arabinoxylan because of their similarity in chemical structure. The XPS analyses of simple reconstituted wheat flours based on two components (starch and protein) or three components (by adding arabinoxylan) demonstrated the ability of XPS to measure the surface composition of the wheat flours. The surface composition of native wheat flour demonstrated an overrepresentation of protein (54%) and lipids (44%) and an underrepresentation of starch (2%) compared to the bulk composition. Results are discussed with regard to difficulties in discriminating arabinoxylans and starch components.
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Affiliation(s)
- Moustafa Saad
- Montpellier SupAgro - INRA, UMR 1208 Joint Unit for Emerging Technology and Polymer Engineering, 2 place Viala, 34060 Montpellier Cedex 1, France
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Tesson B, Genet MJ, Fernandez V, Degand S, Rouxhet PG, Martin-Jézéquel V. Surface Chemical Composition of Diatoms. Chembiochem 2009; 10:2011-24. [DOI: 10.1002/cbic.200800811] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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Genet MJ, Cogels P, Adriaensen Y, Rouxhet PG. Analysis of the oil–water interface by XPS at low temperature. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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10
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Ahimou F, Boonaert CJP, Adriaensen Y, Jacques P, Thonart P, Paquot M, Rouxhet PG. XPS analysis of chemical functions at the surface of Bacillus subtilis. J Colloid Interface Sci 2007; 309:49-55. [PMID: 17316673 DOI: 10.1016/j.jcis.2007.01.055] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 01/05/2007] [Accepted: 01/10/2007] [Indexed: 11/26/2022]
Abstract
The surface chemical composition of nine strains of Bacillus subtilis was determined by X-ray photoelectron spectroscopy. Regressions between elemental concentrations and concentrations associated with different components of C1s, N1s, and O1s peaks provided a more precise validation of the procedure used for peak decomposition and allowed the assignment of the peak components to be completed or strengthened. The component of the O1s peak appearing around 531.2 eV was shown to contain a contribution of oxygen from phosphate groups (PO, PO-), the other contribution being due to oxygen involved in amide functions. The surface negative charge may be fully attributed to phosphate groups, despite the observation of two types of zeta potential vs pH curves. The strains exhibiting a sharp variation of the zeta potential (range of -35 to -55 mV) between pH 2 and 4.7 were characterized by a high phosphate surface concentration and by an excess (about 25%) of phosphate with respect to the sum of potassium, an exchangeable cation, and protonated nitrogen, attributed to protein or to alanine involved in teichoic acids.
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Affiliation(s)
- François Ahimou
- Unité de Chimie Biologique Industrielle, Faculté Universitaire des Sciences Agronomiques de Gembloux, Passage des Déportés 2, B-5030 Gembloux, Belgium
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11
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Jacquemart I, Pamuła E, De Cupere VM, Rouxhet PG, Dupont-Gillain CC. Nanostructured collagen layers obtained by adsorption and drying. J Colloid Interface Sci 2006; 278:63-70. [PMID: 15313638 DOI: 10.1016/j.jcis.2004.05.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 05/24/2004] [Indexed: 11/30/2022]
Abstract
The supramolecular organization of collagen adsorbed from a 7 microg/ml solution on polystyrene was investigated as a function of the adsorption duration (from 1 min to 24 h) and of the drying conditions (fast drying under a nitrogen flow, slow drying in a water-saturated atmosphere). The morphology of the created surfaces was examined by atomic force microscopy (AFM), while complementary information regarding the adsorbed amount and the organization of the adsorbed layers was obtained using radioassays, X-ray photoelectron spectroscopy (XPS), and wetting measurements. The collagen adsorbed amount increased up to an adsorption duration of 5 h and then leveled off at a value of 0.9 microg/cm2. For samples obtained by fast drying, modeling of the N/C ratios obtained by XPS in terms of thickness and surface coverage, in combination with the adsorbed amount, water contact angle measurements and AFM images, indicated that the adsorbed layer formed a felt starting from 30 min of adsorption, the density and/or the thickness of which increased with the adsorption time. Upon slow drying, the collagen layers formed after adsorption times up to about 2 h underwent a strong reorganization. The obtained nanopatterns were attributed to dewetting, the liquid film being ruptured and adsorbed collagen being displaced by the water meniscus. At higher adsorption times, the organization of the collagen layer was similar to that obtained after fast drying, because the onset of dewetting and/or collagen displacement were prevented by the high density of the collagen felt.
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Affiliation(s)
- I Jacquemart
- Unité de chimie des interfaces, Université catholique de Louvain, Croix du Sud 2/18, 1348 Louvain-la-Neuve, Belgium
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12
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Gaiani C, Ehrhardt JJ, Scher J, Hardy J, Desobry S, Banon S. Surface composition of dairy powders observed by X-ray photoelectron spectroscopy and effects on their rehydration properties. Colloids Surf B Biointerfaces 2006; 49:71-8. [PMID: 16621476 DOI: 10.1016/j.colsurfb.2006.02.015] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Accepted: 02/28/2006] [Indexed: 10/24/2022]
Abstract
The surface composition of three dairy powders was investigated by X-ray photoelectron spectroscopy. These spray-dried casein powders were more or less enriched in hygroscopic material (lactose and/or minerals). The principal limitation of these high protein content powders is their poor rehydration ability. Consequently, information about surface composition is required in order to get a better understanding of rehydration behaviour (i.e. wetting time and time of rehydration). The obtained results indicate that the surface of the three powders was dominated by proteins. Lactose and minerals are marginal compounds at the surface whereas the surface coverage of fat was over represented. A correlation between the lactose surface content and the wetting time of the powders was found, but no relationship with the surface fat. Moreover, as the surface is partly depleted in minerals and lactose, it is concluded that these compounds are principally located in the bulk of the particle. Therefore this observation could be related with a wetting time of the powders only slightly affected by the addition of hygroscopic material whereas the time of rehydration was strongly improved; powder wetting being more affected by the surface composition whereas powder dispersion being more influenced by the powder bulk composition.
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Affiliation(s)
- C Gaiani
- Laboratoire de Sciences et Génie Alimentaires, LSGA, 2 avenue de la Forêt de Haye, B.P. 172, 54505 Vandoeuvre Lès Nancy, France
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Iguerb O, Demoustier-Champagne S, Marchand-Brynaert J, Daoust D, Sclavons M, Devaux J. Modification of polyolefin films surface with sodium hypochlorite. J Appl Polym Sci 2006. [DOI: 10.1002/app.23409] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Dupont-Gillain CC, Jacquemart I, Rouxhet PG. Influence of the aggregation state in solution on the supramolecular organization of adsorbed type I collagen layers. Colloids Surf B Biointerfaces 2005; 43:179-86. [PMID: 15961296 DOI: 10.1016/j.colsurfb.2004.12.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 12/01/2004] [Accepted: 12/07/2004] [Indexed: 11/15/2022]
Abstract
In the last years, adsorbed collagen was shown to form layers with a supramolecular organization depending on the substrate surface properties and on the preparation procedure. If the concentration of collagen and the duration of adsorption are sufficient, fibrillar collagen structures are formed, corresponding to assemblies of a few molecules. This occurs more readily on hydrophobic compared to hydrophilic surfaces. This study aims at understanding the origin of such fibrillar structures and in particular at determining whether they result from the deposition of fibrils formed in solution or from the building of assemblies at the interface. Therefore, type I collagen solutions with an increasing degree of aggregation were prepared, using the "neutral-start" approach, by ageing pH 5.8 solutions at 37 degrees C for 15 min, 2 or 7 days. The obtained solutions were used to investigate the influence of collagen aggregation in solution on the supramolecular organization of adsorbed collagen layers, which was characterized by X-ray photoelectron spectroscopy and atomic force microscopy. Polystyrene and plasma-oxidized polystyrene were chosen as substrates for the adsorption. The size and the density of collagen fibrils at the interface decreased upon increasing the degree of aggregation of collagen in solution. This is explained by a competitive adsorption process between monomers and aggregates of the solution, turning at the advantage of the monomers. More aggregated solutions, which are thus depleted in free monomers, behave like less concentrated solutions, i.e. lead to a lower adsorbed amount and less fibril formation at the interface. This study shows that the supramolecular fibrils observed in adsorbed collagen layers, especially on hydrophobic substrates, are not formed in the solution, prior to adsorption, but are built at the interface, through the assembly of free segments of adsorbed molecules.
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Affiliation(s)
- Christine C Dupont-Gillain
- Unité de Chimie des Interfaces, Université Catholique de Louvain, Croix du Sud 2/18, 1348 Louvain-la-Neuve, Belgium.
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15
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Genet MJ, Jacques C, Mozes N, Hove CV, Lejeune A, Rouxhet PG. Use of differential charging to analyse microscopic specimens ofAzolla leaves by XPS. SURF INTERFACE ANAL 2002. [DOI: 10.1002/sia.1427] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Thomas F, Bard E, Rouillier M, Prélot B, Mathieu L. Filtration–elution of Cryptosporidium oocysts assisted by electrostatic interactions. Colloids Surf A Physicochem Eng Asp 2001. [DOI: 10.1016/s0927-7757(01)00836-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17
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Boonaert CJ, Rouxhet PG. Surface of lactic acid bacteria: relationships between chemical composition and physicochemical properties. Appl Environ Microbiol 2000; 66:2548-54. [PMID: 10831437 PMCID: PMC110580 DOI: 10.1128/aem.66.6.2548-2554.2000] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The surface chemical composition and physicochemical properties (hydrophobicity and zeta potential) of two lactic acid bacteria, Lactococcus lactis subsp. lactis bv. diacetilactis and Lactobacillus helveticus, have been investigated using cells harvested in exponential or stationary growth phase. The surface composition determined by X-ray photoelectron spectroscopy (XPS) was converted into a molecular composition in terms of proteins, polysaccharides, and hydrocarbonlike compounds. The concentration of the last was always below 15% (wt/wt), which is related to the hydrophilic character revealed by water contact angles of less than 30 degrees. The surfaces of L. lactis cells had a polysaccharide concentration about twice that of proteins. The S-layer of L. helveticus was either interrupted or crossed by polysaccharide-rich compounds; the concentration of the latter was higher in the stationary growth phase than in the exponential growth phase. Further progress was made in the interpretation of XPS data in terms of chemical functions by showing that the oxygen component at 531.2 eV contains a contribution of phosphate in addition to the main contribution of the peptide link. The isoelectric points were around 2 and 3, and the electrophoretic mobilities above pH 5 (ionic strength, 1 mM) were about -3.0 x 10(-8) and -0.6 x 10(-8) m(2) s(-1) V(-1) for L. lactis and L. helveticus, respectively. The electrokinetic properties of the latter reveal the influence of carboxyl groups, while the difference between the two strains is related to a difference between N/P surface concentration ratios, reflecting the relative exposure of proteins and phosphate groups at the surface.
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Affiliation(s)
- C J Boonaert
- Unité de Chimie des Interfaces, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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Dupont-Gillain CC, Nysten B, Hlady V, Rouxhet PG. Atomic Force Microscopy and Wettability Study of Oxidized Patterns at the Surface of Polystyrene. J Colloid Interface Sci 1999; 220:163-169. [PMID: 10550254 PMCID: PMC3261235 DOI: 10.1006/jcis.1999.6524] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The surface properties of patterned surfaces made by a combination of photolithography and oxygen plasma treatment of polystyrene (PS) were investigated. PS and plasma-treated PS (PSox) were first characterized using X-ray photoelectron spectroscopy and the study of wetting dynamics (Wilhelmy plate method) in water and in solutions of different pH. The results indicated that the PSox surface may be viewed as covered with a polyelectrolyte-like gel, which swells depending on pH. It was then shown, using atomic force microscopy (AFM), that the adhesion force measured on PS with a silicon tip in water was higher compared with that measured on PSox. This feature allowed imaging of the oxidation patterns using the adhesion mapping mode. The origin of the pulloff force contrast, which could not be explained by combining Johnson-Kendall-Roberts theory and thermodynamic considerations, was attributed to repulsion between the tip and hydrated polymer chains present on the oxidized surface. Imaging was also performed in the lateral force mode, a higher friction being recorded on PS than on PSox. Copyright 1999 Academic Press.
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Affiliation(s)
- Christine C. Dupont-Gillain
- Unité de chimie des interfaces, Université Catholique de Louvain, Place Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium
| | - Bernard Nysten
- Unité de chimie et de physique des hauts polymères, Université Catholique de Louvain, Place Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium
| | - Vladimir Hlady
- Department of Bioengineering, University of Utah, Salt Lake City, Utah 84112
| | - Paul G. Rouxhet
- Unité de chimie des interfaces, Université Catholique de Louvain, Place Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium
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Haycox CL, Leach-Scampavia D, Olerud JE, Ratner BD. Quantitative detection of silicone in skin by means of electron spectroscopy for chemical analysis (ESCA). J Am Acad Dermatol 1999; 40:719-25. [PMID: 10321600 DOI: 10.1016/s0190-9622(99)70153-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Evaluation of silicone-induced morbidity in skin has been hampered by the difficulty of detecting silicone in tissue because conventional methods are nonquantitative and insensitive. OBJECTIVE We attempted to determine whether silicone could be identified and quantitated in skin by means of electron spectroscopy for chemical analysis (ESCA). METHODS Skin biopsy specimens were obtained from the nose, chin, malar region, and inner arm of a patient who had received injections of silicone gel in his nose and chin. Frozen sections were dried under vacuum and examined by means of ESCA. Contiguous sections were examined by light microscopy. RESULTS The surface concentrations of silicone were as follows: chin, 20.6% +/- 3.6%; nose, 19.0%; malar region, 2.6% +/- 1.6%; inner arm, 0.0% +/- 0.0%. Light microscopy revealed homogeneous "globules" consistent with silicone in the chin and nose sections only; the malar region and inner arm sections showed no evidence of silicone. CONCLUSION ESCA can be used to detect silicone in skin in a specific, highly sensitive, and quantitative manner. This is the first report of quantification of silicone in skin by means of ESCA.
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Affiliation(s)
- C L Haycox
- Department of Medicine (Dermatology), University of Washington, Seattle 98195-6524, USA.
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Dupont-Gillain CC, Nysten B, Rouxhet PG. Collagen adsorption on poly(methyl methacrylate): net-like structure formation upon drying. POLYM INT 1999. [DOI: 10.1002/(sici)1097-0126(199904)48:4<271::aid-pi119>3.0.co;2-j] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The surface physico-chemical properties (hydrophobicity, electrophoretic mobility, chemical composition) of a large set of top- and bottom-fermenting brewing yeasts, harvested in the exponential and stationary growth phases, have been investigated. Bottom- and top-fermenting strains showed different surface properties. Top strains were generally more hydrophobic than bottom strains, due to higher surface protein concentrations. Bottom strains possessed higher surface phosphate concentrations. The different profiles of electrophoretic mobility versus pH for top and bottom strains could be explained by modelling the surface charge according to the surface chemical composition as given by X-ray photoelectron spectroscopy. For bottom strains, the electrical properties were mainly controlled by phosphate, resulting in a low isoelectric point (pH 2 or below) and an electrophoretic mobility that did not become much more negative above pH 4. For the top strains, they were mainly determined by the balance of protonated amino- and carboxylate groups in proteins, which gave a high isoelectric point (pH 4) and an electrophoretic mobility changing greatly with pH in the range of 2 to 7. No difference in surface properties was found between flocculating and non-flocculating strains, or between cells from the exponential and stationary growth phases, even for strains where flocculation occurred during the transition from one growth phase to the other.
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Affiliation(s)
- P B Dengis
- Unité de Chimie des Interfaces, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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Hietala T, Mozes N, Genet MJ, Rosenqvist H, Laakso S. Surface lipids and their distribution on willow (Salix) leaves: a combined chemical, morphological and physicochemical study. Colloids Surf B Biointerfaces 1997. [DOI: 10.1016/s0927-7765(96)01339-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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