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Penland M, Pawtowski A, Pioli A, Maillard MB, Debaets S, Deutsch SM, Falentin H, Mounier J, Coton M. Brine salt concentration reduction and inoculation with autochthonous consortia: Impact on Protected Designation of Origin Nyons black table olive fermentations. Food Res Int 2022; 155:111069. [DOI: 10.1016/j.foodres.2022.111069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/04/2022]
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Boussekine R, Bekhouche F, Debaets S, Thierry A, Maillard MB, Falentin H, Pawtowski A, Barkat M, Coton M, Mounier J. Deciphering the Microbiota and Volatile Profiles of Algerian Smen, a Traditional Fermented Butter. Microorganisms 2022; 10:microorganisms10040736. [PMID: 35456786 PMCID: PMC9028027 DOI: 10.3390/microorganisms10040736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 12/04/2022] Open
Abstract
In Algeria, Smen is a fermented butter produced in households using empirical methods. Smen fermentation is driven by autochthonous microorganisms; it improves butter shelf-life and yields highly fragrant products used as ingredients in traditional dishes as well as in traditional medicine. The present study is aimed at investigating microbial diversity and dynamics during Algerian Smen fermentation using both culture-dependent and culture-independent approaches, as well as by monitoring volatile organic compound production. To reach this goal, fifteen Smen samples (final products) produced in households from different regions in Algeria were collected and analyzed. In addition, microbial and volatile compound dynamics at the different stages of Smen manufacturing were investigated for one Smen preparation. The results showed that Smen is a microbiologically safe product, as all hygiene and safety criteria were respected. The dominant microorganisms identified by both techniques were LAB and yeasts. Lactococcus spp. and Streptococcus thermophilus were the main bacterial species involved in spontaneous raw milk fermentation preceding butter-making, while lactobacilli and enterococci were the only bacteria found to be viable during Smen maturation. Regarding fungal diversity, yeast species were only recovered from two mature Smen samples by culturing, while different species (e.g., Geotrichum candidum, Moniliella sp.) were identified in all samples by the culture-independent approach. Using microbial analysis of a single batch, many of these were found viable during manufacturing. Concerning the volatile profiles, they were highly diverse and characterized by a high prevalence of short chain fatty acids, methylketones, and esters. Correlation analysis between microbial diversity and volatile profiles showed that several yeast (Moniliella sp., K. marxianus) and LAB (e.g., Lactococcus spp., S. thermophilus) species were strongly correlated with one or more volatile organic compound families, including several ethyl esters and methyl ketones that can be linked to pleasant, sweetly floral, fruity, buttery, and creamy odors. This study clearly identified key microorganisms involved in Smen fermentation and maturation that could be used in the future for better fermentation control and improvement of quality attributes.
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Affiliation(s)
- Rania Boussekine
- Laboratoire de Biotechnologie et Qualité des Aliments (BIOQUAL), Institut de la Nutrition, de l’Alimentation et des Technologies Agro-Alimentaires (INATAA), Université Frères Mentouri Constantine 1, Route de Ain-El-Bey, Constantine 25000, Algeria; (R.B.); (F.B.); (M.B.)
| | - Farida Bekhouche
- Laboratoire de Biotechnologie et Qualité des Aliments (BIOQUAL), Institut de la Nutrition, de l’Alimentation et des Technologies Agro-Alimentaires (INATAA), Université Frères Mentouri Constantine 1, Route de Ain-El-Bey, Constantine 25000, Algeria; (R.B.); (F.B.); (M.B.)
| | - Stella Debaets
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, Univ Brest, F-29280 Plouzané, France; (S.D.); (A.P.); (M.C.)
| | - Anne Thierry
- STLO, Institut Agro, INRAE, F-35000 Rennes, France; (A.T.); (M.-B.M.); (H.F.)
| | | | - Hélène Falentin
- STLO, Institut Agro, INRAE, F-35000 Rennes, France; (A.T.); (M.-B.M.); (H.F.)
| | - Audrey Pawtowski
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, Univ Brest, F-29280 Plouzané, France; (S.D.); (A.P.); (M.C.)
| | - Malika Barkat
- Laboratoire de Biotechnologie et Qualité des Aliments (BIOQUAL), Institut de la Nutrition, de l’Alimentation et des Technologies Agro-Alimentaires (INATAA), Université Frères Mentouri Constantine 1, Route de Ain-El-Bey, Constantine 25000, Algeria; (R.B.); (F.B.); (M.B.)
| | - Monika Coton
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, Univ Brest, F-29280 Plouzané, France; (S.D.); (A.P.); (M.C.)
| | - Jérôme Mounier
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, Univ Brest, F-29280 Plouzané, France; (S.D.); (A.P.); (M.C.)
- Correspondence: ; Tel.: +33-(0)2-90-91-51-21
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Quemener M, Dayras M, Frotté N, Debaets S, Le Meur C, Barbier G, Edgcomb V, Mehiri M, Burgaud G. Highlighting the Biotechnological Potential of Deep Oceanic Crust Fungi through the Prism of Their Antimicrobial Activity. Mar Drugs 2021; 19:md19080411. [PMID: 34436250 PMCID: PMC8399467 DOI: 10.3390/md19080411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/03/2022] Open
Abstract
Among the different tools to address the antibiotic resistance crisis, bioprospecting in complex uncharted habitats to detect novel microorganisms putatively producing original antimicrobial compounds can definitely increase the current therapeutic arsenal of antibiotics. Fungi from numerous habitats have been widely screened for their ability to express specific biosynthetic gene clusters (BGCs) involved in the synthesis of antimicrobial compounds. Here, a collection of unique 75 deep oceanic crust fungi was screened to evaluate their biotechnological potential through the prism of their antimicrobial activity using a polyphasic approach. After a first genetic screening to detect specific BGCs, a second step consisted of an antimicrobial screening that tested the most promising isolates against 11 microbial targets. Here, 12 fungal isolates showed at least one antibacterial and/or antifungal activity (static or lytic) against human pathogens. This analysis also revealed that Staphylococcus aureus ATCC 25923 and Enterococcus faecalis CIP A 186 were the most impacted, followed by Pseudomonas aeruginosa ATCC 27853. A specific focus on three fungal isolates allowed us to detect interesting activity of crude extracts against multidrug-resistant Staphylococcus aureus. Finally, complementary mass spectrometry (MS)-based molecular networking analyses were performed to putatively assign the fungal metabolites and raise hypotheses to link them to the observed antimicrobial activities.
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Affiliation(s)
- Maxence Quemener
- Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Université de Brest, F-29280 Plouzané, France; (M.Q.); (N.F.); (S.D.); (C.L.M.); (G.B.)
| | - Marie Dayras
- Marine Natural Products Team, Institut de Chimie de Nice, UMR 7272, Université Côte d’Azur, CNRS, 06108 Nice, France; (M.D.); (M.M.)
| | - Nicolas Frotté
- Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Université de Brest, F-29280 Plouzané, France; (M.Q.); (N.F.); (S.D.); (C.L.M.); (G.B.)
| | - Stella Debaets
- Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Université de Brest, F-29280 Plouzané, France; (M.Q.); (N.F.); (S.D.); (C.L.M.); (G.B.)
| | - Christophe Le Meur
- Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Université de Brest, F-29280 Plouzané, France; (M.Q.); (N.F.); (S.D.); (C.L.M.); (G.B.)
| | - Georges Barbier
- Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Université de Brest, F-29280 Plouzané, France; (M.Q.); (N.F.); (S.D.); (C.L.M.); (G.B.)
| | - Virginia Edgcomb
- Departments of Geology and Geophysics and Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA;
| | - Mohamed Mehiri
- Marine Natural Products Team, Institut de Chimie de Nice, UMR 7272, Université Côte d’Azur, CNRS, 06108 Nice, France; (M.D.); (M.M.)
| | - Gaëtan Burgaud
- Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Université de Brest, F-29280 Plouzané, France; (M.Q.); (N.F.); (S.D.); (C.L.M.); (G.B.)
- Correspondence: ; Tel.: +33-290915148
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Nodem Sohanang FS, Coton M, Debaets S, Coton E, Ngoune Tatsadjieu L, Mohammadou BA. Bacterial diversity of traditional fermented milks from Cameroon and safety and antifungal activity assessment for selected lactic acid bacteria. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2020.110635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Coton M, Bregier T, Poirier E, Debaets S, Arnich N, Coton E, Dantigny P. Production and migration of patulin in Penicillium expansum molded apples during cold and ambient storage. Int J Food Microbiol 2020; 313:108377. [DOI: 10.1016/j.ijfoodmicro.2019.108377] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/23/2019] [Accepted: 09/27/2019] [Indexed: 11/25/2022]
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Coton M, Auffret A, Poirier E, Debaets S, Coton E, Dantigny P. Production and migration of ochratoxin A and citrinin in Comté cheese by an isolate of Penicillium verrucosum selected among Penicillium spp. mycotoxin producers in YES medium. Food Microbiol 2019; 82:551-559. [DOI: 10.1016/j.fm.2019.03.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 11/28/2022]
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Mieszkin S, Hymery N, Debaets S, Coton E, Le Blay G, Valence F, Mounier J. Action mechanisms involved in the bioprotective effect of Lactobacillus harbinensis K.V9.3.1.Np against Yarrowia lipolytica in fermented milk. Int J Food Microbiol 2017; 248:47-55. [DOI: 10.1016/j.ijfoodmicro.2017.02.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 12/16/2016] [Accepted: 02/20/2017] [Indexed: 10/20/2022]
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Gillot G, Jany JL, Dominguez-Santos R, Poirier E, Debaets S, Hidalgo PI, Ullán RV, Coton E, Coton M. Genetic basis for mycophenolic acid production and strain-dependent production variability in Penicillium roqueforti. Food Microbiol 2016; 62:239-250. [PMID: 27889155 DOI: 10.1016/j.fm.2016.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 08/29/2016] [Accepted: 10/03/2016] [Indexed: 11/16/2022]
Abstract
Mycophenolic acid (MPA) is a secondary metabolite produced by various Penicillium species including Penicillium roqueforti. The MPA biosynthetic pathway was recently described in Penicillium brevicompactum. In this study, an in silico analysis of the P. roqueforti FM164 genome sequence localized a 23.5-kb putative MPA gene cluster. The cluster contains seven genes putatively coding seven proteins (MpaA, MpaB, MpaC, MpaDE, MpaF, MpaG, MpaH) and is highly similar (i.e. gene synteny, sequence homology) to the P. brevicompactum cluster. To confirm the involvement of this gene cluster in MPA biosynthesis, gene silencing using RNA interference targeting mpaC, encoding a putative polyketide synthase, was performed in a high MPA-producing P. roqueforti strain (F43-1). In the obtained transformants, decreased MPA production (measured by LC-Q-TOF/MS) was correlated to reduced mpaC gene expression by Q-RT-PCR. In parallel, mycotoxin quantification on multiple P. roqueforti strains suggested strain-dependent MPA-production. Thus, the entire MPA cluster was sequenced for P. roqueforti strains with contrasted MPA production and a 174bp deletion in mpaC was observed in low MPA-producers. PCRs directed towards the deleted region among 55 strains showed an excellent correlation with MPA quantification. Our results indicated the clear involvement of mpaC gene as well as surrounding cluster in P. roqueforti MPA biosynthesis.
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Affiliation(s)
- Guillaume Gillot
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Jean-Luc Jany
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Rebeca Dominguez-Santos
- Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, 24071 León, Spain; Instituto de Biotecnología de León (INBIOTEC), Avenida Real n°1, Parque Científico de León, 24006 León, Spain
| | - Elisabeth Poirier
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Stella Debaets
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Pedro I Hidalgo
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Ricardo V Ullán
- mAbxience, Upstream Production, Parque Tecnológico de León, Julia Morros s/n, Armunia, 24009, León, Spain
| | - Emmanuel Coton
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Monika Coton
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France.
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Burgaud G, Coton M, Jacques N, Debaets S, Maciel NOP, Rosa CA, Gadanho M, Sampaio JP, Casaregola S. Yamadazyma barbieri f.a. sp. nov., an ascomycetous anamorphic yeast isolated from a Mid-Atlantic Ridge hydrothermal site (−2300 m) and marine coastal waters. Int J Syst Evol Microbiol 2016; 66:3600-3606. [DOI: 10.1099/ijsem.0.001239] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Gaëtan Burgaud
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle de Brest Iroise, 29280 Plouzané, France
| | - Monika Coton
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle de Brest Iroise, 29280 Plouzané, France
| | - Noémie Jacques
- Micalis Institute, INRA, AgroParisTech, CIRM-Levures, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Stella Debaets
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle de Brest Iroise, 29280 Plouzané, France
| | - Natália O. P. Maciel
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Carlos A. Rosa
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Mário Gadanho
- Biosystems and Integrative Sciences Institute (BioISI), Edifício TecLabs, Campus da FCUL, Campo Grande, 1749-016 Lisboa, Portugal
| | - José Paulo Sampaio
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Serge Casaregola
- Micalis Institute, INRA, AgroParisTech, CIRM-Levures, Université Paris-Saclay, 78350 Jouy-en-Josas, France
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Gillot G, Jany JL, Coton M, Le Floch G, Debaets S, Ropars J, López-Villavicencio M, Dupont J, Branca A, Giraud T, Coton E. Insights into Penicillium roqueforti Morphological and Genetic Diversity. PLoS One 2015; 10:e0129849. [PMID: 26091176 PMCID: PMC4475020 DOI: 10.1371/journal.pone.0129849] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/12/2015] [Indexed: 11/18/2022] Open
Abstract
Fungi exhibit substantial morphological and genetic diversity, often associated with cryptic species differing in ecological niches. Penicillium roqueforti is used as a starter culture for blue-veined cheeses, being responsible for their flavor and color, but is also a common spoilage organism in various foods. Different types of blue-veined cheeses are manufactured and consumed worldwide, displaying specific organoleptic properties. These features may be due to the different manufacturing methods and/or to the specific P. roqueforti strains used. Substantial morphological diversity exists within P. roqueforti and, although not taxonomically valid, several technological names have been used for strains on different cheeses (e.g., P. gorgonzolae, P. stilton). A worldwide P. roqueforti collection from 120 individual blue-veined cheeses and 21 other substrates was analyzed here to determine (i) whether P. roqueforti is a complex of cryptic species, by applying the Genealogical Concordance Phylogenetic Species Recognition criterion (GC-PSR), (ii) whether the population structure assessed using microsatellite markers correspond to blue cheese types, and (iii) whether the genetic clusters display different morphologies. GC-PSR multi-locus sequence analyses showed no evidence of cryptic species. The population structure analysis using microsatellites revealed the existence of highly differentiated populations, corresponding to blue cheese types and with contrasted morphologies. This suggests that the population structure has been shaped by different cheese-making processes or that different populations were recruited for different cheese types. Cheese-making fungi thus constitute good models for studying fungal diversification under recent selection.
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Affiliation(s)
- Guillaume Gillot
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, Plouzané, France
| | - Jean-Luc Jany
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, Plouzané, France
| | - Monika Coton
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, Plouzané, France
| | - Gaétan Le Floch
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, Plouzané, France
| | - Stella Debaets
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, Plouzané, France
| | - Jeanne Ropars
- Origine, Structure, Evolution de la Biodiversité, UMR 7205 CNRS-MNHN, Muséum National d’Histoire Naturelle, CP39, Paris Cedex 05, France
- Ecologie, Systématique et Evolution, Université Paris-Sud, Orsay cedex, France
- CNRS, Orsay cedex, France
| | - Manuela López-Villavicencio
- Origine, Structure, Evolution de la Biodiversité, UMR 7205 CNRS-MNHN, Muséum National d’Histoire Naturelle, CP39, Paris Cedex 05, France
| | - Joëlle Dupont
- Origine, Structure, Evolution de la Biodiversité, UMR 7205 CNRS-MNHN, Muséum National d’Histoire Naturelle, CP39, Paris Cedex 05, France
| | - Antoine Branca
- Ecologie, Systématique et Evolution, Université Paris-Sud, Orsay cedex, France
- CNRS, Orsay cedex, France
| | - Tatiana Giraud
- Ecologie, Systématique et Evolution, Université Paris-Sud, Orsay cedex, France
- CNRS, Orsay cedex, France
| | - Emmanuel Coton
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et d’Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, Plouzané, France
- * E-mail:
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Mounier J, Gouëllo A, Keravec M, Le Gal S, Pacini G, Debaets S, Nevez G, Rault G, Barbier G, Héry-Arnaud G. Use of denaturing high-performance liquid chromatography (DHPLC) to characterize the bacterial and fungal airway microbiota of cystic fibrosis patients. J Microbiol 2014; 52:307-14. [PMID: 24535743 DOI: 10.1007/s12275-014-3425-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 10/15/2013] [Accepted: 10/21/2013] [Indexed: 11/28/2022]
Abstract
The aim of this study was to evaluate the use of denaturing high-performance liquid chromatography (DHPLC) to characterize cystic fibrosis (CF) airway microbiota including both bacteria and fungi. DHPLC conditions were first optimized using a mixture of V6, V7 and V8 region 16S rRNA gene PCR amplicons from 18 bacterial species commonly found in CF patients. Then, the microbial diversity of 4 sputum samples from 4 CF patients was analyzed using cultural methods, cloning/sequencing (for bacteria only) and DHPLC peak fraction collection/sequencing. DHPLC analysis allowed identifying more bacterial and fungal species than the classical culture methods, including well-recognized pathogens such as Pseudomonas aeruginosa. Even if a lower number of bacterial Operational Taxonomic Units (OTUs) was identified by DHPLC, it allowed to find OTUs unidentified by cloning/sequencing. The combination of both techniques permitted to correlate the majority of DHPLC peaks to defined OTUs. Finally, although Aspergillus fumigatus detection using DHPLC can still be improved, this technique clearly allowed to identify a higher number of fungal species versus classical culture-based methods. To conclude, DHPLC provided meaningful additional data concerning pathogenic bacteria and fungi as well as fastidious microorganisms present within the CF respiratory tract. DHPLC can be considered as a complementary technique to culture-dependent analyses in routine microbiological laboratories.
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Affiliation(s)
- Jérôme Mounier
- EA 3882-Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, Université de Brest, Brest, F-29200, France
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Maurice S, Coroller L, Debaets S, Vasseur V, Le Floch G, Barbier G. Modelling the effect of temperature, water activity and pH on the growth of Serpula lacrymans. J Appl Microbiol 2011; 111:1436-46. [DOI: 10.1111/j.1365-2672.2011.05161.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nevarez L, Vasseur V, Debaets S, Barbier G. Use of response surface methodology to optimise environmental stress conditions on Penicillium glabrum, a food spoilage mould. Fungal Biol 2010; 114:490-7. [PMID: 20943160 DOI: 10.1016/j.funbio.2010.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 10/29/2009] [Accepted: 03/24/2010] [Indexed: 11/18/2022]
Abstract
Fungi are ubiquitous microorganisms often associated with spoilage and biodeterioration of a large variety of foods and feedstuffs. Their growth may be influenced by temporary changes in intrinsic or environmental factors such as temperature, water activity, pH, preservatives, atmosphere composition, all of which may represent potential sources of stress. Molecular-based analyses of their physiological responses to environmental conditions would help to better manage the risk of alteration and potential toxicity of food products. However, before investigating molecular stress responses, appropriate experimental stress conditions must be precisely defined. Penicillium glabrum is a filamentous fungus widely present in the environment and frequently isolated in the food processing industry as a contaminant of numerous products. Using response surface methodology, the present study evaluated the influence of two environmental factors (temperature and pH) on P. glabrum growth to determine 'optimised' environmental stress conditions. For thermal and pH shocks, a large range of conditions was applied by varying factor intensity and exposure time according to a two-factorial central composite design. Temperature and exposure duration varied from 30 to 50 °C and from 10 min to 230 min, respectively. The effects of interaction between both variables were observed on fungal growth. For pH, the duration of exposure, from 10 to 230 min, had no significant effect on fungal growth. Experiments were thus carried out on a range of pH from 0.15 to 12.50 for a single exposure time of 240 min. Based on fungal growth results, a thermal shock of 120 min at 40 °C or a pH shock of 240 min at 1.50 or 9.00 may therefore be useful to investigate stress responses to non-optimal conditions.
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