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Benhasna S, Boudemagh A. Alternative protocol leading to rapid identification of Actinomycetes isolated from Algerian desertic soil by MALDI-TOF mass spectrometry. J Microbiol Methods 2024; 223:106984. [PMID: 38955305 DOI: 10.1016/j.mimet.2024.106984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 06/19/2024] [Accepted: 06/29/2024] [Indexed: 07/04/2024]
Abstract
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is the first-line method for the rapid identification of most cultured microorganisms. As for Streptomyces strains, MALDI-TOF MS identification is complicated by the characteristic incrustation of colonies in agar and the strong cell wall of Actinomycetes cells requiring the use of alternative protein extraction protocols. In this study, we developed a specific protocol to overcome these difficulties for the MALDI-TOF MS identification of Actinomycetes made on solid medium. This protocol includes incubation of colony removed from agar plate with the beta-agarase enzyme, followed by a mechanical lysis and two washes by phosphate buffer and ethanol. Twenty-four Streptomyces and two Lentzea strains isolated from Algerian desertic soils were first identified by 16S rRNA sequencing as gold standard method, rpoB gene was used as a secondary gene target when 16S rRNA did not allow species identification. In parallel the isolates were identified by using the MALDI-TOF MS protocol as reported. After the expansion of the database with the inclusion of this MSPS, the strains were analyzed again in MALDI Biotyper, and all were identified. This work demonstrates that the rapid identification of Actinomycetes can be obtained without protein extraction step frequently used in MALDI-TOF mass spectrometry with this type of microorganisms.
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Affiliation(s)
- Sarra Benhasna
- Laboratory of Molecular and Cellular Biology, Constantine1-Frères Mentouri University, Chaâbat Erssas Campus, Ain El Bey Road, 25000 Constantine, Algeria; Department of Microbiology, Constantine1-Frères Mentouri University, Ain El Bey Road, 25000 Constantine, Algeria.
| | - Allaoueddine Boudemagh
- Laboratory of Molecular and Cellular Biology, Constantine1-Frères Mentouri University, Chaâbat Erssas Campus, Ain El Bey Road, 25000 Constantine, Algeria
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Calabrese V, Schmitz-Afonso I, Riah-Anglet W, Trinsoutrot-Gattin I, Pawlak B, Afonso C. Direct introduction MALDI FTICR MS based on dried droplet deposition applied to non-targeted metabolomics on Pisum Sativum root exudates. Talanta 2023; 253:123901. [PMID: 36088848 DOI: 10.1016/j.talanta.2022.123901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 12/13/2022]
Abstract
Non-targeted metabolomic approaches based on direct introduction (DI) through a soft ionization source are nowadays used for large-scale analysis and wide cover-up of metabolites in complex matrices. When coupled with ultra-high-resolution Fourier-Transform ion cyclotron resonance (FTICR MS), DI is generally performed through electrospray (ESI), which, despite the great analytical throughput, can suffer of matrix effects due to residual salts or charge competitors. In alternative, matrix assisted laser desorption ionization (MALDI) coupled with FTICR MS offers relatively high salt tolerance but it is mainly used for imaging of small molecule within biological tissues. In this study, we report a systematic evaluation on the performance of direct introduction ESI and MALDI coupled with FTICR MS applied to the analysis of root exudates (RE), a complex mixture of metabolites released from plant root tips and containing a relatively high salt concentration. Classic dried droplet deposition followed by screening of best matrices and ratio allowed the selection of high ranked conditions for non-targeted metabolomics on RE. Optimization of MALDI parameters led to improved reproducibility and precision. A RE desalted sample was used for comparison on ionization efficiency of the two sources and ion enhancement at high salinity was highlighted in MALDI by spiking desalted solution with inorganic salts. Application of a true lyophilized RE sample exhibited the complementarity of the two sources and the ability of MALDI in the detection of undisclosed metabolites suffering of matrix effects in ESI mode.
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Affiliation(s)
- Valentina Calabrese
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 Rue Tesnières, 76821, Mont-Saint-Aignan, Cedex, France
| | - Isabelle Schmitz-Afonso
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 Rue Tesnières, 76821, Mont-Saint-Aignan, Cedex, France.
| | - Wassila Riah-Anglet
- UniLaSalle, AGHYLE Research Unit UP 2018.C101, Rouen Team, 76134 Mont-Saint Aignan, SFR Normandie Végétal FED 4277, 76000, Rouen, France
| | - Isabelle Trinsoutrot-Gattin
- UniLaSalle, AGHYLE Research Unit UP 2018.C101, Rouen Team, 76134 Mont-Saint Aignan, SFR Normandie Végétal FED 4277, 76000, Rouen, France
| | - Barbara Pawlak
- Laboratoire GlycoMEV UR 4358, Université de Rouen Normandie, SFR Normandie Végétal FED 4277, 76000, Rouen, France
| | - Carlos Afonso
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 Rue Tesnières, 76821, Mont-Saint-Aignan, Cedex, France
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