title: Characteristics of volatile organic compounds produced from five pathogenic bacteria by headspace-solid phase micro-extraction/gas chromatography-mass spectrometry.
abstract: The characteristics of volatile compounds from five different bacterial species, Escherichia coli O157:H7, Salmonella Enteritidis, Shigella flexneri, Staphylococcus aureus, and Listeria monocytogenes, growing, respectively, in trypticase soy broth were monitored by headspace solid-phase micro-extraction/gas chromatography-mass spectrometry. The results showed that most volatile organic compounds (VOCs) of five pathogens started to increase after the sixth to tenth hour. Methyl ketones and long chain alcohols were representative volatiles for three Gram-negative bacteria. The especially high production of indole was characterized to E. coli O157:H7. The production of 3-hydroxy-2-butanone was indicative of the presence of two Gram-positive bacteria. Both 3-methyl-butanoic acid and 3-methyl-butanal were unique biomarkers for S. aureus. The population dynamics of individual pathogen could be monitored using the accumulation of VOCs correlated with its growth. And these five pathogens could be distinguishable though principle component analysis of 18 volatile metabolites. Moreover, the mixed culture of S. aureus and E. coli O157:H7 was also investigated. The levels of 3-methyl-butanal and 3-methyl-butanoic acid were largely reduced; while the level of indole almost unchanged and correlated with E. coli O157:H7 growth very well. The characteristics of volatiles from the five foodborne pathogens could lay a fundamental basis for further research into pathogen contamination control by detecting volatile signatures of pathogens.
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
authors.forename: Junni
authors.initials: J
authors.lastname: Tang
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Shi
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Tang
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000093:Acetoin / Q000378:metabolism; D000438:Alcohols / Q000737:chemistry; D015415:Biomarkers / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D019453:Escherichia coli O157 / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D005516:Food Microbiology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007211:Indoles / Q000378:metabolism; D007659:Ketones / Q000737:chemistry; D008089:Listeria monocytogenes / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D012477:Salmonella enteritidis / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D012763:Shigella flexneri / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000438:Alcohols; D015415:Biomarkers; D003470:Culture Media; D007211:Indoles; D007659:Ketones; D055549:Volatile Organic Compounds; C030374:indole; D000093:Acetoin
keywords: HS-SPME/GC-MS; VOCs; differentiation; pathogenic bacteria; time-dependent production