Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) was used for characterizing intact plasmalogen phospholipid molecules in beer-spoilage bacteria. Identification of intact plasmalogens was carried out using collision-induced dissociation and the presence of suitable marker molecular species, both qualitative and quantitative, was determined in samples containing the anaerobic bacteria Megasphaera and Pectinatus. Using selected ion monitoring (SIM), this method had a limit of detection at 1 pg for the standard, i.e. 1-(1Z-octadecenyl)-2-oleoyl-sn-glycero-3-phosphoethanolamine and be linear in the range of four orders of magnitude from 2 pg to 20 ng. This technique was applied to intact plasmalogen extracts from the samples of contaminated and uncontaminated beer without derivatization and resulted in the identification of contamination of beer by Megasphaera and Pectinatus bacteria. The limit of detection was about 830 cells of anaerobic bacteria, i.e. bacteria containing natural cyclopropane plasmalogenes (c-p-19:0/15:0), which is the majority plasmalogen located in both Megasphaera and Pectinatus. The SIM ESI-MS method has been shown to be useful for the analysis of low concentration of plasmalogens in all biological samples, which were contaminated with anaerobic bacteria, e.g. juice, not only in beer. Significance and impact of the study: Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) using collision-induced dissociation was used to characterize intact plasmalogen phospholipid molecules in beer-spoilage anaerobic bacteria Megasphaera and Pectinatus. Using selected ion monitoring (SIM), this method has a detection limit of 1 pg for the standard 1-(1Z-octadecenyl)-2-oleoyl-sn-glycero-3-phosphoethanolamine and is linear within four orders of magnitude (2 pg to 20 ng). The limit of detection was about 830 cells of bacteria containing natural cyclopropane plasmalogen (c-p-19:0/15:0). SIM ESI-MS method is useful for analyzing low concentrations of plasmalogens in biological samples contaminated with anaerobic bacteria, e.g. beer or juice.

• MeSH
• Spectrometry, Mass, Electrospray Ionization MeSH
• Limit of Detection MeSH
• Megasphaera classification   isolation & purification   metabolism   MeSH
• Pectinatus classification   isolation & purification   metabolism   MeSH
• Beer microbiology   MeSH
• Plasmalogens analysis   MeSH
• Food Microbiology methods   MeSH
• Tandem Mass Spectrometry MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The inter- and intraspecies variability of lactate dehydrogenase (ldh) gene was determined among the predominant ruminal lactate utilizing bacteria. Nearly complete nucleotide sequences of ldh gene, encoding NAD-dependent lactate dehydrogenase of three Megasphaera elsdenii and six Selenomonas ruminantium strains, were obtained and compared. Phylogenetic analyses revealed a limited variability between the ldh sequences studied. The majority of differences observed were silent mutations at the 3rd position of codons. Surprisingly, the intraspecies diversity of the ldh gene among S. ruminantium isolates was higher than the interspecies level between S. ruminantium and M. elsdenii, which strongly suggests the possibility of acquisition of this gene by horizontal gene transfer.

• MeSH
• Acidosis, Lactic metabolism   MeSH
• Rumen microbiology   MeSH
• Bacterial Proteins genetics   MeSH
• Point Mutation MeSH
• DNA, Bacterial genetics   chemistry   MeSH
• Phylogeny MeSH
• Genetic Variation MeSH
• L-Lactate Dehydrogenase genetics   MeSH
• Megasphaera MeSH
• Molecular Sequence Data MeSH
• Sequence Analysis, DNA MeSH
• Sequence Homology MeSH
• Selenomonas MeSH
• Cluster Analysis MeSH
• Animals MeSH
• Check Tag
• Animals MeSH

• MeSH
• Drug Resistance, Microbial genetics   immunology   MeSH
• Rumen microbiology   MeSH
• Financing, Government MeSH
• Genome, Bacterial MeSH
• Megasphaera genetics   growth & development   MeSH
• Sheep microbiology   MeSH
• Polymerase Chain Reaction methods   utilization   MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Cattle microbiology   MeSH
• Animals MeSH
• Check Tag
• Cattle microbiology   MeSH
• Animals MeSH

• MeSH
• Acidaminococcus MeSH
• Acinetobacter MeSH
• Bacteria MeSH
• Gram-Negative Aerobic Rods and Cocci MeSH
• Kingella MeSH
• Clinical Laboratory Techniques MeSH
• Megasphaera MeSH
• Moraxella MeSH
• Neisseria MeSH
• Veillonella MeSH
• Publication type
• Handbook MeSH

• Conspectus
• Mikrobiologie
• NML Fields
• mikrobiologie, lékařská mikrobiologie
• infekční lékařství