title: Peptide diversity in strains of the cyanobacterium Microcystis aeruginosa isolated from Portuguese water supplies.
abstract: Strains of the cyanobacterium Microcystis aeruginosa were isolated into pure culture from a variety of lakes, rivers, and reservoirs in Portugal. Samples were tested with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) to investigate the presence of various peptide groups including aeruginosins, microginins, anabaenopeptins, cyanopeptilins, microcystins, and microviridins and other peptide-like compounds. Binary data, based on the presence and absence of different peptide groups, were analyzed by phylogenetic inference. DNA was also extracted from the samples and tested using a range of primers. Those strains that gave positive results for a Microcystis-specific primer pair were further analyzed for the presence of genes linked to the biosynthesis of microginin and microcystin. The results showed that a wide range of microcystin forms were produced by the strains among which MC-LR, -FR, -RR, -WR, and -YR were the most common. The peptide profiles obtained from the MALDI analysis were assessed using cluster analysis which resulted in the formation of distinct groups or chemotypes.
authors.affiliation: Centro Interdisciplinar de Investigação Marinha e Ambiental, CIIMAR/CIMAR-LA, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Martins
authors.forename: Martin L
authors.initials: ML
authors.lastname: Saker
authors.forename: Cristiana
authors.initials: C
authors.lastname: Moreira
authors.forename: Martin
authors.initials: M
authors.lastname: Welker
authors.forename: Jutta
authors.initials: J
authors.lastname: Fastner
authors.forename: Vitor M
authors.initials: VM
authors.lastname: Vasconcelos
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D047630:Depsipeptides / Q000096:biosynthesis / Q000737:chemistry; D052998:Microcystins / Q000096:biosynthesis / Q000737:chemistry; D046931:Microcystis / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology; D009842:Oligopeptides / Q000096:biosynthesis / Q000737:chemistry; D010452:Peptide Biosynthesis; D010453:Peptide Synthases / Q000235:genetics; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011174:Portugal; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D047630:Depsipeptides; D052998:Microcystins; D009842:Oligopeptides; D010455:Peptides; D010453:Peptide Synthases; C432283:microcystin synthetase A