title: Large scale MALDI-TOF MS based taxa identification to identify novel pigment producers in a marine bacterial culture collection.
abstract: A challenge in the rational exploitation of microbial culture collections is to avoid superfluous testing of replicas. MALDI-TOF MS has been shown to be an efficient dereplication tool as it can be used to discriminate between bacterial isolates at the species level. A bacterial culture collection of more than 10,000 heterotrophic marine bacterial isolates from sea-water surface layers of the Norwegian Trondheimsfjord and neighbouring coastal areas has been established. A sub-collection of pigmented isolates was earlier screened for novel carotenoids with UVA-Blue light absorbing properties. This was a comprehensive analytical task and it was observed that a significant number of extracts with identical pigment profile were recovered. Hence, this study was undertaken to explore the use of MALDI-TOF MS as a dereplication tool to quickly characterize the bacterial collection. Furthermore, LC-DAD-MS analysis of pigment profiles was performed to check if pigment profile diversity was maintained among isolates kept after the potential MALDI-TOF MS selection step. Four hundred isolates comprising both pigmented and non-pigmented isolates were used for this study. The resulting MALDI-TOF MS dendrogram clearly identified a diversity of different taxa and these were supported by the pigment profile clustering, thus linking the pigment production as species-specific properties. Although one exception was found, it can be concluded that MALDI-TOF MS dereplication is a promising pre-screening tool for more efficient screening of microbial culture collection containing pigments with potential novel properties.
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491, Trondheim, Norway.
authors.forename: Marit H
authors.initials: MH
authors.lastname: Stafsnes
authors.forename: Marius
authors.initials: M
authors.lastname: Dybwad
authors.forename: Anders
authors.initials: A
authors.lastname: Brunsvik
authors.forename: Per
authors.initials: P
authors.lastname: Bruheim
mesh_terms: D001419:Bacteria / Q000737:chemistry* / Q000145:classification* / Q000378:metabolism; D016000:Cluster Analysis; D009664:Norway; D010802:Phylogeny; D010860:Pigments, Biological / Q000032:analysis; D012623:Seawater / Q000382:microbiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D010860:Pigments, Biological