Blar i forfatter Artikler, rapporter og annet (kjemi) "Hansen, Hilde"
-
The alternative sigma factor RpoQ regulates colony morphology, biofilm formation and motility in the fish pathogen Aliivibrio salmonicida
Khider, Miriam; Willassen, Nils Peder; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-12)<i>Background</i>: Quorum sensing (QS) is a cell-to cell communication system that bacteria use to synchronize activities as a group. LitR, the master regulator of QS in <i>Aliivibrio salmonicida</i>, was recently shown to regulate activities such as motility, rugosity and biofilm formation in a temperature dependent manner. LitR was also found to be a positive regulator of <i>rpoQ</i>. RpoQ ... -
The autoinducer synthases LuxI and AinS are responsible for temperature-dependent AHL production in the fish pathogen Aliivibrio salmonicida
Hansen, Hilde; Purohit, Amit Anand; Leiros, Hanna-Kirsti S.; Johansen, Jostein; Kellermann, Stefanie J.; Bjelland, Ane Mohn; Willassen, Nils Peder (Journal article; Tidsskriftartikkel, 2015-03-24)Background: Quorum sensing (QS) is a cell-to-cell communication system used by bacteria to regulate activities such as virulence, bioluminescence and biofilm formation. The most common QS signals in Gram-negative bacteria are N-acyl-homoserine lactones (AHLs). Aliivibrio salmonicida is the etiological agent of cold water vibriosis in Atlantic salmon, a disease which occurs mainly during seasons ... -
Complete genome sequence of Photobacterium ganghwense C2.2: A new polyhydroxyalkanoate production candidate
Lascu, Irina; Mereuță, Ioana; Chiciudean, Iulia; Hansen, Hilde; Avramescu, Sorin Marius; Tănase, Ana-Maria; Stoica, Ileana (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-01)Polyhydroxyalkanoates (PHAs) are biodegradable bioplastics that can be manufactured sustainably and represent a promising green alternative to petrochemical-based plastics. Here, we describe the complete genome of a new marine PHA-producing bacterium—Photobacterium ganghwense (strain C2.2), which we have isolated from the Black Sea seashore. This new isolate is psychrotolerant and accumulates PHA ... -
Differential expression profiling of ΔlitR and ΔrpoQ mutants reveals insight into QS regulation of motility, adhesion and biofilm formation in Aliivibrio salmonicida
Khider, Miriam; Hjerde, Erik; Hansen, Hilde; Willassen, Nils Peder (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-15)<i>Background</i>: The coordination of group behaviors in bacteria is achieved by a cell-cell signaling process called quorum sensing (QS). QS is an intercellular communication system, which synchronously controls expression of a vast range of genes in response to changes in cell density and is mediated by autoinducers that act as extracellular signals. <i>Aliivibrio salmonicida</i>, the causative ... -
Exploring the transcriptome of luxI- and ΔainS mutants and the impact of N-3-oxo-hexanoyl-L- and N-3-hydroxy- decanoyl-L-homoserine lactones on biofilm formation in Aliivibrio salmonicida
Khider, Miriam; Hansen, Hilde; Hjerde, Erik; Johansen, Jostein A; Willassen, Nils Peder (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-30)<i>Background</i>: Bacterial communication through quorum sensing (QS) systems has been reported to be important in coordinating several traits such as biofilm formation. In <i>Aliivibrio salmonicida</i> two QS systems the LuxI/R and AinS/R, have been shown to be responsible for the production of eight acyl-homoserine lactones (AHLs) in a cell density dependent manner. We have previously ... -
High natural PHA production from acetate in Cobetia sp. MC34 and Cobetia marina DSM 4741T and in silico analyses of the genus specific PhaC2 polymerase variant
Christensen, Mikkel; Jablonski, Piotr; Altermark, Bjørn; Irgum, Knut; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-20)Background: Several members of the bacterial Halomonadacea family are natural producers of polyhydroxyalkanoates (PHA), which are promising materials for use as biodegradable bioplastics. Type-strain species of Cobetia are designated PHA positive, and recent studies have demonstrated relatively high PHA production for a few strains within this genus. Industrially relevant PHA producers may therefore ... -
The immediate global responses of Aliivibrio salmonicida to iron limitations
Thode, Sunniva Katharina; Kahlke, Tim; Robertsen, Espen Mikal; Hansen, Hilde; Haugen, Peik (Journal article; Tidsskriftartikkel, 2015-02-04)<i>Background</i>: Iron is an essential micronutrient for all living organisms, and virulence and sequestration of iron in pathogenic bacteria are believed to be correlated. As a defence mechanism, potential hosts therefore keep the level of free iron inside the body to a minimum. In general, iron metabolism is well studied for some bacteria (mostly human or animal pathogens). However, this area ... -
Presence of acyl-homoserine lactones in 57 members of the Vibrionaceae family
Purohit, Amit Anand; Johansen, Jostein a; Hansen, Hilde; Leiros, Hanna-Kirsti S.; Kashulin, Alexander; Karlsen, Christian; Smalås, Arne O.; Haugen, Peik; Willassen, Nils Peder (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-05-31)Aims: The aim of this study was to use a sensitive method to screen and quantify 57 Vibrionaceae strains for the production of acyl-homoserine lactones (AHLs) and map the resulting AHL profiles onto a host phylogeny.<p> <p>Methods and Results: We used a high-performance liquid chromatography– tandem mass spectrometry (HPLC-MS/MS) protocol to measure AHLs in spent media after bacterial growth. ... -
Towards high-throughput screening (HTS) of polyhydroxyalkanoate (PHA) production via Fourier transform infrared (FTIR) spectroscopy of Halomonas sp. R5-57 and Pseudomonas sp. MR4-99
Christensen, Mikkel; Chiciudean, Iulia; Jablonski, Piotr; Tănase, Ana-Maria; Shapaval, Volha; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-08) -
A unique class I polyhydroxyalkanoate synthase (PhaC) from Brevundimonas sp. KH11J01 exists as a functional trimer: A comparative study with PhaC from Cupriavidus necator H16
Assefa, Netsanet Gizaw; Hansen, Hilde; Altermark, Bjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-06)Polyhydroxyalkanoates (PHAs) are natural biodegradable polyesters that are produced by numerous prokaryotic microorganisms primarily as a carbon- and energy reserve. The PhaC enzyme catalyzes the last step in the PHA biosynthesis pathway and synthesizes PHA polymers from hydroxyalkanoic acids. A type I PhaC from a PHAproducing marine bacterium Brevundimonas sp. KH11J01 (BrPhaC) was identified, ...