These effects after 6 h could be partially correlated with the nonmotile phenotype of the ompR mutant, because a similar biofilm structure was observed with the nonmotile flhDC mutant. Furthermore, the reduction in the biofilm formation capacity of the ompR strain after 24 h might be correlated with the low adhesion abilities of this mutant. Reduced

adherence could be responsible for the less efficient attachment of cells and the loose structure of the biofilm. These results also suggest that the loss of YompC from the outer membrane MK-1775 mw of the ompR mutant contributed to the reduced biofilm formation by this strain. The regulation of motility and biofilm development by OmpR in strain Ye9 (serotype O9, biotype 2) seems to be different from that in Y. enterocolitica JB580v (serotype O8 biovar 1B). Kim et al. (2008) demonstrated the importance of OmpR in the motility of JB580v, but the ompR mutant of this strain, unlike that of Ye9, showed no impairment in flagella production. In addition, contrary to our findings, the OmpR of JB580v appeared not to perform a regulatory function in biofilm initiation and production. The Y. enterocolitica species selleck kinase inhibitor is quite heterogeneous with six distinct biovars (1A, 1B, 2, 3, 4 and 5) distinguished according to their pathogenicity, geographic distribution and ecological

niche (Bottone, 1999). It has been shown that the highly pathogenic strain 8081 of Y. enterocolitica biovar 1B contains an assortment Teicoplanin of genes not present in the biovar 2 and vice versa (Thomson et al., 2006). The results of the present study and those of Kim et al. (2008) suggest that genetic variation in separate

biovars of Y. enterocolitica may lead to different flagella and biofilm production phenotypes. In addition, this study shows that merely recording the many phenotypic changes caused by mutation of OmpR is insufficient to discern which of the functions of this regulator are responsible for certain behaviors of Y. enterocolitica cells that confer an advantage in a particular ecological niche. This work was supported by Warsaw University (grant BW 2007) and by the Polish Ministry of Science and Higher Education (grant N303 009 32/0537). “
“Kochi Core Center, Japan Agency for Marine – Earth Science and Technology (JAMSTEC), Nankoku, Kochi, Japan A total of 71 isolates were collected from lake sediment and soil surrounding lakes in the Skarvsnes area, Antarctica. Based on ITS region sequence similarity, these isolates were classified to 10 genera. Twenty-three isolates were categorized as ascomycetous fungi from five genera (Embellisia, Phoma, Geomyces, Tetracladium or Thelebolus) and 48 isolates were categorized as basidiomycetous fungi in five genera (Mrakia, Cryptococcus, Dioszegia, Rhodotorula or Leucosporidium). Thirty-five percent of culturable fungi were of the genus Mrakia. Eighteen isolates from eight genera were selected and tested for both antifreeze activity and capacity for growth under temperatures ranging from −1 to 25 °C.