RT Journal Article SR Electronic(1) A1 Dalisay, Doralyn S. A1 Webb, Jeremy S. A1 Scheffel, André A1 Svenson, Charles A1 James, Sally A1 Holmström, Carola A1 Egan, Suhelen A1 Kjelleberg, StaffanYR 2006 T1 A mannose-sensitive haemagglutinin (MSHA)-like pilus promotes attachment of Pseudoalteromonas tunicata cells to the surface of the green alga Ulva australis JF Microbiology, VO 152 IS 10 SP 2875 OP 2883 DO https://doi.org/10.1099/mic.0.29158-0 PB Microbiology Society, SN 1465-2080, AB This study demonstrates that attachment of the marine bacterium Pseudoalteromonas tunicata to the cellulose-containing surface of the green alga Ulva australis is mediated by a mannose-sensitive haemagglutinin (MSHA-like) pilus. We have identified an MSHA pilus biogenesis gene locus in P. tunicata, termed mshI1I2JKLMNEGFBACDOPQ, which shows significant homology, with respect to its genetic characteristics and organization, to the MSHA pilus biogenesis gene locus of Vibrio cholerae. Electron microscopy studies revealed that P. tunicata wild-type cells express flexible pili peritrichously arranged on the cell surface. A P. tunicata mutant (SM5) with a transposon insertion in the mshJ region displayed a non-piliated phenotype. Using SM5, it has been demonstrated that the MSHA pilus promotes attachment of P. tunicata wild-type cells in polystyrene microtitre plates, as well as to microcrystalline cellulose and to the living surface of U. australis. P. tunicata also demonstrated increased pilus production in response to cellulose and its monomer constituent cellobiose. The MSHA pilus thus functions as a determinant of attachment in P. tunicata, and it is proposed that an understanding of surface sensing mechanisms displayed by P. tunicata will provide insight into specific ecological interactions that occur between this bacterium and higher marine organisms., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.29158-0