Visible biofilm remained after draining the tubing for the reference strain (DAY286) and the hwp1/hwp1 mutant, while no visible biofilm remained for the bcr1/bcr1 mutant. There was some residual NVP-BSK805 datasheet biofilm left after draining the tubing colonized by the als3/als3 mutant (before the ethanol rinse steps), but the adhesion to the surface was clearly much less than the reference strain. SEM images of the tubing

in the second row indicated that multilayer biofilm remained on the surface of the tubing for the reference strain and the hpw1/hpw1 mutant, while very few cells could be found for the bcr1/bcr1 and als3/als3 mutants. The most heavily colonized regions that were found are shown. (The ethanol dehydration removed all visible biofilm from the tubing for bcr1/bcr1 and als3/als3 mutant strains). Comparison of the firmly and loosely attached biofilm suggests that glycosylation, vesicle trafficking and transport contribute to the adhesive phenotype As shown in Figure (2d and 2e) a visible multilayered biofilm structure withstands MEK inhibitor the substantial shear force applied by draining the tubing for biofilms cultured for 1 h. A portion of the 1 h biofilms is typically removed from the surface

by this procedure. These two subpopulations are referred to as the 1 h firmly (1h F) and 1 h loosely (1h L) attached biofilm. We reasoned that comparing the transcriptional profiles of these two subpopulations might uncover genes that were subsequently differentially regulated to mediate detachment in our flow model. The comparison of 1h F and 1h L biofilms revealed 22 upregulated and 3 repressed transcripts (see Additional file 1). Upregulated genes fell into process ontological categories of vesicular trafficking, glycosylation

and transport. RT-qPCR confirmed Fenbendazole the changes in transcript levels of some genes enriched in glycosylation and vesicle trafficking functions that exhibited relatively small fold changes (Table 2). The distinct pattern of expression of these genes within the context of the time course analysis is discussed in the next section. Table 2 Genes up regulated in the 1hF/1hL comparison Gene Orf Microarray1 RT Q-PCR2 Vesicular trafficking SSS1 orf19.6828.1 1.56 1.63 ± 0.01 ERV29 orf19.4579 1.60 3.73 ± 0.41 SEC22 orf19.479.2 1.44 2.24 ± 0.1 EMP24 orf19.6293 1.44 1.24 ± 0.1 CHS7 orf19.2444 1.44 1.65 ± 0.12 YOP1 orf19.2168.3 1.55 1.67 ± 0.15 Glycosylation PMT4 orf19.4109 1.63 ND3 DPM2 orf19.1203.1 1.61 2.33 ± 0.11 DPM3 orf19.4600.1 1.48 2.12 ± 0.2 WBP1 orf19.2298 1.44 4.75 ± 0.11 Transport ADP1 orf19.459 1.68 ND CTR1 orf19.3646 1.54 ND ADY2 orf19.1224 1.69 ND TNA1 orf19.2397 1.68 ND ALP1 orf19.2337 1.58 ND 1Average fold change 2Log2 ratios. Each value is the mean ± standard deviation of two independent experiments each with three replicates.