title: Biofilm formation by Escherichia coli in hypertonic sucrose media.
abstract: High osmotic environments produced by NaCl or sucrose have been used as reliable and traditional methods of food preservation. We tested, Escherichia coli as an indicator of food-contaminating bacterium, to determine if it can form biofilm in a hyperosmotic environment. E. coli K-12 IAM1264 did not form biofilm in LB broth that contained 1 M NaCl. However, the bacterium formed biofilm in LB broth that contained 1 M sucrose, although the planktonic growth was greatly suppressed. The biofilm, formed on solid surfaces, such as titer-plate well walls and glass slides, solely around the air-liquid interface. Both biofilm forming cells and planktonic cells in the hypertonic medium adopted a characteristic, fat and filamentous morphology with no FtsZ rings, which are a prerequisite for septum formation. Biofilm forming cells were found to be alive based on propidium iodide staining. The presence of 1 M sucrose in the food environment is not sufficient to prevent biofilm formation by E. coli.
authors.affiliation: Department of Food Science and Technology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan.
authors.forename: Taketo
authors.initials: T
authors.lastname: Kawarai
authors.forename: Soichi
authors.initials: S
authors.lastname: Furukawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Narisawa
authors.forename: Chisato
authors.initials: C
authors.lastname: Hagiwara
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ogihara
authors.forename: Makari
authors.initials: M
authors.lastname: Yamasaki
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms; D003470:Culture Media; D048168:Escherichia coli K12 / Q000502:physiology*; D005519:Food Preservation; D006982:Hypertonic Solutions; D009995:Osmosis; D044367:Phase Transition; D012965:Sodium Chloride / Q000737:chemistry*; D013395:Sucrose / Q000737:chemistry*
chemical_list: D003470:Culture Media; D006982:Hypertonic Solutions; D012965:Sodium Chloride; D013395:Sucrose