Distribution of Cells between Solid/Liquid and Liquid/Liquid Interfaces

• Published in: Biotechnology progress Vol. 20; no. 1; pp. 289 - 298
• Main Authors: Bermudez, Ondrea, Forciniti, Daniel
• Format: Journal Article
• Language: English
• Published: USA American Chemical Society 2004; American Institute of Chemical Engineers
• Subjects: ATP; Bacterial Adhesion - physiology; Biological and medical sciences; Biotechnology; Cell Adhesion; Cell Count - methods; Cell Culture Techniques - methods; Cell Division; Durapatite - chemistry; Fundamental and applied biological sciences. Psychology; Growth curves; Hydroxyapatite; Liquids; Nutrient availability; Phase Transition; Polyethylene glycol; Polymers - chemistry; Q1; Q2; Salts; Salts - chemistry; Scanning electron microscopy; Solutions - chemistry; Streptococcus sanguinis; Streptococcus sanguis - cytology; Streptococcus sanguis - physiology; Surface Properties; Liquid solid; Distribution; Liquid liquid interface
• ISSN: 8756-7938; 1520-6033
• DOI: 10.1021/bp0201253

The use of aqueous two‐phase systems (ATPSs) and each systemapos;s individual phase‐forming species to prevent Streptococcus sanguis attachment onto hydroxyapatite discs was explored. The strategy that we followed was to attach the cells to a solid surface in the presence of an additional interface. Conditions under which, simultaneously, the phase‐forming species form two phases and the cells proliferate were identified. Growth curves were constructed in the presence of various polymers and salts commonly used to prepare ATPSs. Several aqueous two‐phase systems were selected such that bacterial growth was comparable to that observed in pure medium. Cells were allowed to attach to hydroxyapatite discs for 7 days in the presence of varying concentrations of media, media with polymer, media with salt, and media with ATPS. Streptococcus sanguis attachment to the disks was evaluated by scanning electron microscopy. The addition of a PEG/Na2SO4 ATPS to high concentrations of yeast‐tryptone (YT) media (>65%) and of a PEG/MgSO4 ATPS to nutrient‐limited media reduces surface coverage of S. sanguis to less than 10%. Comparison of the attachment levels for the systems containing PEG/Na2SO4 to media containing the individual phase‐forming species and to the YT reference systems indicated that nutrient availability did not affect attachment.