Transport of gases and liquids through dense microbial cell aggregates cultured within hollow fiber membrane bioreactors

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5482231

Libicki, S B

The transport properties of liquids and dissolved gases in microbial cell aggregates were examined. An annular hollow fiber membrane bioreactor designed for this purpose, allowed a cell aggregate of well-defined geometry to be cultured between two retaining fibers. The transport of an inert substance through a lamellar annular hollow fiber reactor has been modeled. Calculations showed that Starling flow, a weak toroidal flow in the reactor, may account for a large fraction of the solute transport. The theoretical predictions were verified experimentally. The effective diffusive permeability of a dissolved tracer (nitrous oxide) was measured in dense microbial cell aggregates (Escherichia coli) ranging from 15% to 95% cell volume fraction. The results showed that the diffusive permeability is a monotonically decreasing function of cell volume fraction and can be described by the Hashin-Shtrikman bounds on transport in a two phase material. Using these bounds, the effective diffusive permeability of nitrous oxide in E. coli cells at 37/sup 0/C was estimated to be 8.6 x 10/sup -9/ mol/m s or 0.24 +/- 0.03 that of the diffusive permeability of the surrounding interstitial fluid. Similar measurements of the diffusive permeability of nitrous oxide in artificial aggregates (compacted cells) and disrupted microbial cells yielded virtually identical results, showing that cell structure and viability have only a small effect. The Darcy permeability of the same microbial aggregates, measured under very low flow conditions, was found to be only weakly dependent on cell volume fraction. Electron micrographs indicate that this was due to clustering of the cells which increased the effective particle size within the cell aggregate.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 5482231
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
59 BASIC BIOLOGICAL SCIENCES
BIOREACTORS
DESIGN
MASS TRANSFER
DIFFUSION
ESCHERICHIA COLI
FIBERS
FLOW MODELS
MEMBRANES
NITROUS OXIDE
PERMEABILITY
BACTERIA
CHALCOGENIDES
MATHEMATICAL MODELS
MICROORGANISMS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)
550700 - Microbiology