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Pulat M, Eksi H, Abbasoglu U. Fluconazole release from hydrogels including acrylamide-acrylic acid-itaconic acid, and their microbiological interactions. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 19:193-205. [DOI: 10.1163/156856208783432480] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Mehlika Pulat
- a Gazi Universitesi Fen, Edebiyat Fakültesi, Kimya Bölümü, Teknikokullar, Ankara, Turkey
| | - Haslet Eksi
- b Gazi Universitesi Fen, Edebiyat Fakültesi, Kimya Bölümü, Teknikokullar, Ankara, Turkey
| | - Ufuk Abbasoglu
- c Gazi Universitesi Fen, Edebiyat Fakültesi, Kimya Bölümü, Teknikokullar, Ankara, Turkey
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Xu X, Stewart PS, Chen X. Transport limitation of chlorine disinfection of Pseudomonas aeruginosa entrapped in alginate beads. Biotechnol Bioeng 2009; 49:93-100. [PMID: 18623558 DOI: 10.1002/(sici)1097-0290(19960105)49:1<93::aid-bit12>3.0.co;2-c] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
An artificial biofilm system consisting of Pseudomonas aeruginosa entrapped in alginate and agarose beads was used to demonstrate transport limitation of the rate of disinfection of entrapped bacteria by chlorine. Alginate gel beads with or without entrapped bacteria consumed chlorine. The specific rate of chlorine consumption increased with increasing cell loading in the gel beads and decreased with increasing bead radius. The value of an observable modulus comparing the rates of reaction and diffusion ranged from less than 0.1 to 8 depending on the bead radius and cell density. The observable modulus was largest for large (3-mm-diameter) beads with high cell loading (1.8 x 10(9) cfu/cm(3)) and smallest for small beads (0.5 mm diameter) with no cells added. A chlorine microelectrode was used to measure chlorine concentration profiles in agarose beads (3.0 mm diameter). Chlorine fully penetrated cell-free agarose beads rapidly; the concentration of chlorine at the bead center reached 50% of the bulk concentration within approximately 10 min after immersion in chlorine solution. When alginate and bacteria were incorporated into an agarose bead, pronounced chlorine concentration gradients persisted within the gel bead. Chlorine did gradually penetrate the bead, but at a greatly retarded rate; the time to reach 50% of the bulk concentration at the bead center was approximately 46 h. The overall rate of disinfection of entrapped bacteria was strongly dependent on cell density and bead radius. Small beads with low initial cell loading (0.5 mm diameter, 1.1 x 10(7) cfu/cm(3)) experienced rapid killing; viable cells could not be detected (<1.6 x 10(5) cfu/cm(3)) after 15 min of treatment in 2.5 mg/L chlorine. In contrast, the number of viable cells in larger beads with a higher initial cell density (3.0 mm diameter, 2.2 x 10(9) cfu/cm(3)) decreased only about 20% after 6 h of treatment in the same solution. Spatially nonuniform killing of bacteria within the beads was demonstrated by measuring the transient release of viable cells during dissolution of the beads. Bacteria were killed preferentially near the bead surface. Experimental results were consistent with transport limitation of the penetration of chlorine into the artificial biofilm arising from a reaction-diffusion interaction. The methods reported here provide tools for diagnosing the mechanism of biofilm resistance to reactive antimicrobial agents in such applications as the treatment of drinking and cooling waters.
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Affiliation(s)
- X Xu
- Center for Biofilm Engineering, Montana Bozeman, Montana 59717, USA
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Ha J, Engler CR, Lee SJ. Determination of diffusion coefficients and diffusion characteristics for chlorferon and diethylthiophosphate in Ca-alginate gel beads. Biotechnol Bioeng 2008; 100:698-706. [PMID: 18080347 DOI: 10.1002/bit.21761] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Diffusion characteristics of chlorferon and diethylthiophosphate (DETP) in Ca-alginate gel beads were studied to assist in designing and operating bioreactor systems. Diffusion coefficients for chlorferon and DETP in Ca-alginate gel beads determined at conditions suitable for biodegradation studies were 2.70 x 10(-11) m(2)/s and 4.28 x 10(-11) m(2)/s, respectively. Diffusivities of chlorferon and DETP were influenced by several factors, including viscosity of the bulk solution, agitation speed, and the concentrations of diffusing substrate and immobilized cells. Diffusion coefficients increased with increasing agitation speed, probably due to poor mixing at low speed and some attrition of beads at high speeds. Diffusion coefficients also increased with decreasing substrate concentration. Increased cell concentration in the gel beads caused lower diffusivity. Theoretical models to predict diffusivities as a function of cell weight fraction overestimated the effective diffusivities for both chlorferon and DETP, but linear relations between effective diffusivity and cell weight fraction were derived from experimental data. Calcium-alginate gel beads with radii of 1.65-1.70 mm used in this study were not subject to diffusional limitations: external mass transfer resistances were negligible based on Biot number calculations and effectiveness factors indicated that internal mass transfer resistance was negligible. Therefore, the degradation rates of chlorferon and DETP inside Ca-alginate gel beads were reaction-limited.
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Affiliation(s)
- Jiyeon Ha
- Samsung Engineering Co. Ltd., R&D Center, Seoul, Republic of Korea
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5
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Schepers AW, Thibault J, Lacroix C. Continuous lactic acid production in whey permeate/yeast extract medium with immobilized Lactobacillus helveticus in a two-stage process: Model and experiments. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2004.07.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Pulat M, Eksi H. Determination of swelling behavior and morphological properties of poly(acrylamide-co-itaconic acid) and poly(acrylic acid-co-itaconic acid) copolymeric hydrogels. J Appl Polym Sci 2006. [DOI: 10.1002/app.25182] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Furusaki S, Seki M. Use and engineering aspects of immobilized cells in biotechnology. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2005; 46:161-85. [PMID: 1636479 DOI: 10.1007/bfb0000710] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A short review of the research in the past two years (1990-1991) on immobilized whole cells, such as microbial, plant, and animal cells, is presented including a discussion from an engineering point of view. Recent works concerning the intraparticle mass transfer effect on immobilized microbial cells by the authors and their co-workers are also introduced. Finally, future prospects of the immobilized cell system will be discussed.
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Affiliation(s)
- S Furusaki
- Department of Chemical Engineering, Faculty of Engineering, University of Tokyo, Japan
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8
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Immobilised Cell Technologies for the Dairy Industry. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/1-4020-3363-x_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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9
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Microfluorimetric analysis of spatial and temporal patterns of immobilized cell growth. Biotechnol Bioeng 2004; 38:340-52. [DOI: 10.1002/bit.260380404] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Cachon R, Molin P, Diviès C. Modeling of continuous Ph-stat stirred tank reactor withLactococcus lactisssp.lactisbv.diacetylactisimmobilized in calcium alginate gel beads. Biotechnol Bioeng 2004; 47:567-74. [DOI: 10.1002/bit.260470509] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Ajbar A. Periodic behaviour of a class of unstructured kinetic models for continuous bioreactors. CAN J CHEM ENG 2001. [DOI: 10.1002/cjce.5450790514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Banerjee I, Modak JM, Bandopadhyay K, Das D, Maiti BR. Mathematical model for evaluation of mass transfer limitations in phenol biodegradation by immobilized Pseudomonas putida. J Biotechnol 2001; 87:211-23. [PMID: 11334665 DOI: 10.1016/s0168-1656(01)00235-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A mathematical model is proposed to analyze the mass transfer limitations in phenol biodegradation using Pseudomonas putida immobilized in calcium alginate. The model takes into account internal and external mass transfer limitations, substrate inhibition kinetics and the dependence of the effective diffusivity of phenol in alginate gel on cell concentration. The model is validated with the experimental data from batch fermentation. The effect of various operating conditions such as initial phenol concentration, initial cell loading, alginate gel loading on the biodegradation of phenol is experimentally demonstrated. Phenol degradation time is found to decrease initially and reach stationary value with increase in cell loading as well as gel loading. The model predicts these trends reasonably well and shows the presence of external mass transfer limitations. A new concept of effectiveness factor is introduced to analyze the overall performance of batch fermentation.
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Affiliation(s)
- I Banerjee
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
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13
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Moon SH, Lee KB, Paruekar SJ. Rigorous model for spherical cell-support aggregate. BIOTECHNOL BIOPROC E 2001. [DOI: 10.1007/bf02942249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Tal Y, Schwartsburd B, Nussinovitch A, van Rijn J. Enumeration and factors influencing the relative abundance of a denitrifier, Pseudomonas sp. JR12, entrapped in alginate beads. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2001; 112:99-106. [PMID: 11234547 DOI: 10.1016/s0269-7491(00)00127-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The relative abundance of the denitrifier, Pseudomonas sp. JR12, was examined in an alginate-based entrapment complex under non-sterile, denitrifying conditions. Immuno-labeling of the Pseudomonas inoculant followed by flow cytometry (FCM) was used for determination of the relative abundance of this bacterium under the various incubation conditions. Additional information on the relative abundance of the inoculant was obtained by a quantitative enzyme-linked immunosorbent assay (ELISA) and results obtained by FCM and ELISA were compared. Ambient nitrate levels controlled the successful, long-term proliferation of the inoculant. At low ambient nitrate levels, Pseudomonas sp. remained the dominant microorganism during incubation. Higher ambient nitrate concentrations, attained by either decreasing the inoculum size of Pseudomonas sp. or raising inlet nitrate concentrations of the medium supplied to the incubation vessels, resulted in a gradual shift toward other, nitrite-accumulating denitrifiers. Thus far, most studies on the use of entrapped microorganisms for bioremediation purposes have been conducted under controlled laboratory conditions. Based on this study, conducted under non-sterile laboratory conditions, it is concluded that in-situ bioremediation using entrapped target microorganisms is bound to fail without a proper understanding of the factors that cause the target microorganism to out-compete undesired microbial invaders. Furthermore, based on the close agreement between the two detection methods used, it is concluded that flow cytometry provides a rapid and accurate tool for the detection of the relative abundance of immuno-labeled target organisms in heterogeneous microbial populations.
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Affiliation(s)
- Y Tal
- Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel
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15
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Laca A, García LA, Díaz M. Analysis and description of the evolution of alginate immobilised cells systems. J Biotechnol 2000; 80:203-15. [PMID: 10949311 DOI: 10.1016/s0168-1656(00)00252-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Different immobilised cells models, including very simple ones, can be useful in the fitting of experimental results. However, goodness or the ability to extrapolate results needs to be in accordance with basic observations and these will also suggest models to be proposed. In this paper, observations of calcium alginate/bacteria systems are used to show the ability of basic models to fit classic observations, as well as how new observations, in this case from electronic microscopy, oblige us to think about more complex mechanisms and mathematical treatments. Nevertheless it is not only important to discuss the model type, but also the type of kinetics assumed in the interior of the beads, as well as the internal structure, the boundary conditions related to bead shredding and cell escape and finally, geometrical effects.
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Affiliation(s)
- A Laca
- Department of Chemical Engineering and Environmental Technology (I.U.B.A), University of Oviedo, Spain
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Swope KL, Flickinger MC. The use of confocal scanning laser microscopy and other tools to characterize Escherichia coli in a high-cell-density synthetic biofilm. Biotechnol Bioeng 2000; 52:340-56. [DOI: 10.1002/(sici)1097-0290(19961020)52:2<340::aid-bit14>3.0.co;2-n] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Parulekar SJ. Analysis of forced periodic operations of continuous bioprocesses: multiple input variations. Chem Eng Sci 2000. [DOI: 10.1016/s0009-2509(99)00317-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Uemoto H, Saiki H. Distribution of Nitrosomonas europaea and Paracoccus denitrificans immobilized in tubular polymeric gel for nitrogen removal. Appl Environ Microbiol 2000; 66:816-9. [PMID: 10653756 PMCID: PMC91901 DOI: 10.1128/aem.66.2.816-819.2000] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To improve the cooperative removal of nitrogen by Nitrosomonas europaea and Paracoccus denitrificans, we controlled their distribution in a tubular gel. When ethanol was supplied inside the tubular gel as an electron donor, their distributions overlapped in the external region of the gel. By changing the electron donor from ethanol to gaseous hydrogen, the distribution of P. denitrificans shifted to the inside of the tube and was separated from that of N. europaea. The separation resulted in an increase of the oxidation rate of ammonia by 25%.
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Affiliation(s)
- H Uemoto
- Bio-Science Department, Central Research Institute of Electric Power Industry, Abiko City, Chiba 270-1194, Japan.
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Abstract
The cultivation of cartilage cells (chondrocytes) in polymer scaffolds leads to implants that may potentially be used to repair damaged joint cartilage or for reconstructive surgery. For this technique to be medically applicable, the physical parameters that govern cell growth in a polymer scaffold must be understood. This understanding of cell behavior under in vitro conditions, where diffusion is the primary mode of transport of nutrients, may aid in the scale-up of the cartilage generation process. A mathematical model of chondrocyte generation and nutrient consumption is developed here to analyze the behavior of cell growth in a biodegradable polymer matrix for a series of different thickness polymers. Recent literature has implied that the diffusion of nutrients is a major factor that limits cell growth (Freed et al., 1994). In the present paper, a mathematical model is developed to directly relate the effects of increasing cell mass in the polymer matrix on the transport of nutrients. Reaction and diffusion of nutrients in the cell-polymer system are described using the fundamental species continuity equations and the volume averaging method. The volume averaging method is utilized to derive a single averaged nutrient continuity equation that includes the effective transport properties. This approach allows for the derivation of effective diffusion and rate coefficients as functions of the cell volume fraction. The cell volume fraction as a function of time is determined by solution of a material balance on cell mass. Growth functions including the Moser, a modified Contois, and an nth-order heterogeneous growth kinetic model are evaluated through a parameter analysis, and the results are compared to experimental data found in the literature. The results indicate that cellular functions in conjunction with mass transfer processes can account partially for the general trends in the cell growth behavior for various thickness polymers. The Contois growth function appeared to describe the data more accurately in terms of the lag period at early times and the long time limits. However, all kinetic growth functions required variations in the kinetic parameters to fully describe the effects of polymer thickness. This result implies that restricted diffusion of nutrients is not the sole factor limiting cell growth when the thickness of the polymer is changed. Therefore, further experimental data and model improvements are needed to accurately describe the cell growth process.
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Affiliation(s)
- C J Galban
- Department of Chemical Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, Florida 32310-6046, USA
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20
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Goodall JL, Peretti SW. Dynamic modeling of meta- and para-nitrobenzoate metabolism by a mixed co-immobilized culture of comamonas spp. JS46 and JS47. Biotechnol Bioeng 1998; 59:507-16. [PMID: 10099365 DOI: 10.1002/(sici)1097-0290(19980820)59:4<507::aid-bit14>3.0.co;2-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A model describing the transient activity of a mixed immobilized culture of Comamonas spp. JS46 and JS47 growing on mixed substrates is presented. The transient periods considered are those following changes in the feed carbon source, which alternated between meta- and para-nitrobenzoate. The feed profile alternately starved one of the species in the mixed culture. The response of the system, as quantified by the reactor effluent substrate concentrations, is dictated by the activity of the biomass and the appropriate biochemical pathway. As detailed mechanistic pathway information is not available, respirometry has been used to characterize both facets of activity. Two parameters were introduced: Psi representing pathway activity and Gamma representing biomass activity; a detailed description of the analysis is included. The model is compared to experimental investigation of the system and describes the reactor response well. The agreement between model and experiment suggests the usefulness of oxygen kinetics as global measurements to describe complex systems when mechanistic detail is not available. Copyright 1998 John Wiley & Sons, Inc.
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Affiliation(s)
- JL Goodall
- Department of Chemical Engineering, North Carolina State University, Box 7905, Raleigh, North Carolina 27695-7905, USA
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21
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Parulekar SJ. Analysis of forced periodic operations of continuous bioprocesses—single input variations. Chem Eng Sci 1998. [DOI: 10.1016/s0009-2509(98)00072-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Laca A, Quirós C, García L, Díaz M. Modelling and description of internal profiles in immobilized cells systems. Biochem Eng J 1998. [DOI: 10.1016/s1369-703x(98)00005-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Markowitz MA, Turner DC, Martin BD, Gaber BP. Diffusion and transfer of antibody proteins from a sugar-based hydrogel. Appl Biochem Biotechnol 1997; 68:57-68. [PMID: 9373930 DOI: 10.1007/bf02785980] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Diffusion of antibody protein from hydrogel films and hydrogel encapsulated in a microcapillary was studied. Thin hydrogel films were formed by crosslinking 6-acryloyl-B-O-methylgalactoside with N,N'-methylene-bis-acrylamide and the diffusive transport of monoclonal antimouse IgG-FITC into and out of the hydrate films was measured. Diffusion coefficients in 2 and 4% crosslinked hydrogel films were measured. The measured diffusion constants determined for IgG in both the 2 and 4% hydrogel films were comparable to the free diffusion of IgG in bulk water (Dmean approximately 10(-7) cm2/s). In addition, 2% crosslinked hydrogels were prepared in a capillary tube and the transport of antimouse IgG-FITC into and out of the hydrated hydrogel was measured. Kinetic analysis indicated that the protein transport through the capillary hydrogel was faster than would be expected for a simple diffusion process. Finally, by utilizing the diffusion of antibody from the capillary hydrogel, transfer of antibody to a silica surface was demonstrated. A capillary hydrogel loaded with antimouse IgG-FITC was used to transfer the protein to a silica surface forming a 30-micron spot of antibody, which was imaged using fluorescence microscopy. These results may lead to the development of a nonlithographic method of patterning antibodies on surfaces for use in integrated microimmunosensors.
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Affiliation(s)
- M A Markowitz
- Laboratory for Molecular Interfacial Interactions, Naval Research Laboratory, Washington, D.C. 20375, USA
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Gikas P, Livingston AG. Specific ATP and specific oxygen uptake rate in immobilized cell aggregates: Experimental results and theoretical analysis using a structured model of immobilized cell growth. Biotechnol Bioeng 1997; 55:660-73. [DOI: 10.1002/(sici)1097-0290(19970820)55:4<660::aid-bit8>3.0.co;2-f] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Leenen EJTM, Boogert AA, van Lammeren AAM, Tramper J, Wijffels RH. Dynamics of artificially immobilizedNitrosomonas europaea: Effect of biomass decay. Biotechnol Bioeng 1997; 55:630-41. [DOI: 10.1002/(sici)1097-0290(19970820)55:4<630::aid-bit5>3.0.co;2-i] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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28
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Yizhou Zheng, Gu T. Analytical solution to a model for the startup period of fixed-bed reactors. Chem Eng Sci 1996. [DOI: 10.1016/0009-2509(96)00225-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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29
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Blanco MD, García O, Trigo RM, Teijón JM, Katime I. 5-Fluorouracil release from copolymeric hydrogels of itaconic acid monoester. I. Acrylamide-co-monomethyl itaconate. Biomaterials 1996; 17:1061-7. [PMID: 8718965 DOI: 10.1016/0142-9612(96)85906-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The aim of this work was to test the application of new copolymeric poly (acrylamide-co-monomethyl itaconate) (A/MMI) hydrogels to 5-fluorouracil (5-FU) release. Three different compositions of copolymers have been studied, 90A:10MMI 75A:25MMI and 60A:40MMI. The equilibrium swelling degree in saline solution was between 76 and 80% depending on the copolymer composition. 5-FU, as the sodium salt, was trapped in the gels by including it in the feed mixture of polymerization. The swelling kinetics of the hydrogels in saline solution were studied at four temperatures, and the diffusion coefficient and the activation energy of the process were obtained. The 5-FU release as a function of temperature and disc load was studied; the diffusion coefficient and the activation energy of the release process were also obtained. The diffusion studies follow Fick's second law.
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Affiliation(s)
- M D Blanco
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Spain
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30
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Tartakovsky B, Kotlar E, Sheintuch M. Coupled nitrification-denitrification processes in a mixed culture of coimmobilized cells: Analysis and experiment. Chem Eng Sci 1996. [DOI: 10.1016/0009-2509(96)00089-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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31
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Walsh PK, Isdell FV, Noone SM, O'Donovan MG, Malone DM. Growth patterns of Saccharomyces cerevisiae microcolonies in alginate and carrageenan gel particles: Effect of physical and chemical properties of gels. Enzyme Microb Technol 1996. [DOI: 10.1016/0141-0229(95)00135-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Optimum design of a series of continuous stirred tank reactors containing immobilised growing cells. Biotechnol Lett 1996. [DOI: 10.1007/bf00143459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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33
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34
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Willaert RG, Baron GV. GEL ENTRAPMENT AND MICRO-ENCAPSULATION: METHODS, APPLICATIONS AND ENGINEERING PRINCIPLES. REV CHEM ENG 1996. [DOI: 10.1515/revce.1996.12.1-2.1] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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35
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Effect of product inhibition patterns on the effectiveness factor of immobilized cell aggregates. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0923-0467(95)03007-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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36
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37
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38
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Huang CT, Yu FP, McFeters GA, Stewart PS. Nonuniform spatial patterns of respiratory activity within biofilms during disinfection. Appl Environ Microbiol 1995; 61:2252-6. [PMID: 7793945 PMCID: PMC167496 DOI: 10.1128/aem.61.6.2252-2256.1995] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Fluorescent stains in conjunction with cryoembedding and image analysis were applied to demonstrate spatial gradients in respiratory activity within bacterial biofilms during disinfection with monochloramine. Biofilms of Klebsiella pneumoniae and Pseudomonas aeruginosa grown together on stainless steel surfaces in continuous-flow annular reactors were treated with 2 mg of monochloramine per liter (influent concentration) for 2 h. Relatively little biofilm removal occurred as evidenced by total cell direct counts. Plate counts (of both species summed) indicated an average 1.3-log decrease after exposure to 2 mg of monochloramine per liter. The fluorogenic redox indicator 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and the DNA stain 4',6-diamidino-2-phenylindole (DAPI) were used to differentiate respiring and nonrespiring cells in biofilms. Epifluorescence micrographs of frozen biofilm cross sections clearly revealed gradients of respiratory activity within biofilms in response to monochloramine treatment. These gradients in specific respiratory activity were quantified by calculating the ratio of CTC and DAPI intensities measured by image analysis. Cells near the biofilm-bulk fluid interface lost respiratory activity first. After 2 h of biocide treatment, greater respiratory activity persisted deep in the biofilm than near the biofilm-bulk fluid interface.
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Affiliation(s)
- C T Huang
- Department of Microbiology, Montana State University, Bozeman 59717, USA
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Dynamic modeling of immobilized Nitrosomonas europaea: Implementation of diffusion limitation over expanding microcolonies. Enzyme Microb Technol 1995. [DOI: 10.1016/0141-0229(94)00105-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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41
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Diffusion-reaction-growth coupling in gel-immobilized cell systems: Model and experiment. Enzyme Microb Technol 1995. [DOI: 10.1016/0141-0229(94)00036-q] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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42
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McFeters GA, Yu FP, Pyle BH, Stewart PS. Physiological assessment of bacteria using fluorochromes. J Microbiol Methods 1995; 21:1-13. [PMID: 11538412 DOI: 10.1016/0167-7012(94)00027-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- G A McFeters
- Microbiology Department, Montana State University, Bozeman 59717, USA
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Abstract
Within an immobilized cell matrix, mass transfer limitations on substrate delivery or product removal can often lead to a wide range of local chemical environments. As immobilized living cell populations actively grow and adapt to their surroundings, these mass transfer effects often lead to strong, time-dependent spatial variations in substrate concentration and biomass densities and growth rates. This review focuses on the methods that have been devised, both experimentally and theoretically, to study the non-uniform growth patterns that arise in the mass transfer limited environment of an immobilization matrix, with particular attention being paid to cell growth in polysaccharide gels.
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Affiliation(s)
- P K Walsh
- School of Biological Sciences, Dublin City University, Ireland
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Cachon R, Catté M, Nommé R, Prévost H, Diviès C. Kinetic Behaviour of Lactococcus lactis ssp. lactis bv. diacetylactis Immobilized in Calcium Alginate Gel Beads. Process Biochem 1995. [DOI: 10.1016/0032-9592(94)00048-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Norton S, Lacroix C, Vuillemard JC. Reduction of Yeast Extract Supplementation in Lactic Acid Fermentation of Whey Permeate by Immobllized Cell Technology. J Dairy Sci 1994. [DOI: 10.3168/jds.s0022-0302(94)77191-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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46
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Norton S, Lacroix C, Vuillemard JC. Kinetic study of continuous whey permeate fermentation by immobilized Lactobacillus helveticus for lactic acid production. Enzyme Microb Technol 1994. [DOI: 10.1016/0141-0229(94)90015-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Hunik JH, Bos CG, van den Hoogen MP, De Gooijer CD, Tramper J. Co-immobilizedNitrosomonas europaea andNitrobacter agilis cells: validation of a dynamic model for simultaneous substrate conversion and growth in ?-carrageenan gel beads. Biotechnol Bioeng 1994; 43:1153-63. [DOI: 10.1002/bit.260431121] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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48
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Controlled release of immobilized cells as a strategy to regulate ecological competence of inocula. BIOTECHNICS/WASTEWATER 1994. [DOI: 10.1007/bfb0008732] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Groboillot A, Boadi DK, Poncelet D, Neufeld RJ. Immobilization of cells for application in the food industry. Crit Rev Biotechnol 1994; 14:75-107. [PMID: 8069936 DOI: 10.3109/07388559409086963] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Immobilization of cells offers advantages to the food process industries, including enhanced fermentation productivity and cell stability and reduced downstream processing costs due to facilitated cell recovery and recycle. This article summarizes the varied immobilization methodologies, including adsorption, entrapment, covalent binding, and microencapsulation. Examples of interest to the food industry are provided, together with a review of the physiological effects of immobilization. Topics in process engineering include immobilized cell bioreactor configurations and the scale-up potential of the various immobilization techniques.
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Affiliation(s)
- A Groboillot
- Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada
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