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Serbov V, Motronenko V. Analysis of Mechanical Factors at Deep Cultivation. INNOVATIVE BIOSYSTEMS AND BIOENGINEERING 2019. [DOI: 10.20535/ibb.2019.3.1.146895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Ehgartner D, Hartmann T, Heinzl S, Frank M, Veiter L, Kager J, Herwig C, Fricke J. Controlling the specific growth rate via biomass trend regulation in filamentous fungi bioprocesses. Chem Eng Sci 2017. [DOI: 10.1016/j.ces.2017.06.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Newton JM, Vlahopoulou J, Zhou Y. Investigating and modelling the effects of cell lysis on the rheological properties of fermentation broths. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Newton JM, Schofield D, Vlahopoulou J, Zhou Y. Detecting cell lysis using viscosity monitoring in E. coli fermentation to prevent product loss. Biotechnol Prog 2016; 32:1069-76. [PMID: 27111912 PMCID: PMC4999026 DOI: 10.1002/btpr.2292] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/14/2016] [Indexed: 11/10/2022]
Abstract
Monitoring the physical or chemical properties of cell broths to infer cell status is often challenging due to the complex nature of the broth. Key factors indicative of cell status include cell density, cell viability, product leakage, and DNA release to the fermentation broth. The rapid and accurate prediction of cell status for hosts with intracellular protein products can minimise product loss due to leakage at the onset of cell lysis in fermentation. This article reports the rheological examination of an industrially relevant E. coli fermentation producing antibody fragments (Fab'). Viscosity monitoring showed an increase in viscosity during the exponential phase in relation to the cell density increase, a relatively flat profile in the stationary phase, followed by a rapid increase which correlated well with product loss, DNA release and loss of cell viability. This phenomenon was observed over several fermentations that a 25% increase in broth viscosity (using induction-point viscosity as a reference) indicated 10% product loss. Our results suggest that viscosity can accurately detect cell lysis and product leakage in postinduction cell cultures, and can identify cell lysis earlier than several other common fermentation monitoring techniques. This work demonstrates the utility of rapidly monitoring the physical properties of fermentation broths, and that viscosity monitoring has the potential to be a tool for process development to determine the optimal harvest time and minimise product loss. © 2016 The Authors. Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers, 32:1069-1076, 2016.
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Affiliation(s)
- Joseph M Newton
- Dept. of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, U.K
| | - Desmond Schofield
- Dept. of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, U.K
| | - Joanna Vlahopoulou
- Research & Development, Procellia Ltd, Netpark Incubator, Thomas Wright Way, Sedgefield, County Durham, TS21 3FD, U.K
| | - Yuhong Zhou
- Dept. of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, U.K
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Enhanced enzyme production with the pelleted form of D. squalens in laboratory bioreactors using added natural lignin inducer. ACTA ACUST UNITED AC 2012; 39:449-57. [DOI: 10.1007/s10295-011-1036-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 08/27/2011] [Indexed: 12/20/2022]
Abstract
Abstract
White-rot fungi are extensively used in various submerged biotechnology processes to produce ligninolytic enzymes. Transfer of the process from the laboratory to the industrial level requires optimization of the cultivation conditions on the laboratory scale. An interesting area of optimization is pellet growth since this morphological form solves problems such as the decreased oxygen concentration, limited heat, and nutrient transport, which usually occur in dispersed mycelium cultures. Many submerged fermentations with basidiomycetes in pellet form were done with Phanerochaete, Trametes, and Bjerkandera species, among others. In our study, another promising basidiomycete, D. squalens, was used for ligninolytic enzyme production. With the addition of wood particles (sawdust) as a natural inducer and optimization of mixing and aeration conditions in laboratory stirred tank (STR) and bubble column (BCR) reactors on pellet growth and morphology, the secretion of laccase and the manganese-dependent peroxidase into the medium was substantially enhanced. The maximum mean pellet radius was achieved after 10 days in the BCR (5.1 mm) where pellets were fluffy and 5 days in the STR (3.5 mm) where they were round and smooth. The maximum Lac activity (1,882 U l−1) was obtained after 12 days in the STR, while maximum MnP activity (449.8 U l−1) occurred after 18 days in the BCR. The pellet size and morphology depended on the agitation and aeration conditions and consequently influenced a particular enzyme synthesis. The enzyme activities were high and comparable with the activities found for other investigations in reactors with basidiomycetes in the form of pellets.
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Bryant DN, Morris SM, Leemans D, Fish SA, Taylor S, Carvell J, Todd RW, Logan D, Lee M, Garcia N, Ellis A, Gallagher JA. Modelling real-time simultaneous saccharification and fermentation of lignocellulosic biomass and organic acid accumulation using dielectric spectroscopy. BIORESOURCE TECHNOLOGY 2011; 102:9675-82. [PMID: 21852118 DOI: 10.1016/j.biortech.2011.07.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 07/15/2011] [Accepted: 07/20/2011] [Indexed: 05/25/2023]
Abstract
Dielectric spectroscopy (DS) is routinely used in yeast and mammalian fermentations to quantitatively monitor viable biomass through the inherent capacitance of live cells; however, the use of DS to monitor the enzymatic break down of lignocellulosic biomass has not been reported. The aim of the current study was to examine the application of DS in monitoring the enzymatic saccharification of high sugar perennial ryegrass (HS-PRG) fibre and to relate the data to changes in chemical composition. DS was capable of both monitoring the on-line decrease in PRG fibre capacitance (C=580 kHz) during enzymatic hydrolysis, together with the subsequent increase in conductivity (G=580 kHz) resulting from the production of organic acids during microbial growth. Analysis of the fibre fractions revealed >50% of HS-PRG lignocellulose had undergone enzymatic hydrolysis. These data demonstrated the utility of DS biomass probes for on-line monitoring of simultaneous saccharification and fermentation (SSF).
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Affiliation(s)
- David N Bryant
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Gogerddan, Aberystwyth, Ceredigion SY23 3EB, UK
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Justice C, Brix A, Freimark D, Kraume M, Pfromm P, Eichenmueller B, Czermak P. Process control in cell culture technology using dielectric spectroscopy. Biotechnol Adv 2011; 29:391-401. [DOI: 10.1016/j.biotechadv.2011.03.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 03/04/2011] [Accepted: 03/06/2011] [Indexed: 10/18/2022]
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Introducing process analytical technology (PAT) in filamentous cultivation process development: comparison of advanced online sensors for biomass measurement. J Ind Microbiol Biotechnol 2011; 38:1679-90. [DOI: 10.1007/s10295-011-0957-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 03/09/2011] [Indexed: 12/24/2022]
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Process analytical technology (PAT) for biopharmaceutical products. Anal Bioanal Chem 2010; 398:137-54. [DOI: 10.1007/s00216-010-3781-x] [Citation(s) in RCA: 227] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 04/20/2010] [Accepted: 04/23/2010] [Indexed: 11/27/2022]
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11
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Lecault V, Patel N, Thibault J. An image analysis technique to estimate the cell density and biomass concentration ofTrichoderma reesei. Lett Appl Microbiol 2009; 48:402-7. [DOI: 10.1111/j.1472-765x.2008.02544.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Borràs E, Blánquez P, Sarrà M, Caminal G, Vicent T. Trametes versicolor pellets production: Low-cost medium and scale-up. Biochem Eng J 2008. [DOI: 10.1016/j.bej.2008.05.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Vaidyanathan S, Macaloney G, Vaughan J, McNeil B, Harvey LM. Monitoring of Submerged Bioprocesses. Crit Rev Biotechnol 2008. [DOI: 10.1080/0738-859991229161] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nordon A, Littlejohn D, Dann AS, Jeffkins PA, Richardson MD, Stimpson SL. In situ monitoring of the seed stage of a fermentation process using non-invasive NIR spectrometry. Analyst 2008; 133:660-6. [DOI: 10.1039/b719318a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ferreira AP, Vieira LM, Cardoso JP, Menezes JC. Evaluation of a new annular capacitance probe for biomass monitoring in industrial pilot-scale fermentations. J Biotechnol 2005; 116:403-9. [PMID: 15748767 DOI: 10.1016/j.jbiotec.2004.12.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Revised: 10/14/2004] [Accepted: 12/06/2004] [Indexed: 10/25/2022]
Abstract
The four-pin electrode capacitance probe has already shown to be a valuable tool for on-line monitoring viable biomass concentration in industrial-type fermentations. A new prototype annular probe was developed and its performance in real-time monitoring the concentration of viable cells during industrial pilot-scale fermentation for the production of an Active Pharmaceutical Ingredient (API) was investigated and compared to the four-pin probe. A set of 14 fermentations was monitored on-line: four of them with the four-pin probe, the remaining with the annular probe. The performance of both the annular and the four-pin electrode probe were compared against each other and against off-line measurements (viscosity and packed mycelial volume). The prototype annular probe showed to have higher signal intensity and sensitivity than the standard four-pin probe, with higher signal-to-noise ratio. Furthermore, its new design and construction proved to be easier to handle in an industrial environment.
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Affiliation(s)
- Ana P Ferreira
- Centre for Biological and Chemical Engineering, IST, Technical University of Lisbon, Av. Rovisco Pais, P-1049-001 Lisbon, Portugal
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Arnold SA, Gaensakoo R, Harvey LM, McNeil B. Use of at-line and in-situ near-infrared spectroscopy to monitor biomass in an industrial fed-batch Escherichia coli process. Biotechnol Bioeng 2002; 80:405-13. [PMID: 12325148 DOI: 10.1002/bit.10383] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
One of the key goals in bioprocess monitoring is to achieve real-time knowledge of conditions within the bioreactor, i.e., in-situ. Near-infrared spectroscopy (NIRS), with its ability to carry out multi-analyte quantification rapidly with little sample presentation, is potentially applicable in this role. In the present study, the application of NIRS to a complex, fed-batch industrial E. coli (RV308/PHKY531) process was investigated. This process undergoes a series of temperature changes and is vigorously agitated and aerated. These conditions can pose added challenges to in-situ NIRS. Using the measurement of a key analyte (biomass) as an illustration, the details of the relationship between the at-line and in-situ use of NIRS are considered from the viewpoint of both theory and practical application. This study shows that NIRS can be used both at-line and in-situ in order to achieve good predictive models for biomass. There are particular challenges imposed by in-situ operation (loss of wavelength regions and noise) which meant the need for signal optimisation studies. This showed that whilst the at-line modelling process may provide some useful information for the in-situ process, there were distinct differences. This study shows that the in-situ use of NIRS in a highly challenging matrix (similar to those encountered in current industrial practice) is possible, and thus extends previous works in the area.
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Affiliation(s)
- S Alison Arnold
- Strathclyde Fermentation Centre, Department of Bioscience and Biotechnology, University of Strathclyde, 204 George Street, Glasgow G1 1XW, United Kingdom.
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Park JP, Kim YM, Kim SW, Hwang HJ, Cho YJ, Lee YS, Song CH, Yun JW. Effect of agitation intensity on the exo-biopolymer production and mycelial morphology in Cordyceps militaris. Lett Appl Microbiol 2002; 34:433-8. [PMID: 12028425 DOI: 10.1046/j.1472-765x.2002.01126.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The influence of agitation intensity on Cordyceps militaris morphology and exo-biopolymer production was investigated in a 5 litre stirred vessel using a six-blade Rushton turbine impeller. METHODS AND RESULTS The mycelial morphology of C. militaris was characterized by means of image analysis, which included mean diameter, circularity, roughness and compactness of the pellets. The morphological parameters of the pellets grown under different stirring conditions were significantly different, which correspondingly altered exo-biopolymer production yields. CONCLUSIONS The compactness of the pellets was found to be the most critical parameter affecting exo-biopolymer biosynthesis; more compact pellets were formed at 150 rev min(-1) with maximum exo-biopolymer production (15 g l(-1)). SIGNIFICANCE AND IMPACT OF THE STUDY The results of this study suggest that morphological change of pellets is a good indicator for identifying the cell activity for exo-biopolymer production.
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Affiliation(s)
- J P Park
- Department of Biotechnology, Taegu University, Kyungsan, Kyungbuk, Korea
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Cho YJ, Hwang HJ, Kim SW, Song CH, Yun JW. Effect of carbon source and aeration rate on broth rheology and fungal morphology during red pigment production by Paecilomyces sinclairii in a batch bioreactor. J Biotechnol 2002; 95:13-23. [PMID: 11879708 DOI: 10.1016/s0168-1656(01)00445-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The influence of carbon source and aeration rate on fermentation broth rheology, mycelial morphology and red pigment production of Paecilomyces sinclairii was investigated in a 5-l stirred-tank bioreactor. The characteristics of P. sinclairii grown on starch and on sucrose medium were comparatively studied: the specific growth rate in sucrose medium (0.04 h(-1)) was higher than that in starch medium, whereas the specific production rate of red pigments (0.04 gg(-1)d(-1)) was favorable in starch medium. P. sinclairii grown in sucrose medium were highly branched and showed longer hyphal lengths than that in starch medium. The consistency index (K) in sucrose medium was markedly higher than that in starch medium due to higher cell mass, while the higher values of flow behavior index (n) were indicated at the late stationary phase in starch medium. The aeration rate was varied within the ranges from 0.5 to 3.5 vvm while running the fermentation at mild agitation of 150 rpm using sucrose as the carbon source. The maximum biomass concentration of P. sinclairii was about 33 gl(-1) with an aeration rate of 1.5 vvm, whereas the maximum yield of red pigment production (4.73 gl(-1)) was achieved with 3.5 vvm. The highly branched cell morphology appeared at 1.5 vvm and the highly vacuolated cell morphology was observed in a high aeration rate (3.5 vvm). There was no significant variance in rheological parameters (K and n) between culture broths from different aeration conditions.
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Affiliation(s)
- Youn Jeung Cho
- Department of Biotechnology, Taegu University, Kyungsan, Kyungbuk 712-714, South Korea
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Stocks SM, Thomas CR. Viability, strength, and fragmentation of Saccharopolyspora erythraea in submerged fermentation. Biotechnol Bioeng 2001; 75:702-9. [PMID: 11745148 DOI: 10.1002/bit.10017] [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: 11/11/2022]
Abstract
Two fermentations of the commercially important erythromycin-producing filamentous bacterium Saccharopolyspora erythraea were conducted in defined media. One was glucose-limited and the other nitrate-limited. The viability of the hyphae was determined using the fluorescent stain BacLight (Molecular Probes, Eugene, OR). Also, the force required to strain hyphae to breakage was determined using micromanipulation and a sensitive force transducer. In both fermentations, fragmentation coincided with the appearance of regions in the mycelia with permeabilised membranes (considered nonviable). Under glucose-limitation, hyphal breaking force rose to 1,050 +/- 130 nN at the end of the growth phase and fell to an undetectable value as a result of glucose exhaustion. Under nitrate-limitation, hyphal breaking force fell from 900 +/- 160 nN during the growth phase to 550 +/- 40 nN in the stationary phase. In both cases image analysis showed that the dimensions of mycelia were of the same order, suggesting that the major factor influencing fragmentation was the appearance of nonviable regions (assumed to be weak). The location in which nonviable regions first appear within hyphae could not be determined because of their appearance coinciding with fragmentation.
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Affiliation(s)
- S M Stocks
- School of Chemical Engineering, The University of Birmingham, B15 2TT, UK
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Neves AA, Pereira DA, Vieira LM, Menezes JC. Real time monitoring biomass concentration in Streptomyces clavuligerus cultivations with industrial media using a capacitance probe. J Biotechnol 2001; 84:45-52. [PMID: 11035186 DOI: 10.1016/s0168-1656(00)00325-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
On-line monitoring biomass concentration in mycelial fed-batch cultivations of Streptomyces clavuligerus grown with soluble and partially insoluble complex media, was investigated with an in-situ capacitance probe fitted to an industrial pilot-plant tank. Standard off-line and on-line biomass determinations, including cell dry weight, packed mycelial volume, viscosity, DNA concentration and total CO(2) evolution in the exhaust gases, were performed throughout the experiments and compared to on-line capacitance measurements. Linear relations between capacitance and all other measurements were developed for both media that hold only in defined process phases, depending on the biomass state and the amount of insoluble matter present. For the industrial complex culture media good linear relations were obtained in the fast growth phase between capacitance and DNA concentration and total CO(2) evolution, while in the subsequent transition and stationary phases only with apparent viscosity was a reasonable correlation found. The capacitance probe was shown to be a valuable tool for real-time monitoring biomass concentration in industrial-like cultivation of mycelial streptomycetes.
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Affiliation(s)
- A A Neves
- Laboratório de Microbiologia, CIPAN, S.A., Vala-do-Carregado, P-2601-906, Castanheira do Ribatejo, Portugal
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Jass J, O'Neill JG, Walker JT. Direct biofilm monitoring by a capacitance measurement probe in continuous culture chemostats. Methods Enzymol 2001; 337:63-70. [PMID: 11398451 DOI: 10.1016/s0076-6879(01)37006-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- J Jass
- Department of Microbiology, Umeå University, S-901 87 Umeå, Sweden
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Yardley JE, Kell DB, Barrett J, Davey CL. On-line, real-time measurements of cellular biomass using dielectric spectroscopy. Biotechnol Genet Eng Rev 2001; 17:3-35. [PMID: 11255671 DOI: 10.1080/02648725.2000.10647986] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- J E Yardley
- Institute of Biological Sciences, University of Wales, Aberystwyth, Ceredigion SY23 3DA, Wales, U.K
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Davies JL, Baganz F, Ison AP, Lye GJ. Studies on the interaction of fermentation and microfiltration operations: erythromycin recovery from Saccharopolyspora erythraea fermentation broths. Biotechnol Bioeng 2000; 69:429-39. [PMID: 10862681 DOI: 10.1002/1097-0290(20000820)69:4<429::aid-bit9>3.0.co;2-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Changes in fermentation media not only affect the performance of the fermentation itself (with regard to the kinetics of biomass and product formation and the yields obtained) but also the initial product-recovery operations downstream of the fermentor. In this work, microfiltration experiments to remove Saccharopolyspora erythraea biomass from fermentation broth and to recover erythromycin were carried out using two fundamentally different media; a soluble complex medium (SCM) and an oil-based process medium (OBM). Small-scale batch fermentations of 14-L working volume were carried out in triplicate using both media. Broth samples were taken from each fermentation at regular intervals from the end of the exponential-growth phase onwards. These were then processed using a Minitan II (acrylic), tangential crossflow-filtration module, fitted with a single 60 cm(2) Durapore hydrophilic 0.2 microm membrane, operated in concentration mode. The OBM fermentations produced higher titers of erythromycin but required longer fermentation times due to increased lag phases and slower maximum-growth rates. The OBM also increased the loading on the membrane; at maximum product titers residual oil concentrations of 3 g. L(-1), antifoam concentrations of 2 g. L(-1) and flour concentrations estimated at approximately 10 g/L(-1) were typical. It was found that both the permeate flux and erythromycin transmission were affected by the choice of medium. The OBM had significantly lower values for both parameters (12.8 Lm(-2) h(-1) and 89.6% respectively) than the SCM (35.9 Lm(-2) h(-1) and 96.7% respectively) when the fermentations were harvested at maximum erythromycin titers. Transmission of erythromycin stayed approximately constant as a function of fermentation time for both media, however, for the OBM the permeate flux decreased with time which correlated with an increase in broth viscosity. The relatively poor microfiltration performance of the OBM medium was, however, offset by the higher titers of erythromycin that were achieved during the fermentation. The filtration characteristics of the SCM broth did not show any correlation with either broth viscosity or fermentation time. Image-analysis data suggested that there was a correlation between hyphal morphology (main hyphal length) and permeate flux (no such correlation was found for the OBM broth). Moreover, it has been shown for the OBM broth that the residual flour had a profound effect on the microfiltration characteristics. The influence of the residual flour was greater than that imposed by the morphology and concentration of the biomass. The understanding of the factors governing the interaction of the fermentation and microfiltration operations obtained in this work provides a first step towards optimization of the overall process sequence.
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Affiliation(s)
- J L Davies
- Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
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Heydarian S, Ison A, Lilly M, Ayazi Shamlou P. Turbulent breakage of filamentous bacteria in mechanically agitated batch culture. Chem Eng Sci 2000. [DOI: 10.1016/s0009-2509(99)00449-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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25
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Davey CL, Kell DB. The influence of electrode polarisation on dielectric spectra, with special reference to capacitive biomass measurements. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0302-4598(98)00131-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Kell D, Todd RW. Dielectric estimation of microbial biomass using the Aber Instruments Biomass Monitor. Trends Biotechnol 1998. [DOI: 10.1016/s0167-7799(98)01175-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
The use of modern analytical online methods such as two-dimensional fluorescence measurements gives new insights into bioprocesses. With the resulting data, it is not only possible to better understand and document, for example, biotransformations, but also to develop efficient control strategies that lead to better productivity and lower costs.
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