Abstract
Measurements of bubble and pellet size distributions are useful for biochemical process optimizations. The accuracy, representation, and simplicity of these measurements improve when the measurement is performed on-line and in situ rather than off-line using a sample. Historical and currently available measurement systems for photographic methods are summarized for bubble and pellet (morphology) measurement applications. Applications to cells, mycelia, and pellets measurements have driven key technological developments that have been applied for bubble measurements. Measurement trade-offs exist to maximize accuracy, extend range, and attain reasonable cycle times. Mathematical characterization of distributions using standard statistical techniques is straightforward, facilitating data presentation and analysis. For the specific application of bubble size distributions, selected bioreactor operating parameters and physicochemical conditions alter distributions. Empirical relationships have been established in some cases where sufficient data have been collected. In addition, parameters and conditions with substantial effects on bubble size distributions were identified and their relative effects quantified. This information was used to guide required accuracy and precision targets for bubble size distribution measurements from newly developed novel on-line and in situ bubble measurement devices.
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Abbreviations
- a 32 :
-
interfacial area, surface area per unit volume, 1/μ
- A :
-
area of object
- A c :
-
experimentally determined constant in Calderbank equation (Eq. 20)
- A 3 :
-
skewness of distribution
- A 4 :
-
kurtosis of distribution
- AR:
-
aspect ratio, longest to shortest diameter
- C :
-
circularity, 1/SF (Eq. 5)
- C v :
-
coefficient of variation
- d :
-
equivalent spherical bubble diameter
- d a :
-
sample mean bubble diameter, arithmetic mean (Eqs. 9, 11–13)
- d F :
-
Feret diameter (Eq. 6), diameter of equivalent circular object with same area as irregularly shaped object
- d g :
-
log-geometric mean diameter (Eq. 3)
- d i :
-
diameter of bubble i
- d long :
-
longest diameter of a single circular object
- d max :
-
maximum stable bubble size; maximum bubble diameter
- d min :
-
minimum bubble diameter
- d short :
-
shortest diameter of a single circular object
- d 30 :
-
volumetric mean diameter (Eq. 4)
- d 32 :
-
Sauter mean diameter (Eq. 2)
- d 50 :
-
median value of diameter; diameter for which normalized cumulative volume curve is 0.5
- d 99 :
-
diameter that is larger than 99% of all diameters in the cumulative number distribution of bubbles
- KLa:
-
volumetric gas–liquid mass transfer coefficient
- N :
-
impeller speed
- n :
-
total number of bubbles, sample size
- n i :
-
number of bubbles of diameter d i
- P :
-
perimeter of object
- P/V L :
-
power input to dispersion per unit liquid volume (gassed power)
- Q :
-
volumetric gas flow rate
- R :
-
roundness
- SF:
-
shape factor (Eq. 5)
- V b :
-
total volume of bubbles
- β:
-
experimentally determined constant in Calderbank equation (Eq. 20)
- γ:
-
experimentally determined constant (Eq. 21)
- δ:
-
experimentally determined constant (Eq. 23)
- ρc :
-
liquid (continuous phase) density
- ρg :
-
gas (dispersed phase) density
- ρp :
-
pellet density
- Φ:
- ɛT :
-
gassed power input per unit mass (Eq. 17)
- μG :
-
gas viscosity
- μL :
-
liquid viscosity
- σa :
-
standard deviation from arithmetic mean
- σg :
-
log-geometric mean standard deviation
- σT :
-
surface tension
- BSA:
-
Bovine serum albumin
- CCD:
-
Solid state charge-coupled device cameras, two-dimensional, self-scanning, electronic analog imaging device
- CC-TV:
-
Closed circuit television, standard camera equipment
- Chalnicon:
-
Sensor tube that has cadmium selenide-based target layer for face plate material
- DAT:
-
Data acquisition time
- EC:
-
Electronic commerce
- fps:
-
Frames per second
- IPS:
-
In-plane-switching, technology to produce high-quality LCDs
- LED:
-
Light emitting diode
- MAT:
-
Measurement acquisition time
- NTSC:
-
National Television System Committee, 525 lines, 30 Hz (Americas and Far East)
- PAT:
-
Process analytical technology
- PC:
-
Personal computer
- RW:
-
Read/write
- SVHS:
-
Super VHS (vertical helical scan), enhanced quality and higher horizontal resolution
References
Adams HL, Thomas CR (1988) The use of image analysis for morphological measurements on filamentous microorganisms. Biotechnol Bioeng 32:707–712
Akita K, Yoshida F (1974) Bubble size, interfacial area, and liquid-phase mass transfer coefficient in bubble columns. Ind Eng Chem Process Des Develop 13(1):84–91
Allen DG, Robinson CW (1989) Hydrodynamics and mass transfer in Aspergillus niger fermentations in bubble column and loop bioreactors. Biotechnol Bioeng 34:731–740
Alves M, Cavaleiro AJ, Ferreira EC, Amaral AL, Mota M, daMotta M, Vivier H, Pons M-N (2000) Characterisation by image analysis of anaerobic sludge under shock conditions. Water Sci Technol 41(12):207–214
Araya-Kroff P, Amaral AL, Neves L, Ferreira EC, Pons M-N, Mota M, Alves MM (2004) Development of image analysis techniques as a tool to detect and quantify morphological changes in anaerobic sludge: I. Application to a granulation process. Biotechnol Bioeng 87(2):184–193
Barigou M, Greaves M (1992) Bubble size distributions in a mechanically agitated gas–liquid contactor. Chem Eng Sci 47(8):2009–2025
Barigou M, Greaves M (1992) Bubble size in the impeller region of a Rushton turbine. Trans IChemE 70(Pt A):153–160
Bittner C, Wehnert G, Scheper T (1998) In situ microscopy for on-line determination of biomass. Biotechnol Bioeng 60(1):24–35
Brentrup L, Onken U (1979) Measurement of bubble size distribution in fermentors. Biotechnol Lett 1(10):427–432
Buchholz R, Schugerl K (1979) Bubble column bioreactors, I. Methods for measuring the bubble size. Eur J Appl Microbiol Biotechnol 6:301–313
Burschäpers J, Schustolla D, Schügerl K, Röper H, de Troostembergh JC (2002) Engineering aspects of the production of sugar alcohols with the osmophilic yeast Moniliella tomentosa var pollinis. Part 2. Batch and fed-batch operation in bubble column and airlift tower loop reactors. Process Biochem 38:559–570
Carlsen M, Spohr AB, Nielsen J, Villadsen J (1996) Morphology and physiology of an α-amylase producing strain of Aspergillus oryzae during batch cultivations. Biotechnol Bioeng 49:266–276
Chen F, Gomez CO, Finch JA (2001) Bubble size measurement in floatation machines. Miner Eng 14(4):427–432
Choi DB, Park EY, Okabe M (1998) Improvement of tylosin production from Streptomyces fradiae culture by decreasing apparent viscosity in an air-lift bioreactor. J Ferment Bioeng 86(4):413–417
Choi DB, Park EY, Okabe M (2000) Dependence of apparent viscosity on mycelial morphology of Streptomyces fradiae culture in various nitrogen sources. Biotechnol Prog 16:525–532
Christiansen T, Sophr AB, Nielsen J (1999) On-line study of growth kinetics of single hyphae of Aspergillus oryzae in a flow-through cell. Biotechnol Bioeng 63(2):147–153
Coelho MAZ, Belo I, Pinheiro R, Amaral AL, Mota M, Coutinho JAP, Ferreira EC (2004) Effect of hyperbaric stress on yeast morphology: study by automated image analysis. Appl Microbiol Biotechnol 66:318–324
Colella D, Vinci D, Bagatin R, Masi M, Bakr EA (1999) A study on coalescence and breakage mechanisms in three different bubble columns. Chem Eng Sci 54:4767–4777
Crawley G, Malcolmson A (2004) Online particle sizing as a route to process optimization. Chem Eng 111(9):37–41
Cronenberg CCH, Ottengraf SPP, van den Heuvel I-C, Pottel F, Sziele D, Schügerl K, Bellgardt KH (1994) Influence of age and structure of Penicillium chrysogenum pellets on the internal concentration profiles. Bioprocess Eng 10:209–216
Cui YQ, van der Lans RGJM, Luyben KCAM (1997) Effect of agitation intensities on fungal morphology of submerged fermentation. Biotechnol Bioeng 55(5):715–726
Dodd PW, Pandit AB, Davidson JF (1988) Bubble size distribution generated by perforated baffle plates in large fermenters. In: King R (ed) 2nd international conference on bioreactor fluid dynamics. Elsevier, New York, pp 319–335
Dudley BT, Howgrave-Graham AR, Bruton AG, Wallis FM (1993) Image analysis to quantify and measure UASB digester granules. Biotechnol Bioeng 42:279–283
Durant G, Cox PW, Formisyn P, Thomas CR (1994) Improved image analysis algorithm for the characterisation of mycelial aggregates after staining. Biotechnol Tech 8(11):759–764
Durant G, Crawley G, Formisyn P (1994) A simple staining procedure for the characterisation of basidiomycetes pellets by image analysis. Biotechnol Tech 8(6):395–400
Franz K, Buchholz R, Schugerl K (1980) Comprehensive study of the gas hold up and bubble size distributions in highly viscous liquids. Chem Eng Commun 5:165–202
Galindo E, Pacek AW, Nienow AW (2000) Study of drop and bubble sizes in a simulated mycelial fermentation broth of up to four phases. Biotechnol Bioeng 69(2):213–221
Gehrig I, Bart H-J, Anke T, Germerdonk R (1998) Influence of morphology and rheology on the production characteristics of the Basidiomycete Cyathus striatus. Biotechnol Bioeng 59(5):525–533
Glasgow LA, Erickson LE, Lee CH, Patel SA (1984) Wall pressure fluctuations and bubble size distributions at several positions in an airlift fermentor. Chem Eng Commun 29:311–336
Greaves M, Barigou M (1988) The internal structure of gas–liquid dispersions in a stirred reactor. In: Proceedings 6th European conference on mixing, BHRA, Fluid Engineering Centre, Bedford, England, pp 313–320
Greaves M, Kobbacy KAH (1984) Measurement of bubble size distribution in turbulent gas–liquid dispersions. Chem Eng Res Des 62(1):3–12
Grimm LH, Kelly S, Hengstler J, Göbel A, Krull R, Hempel DC (2004) Kinetic studies on the aggregation of Aspergillus niger conidia. Biotechnol Bioeng 87(2):213–218
Gualtieri P, Coltelli P (1991) A real-time automated system for the analysis of moving images. J Comput Assist Microsc 3(1):15–21
Hotop S, Möller J, Dullau T, Schügerl K (1989) Influences of preculture conditions on the morpholgy of Pencillium chrysogenum. In: Dechema Biotechnol. Conf. 3. VCH Verlagsgesellschalt, Weinheim, pp 597–601
Hotop S, Möller J, Niehoff J, Schügerl K (1993) Influence of the preculture conditions on the pellet size distribution of Penicillium chrysogenum cultivations. Process Biochem 28(2):99–104
Jeison D, Chamy R (1998) Novel technique for measuring the size distribution of granules from anaerobic reactors for wastewater treatment. Biotechnol Tech 12(9):659–662
Joeris K, Frerichs J-G, Konstantinov K, Scheper T (2002) In situ microscopy: on-line process monitoring of mammalian cell cultures. Cytotechnology 38:129–134
Junker B (1988) Assessment of oxygen transfer in water-in-perfluorocarbon dispersions. PhD thesis, MIT, pp 146–147
Junker BH, Hatton TA, Wang DIC (1990) Oxygen transfer enhancement in aqueous/perfluorocarbon fermentation systems: I. Experimental observations. Biotechnol Bioeng 35:578–585
Junker BH, Hesse M, Burgess B, Masurekar P, Connors N, Seeley A (2004) Early phase process scale up challenges for fungal and filamentous bacterial cultures. Appl Biochem Biotechnol 119:241–277
Jüsten P, Paul GC, Nienow AW, Thomas CR (1996) Dependence of mycelial morphology on impeller type and agitation intensity. Biotechnol Bioeng 52:672–684
Kawalec-Pietrenko BT (1992) Time-dependent gas hold-up and bubble size distributions in a gas–highly viscous liquid–solid system. Chem Eng J 50:B29–B37
Kawalec-Pietrenko B, Pietrenko W (1999) Generation of small bubbles and small bubble–liquid mass transfer in airlift reactors containing highly viscous liquids. Bioprocess Eng 21:89–95
Kumar R, Kuloor NR (1970) The formation of bubbles and drops. In: Drew TB, Cokelet GR, Hoopes, JW Jr, Vermeulen T (eds) Adv Chem Eng, vol 8. Academic, New York, pp 255–368
Laakkonen M, Honkanen M, Saarenrinne P, Aittamaa J (2005) Local bubble size distributions, gas–liquid interfacial areas and gas holdups in a stirred vessel with particle image velocimetry. Chem Eng J 109:37–47
Lage PLC, Esposito RO (1999) Experimental determination of bubble size distributions in bubble columns: prediction of mean bubble diameter and gas hold up. Powder Technol 101:142–150
Leschonski K (1986) Particle characterization, present state and possible future trends. Part Charact 3:99–103
Li ZJ, Shukla V, Fordyce AP, Pedersen AG, Wenger KS, Marten MR (2000) Fungal morphology and fragmentation behavior in a fed-batch Aspergillus oryzae fermentation at the production scale. Biotechnol Bioeng 70(3):300–312
Litchfield JB, Reid JF, Richburg BA (1992) Machine vision microscopy for on-line sampling analysis and control. In: Karim MN, Stephanopoulos G (eds) IFAC modeling and control of biotechnical processes. Pergamon Press, Oxford, pp 275–278
Loera O, Viniegra-Gonźalez G (1998) Identification of growth phenotypes in Aspergillus niger pectinase over-producing mutants using image analysis procedures. Biotechnol Tech 12(11):801–804
Lübbert A (1992) Advanced methods for bioreactor characterization. J Biotechnol 25:145–182
Lucatero S, Larralde-Corona CP, Corkidi G, Galindo E (2003) Oil and air dispersion in a simulated fermentation broth as a function of mycelial morphology. Biotechnol Prog 19:285–292
Luo R, Song Q, Yang XY, Wang Z (2002) A three-dimensional photographic method for measurement of phase distribution in dilute bubble flow. Exp Fluids 32:116–120
Ma N, Chalmers JJ, Aunins JG, Zhou W, Xie L (2004) Quantitative studies of cell–bubble interactions and cell damage at different Pluronic F-68 and cell concentrations. Biotechnol Prog 20:1183–1191
Machon V, Pacek AW, Nienow AW (1997) Bubble sizes in electrolyte and alcohol solutions in a turbulent stirred vessel. Trans IChemE 75(Pt A):339–348
Malysa K, Ng S, Cymbalisty L, Czarnecki J, Masliyah J (1999) A method of visualization and characterization of aggregate flow inside a separation vessel, part 1. Size, shape and rise velocity of the aggregates. Int J Miner Process 55:171–188
Metz B, De Bruijn EW, Van Suijdam JC (1981) Method for quantitative representation of the morphology of molds. Biotechnol Bioeng 23:149–162
Meyerhoff J, Bellgardt KH (1995) A morphology-based model for fed-batch cultivations of Pencillium chrysogenum growing in pellet form. J Biotechnol 38:201–207
Miyahara T, Hayashino T (1995) Size of bubbles generated from perforated plates in non-Newtonian liquids. J Chem Eng Jpn 28(5):596–600
Miyahara T, Matsuba Y, Takahashi T (1983) The size of bubbles generated from perforated plates. Int Chem Eng 23(3):517–523
Moo-Young M, Blanch HW (1981) Design of biochemical reactors, mass transfer criteria for simple and complex systems. Adv Biochem Eng 19:1–69
Moreira MT, Sanromán A, Feijoo G, Lema JM (1996) Control of pellet morphology of filamentous fungi in fluidized bed bioreactors by means of a pulsing flow. Application to Aspergillus niger and Phanerochaete chrysosporium. Enzym Microb Technol 19:261–266
Moreira MT, Feijoo G, Sanromán A, Lema JM (1996) Effect of pulsation on morphology of Aspergillus niger and Phanerochaete chrysosporium in a fluidized-bed reactor. In: Wijffels RH, Buitelaar RM, Bucke C, Tramper J (eds) Immobilized cells: basics and applications, vol 11. Elsevier, Amsterdam, pp 518–523
Nakanoh M, Yoshida F (1980) Gas absorption by Newtonian and non-Newtonian liquids in a bubble column. Ind Eng Chem Process Des Dev 19:190–195
Nielsen J, Krabben P (1995) Hyphal growth and fragmentation of Penicillium chrysogenum in submerged cultures. Biotechnol Bioeng 46:588–598
Nielsen J, Johansen CL, Jacobsen M, Krabben P, Villadsen J (1995) Pellet formation and fragmentation in submerged cultures of Penicillium chrysogenum and its relation to penicillin production. Biotechnol Prog 11:93–98
O’Connor CT, Randall EW, Goodall CM (1990) Measurement of the effects of physical and chemical variables on bubble size. Int J Miner Process 28:139–140
Pacek AW, Moore IPT, Nienow AW, Calabrese RV (1994) Video technique for measuring dynamics of liquid–liquid dispersion during phase inversion. AIChE J 40(12):1940–1949
Pacek AW, Man CC, Nienow AW (1998) On the Sauter mean diameter and size distributions in turbulent liquid/liquid dispersions in a stirred vessel. Chem Eng Sci 52(11):2005–2011
Packer HL, Thomas CR (1990) Morphological measurements on filamentous microorganisms by fully automatic image analysis. Biotechnol Bioeng 35:870–881
Packer HL, Keshavarz-Moore E, Lilly MD, Thomas CR (1992) Estimation of cell volume and biomass of Penicillium chrysogenum using image analysis. Biotechnol Bioeng 39:384–391
Pan X-H, Luo R, Yang X-Y, Yang H-J (2002) Three dimensional particle image tracking for dilute particle–liquid flows in a pipe. Meas Sci Technol 13(8):1206–1216
Papagianni M (2004) Fungal morphology and metabolite production in submerged mycelial processes. Biotechnol Adv 22:189–259
Papagianni M, Mattey M, Kristiansen B (1998) Citric acid production and morphology of Aspergillus niger as functions of the mixing intensity in a stirred tank and a tubular loop bioreactor. Biochem Eng J 2:197–205
Parthasarathy R, Ahmed N (1996) Size distributions of bubbles generated by fine-pore spargers. J Chem Eng Jpn 29(6):1030–1034
Patel SA, Glasgow LA, Erickson LE, Lee CH (1986) Characterization of the downflow section of an airlift column using bubble size distribution measurements. Chem Eng Commun 44:1–20
Paul GC, Thomas CR (1998) Characterisation of mycelial morphology using image analysis. Adv Biochem Eng Biotechnol 60:1–59
Paul GC, Kent CA, Thomas CR (1992) Quantitative characterization of vacuolization in Penicillium chrysogenum using automatic image analysis. Trans IchemE 70:13–20
Pichon D, Vivier H, Pons MN (1993) Growth monitoring of filamentous microorganisms by image analysis. In: Karim MN, Stephanopoulos G (eds) Modeling and control of biotechnology processes. Pergamon, New York, pp 307–317
Pichon D, Vivier H, Pons MN (1993) Growth monitoring of mammalian cells on microcarriers by image analysis. In: Karim MN, Stephanopoulos G (eds) Modeling and control of biotechnology processes. Pergamon, New York, pp 311–314
Pons MN, Wagner A, Vivier H, Marc A (1992) Application of quantitative image analysis to a mammalian cell line grown on microcarriers. Biotechnol Bioeng 40:187–193
Pottel F, Bellgardt KH (1992) Investigation of morphology of pellets during cultivations of Penicillium chrysogenum by digital image processing. In: Dechema biotechnology conference 5 (pt A). Microbial principles in bioprocesses: cell culture technology, downstream processing and recovery. VCH-Verlagsgesellschaft, Karlsruhe, pp 381–386
Pulido-Mayoral N, Galindo E (2004) Phase dispersion and oxygen transfer in a simulated fermentation broth containing caster oil and proteins. Biotechnol Prog 20:1608–1613
Randall EW, Goodall CM, Fairlamb PM, Dold PL, O’Connor CT (1989) A method for measuring the sizes of bubbles in two- and three-phase systems. J Phys E Sci Instrum 22(10):827–833
Reichl U, Gilles ED (1991) Investigations of pellet-forming microorganisms by means of an image processing system. In: Reuss M, Chmiel H, Gilles ED (eds) Biochemical engineering. Gustav Fischer, Stuttgart, pp 336–339
Reichl U, King R, Gilles ED (1992) Characterization of pellet morphology during submerged growth of Streptomyces tendae by image analysis. Biotechnol Bioeng 39(2):164–170
Rinas U, El-Enshasy H, Emmler M, Hille A, Hempel D, Horn H (2005) Model-based prediction of substrate conversion and protein synthesis and excretion in recombinant Aspergillus niger biopellets. Chem Eng Sci 60:2729–2739
Rodger WA, Trice VG, Rushton JH (1956) Effect of fluid motion on interfacial area of dispersions. Chem Eng Prog 52(12):515–520
Russ JC (1995) The image processing handbook, 2nd edn. CRC Press, Boca Raton
Ryoo D (1999) Fungal fractal morphology of pellet formation in Aspergillus niger. Biotechnol Tech 13:33–36
Saberi S, Shakourzadeh K, Bastoul D, Militzer J (1995) Bubble size and velocity measurement in gas–liquid systems: applications of fiber optic techniques to pilot plant scale. Can J Chem Eng 73:253–257
Schafer R, Merten C, Eigenberger G (2002) Bubble size distributions in a bubble column reactor under industrial conditions. Exp Therm Fluid Sci 26:595–604
Shenoy P (2004) Process analytical technology. Pharma Times 36:37–38
Song Q, Luo R, Yang XY, Wang Z (2001) Phase distributions for upward laminar dilute bubbly flows with non-uniform sizes in a vertical pipe. Int J Multiph Flow 27:379–390
Sotiriadis AA, Thorpe RB, Smith JM (2005) Bubble size and mass transfer characteristics of sparged downwards two-phase flow. Chem Eng Sci 60:5917–5929
Spohr A, Dam-Mikkelsen C, Carlsen M, Nielsen J (1998) On-line study of fungal morphology during submerged growth in a small flow-through cell. Biotechnol Bioeng 58(5):541–553
Srivastava P, Hahr O, Buchholz R, Worden RM (2000) Enhancement of mass transfer using colloidal liquid aphrons: measurement of mass transfer coefficients in liquid–liquid extraction. Biotechnol Bioeng 70(5):525–532
Stravs AA, Pittet A, von Stockar U, Reilly PJ (1986) Measurement of interfacial areas in aerobic fermentations by ultrasonic pulse transmissions. Biotechnol Bioeng 28:1302–1309
Taboada B, Larralde P, Brito T, Vega-Alvarado L, Diaz R, Galindo E, Corkidi G (2003) Image acquisition of multiphase dispersions in fermentation processes. J Appl Sci Technol 1(1):78–82
Takahashi K, Nienow AW (1993) Bubble sizes and coalescence rates in an aerated vessel agitated by a Rushton turbine. J Chem Eng Jpn 26(5):536–542
Takahashi K, McManamey WJ, Nienow AW (1992) Bubble size distributions in impeller region in a gas-sparged vessel agitated by a Rushton turbine. J Chem Eng Jpn 25:427–432
Tamura S, Park Y, Toriyama M, Okabe M (1997) Change of mycelial morphology in tylosin production by batch culture of Streptomyces fradiae under various shear conditions. J Ferment Bioeng 83(6):523–528
Tough AJ, Prosser JI (1996) Experimental verification of mathematical model for pelleted growth of Streptomyces coelicolor A3(2) in submerged batch culture. Microbiology 142(3):639–648
Treskatis S-K, Orgeldinger V, Wolf H, Gilles ED (1997) Morphological characterization of filamentous microorganisms in submerged cultures by on-line digital image analysis and pattern recognition. Biotechnol Bioeng 53:191–201
Tucker KG, Kelly T, Delgrazia P, Thomas CR (1992) Fully-automatic measurement of mycelial morphology by image analysis. Biotechnol Prog 8:353–359
Vanhoutte B, Pons MN, Thomas CR, Louvel L, Vivier H (1995) Characterization of Penicillium chrysogenum physiology in submerged cultures by color and monochrome image analysis. Biotechnol Bioeng 48:1–11
van Suijdam JC, Metz B (1981) Influence of engineering variables upon the morphology of filamentous molds. Biotechnol Bioeng 23:111–148
Vardar-Sukan F (1985) Dynamics of oxygen mass transfer in bioreactors. Part I. Operating variables affecting mass transfer. Proc Biochem 20(6):181–184
Vecht-Lifshitz SE, Magdassi S, Braun S (1990) Pellet formation and cellular aggregation in Streptomyces tendae. Biotechnol Bioeng 35:890–896
Vega-Alvarado L, Cordova MS, Taboada B, Galindo E, Corkidi G (2004) Online Sauter diameter measurement of air bubbles and oil drops in stirred bioreactors using Hough transform. In: Campilho A, Kamel M (ed) ICIAR 2004, image analysis and recognition, pt. 2 proceedings. LNCS 3212. Springer, Berlin, pp 834–840
Vermeulen T, Williams GM, Langlois GE (1955) Interfacial area in liquid–liquid and gas–liquid agitation. Chem Eng Prog 51(2):85F–94F
Walter JF, Blanch HW (1986) Bubble break-up in gas–liquid bioreactors: break-up in turbulent flows. Chem Eng J 32:B7–B17
Wittler R, Baumgartl H, Lübbers DW, Schügerl K (1986) Investigations of oxygen transfer into Penicillium chrysogenum pellets by microprobe measurements. Biotechnol Bioeng 28:1024–1036
Yang H, Reichl U, King R, Gilles ED (1992) Measurement and simulation of the morphological development of filamentous microorganisms. Biotechnol Bioeng 39:44–48
Zalewski K, Buchholz R (1996) Morphological analysis of yeast cells using an automated image processing system. J Biotechnol 48:43–49
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Junker, B. Measurement of bubble and pellet size distributions: past and current image analysis technology. Bioprocess Biosyst Eng 29, 185–206 (2006). https://doi.org/10.1007/s00449-006-0070-3
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DOI: https://doi.org/10.1007/s00449-006-0070-3