Kooy, F.K., Beeftink, H.H., Eggink, G., Tramper, J., Boeriu, C.G.
Hyaluronan (HA) is a polysaccharide with high-potential medical applications, depending on the chain length and the chain length distribution. Special interest goes to homogeneous HA...
Membrane applications for antibiotics production (2009)
Beeftink, H.H., Tramper, J., Boom, R.M.
In the enzymatic production of antibiotics, membranes can be used for different purposes. Since the enzyme is a cost-determining factor, membrane bioreactors in which the ultrafiltration membrane's...
Drissen, R.E.T., Maas, R.H.W., Tramper, J., Beeftink, H.H.
In ethanol production from cellulose, enzymatic hydrolysis, and fermentative conversion may be performed sequentially (separate hydrolysis and fermentation, SHF) or in a single reaction vessel...
Cell cultures from the symbiotic soft coral Sinularia flexibilis (2008)
Mohammad K. Khalesi, D. K. Aanen, H. H. Beeftink, R. H. Wijffels
Briels, W.J., Bussmann, P.J.T., Beeftink, H.H., Boom, R.M.
The rich phase behavior of granular beds of bidisperse hard spherical particles in a rotating horizontal drum is studied by Discrete Element Method (DEM) simulations. Several flow regimes and various...
Kootstra, A.M.J., Mosier, N.S., Scott, E.L., Beeftink, H.H., Sanders, J.P.M.
Sugar degradation occurs during acid-catalyzed pretreatment of lignocellulosic biomass at elevated temperatures, resulting in degradation products that inhibit microbial fermentation in the ethanol...
Briels, W.J., Bussmann, P.J.T., Beeftink, H.H., Boom, R.M.
The rich phase behavior of granular beds of bidisperse hard spherical particles in a rotating horizontal drum is studied by Discrete Element Method (DEM) simulations. Several flow regimes and various...
Cell cultures from the symbiotic soft coral Sinularia flexibilis (2008)
Khalesi, M.K., Vera-Jimenez, N.I., Aanen, D.K., Beeftink, H.H., Wijffels, R.H.
The symbiotic octocoral Sinularia flexibilis is a producer of potential pharmaceuticals. Sustainable mass production of these corals as a source of such compounds demands innovative approaches,...
Otter Den, W.K., Briels, W.J., Bussmann, P.J.T., Beeftink, H.H., Boom, R.M.
The rich phase behavior of granular beds of bidisperse hard spherical particles in a rotating horizontal drum is studied by Discrete Element Method (DEM) simulations. Several flow regimes and various...
Khalesi, M.K., Beeftink, H.H., Wijffels, R.H.
The branching zooxanthellate soft coral Sinularia flexibillis releases antimicrobial and toxic compounds with potential pharmaceutical importance. As photosynthesis by the symbiotic algae is vital to...
Drissen, R.E.T., Maas, R.H.W., Kabel, M.A., Schols, H.A., Tramper, J., ...
The kinetics of cellulose hydrolysis by commercially available Cellubrix were described mathematically, with Avicel and wheat straw as substrates. It was demonstrated that hydrolysis could be...
Web-based education in bioprocess engineering (2007)
Sessink, O.D.T., Beeftink, H.H., Hartog, R., Tramper, J.
The combination of web technology, knowledge of bioprocess engineering, and theories on learning and instruction might yield innovative learning material for bioprocess engineering. In this article,...
Biocatalysts: Measurement, modelling and design of heterogeneity (2007)
Multiple phenomena are involved in conversions by immobilized biocatalysts. A paradox is identified between analytical desires on one hand and analytical boundary conditions on the other: while the...
Web-based education in bioprocess engineering (2007)
Sessink, O.D.T., Beeftink, H.H., Hartog, R.J.M., Tramper, J.
The combination of web technology, knowledge of bioprocess engineering, and theories on learning and instruction might yield innovative learning material for bioprocess engineering. In this article,...
Flow-dependent growth in the zooxanthellate soft coral Sinularia flexibilis (2007)
Khalesi, M.K., Beeftink, H.H., Wijffels, R.H.
Growth characteristics of colonies of the branching zooxanthellate octocoral Sinularia flexibilis, with potential pharmaceutical importance, were measured over a range of water velocities. The...
Proteus: A lecturer-friendly adaptive tutoring system (2007)
Sessink, O.D.T., Beeftink, H.H., Tramper, J., Hartog, R.J.M.
Effectively targeting a heterogeneous student population is a common challenge in academic courses. Most traditional learning material targets the ¿average student,¿ and is suboptimal for students...
Drissen, R.E.T., Maas, R.H.W., Kabel, M.A., Schols, H.A., Tramper, J., ...
The kinetics of cellulose hydrolysis by commercially available Cellubrix were described mathematically, with Avicel and wheat straw as substrates. It was demonstrated that hydrolysis could be...
Modelling ethanol production from cellulose (2007)
Co-production of bioethanol, lactic acid, electricity and heat from lignocellulosic biomass Public report EET project K01116 J.H. Reith J.A.M. de Bont (editors) SEPTEMBER 2007
Virtual parameter-estimation experiments in Bioprocess-Engineering education (2006)
Sessink, O.D.T., Beeftink, H.H., Hartog, R.J.M., Tramper, J.
Cell growth kinetics and reactor concepts constitute essential knowledge for Bioprocess-Engineering students. Traditional learning of these concepts is supported by lectures, tutorials, and...
A multicomponent reaction-diffusion model of a heterogeneously distributed immobilized enzyme (2006)
Kallenberg, A.I., Paasman, M.A., Tramper, J., ...
A physical model was derived for the synthesis of the antibiotic cephalexin with an industrial immobilized penicillin G acylase, called Assemblase. In reactions catalyzed by Assemblase, less product...
Controlled biosynthesis of glycoseaminoglycan polymers (2006)
Kooy, F.K., Beeftink, H.H., Boeriu, C.G., Eggink, G., Tramper, J.
Field-emission scanning electron microscopy (FESEM) was used in a technical feasibility study to obtain insight into the internal morphology and the intraparticle enzyme distribution of Assemblase®,...
Enzyme distribution and matrix characteristics in biocatalytic particles (2005)
Boom, R.M., Paasman, M.A., Tramper, J., Beeftink, H.H.
In a study of Assemblase®, an industrial immobilized penicillin-G acylase, various electron microscopic techniques were used to relate intra-particle enzyme heterogeneity with the morphological...
Fluidized-bed and packed-bed characteristics of gel beads (2005)
Tramper, J., Rinzema, A., Beeftink, H.H.
A liquid-fluidized bed or packed bed with gel beads is attractive as an immobilized-cell bioreactor. The performance of such bioreactors is influenced by the physical behavior of these beads. Three...
Database functionality for learning objects (2005)
Sessink, O.D.T., Beeftink, H.H., Hartog, R.J.M.
The development of student-activating digital learning material in six research projects revealed several shortcomings in the current learning management systems. Once the SCORM 2004 and the IMS...
Securing web-based exams (2004)
Sessink, O.D.T., Beeftink, H.H., Tramper, J., Hartog, R.J.M.
Learning management systems may offer web-based exam facilities. Such facilities entail a higher risk to exams fraud than traditional paper-based exams. The article discusses security issues with...
Author-defined storage in the next generation learning management systems (2003)
Sessink, O.D.T., Beeftink, H.H., Tramper, J., Hartog, R.J.M.
Process intensification: A case for solid-to-solid biocatalysis (2003)
Beeftink, H.H., Michielsen, M.J.F., Ooijkaas, L.P., Tramper, J.
Tramper, J., Joerink, M., Beeftink, H.H.
The macroscopic kinetic behavior of an industrially employed immobilized penicillin-G acylase, called Assemblase, formed the basis for a discussion on some simple intraparticle biocatalytic model...
Optimisation of microbial 3-methylcatechol production as affected by culture conditions (2002)
Hüsken, L.E., Beeftink, H.H., Tramper, J., Wery, J.
Pseudomonas putida MC2 can be used to produce catechols. The accumulation, specific and volumetric production rates of 3-methylcatechol from toluene have been studied. Production rates were shown to...
In situ product removal during enzymatic cephalexin synthesis by complexation (2002)
Nierstrasz, V.A., Bosma, R., Kemperman, G.J., Strubel, M., Ooijkaas, L.P., ...
In this paper, `complexation' indicates the formation of clathrate type inclusion compounds of cephalexin with naphthalene derivatives. These inclusion compounds readily crystallise in solution,...
Integrated reactor concepts for the enzymatic kinetic synthesis of cephalexin (2002)
Nierstrasz, V.A., Bosma, R., Kroon, P.J., Tjeerdsma, P.S., DeVroom, E., ...
Integrated process concepts for enzymatic cephalexin synthesis were investigated by our group, and this article focuses on the integration of reactions and product removal during the reactions. The...
Process design for enzymatic adipyl-7-ADCA hydrolysis (2002)
Nierstrasz, V.A., Bosma, R., Dijkstra, Z.J., Beeftink, H.H., ...
Assessment of intraparticle biocatalytic distributions as a tool in rational formulation (2002)
Research has shown that the intraparticle biocatalytic distribution has extensive effects on the properties of various (industrial) biocatalytic particles and their performance in (bio-) chemical...
Process design for enzymatic Adipyl-7-ADCA hydrolysis (2002)
Nierstrasz, V.A., Bosma, R., Dijkstra, Z.J., Beeftink, H.H., ...
In situ product removal during enzymatic cephalexin synthesis by complexation (2002)
Nierstrasz, V.A., Bosma, R., Kemperman, G.J., Strubel, M., Ooijkaas, L.P., ...
Integrated reactor concepts for the enzymatic kinetic synthesis of cephalexin (2002)
Nierstrasz, V.A., Bosma, R., Kroon, P.J., Tjeerdsma, P.S., Vroom, E. De, ...
Nierstrasz, V.A., Moody, H.M., Hoogschagen, M.J., Kroon, P.J., Bosma, R., ...
During enzymatic kinetic synthesis of cephalexin, an activated phenylglycine derivative (phenylglycine amide or phenylglycine methyl ester) is coupled to the nucleus 7-aminodeacetoxycephalosporanic...
Integrated bioproduction and extraction of 3-methylcatechol (2001)
Hüsken, L.E., Dalm, M.C.F., Tramper, J., Wery, J., Beeftink, H.H.
Solid-to-solid bioconversions: batch or continuous? (2001)
Michielsen, M.J.F., Wijffels, R.H., Tramper, J., Beeftink, H.H.
Biocatalytic production of semi-synthetic cephalosporis: process technology and integration (2001)
Tramper, J., Beeftink, H.H., Janssen, A.E.M., Ooijkaas, L.P., Strubel, M., ...
Growth of Ca-D-malate crystals in a bioreactor (2000)
Michielsen, M.J.F., Frielink, C., Wijffels, R.H., Tramper, J., Beeftink, H.H.
To develop a bioreactor for solid-to-solid conversions, the conversion of solid Ca-maleate to solid Ca-D-malate by permeabilized Pseudomonas pseudoalcaligenes was studied. In a bioreactor seeded with...
Modeling solid-to-solid biocatalysis : Integration of six consecutive steps (2000)
Michielsen, M.J.F., Frielink, C., Wijffels, R.H., Tramper, J., Beeftink, H.H.
A quantitative model for the conversion of a solid-substrate salt to a solid-product salt in a batch bioreactor seeded with product crystals is presented. The overall process consists of six serial...
Effect of temperature of the saccharide composition obtained after alpha-amylosysis of starch (1999)
Marchal, L.M., Goetheer, E., Schimmelpennink, E.B., Bergsma, J., Beeftink, H.H., ...
Stabilization of maleate-hydratase activity of permeabilized Pseudomonas pseudoalcaligenes (1999)
Michielsen, M.J.F., Frielink, C., Meijer, E.A., Wijffels, R.H., Tramper, J., ...
Thermodynamically controlled synthesis of cefamandole (1999)
Nierstrasz, V.A., Bosma, R., Kroon, P.J., Beeftink, H.H., Janssen, A.E.M., ...
Thermodynamically controlled synthesis of cefamandole (1999)
Nierstrasz, V.A., Bosma, R., Kroon, P.J., Beeftink, H.H., Janssen, A.E.M., ...
Kinetics of D-malate production by permeabilized Pseudomonas pseudoalcaligenes. (1998)
Michielsen, M.J.F., Meijer, E.A., Wijffels, R.H., Tramper, J., Beeftink, H.H.
Dissolution kinetics of Ca-maleate crystals: evalution for biotransformation reactor design. (1998)
Michielsen, M.J.F., Reijenga, K.A., Wijffels, R.H., Tramper, H., Beeftink, H.H.
Serial air-lift bioreactors for the approximation of aerated plug flow. (1997)
Bakker, W.A.M., Overdevest, P.E.M., Beeftink, H.H., Tramper, J.
Structure and Dynamics of Anaerobic Bacterial Aggregates in a Gas-Lift Reactor
Beeftink, H. H., Staugaard, P.
Anaerobic mixed-culture aggregates, which converted glucose to acetic, propionic, butyric, and valeric acids, were formed under controlled conditions of substrate feed (carbon limitation) and...
Structure and Dynamics of Anaerobic Bacterial Aggregates in a Gas-Lift Reactor
Beeftink, H. H., Staugaard, P.
Anaerobic mixed-culture aggregates, which converted glucose to acetic, propionic, butyric, and valeric acids, were formed under controlled conditions of substrate feed (carbon limitation) and...