39 icalEngineering, and has been a 20,40–42 This paper details various ddin,SchoolofChem 43,44 2011 Society of Chemical Industry Universitas Lampung, Bandar Lampung c When an enzyme is on the membrane, 45,46 and Subhash Bhatia ∗ a and suspended enzymes; hydrolysis reactions; esterification; Correspondenceto:AzlinaHarun Kamaru Universiti Sains Malaysia, 14300 Nibong Tebal, PulauE-mail: Pinang, [email protected] Malaysia. School ofMalaysia, Chemical 14300 Nibong Tebal, Engineering, Pulau Pinang, Malaysia Engineering Campus,Department of Chemical Universiti Engineering, Sains 35145, Lampung, Indonesia Work on two separate phase-enzymatic membrane reactors ∗ a b ve process since it has a large interfacial area and exchange ts. Many factors influence its successful operation, and these es were resolved primarily by kinetic resolution, but dynamic n hydrolytic reactions, but esterification processes were also determining factors of thein TSP-EMR, development which should of be thetechnology examined technology. with Different its different applications characteristics of are described. the employed in plant-scale capacities. (TSP-EMR or biphasic EMR) were started many years after Rony published a pioneeringhollow report fibre membranes on (HFM).still Up enzymes to uses immobilization now, the the in HFMand TSP-EMR, as which achiral the enzymes compounds dock,Production such has of processed the as racemic single drugs,used enantiomers this acids, EMR from type. an esters Thekinetic achiral technology resolution and of was substrate the encouraged racemic oils. compounds, in dynamic TSP-EMR: BASIC NEEDS Immobilization of enzymesnecessary at for EMR organic–aqueousat implementation. these interfaces Many interfaces. is enzymes are active eration, membrane material and size, enzyme preparation and uld be specified. The immobilization site, reactor arrangement, tion and immobilized or suspended enzyme(s) are determined The The 1–12 30–32 25–27 23,24 13–15 Compared 28,29 to US$ 225 billion 16 thus selective removal of -blockers, the distomers give β 21,22 : 1032–1048 www.soci.org Azlina Harun Kamaruddin 18–20 86 a,b 2011; Studies show that one of the best approaches 33 enzymatic membrane reactors; operational factors; immobilised Many methods have been applied to generate single Therefore, it is an attractive alternative to the enzymatic 37,38
17 34–36 -blocking effects, reduce the overall drug selectivity, produce
β 2011 Society of Chemical Industry Enzymatic resolution of racemic compounds in membrane c to improveEMR. economic and technical competitiveness is the products from reactioninhibited sites or increases thermodynamically unfavourable conversion reactions. of product- processes. reactors (enzymatic membranebenefits. reactors Conversion and ortake separation place EMR) in of give a the single many operation, enantiomers can need for single enantiomericfrom the synthetic world market, where drugs consumption of canincreased single rapidly enantiomers be from US$ 74.4 observed billion in 1996 EMR overcomes disadvantages of batch stirred tank reactors, J Chem Technol Biotechnol They could provideenantiomers. an efficient and cleaner route to single consumes low energy and is easy to scale-up. side-effects as the eutomers or possibly cause adverse effects. no These facts emphasize they usuallytions. do not Hence, contribute enantiomers to should medica- be used individually. INTRODUCTION Enantiomers of drugs oftenpharmacodynamic have properties. As different in pharmacokinetic and Abstract A two separate phase-enzymatic membrane reactor is an attracti phase operations Joni Agustian, surfaces, simultaneous reaction and separationinclude and characteristics other of benefi the enzyme, membrane,are circulating fluids the and reactor main operations. factor, Althoughdevelopment, the the other solubility operating of substrates conditions factors and products, must type ofloading op be procedure, and considered cleanliness of before, the recirculated during fluids or sho after itslater. application. Some factors At still the needcapacity initial further to studies. stage process Utilization racemic of of and achiral the reactor kinetic compounds. technology resolution The is has racemat described been for exploited.exploited. use The from technology multigram- focused to o plant-scale Keywords: the determining factors in two separate Enzymatic membrane reactors: (wileyonlinelibrary.com) DOI 10.1002/jctb.2575 Review Received: 30 August 2010 Revised: 10 December 2010 Accepted: 10 December 2010 Published online in Wiley Online Library: 19 January 2011 dissolved or no-solvent operation, classic or emulsion opera kinetic resolution in 2005. enantiomeric synthetic drugs. with other technologies,stability, better control the of single enantiomers EMR production, enriched and has concentrated high products productivity and decreased and reaction times.
1032 1033 Xin but It is 97 93,94 89–92 Although higher 57,101–103 wileyonlinelibrary.com/jctb 36,37,50 For the TSP-EMR, temperature, 71 Many lipases show high activity in hy- 98 99,100 Although the reactor design for the biphasic 92,96 suggested an aqueous-organic biphasic system or a water 95 . In the biphasic system, characteristics of the organic solvent Operating conditions of the TSP-EMR are described in Table 1. pH of the aqueousimmobilized phase, enzyme, concentration transmembrane of pressure thethe and substrate(s) organic and flow and aqueous phase rate are of conditionedMost during operation. of thethe factors optimum could performance;activity however, be during the the managed processes immobilized is externallyby not enzyme evaluating controlled; to enzyme this deactivation. is achieve determined system has severaldrug complications, solubility problem the and system forms overcomes irreversible the reactions. are important since thevaries enzymatic significantly. activity in the organic phase The technology isrun mostly in applied in batchperformed hydrolytic at recirculation mild reactions, temperatures, mode.low and transmembrane relatively pressures In and long medium flow reaction rates general,and in times, the lumen-side shell- operations to give are lowhigh selectivities. to The organic high and aqueous conversions phases are andboth fed through medium sides to ofduring the experiments. HFM modules. All parameters are measured Fluids characteristics Enzymes are stable and active in organic solvents, drophobic solvents with low polarities. saturated organic solvent reactiondrugs. in Lipases hydrolysis are ofinterfaces. found the to racemic be effective at the organic–water of gas phase,issue, but etc. other sensitive (Fig. factors 2). should alsoduring be Operating considered and before, after conditions application. are the main Operating conditions Operatingconditionsisoneofthemostimportantfactors,involved in scale-up of a reaction process. a certain amountneeded to of keep them water in catalytically active bound conformation. on to enzyme surfaces is et al undeniable that the solvent andon water enantioselectivity. content may have effects 2011 Society of Chemical Industry c as illustrated andreduction Use of HFM to 29,47 49,50 They also have high The modules have 50,56 ) has to be moved to 35,70 S 32,57–59 and enzyme conformational 54,55 50,57,60–62 This system is of interest when Use of this biphasic EMR is highly : 1032–1048 48 64,67 ) has to be transported from the 86 P 51–53 2011; Other membrane configurations having only one However, they have several drawbacks, for instance diffusion resistance 68,69 Materials transportation in an enzymatic membrane reactor. 63 62–66 The TSP-EMR is formed by two immiscible fluids, a continuous The HFM modules have four separate openings, an inlet and Two separate phase enzymatic membrane reactor www.soci.org enzyme sites, and productreaction sites ( to the other side of the membrane in Fig. 1. Catalytic activity ofapplicable the to enzyme the on two the separate interface phase makes membrane-based it system. organic phase and a continuous aqueousenzyme-membranes phase, separated interfaces. by the attractive when HFM are employed. an outlet forwhich each allow side continuous ofTransport flows could the be across achieved membrane using the hydrophobicpositive as membranes pressure membrane and on shown the surfaces. in aqueous sideand Fig. or 1, positive hydrophilic membranes pressure on the organic side. high interfacial area, absenceflow of rates, emulsion, no no unloadingdensity flooding difference at between at phases. low high flow rates and do not require J Chem Technol Biotechnol OPERATING CONSIDERATIONS: THE DETERMINING FACTORS Development ofenzyme the loading TSP-EMR procedure, involves membrane type operational and strategy, material, use Figure 1. in order for reaction to occur, substrate ( of down-stream processes. house the enzymes hasimmobilization advantages methods. Large over exchange conventional surface per enzymes unitis volume provided by these membranes. changes. products are insoluble inand the separation organic can phase besimplifiedprocess,reductioninproductioncost, since performed the simultaneously, reaction leading to a solutions must be free of particulate materials,of use of fibre, specific type connection to downstream/permeate-sidewound are such not suitable for as the application. the spiral- volumetric productivity, simultaneouseasily products reutilized, separation, cheap enzyme are fixation,catalytic little activity, high loss substrate of concentration, theactivity. and enzyme stable lipases : 1032–1048 108 This reduces 86 63 2011; called the TSP-EMR with 40 Only a small conversion difference 48 J Chem Technol Biotechnol suggested using an extremely pure liquid to Hydrolysis of oils also proceeded in a no-solvent 107 56 . 1 The increase of olive oil concentrations led to the − 76,77 min µ Cleanliness of the liquid/air phase is also an important factor. system. The solution must be free of particulate materials. key reactant(s) feda through ‘multiphase a EMR’; water-immisciblereactant(s) organic while is phase the referredin to aqueous Table as 1, phase the mostSince dissolving operations ‘extractive’ TSP-EMR key are type. operations based As areand on separation, described based the the reactant(s) on multiphase must simultaneousThis type. not means that mix reaction in the with multiphase TSP-EMR, the the substrate(s) product(s). should have high solubility in the organicaqueous solvent and phase. not In dissolve in contrast,in the the the product(s) aqueous phase, mustproblems. so dissolve Hence, the that easily solubility they behaviour canproduct(s) of must the be be substrate(s) considered, transported and since without many commercial organic Multiphase or extractive TSP-EMR In dissolved operation, substratesorganic can or be supplied aqueous either phase. in Matson the membranes fouling caused by unwanted materials thus increasing the membrane service life. Installation ofunits filters before and the reactor usematter. of Breslau non-corrosive materials prevents particulate avoid blockage or contamination of the membranes. Dissolved- or no-solvent operation Operating the TSP-EMRsolvents for to drugs dissolve the resolutionphase racemic uses (Table drugs 1). the and Dissolved-solvent tothe organic operations form are substrates the applied organic areoperations when solid have been compounds developedorganic or with phase. viscous no For solvent liquids. example,porcine added Some to ethyl liver the butyrate esterase was9600 in hydrolysed several by hours at the reaction rate of was found when this biphasicof EMR an was organic operated solvent in (60%) the or presence with the pure oil (50%). increase of catalytic efficiency. 73 . used Its re- )shifts et al 106 43 w . a 104 et al Hydrophobic 105 www.soci.org J Agustian, AH Kamaruddin, S Bhatia 2011 Society of Chemical Industry c Hydrophobic solvents 103 These results show that different This solution reduced the inhibitory 75 44 Albeit phosphate buffers were a good 56,85,86 found similar results in which the aqueous phase 44 . Factors in TSP-EMR operation. et al As described in Table 1, a common aqueous phase is phosphate are not dissolved easily in thein aqueous the phase, HFM so good modules interfaces based-on can strongly hydrophobic be solvents formed. suchTable Thus, as 1. The many those moisture content shown TSP-EMRs plays a in key are roleesterification in in enzyme-mediated organic media since high water activity ( product, shortened reaction time,and increased improved the the enantioselectivity. rate of reaction the chemical equilibrium towards the reverse reaction. aqueous phase, they occasionallya could proper not aqueous be environment. usedmethyl-methoxy As to phenylglycidate provide in (MMPG), hydrolysis the ofled phosphate to the buffer base-catalysed hydrolysis racemic of the substrateby-product, to form which aldehyde inhibitedhydrolysis, enzyme researchers activity; used hencealdehyde in contamination. a MMPG bisulphite solution to prevent solvents have lower capability to remove water fromso the that enzymes, in these solvents the enzymes have higher activity. buffer solution at pH values of 5.5–8.5. Kamaruddin wileyonlinelibrary.com/jctb concluded that the pHprocesses of greatly the influenced aqueous the phasephosphate lipase buffer during at enantioselectivity, pH hydrolytic 8 and resulted a in theenantioselectivity. highest optical During purity and esterificationthe of conversion racemic increased ketoprofen, but as pH it was dropped changed at from pH 6.0 to 8. 7.0, enantioselectivity is found insolvents hydrophilic provide solvents, higher hydrophobic reaction rates. Figure 2. quirement may vary as the solvent is changed. bisulphite solution pH 8.5, whichin produced enantioselectivity, a although pH significant 8.0 increase showed higher productivity. Dodds at pH 8 gavepH high 7 enantiomeric produced excess,of greater although the the hydrolysis. aqueous buffer Because at pH,added of to sodium the the hydroxide importance aqueous solutionbuffer phase was condition. during frequently TSP-EMR runs to maintain reactions require a different aqueous phase. Lopez
1034
1035
Recirculation
4 ufrp . 0 DN DBatch- ND ND ND 500 8.0 pH buffer 40,74 ty uyaeN,N-ovn S L pnePN5 .010Ehlbtrt 0 PO 500 butyrate Ethyl 0.80-1.0 50 PAN Sponge PLE NSO No-Solvent ND, butyrate Ethyl
Flow
Recirculation Counter substrate
4 56 Batch- Horizontal, ND 45 500 8 pH buffer ty uyaeN-ovn,05Lpure L 0.5 No-Solvent, butyrate Ethyl S L pneN D10Ehlbtrt 0 PO 500 butyrate Ethyl 1.0 ND ND Sponge PLE NSO
Recirculation
4
-lcdlbtrt D oSletNOPLSog A D08 lcdlbtrt 5-5 PO 250-350 butyrate Glycidyl 0.85 ND PAN Sponge PPL NSO No-Solvent ND, butyrate )-glycidyl ( ufrp . 5-5 DN DBatch- ND ND ND 250-350 7.8 pH buffer 40,56 ±
Recirculation wileyonlinelibrary.com/jctb
4 75 Batch- ND 40 ND ND 7 pH buffer -eorfn2-5m PCL pneP 0005Dclrpoae-hxn 0PO 40 hexane - Dichloropropane 0.015 10 PS Sponge CALB MP mM 20-35 )-ketoprofen ( ±
Recirculation
4 ufrp . 0 DN DBatch- ND ND ND 300 5.5 pH buffer 40 -bpoe PCLSog A D08 etnl30PO 300 Pentanol 0.85 ND PAN Sponge CCL MP M 2 )-ibuprofen ( ±
Recirculation
4 -bpoe se 0 ME epoeSog A 0N ylhxn 0 PO 400 Cyclohexane ND 50 PAN Sponge Seaprose EX mM 500 ester )-ibuprofen ( ufrp . 0 DN DBatch- ND ND ND 400 7.0 pH buffer 74 ±
Recirculation
4
ufrp . DHxn DN TN Batch- ND RT ND ND Hexane ND 7.0 pH buffer PO 1.90 18 Cellulose Lumen 6 Prozyme EX 41 -bpoe se 25 L g 32.51 ester )-ibuprofen (
±
1 −
Recirculation
4
XPoye6LmnPNN .5Ccoeae-oun DPO ND -Toluene Cyclohexane 0.85 ND PAN Lumen 6 Prozyme EX ufrp . DN 0N Batch- ND 30 ND ND 7.0 pH buffer 41 -bpoe se 6 L g 161 ester )-ibuprofen (
±
1 −
Recirculation
4
-bpoe se 46 L g 64.60 ester )-ibuprofen ( rzm pnePN5 . ylhxn DPO ND Cyclohexane 1.0 50 PAN Sponge 6 Prozyme CCL EX ufrp . DN 0N Batch- ND 20 ND ND 7.0 pH buffer 41
± +
1 −
Recirculation
4 -bpoe se D oSletNOCLSog A D08 ( 0.85 ND PAN Sponge CCL NSO No-Solvent ND, ester )-ibuprofen ( -bpoe se 0-5 PO 400-450 ester )-ibuprofen ufrp . 0–5 DN DBatch- ND ND ND 400–450 7.8 pH buffer 40,41 ± ±
Flow
Recirculation Counter
4 32,33,73 Batch- Horizontal, 40 40 50–450 8 pH buffer -bpoe se 510m PCLSog,LmnPN5 .9 sotn 020PO 50-250 Isooctane 0.093 50 PAN Lumen Sponge, CRL MP mM 25–100 ester )-Ibuprofen ( ±
Flow
Counter Recirculation
2011 Society of Chemical Industry
4 -arxnetrN PCLSog A5 DIocaeN PO ND Isooctane ND 50 PA Sponge CRL MP ND ester )-naproxen ( ufrp . DN DHorizontal, ND ND ND 7.0 pH buffer 72 Batch-
± c