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Journal of Scientific & Industri al Research Vo1.59, April 2000, pp 286-293
Detoxification of Phenols and Aromatic Amines from Polluted Wastewater by Using Phenol Oxidases
Qayyum Husain * and Ulfat Jan
Department of Bioche mi stry, Faculty o f Life Sciences , Aligarh Mus lim U ni vers ity, Aligarh 202002, India
Received: 30 August 1999; accepted: 15 November 1999
The applications of treatment of industri al wastewater containing phenol s and aromat ic amines have received increased atten ti on in recent past. Classical chemical and physical methods arc not successfu l due to varying drawbacks in these methods. Biological treatment o f was tewater is also facing some serious limitations and is more expensive. It is expected that those methods based on oxido-reducti ve enzymes have the potential to detoxify the was tewater contai ning pheno ls and aromati c amines and can provide an a lternative procedure to all other known methods. An advant age of this procedure is that these enzymes ac t on a broad range of substrates and under the low concent ra tion of substrates . Nu merous phenol-axidases are described here such as perox idases, tyrosinases, and laccases. An attempt has been made to review the work carried out by using sol ubl e as well as immobiiized ox ido-reductive enzymes fo r the remo val o f phenols and aromati c ami nes from industrial wastewaters.
Introduction
Decades of industrial acti vity have resulted in the synthesis and introduction of a plethora of tox ic chemicals into the biosphere. However, "Management" of these wastes cannot be equated with safe di sposa l. Continuation of thi s trend may have catastrophic impact on human health and environment. Therefore, effective means of solving thi s po llution problem must be developed to preserve the quality of life for future generations. Phenols and aromatic amines are the most important c lasses of synthetic industrial chemicals and are often present in the industri al effluents from various manufacturing operations I. Numerous chemical industries, sending these tox ic chemicals in the environment, are: coal conversion , petroleum refinin g, res in and plasti c, dyes and other organic chemicals, textile, timber, mining and dress ing, pulp and paper2-4. In addition, among the different classes of pollutants those that enter the environment , some of them are also deri ved from agricultural acti v i t i ~s . Large scale use of herbicides, insecti sides and pes ticides in agriculture contributes to the presence of these hazardous material s in the surface and in the ground water. Phenol s and aromatic amines are also released as intermediary products during the microbial degradation of pest icides or some other xenobiotics5.0 . The vast majority of phenol s have been classified as tox ic ity priority pollutants and some of them are even known suspected * Author for co rresponde nce
carc inogens 7- 111. The pollutants such as phenols and aromatic amines play an important ro le in the ecolog ica l balance of some of the compartments of so il and water". The presence of these che mical in ground water or in drinking water pose a significant hea lth risk. Therefore, the decontamination of these molecules from an industrial aqueous effluent, is an important practical aspect prior to the ir final di scharge. umerous methods have been tried in recent years to remove o r to transform these molecules .
Con ventional phys ical and chemical methods for the removal or transformation of phenols and aromatic amines are actually outdated due to their limitations, such as high cost, incompleteness of purification, formation of hazardous byproducts and due to app licability to onl y a limited range of phenol concentrati o 12-15 However, one of the most promis ing way to remove these substances, is via bi olog ical treatment, us ing d ifferent types of micro-organi sms due to its potential it ies for complete mineralization 10-211 .
There are certain limitations of us ing microbes for treat ing these po llutants such as those h igh cost o f production of microbial culture, limited mobility and survival of cells in the soil , alternate carbon ources, completion of the indigenous population and metabo lic inhibi tion 2 1
,22 . Numerous organisms have been used for the complete degradation of phenols and other related chemicals but much success has not been achieved yet23-25.
HUSAIN & JAN : DETOXIFICATION OF PHENOLS AND AROMATIC AMINES 287
Enzymatic Treatment of Phenols and Aromatic Amines
In the recent past an enzymatic approach has attracted much interest, as an alternative method to the conventional, physical an-i chemical procedures for the removal of phenols and aromatic amines from wastewaters. In early I 980s, researchers first time developed an idea of using ox ido-reductive enzymes for treating wastewater containing these toxic chemicals26
.30. Some work
ers suggested that enzymes could be used to oxidize phenol s to free radicals or to quinones and benzoquinoneimine30. These oxidation products can couple to each other resulting in the formation of water insoluble oligomers or polymers. These insoluble complexes are less toxic as compared to their so luble substrates and can be easily removed from the reaction mixture by simple filtration or sedimentation or centrifugation26 .. 31• A wide spectmm of oxidoreductive enzy mes have been considered for these studies, such as perox idases26 .. 2Y , laccases6.32 and tyrosinases3o. It has been demonstrated that peroxidases from different sources can be used in the decontaminati on of phenols and aromatic am ines" .. 3Y .
An advantage of thi s enzymatic approach is that these enzymes can react with a broad range of phenols under the dilute condition and are less sensiti ve to operational upsets than the microbial populations30.
The work on the use of horseradish peroxidase in the detoxi ficati on of various phenols and other aromatic compounds has been in focus due to economical source
of enzyme, slow inhibition caused by product and the action of enzyme on a wide spectrum of substrates. Horseradish peroxidase catalyzes the precipitation of phenols and aromatic amines from aqueous solution and decolorization of phenolic industrial eftluents26 .. 2X.40. Various phenols and aromatic amines are oxidized and the corresponding free radicals by perox idases in the presence of hydrogen peroxide as an oxidant are formed . Free radicals polymerize to form the products which are less soluble in water4 1
• Peroxidase catalyzes the polymerization of phenols by three distinct reaction steps, initiation, radical-radical coupling and radical tran sf~r ' .
The major problem in the development of peroxidase based catalysis for industri al applications is the susceptibility of the enzyme to inactivation42
.. 44
, which is caused by adsorption of enzyme molecules on the final product of reaction . Some researchers have reported the add ition of certain adsorbants in the reaction mixture to prevent the inactivation of peroxidase during the catalytic cycle. These additives adsorb the product of reaction and thus prevent the loss of enzyme activity3~ 30 . Wu et a /4
-' have optimized the reaction conditions for enzymatic removal of phenols from wastewater by using perox idase in the presence of polyethylene glycol. The presence of thi s adsorbant helps in increasing the shelf-life of enzyme. In another study, Tatasumi et al.46 have shown that phenols could be effectively removed by treatment with horseradish peroxidase in the presence of a coagulant. Peroxidase when used alone gets rapidly inacti vated during the reaction while in the presence of the coagulant the amount of peroxidase required for the removal
Dr QayyulII Husain is presently working as a Reader in the Department of Biochemistry, Faculty of Life Sc iences. Aligarh Muslim University (AMU), Aligarh. He obtained his both Master 's deg ree and M.Phil in Biochemistn ' fro m AMU. SlIbseqllently he was also awarcled Ph.D f or his work on "The Imm obilization of Some Glycoenzyml's Using Concanavalin A As A Support " by AMU. He did his pos/-doctoral work on "The Role of Serine-threonine Proteinphosphatases Dllring the Development and Differentiation of Dictyostelillm-discoideum " at the FacilIty of Biolog \', Uni versity of Kons/(lnz, Germany. Dllring his post-doclOral work in German); he was awarded with the German Academic !:.x c/wnge Service Fellowship (DAAD -F ellowship). He joined AM U as a Lecturer in 1988 and since then he has worked on variolls aspect of enzymes and cells immobilization. Recently, he is working as a co-investigator on {/ UGC sponsored project "Polyc/onal AllIibody Mediated Immobilization of Some Enzymes. " At the same time he is also involved in the sw dy of immobilized phenol oxidases fo r the decontamination of phenols and aromatic wllines from indllstrial eJJ7uents. He has 15 y of research experience and has mallY international and national publications 10 his credit. His cllrrent interest is in the area of enzyme- immobilizatioll and its applicatiolls in various fields, particlliarly in the area of en virollmen/(ll technology.
Miss Ulfat Jan is presently working as a Research Fellow in the Department of Biochemistry, Faculty of Life Sciences, Aligarh Mll slim University, Aligarh. She obtained her M.Sc degree in Biochemistry from Kashmir University, SrinagCll; India. Presen tly she is working on the removal of phenols and aromatic aminesfrom wastewaters by using immobilized phenol oxidases.
288 J SCI IND RES VOL 59 APRIL 2000
of phenols is reduced and enzyme remain s acti ve during the e treatment. Arsegue l and Baboulene47 have demonstrated the acti on of peroxidase in the presence of a minerals and have shown that it could pro long the action of enzyme by adsorbing reaction products. Dec and Bollag4X
have used plant materi als for the detox ification of polluted water conta ining phenol s and chlorophenol s. This decontamination effect was due to the presence of peroxidases in the plant ti ssues. An industri al water conta ining vari ous chl orophenols was success fully treated with minced horseradish, potato and white radish. Horseradi sh medi ated re mova l of 2,4 dichlorophenol from mode l was te wate r was quite comparabl e w ith th at achieved by using purified horseradi sh perox idase. In a further study the selected removal of aromatic contami nants from water was observed by using a funga l perox idase from Coprinus moccrrohizus in batch reactors3X
•
The cost of the perox idase is compet it ive due to the use of expensi ve hydrogen perox ide in the trea tment of industri al effluents. The use of haemoglobin has been suggested as an alternati ve source, as it has perox idase acti vity and it is more abundant and cheaper pro te in ~~.
However use of hydrogen peroxide as an ox idant is found essentia l in e ither case.
Laccase and tyros inase require molecul ar oxygen for the formation of o ligomeric or po lymeric henols. Laccase can be eas ily isolated from the culture medium of Coriolus versicolor~()' ''' and it can act on a broad range of sub s titut ed ph e no ls 32 . Th e mec ha ni s m of dephenoli zation by laccase is the same as for perox idase. Thus, laccase ox idi zes phenols to the corresponding radicals which spontaneously polymeri ze to form insoluble compounds52. Moreover, laccase is also capable of cross-coupling toxic molecules with naturally occurring phenol s like syring ic ac id and vanillic ac id s"3"'~ and converts them into humic like polymers"""'6 . In an aerated liquid medium laccase can polymerize successfull y lignosulphonates from spent sulphite effluents.,7. Phenolic azodyes have been oxidi zed by using laccase from Pyricularia oryzae. It has been suggested that laccase oxidation can result in the detoxificati on of azo dyes"x.
The use of tyros inase was proposed as a cheaper alternative to horseradi sh peroxidase because it uses molecular oxygen as an oxidant instead of expens ive hydrogen peroxide. The cost of the laccase isolation from microbial sources is also a hurdle in the use of enzymes for the decontamination of various wastewaters. An easy ava ilability of ty ros inase and utili zation of free oxygen as an ox idant, will defini te ly reduce the cost of phenols
and aromatic a mines detoxificati on from indust ri a l wastewaters. An advantage of using tyrosinase as the dephenolizing enzy me was shown by some worke rs. Atlow and his co-workers have reported that the crude preparation of tyros i nase from mushroom was qui te comparable to the pure e nzyme in c learing t e phenols from coke plant was tewater31l.
There are certa in drawbacks in the use of ty rosinase, such as the format ion of low molecular weight o li gomers which remain in soluti on, less fo rmati on of insoluble prec ipitate and in acti vati on of enzy me by reactive in termedi ates during reacti o n 305~ . 1 order to overcome these limitations a two-step approach was suggested . The use of additives removes the reactive intermediate species by adsorbing from the olution and forming insol uble precipitate. Recentl y, ch itosan has been used as a suitabl e adso rbant during the ty rosi nase catalyzed reaction. Chitosan is a polysaccharide and obtained fro m waste material of she llfi sh indu try. This polymer contai ns amino groups whic h specifically binds with benzoquinone molecules and form in soluble aggregate which can be eas ily removed by centrifugation or fil trati onOil
.
Wada et 0 1.61.62 have in vestigated the remova l of phenols from industrial wastewater by us ing tyros inase, no precipitate was observed but a colour change from co lourless to dark brown was seen. The coloured product was precipitated by adding chi tosan and the reduction rate of phenols was reported to be enhanced in the presence of c hitosan. However, it has become necessary to add a large quantity of chitosan (1.4 mg/m l) is required for the complete removal of coloured products62
.
Sun e l al.63 have also described the effec t of chitosan on the tyrosinase catalyzed reaction duting the removal of phenols from the reacti on mix ture. C resol was treated with tyrosinase and it was observed that the enzyme go t stabili zed in the presence of chitosan. These findi ngs further strengthen the significance of adso rption on the chitosan during the action of tyrosinase fo r the remova l of co loured products formed by enzymatic reaction. It was observed that almost whole p enol was converted into oxidized product in the presence of this adsorbant6.\
Payne et al.M have successfully explored the feas ibility of an enzymatic approach to separate phenols from nonphenols. They have reported two-step approach to remove selectively phenol s from the mi xtures containing non-phenolic isomers. The procedure involves the li se of enzyme, tyros inase wh ich catalyzes the oxidation of phenols into a-qu inone products and adsorbant, chitosan
HUSAIN & JAN: DETOXIFICATION OF PHENOLS AND AROMATIC AMINES 289
Table I - Enzymes used in the detoxification of phenols and aromatic amines
Name of enzymes Source Ref.
Chloroperoxidase
Laccase
Caldariol1l),ces JlIlI1ago
Tral1letes versicolor
Coriolus versicolo r
36, 37, 39 94
6, 32, 50-57, 84
Lignin peroxidase Chrysollilica sitophila 37,85-87 Phanerochaele CI)'sosphorillll1 82
Manganese peroxidase Lentinllia edodes 90-92
Peroxidase A rl1loracia m sticana (Horseradish) Caprinus cinereas
26-31 , 46, 88, 89 38,44
Caprin liS macrrohiZlIs 31, 38 Raphanus sativlIs (White radish) Rrassica rapa (Turnip)'
48 95
Tyrosinase AgariCils bispora (M ushrooms) Sololllul/ tllberOSlI1I1 (Potato)
30, 60-64, 93, 94 48
which can specifically adsorb reaction product. In another study, the same effect of chitosan on the tyrosinase catalyzed reaction has been reported during the removal of phenol s from the reaction mixture. The treatment of cresol with tyrosinase in the presence of chitosan , results in the stabilization of enzyme. This enzyme preparation appears to be quite effective in re moving the coloured product formed during the reactiono,.
Oxido-reductive enzymes have been shown to be able to remove various phenols and aromatic amines from an aqueous solution and to decolourize phenolic industrial waste (Table I ). It has been already demonstrated that phenols could be effectively removed by treatment with oxido-reductive enzymes in the presence of a coagulant. Nume rous coagulants have been tried for thi s purpose. However, the enzymes used in these processes quickly get inactivated during the progress of reaction . Coagulant prevents their inactivation and reduces the amount of enzymes used for phenol detoxification. In a most recent study Lee et ai.o5 have described an enzymatic method for the removal of phenols from wastewater of the phenolic resin manufacturing. An enzyme used
was a thermostable ~-tyrosinase which catalyzed the synthesis of L-tyrosine from phenol , pyruvate and ammonia. This enzymic removal of phenol was effective at
pH values from 6.5-9.0 and below 70°C. Wastewater containing 10 mM phenol was successfully reduced to 8
mM in 24 h by this enzyme at 37°C.
In addition to mushroom tyrosinase, other plant sources should be evaluated for the decontaminati on potential because polyphenol oxidases do not require the addition of expensive H
20
2. The presence of such en
zymes in plants is well documented by various workers. There is quite early report about the presence of laccase activity in Japanese lacquer tree Rhus verniciferaoo and in mango fruits67
. Various aspects of polyphenol oxidases in plants were extensively reviewed by Mayor and HareV>X and pesticide metabolism mediated by various oxidoreductive enzymes in higher plants has been described by Lamoureux and FrearOY. Oda et aL.70 have reported oxido-reductive enzyme activity in spinach leaves and SoderhalF' has discovered a latent polyphenol oxidase from carrot. The search is continuing to isolate various polyphenol oxidases from cheaper plant sources which can be exploited for the detoxification of industrial effluents. The major reasons that enzymatic treatments have not been applied on an industrial scale are due to the huge volume of polluted environments demanding bio-remediation . For instance, hundreds of thousands of liters of wastewater is produced daily from an average
290 J SCI IND RES VOL 59 APRIL 2000
industrial site and hundreds of tonnes of soil may be contaminated through continuous industrial emission or through a single spill accident. Use of soluble enzyme is practically impossible for determination of such as an extensive contamination. The applications of soluble enzymes also suffers from certain other drawbacks such as thermal instability, susceptibility to attack by proteases, activity inhibition and the lack of know how for separating and reusing free catalyst at the end of the reactionn . Another important disadvantage of using soluble enzymes in the detoxification of these hazardous molecules is that the free enzyme cannot be used in continuous processes. To overcome all these limitations, enzyme immobilization has been suggested. Numerous matrices or supports have been employed for the immobilization of various enzymes73-75. Enzyme immobilization is excellent due to its high storage, operational stability, and better control towards catalytic processes7(,.7X. In addition , immobilization allows no contamination of the solution treated by enzymes because the immobili zed enzymes can eas il y be separated from the reacti on mixture and can be used effi ciently in the reactors7X.
Immobilization of Phenol Oxidases for the Detoxification of Phenols
Phenol oxidases like other enzymes have been successfully immobilized on various natural and sy nthetic carriers like soils, clays, Sepharose 4B, AE-cellu lose, etc. 7'J.X3 Early immobilized preparations were not successfully used for the detoxification of phenols and aromatic amines due to above mentioned draw-backs. Davis and BurnsX4 have reported the rol e of alginate entrapped phenol oxidases in the removal of colour fro m phenolic indu strial effluents. Entrapped enzyme exhibited higher decolourization as compared to the so luble enzyme. However, the beads were not suitable for continuolls lise in the reactors due to leakage of enzymes into the solution . In an another study, Wada et al.ol have developed an immobilized preparation of tyrosin ase by using the amino groups of the enzymes onto magnetite. This immobilization method could improve storage and operational stabilities. Para-substituted phenol s were found as a etter substrate than the 0- and m-substituted phenols in immobilized preparations. Immobilized lignin peroxidase from Chrysonilica sitophila decolorizes phenolic kraft effluent from pulp millsx5 . Lentinula edodes has been immobilized in a packed bed reactor and could efficiently be used to degrade tox ic chlorophenols and deco lorize kraft effl uents. ~-glucosidase, laccase, lignin peroxidase and manganese peroxidase were acti vely in-
volved in this processXfi.X7 . Siddique et al. XH have described
the removal of p-chlorophenol from an aqueous so lution by horseradish peroxidase. The enzyme was immobilized on three different reactors matrices . However, the immobilized preparation was not found successfu l for repeated use. Horseradish peroxidase was immobilized onto magnetite by physical adsorpti on and thi s method proved more successful as compared to crosslinking method because the enzyme retained nearl y complete activity on the matrix. Magnetite bound peroxidase was used for the treatment of variou ' chlorophenols and the preparation was 100 per cent efficient in clearing phenol s and their derivative from solutions. Although soluble enzyme are not effici ent for complete removal of each chlorophenols x~ .
In some recent studi es, Grabski el (!f.Y0.~1 have shown the degradation of various organopollutants by usi ng immobili zed manganese perox idase. In another study the same workers have used the immobilized manganese perox idase in a two-stage bioreactor for catal ytic generation of chelated Mn3+ and for ubsequent oxidation of chlorophenol. 78 per cent oxidation of 1.0 mM Mn 2
+ to Mn3+ was initially meas red under optimized conditions. After 24 h of contin ous operation under optimized reacti on conditions, the reactor still oxidized 1.0 mM Mn2
+ to Mn3+ with 69 per cent efficiency corre
sponding to 88 per cent of initial Manganese peroxidase act ivit/1
.
Tyrosinase was immobilized on magnetite using amino groups of enzyme, for the purpose of removing phenols from wastewater. Immobilized preparation was superior in operational and storage stability as compared to the soluble enzyme. p-Substituted pheno l was removed more efficiently than the /11- and a-substitu ted pheno ls by immobilized enzyme preparationol . Wada ef al.62 have demonstrated the immobilization of tyros inase on the cation-exchange res in via amino groups and thi s preparation was found to be effective in treating a large volume of wastewater conta ining phenol s. A combination of immobilized enzyme and chitosan was espec ially effective in removing toxic phenol from aqueous so lution. Tyrosinase immobilized by this method was successful in removing 100 per cent pheno l in 2 h and a marginal reduction in activity was observed after ten repeated treatments. Immobilization of tyrosinase on magnetite gave a good retention of activity, nearly 80 per cent and storage stability. A marginal loss of 5 per cent activity after IS d of storage at ambient temperature was observed. In the treatment of immobili zed ty-
HUSAIN & JAN : DETOXIFICATION OF PHENOLS AND AROMATIC AMINES 29 1
rosinase, coloured enzymatic reaction products were removed by less amount of coagulant as compared to the soluble enzyme. Synthetic cation polymers containing amino groups were more effective than chitosan in removing the coloured product formed during the tyrosinase reaction93 . Although enzyme was immobilized on magnetite and better results were shown by adsorbants synthetic cation polymers. This immobilized preparation could be reused for the removal of chlorophenols93
.
The addition of adsorbants becomes necessary for the rapid removal of coloured product formed during the oxidation of various phenols by oxido-reductive enzymes. However, Crecchio el aU4 have developed a new approach for the immobilization of these enzymes. Organogels have been employed for the immobilization of lacease and tyrosinase. These gels were obtained by simple gelation of reverse micells. Organogels immobilized enzymes preparation exhibited high operational stability and resistant to heat and proteolytic denaturation . A column packed with gel immobilized tyrosinase was used to demon strate the reusability of the technique94
. These columns were used several times without loosing much efficiency. An additional advantage of thi s method is that there is no add ition of the adsorbant during the catalytic process and it will simplify the removal of phenols and aromatic amines at large scale. More recently, some research workers have investigated, ror the first time the role of turnip peroxidases in the decontamination of various phenols. A partially puri fied preparation of turnip peroxidases was entrapped into calcium alginate beads directly and after the cross-linking with glutaraldehyde. Both immobilized preparations and soluble enzyme preparation were used for the treatment of various phenols present in the model wastewater. The higher removal of phenols from the model wastewater was achieved by immobilized enzyme. Cross-linked entrapped enzyme exhibits higher stabi lity and reusability as compared to the soluble and directly entrapped enzyme preparation (Mushtapa S, Jan U & Husain Q, 1999, Unpublished Worlk) .
Conclusions
It is evident from the literature that the applications of ox ido-reductive enzymes for the treatment of industrial effluents has been well recognized. However, the most of the work presented here is restricted only to the model wastewaters. This work indicates the potential of various phenol oxidases in the treatment of indus-
trial effluents . It is mentioned that those methods based on oxido-reductive enzymes have significant advantages over the physico-chemical and biological processes, whereas the information regarding the use of these enzymes at commercial level is still in infancy. Therefore, it is suggested that more detailed research, on the immobilized enzymes and their applications at the industrial level is necessary. However, the cost of enzymes and support for preparing the immobilized enzyme is al so a major drawback in using these enzymes for detoxification . For making these preparations more successful commercially, efforts should be made to search new cheaper sources of enzymes and supports. In order to prevent the inactivation of enzymes during reaction , some new adsorbants of the intermediate product should be searched for removal from the wastewaters.
Acknowledgements The authors are thankful to Dr Faheem Haleem
Khan and Dr Farah Khan , Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh for their valuable suggestions .
References
Keith L H & Telli ard W A. En viron Sci Tee/lllol , 12 (1979) -+ 16.
2 Zi lli M, Coverti A, Lodi A, Del Borghi M & Ferrai olo G, Biotechnol Bioeng, 41 ( 1993) 693.
3 Chang Y H, Li C T, Chang M C & Shich W K, Biotee/lIwl Bioeng, 60 (1998) 391.
4 Peyton T 0 , Enz Microbial Tee/lI1ol, 6 ( 1984) 146.
5 Berry D F & Boyd S A, Soil Bioi Biochelll . 17 ( 1985) 631.
6 Ruggier ° P, Sarkar J M & Boll ag J M, Soil Sci, 147 (1989) 361.
7 US Development o f" Health and Human Sciences, Toxicological "Profile fo r Chlorophennols", 1998.
8 Hottenstein C S, Jourdon S W, Hayes M C, Rubio F M, Herzog D P & Lawruk T S, Environ Sci Technol, 29 ( 1995) 2754.
9 Buchanan 1 D & Ni cell J A, Biotec/1I 101 Bioeng, 54 (1997) 25 1.
10 Karamanev D G, Chavari e C & Samson R, Biotechnoll3 iael/g, 57 (1998) 471.
II Ahborg U G & Thllnderberg T M, CRC Rev Taxical, 7 ( 1980) I.
12 Lanouette K H, Chem Eng, 84 (1977) 99.
13 Klein J A & Lee D D. l3iotee//lwll3ioeng SYIIIP , 8 (1978) 379.
14 Bret scher M, in Wa ter Disposal in the Chelllicai ll/dllst,..", l:ditcd by T Leissinger et a/~, 198 1, 169.
15 US En vironmental Protection Agel/cy, 1988IPublication EPN540/ 2-88/004, Wash ington, DC.
292 J SCI IND RES VOL 59 APRIL 2000
16 Baker M D & Mayfield C I, Wat Air Soil Poll, 13 (1986) 411 . 44 Aitken M D & Heck P E, Biotechnol Prog, 14 (1998) 487.
17 Bumpus T A, Tien M, WrightD & Aust S D, Science , 228 (1985) 45 Wu J, Taylor K E, Bewtra J K & Bigwas N, Wat. Res, 27 (1993) 1434. 1701.
18 Lal R & Shivaji S, CRC Cril Rev Biotechnol, 3 (1986) I. 46 Tatsumi K, Ichikawa H & Wada S, Wat Sci, 30 (1994) 79.
19 Donaldson T L, Strandberg G W, Hewitt J D, Shields G R & 47 Arseguel D & Baboulene M, J Chem 7eeil1101 Bioteclinol , 61 Worden R M, Environ Prog, 6 (1987) 205. (1994)331.
20 Worden R M & Donaldson T L, Biotechnol Bioeng, 30 (1987) 48 Dec J & BolJag J M, Biotechnol Bioeng, 44 (1994) 1132. 398. 49 Chapsal J M, Bourbiot M M & Thomas D, Wat Res, 20 (1986)
21 Goldstein R M, Malorey L M & Alexander M, Appl Environ 709. Microbial , 50 (1985) 977.
50 Mosbach R, Biochilll Biophys Acta, 73 (1963) 205. 22 Keamery P C, Karns J S & Mubry W W, in Pesticide Science
51 Dec J & BolJag J M, Arch Environ Contamin Toxicol, 19 (1990) and Biotechnology (Blackwell Scientific Boston, MA) 1987, 534. pp 59.
Karamanev D G & Mikolov L N, Bioprocess Eng , 6 (1991 ) 127. 52 Bollag J M, in Metal iuns in Biological Systems, edited by H
23 Sigel and A Sigel (Marcel Dekker, New York) 1992, pp 205.
24 Stephenson T, Biotechnol Lett, 12 (1990) 843. 53 Leonowicz A, Edgehill R U & Bollag J M, Arch Microbial , 137
25 Hill G A, Miline B J & Nawrocke P A, Appl Environ Microbiol, (1984) 89. 46 (1996) 163. 54 Bollag J M & Liu S Y, Pest Biochem Physiol, 23 (1985) 261.
26 Klibanov A M, Alberti B N, Morris E D & Felschin Z M, J Appl 55 Bollag J M, Liu S Y & Minard R D, Soil Sci Soc Am J, 44 ( 1980)
Biochem , 2 (1980) 414. 52. 27 Klibanov A M & Morris E D, Enz Microbial Tecllllol, 3 (1981)
56 Bollag J M & Bollag W B, Int J Environ Anal Chelll, 39 (1990) 119. 147.
28 Alberti B N & Klibanov AM, Biotechnol Biueng, 11 (1981 ) 57 Forss K, Jokincn K, Savolainen M & Williamson H, in Pruc
119. Fourth Int S)'mp Wood Pulp Chem, 1 (1987) 179.
29 Klibanov A M, Tu T M & Scott K P, Science, 227 (1983) 259. 58 Muralikrishna C & Ranganathan V, Appl En viron Microbial, 61
30 Atlow S C, Bonadonna-Aparo L & Klibanov A M, Biotechnol (1995) 4374. Bioeng, 26 (1984) 599.
59 Walsch C, in Enzymatic Reaction Mechanisms (W H Freeman 3 1 Aitkin M D, Venkatadri R & Irvine R, Wat Res, 23 (1989) 443. Co, San Francisco) 1979, pp 461.
32 Shuttleworth K L & Bollag J M, Enz Microbial Technol, 8 ( 1986) 60 Tatsumi K, Ichikawa H & Wada S, Proc Asian Waterqllal , 91 171. ( 1991) 56.
33 Maloney S W, Manem J, Mallevialle J & Fiessinger F, Ellviroll 61 Wada S, Ichikawa H & Tatsumi K, Wat Sci Tecl1l1ol, 26 (1992) 9. Sci Technol, 20 (1986) 249. 62 Wada S, Ichikawa H & Tatsumi K, Biotechllol Bioeng, 42 ( 1993)
34 Nakamoto S & Machida N, Wat Res, 26 (1992) 49. 854.
35 Nicell J A, Bewtra J K, Biswas N & Taylor E, Wat Res, 27 (1993) 63 Sun W Q, Pay ne F, Moas M S L, Chu J H & Wall ace K K, 1629. Biutechnol Prog, II ( 1992) 179.
36 Carmichael R, Fedorak PM & Pickard M A, Biotechllol Lett , 7 64 Payne G F, Sun W Q & Sohrab A, Bintechnol Bioellg, 40 ( 1992) (1985) 289. 1011.
37 Aitken M D, Massey I J, Chen T & Heck P E, Wat Res, 28 (1994) 65 Lee S Q, Hong S I & Seung M H, Ellz Microbiol Technol, 19 1879. ( 1996) 374.
38 AI-Kassim L. Taylor K E, Nicell J A, Bewtra J K & Biswas N, J 66 Yoshi da H, .I Chem Soc, 43 ( 1883) 472. Chem Techllul Biotecll11ol, 61 ( 1994) 179. 67 Joel D M, Marbach I & Mayer A M, Phytocl cmistry, 17 (1978)
39 Seelback K, Van Deurzen M P J, Van Rantwijk F & Sheldon R 796. A, Bioteellllol Bioellg, 55 (1997) 283. 68 Maycr A M & Harel E, Pliytochelllisl/ )', 18 (1979) 193.
40 Pacice M G & Jurasek I, Biotechllol Bioellg , 26 (1984) 477. 69 Lamoureux G L & Frcar D S, ACS Symp Ser, 97 ( 1979) 77. 4 1 Ryu K, McEldoon J P, Pakora A R, Cyrus W & Dordick J S, 70 Oda Y, Kato H, Isoda Y, Takahashi N, Yamamoto T, Takada Y &
Biotechnol Bioellg, 42 (1993) 807. Kudo S, Agric BioI Chem , 53 ( 1989) 2053. 42 Kohlor H & Jenzer H, Free Rad Biol Med, 6 (1989) 323. 71 Soderhalll, Phytochemistry, 39 ( 1995) 33. 43 Hiner AN P, Hemandez- Rui z J & Amao M B, Bioteeil/w l Bioellg,
50 (1996) 655. 72 Nannipieri P & Bollag J M, J Ellviron Qual, 20 (1991) 510.
HUSAIN & JAN : DETOXIFICATION OF PHENOLS AND AROMATIC AMINES 293
73 Mosbach K, Methods in Enzymology, Vol 135 (Academic Press, 84 Davis S & Burns R G, Appl Microbiol Biotechnol, 32 ( 1990) New York) 1987. 721.
74 Kennedy J F & Cabral J M S, Enzyme Immobilization , edited by 85 Frereer I, Dezotti M & Durran N, Biotechnol Lell, 13 ( 1991 ) H J Rehm, G Reed and J F Kennedy, in Enzyme Technology, 577. Biotechnology, (VCH Verlagsgesellschaft Gmbtt. Weinheim.
86 Durran N, Esposito E & Canhos V p. in Cellulosics: Pulp. Fibre Germany).7A, 1987.347. and Environmental Aspects, edited by J F Kennedy, GO Philips
75 Veliky I A & McLean R J C, in Immobilized Biosystems; Th eOl)1 and P A Williams (Ellis Harwood, New York. USA) 1993. pp and Practical Applications (Blackie Academic and Professional 493.
Press, London) 1994. 87 Esposito E, Durran N, Freer J , Baeza J & Innocentini-Mei L H,
76 Saleemuddin M & Husain Q. Enz Microbiol Tee/lIlol , 13 ( 1991) Proc CHEMPOR, Int Chem En8 Conf, Porto, Portugal ( 1993).
290. 20 1.
77 Monsan P & Combes D, in Methods Enzymology, edited by K 88 Siddique M H, Pierre C C. S T Biswas N, Bewtra J K & Taylor K Mosback . (Academic Press. New York) Vol 137. 1988. 584. E. Wat Res. 27 ( 1993) 883.
78 Husain Q. Iqbal J & Saleemuddin M. Biotechnol Bioeng , 27 89 Tatsumi K, Wada S & Ichikawa H. BioteciJnol Bioeng, 51 (1996)
( 1985) 1102. 126.
79 Leonowicz A. Sarkar J M & Boll ag J M, Appl Microbiol 90 Grabski A C. Coleman P L, Drtina G J & Burgess R R, Apl'l
Biotechnol , 29 ( 1988) 129. Biochem Biotecllllol. 55 ( 1995) 55.
80 Sarkar J M, Leonowicz A & Bollag J M, Soil Bioi Biochem. 21 91 Grabski A C, Rasmussen J K; Coleman P L & Burgess R R, Appl ( 1989) 223 . Biochem Biotecllllol. 60 ( 1996) I.
8 1 Hu sain S. Hu sain Q & Saleemuddin M, Indian J Biochelll 92 Grabski A C. Grimek H J & Burgess R R. Biotechnol Bioel/g . 60 Biophys, 29 ( 1992) 482. ( 1998) 204.
82 Asther M & Meunier J C. Appl Biochelll Biotechl/ol. 38 ( 1993) 93 Wada S, Ichikawa H & Tatsumi K. Biotechl/ol Bioeng , 45 ( 1995 )
57. 304.
83 Jian G, Pei-Sheng M & Gaoxiang, Appl Biochelll BiotechlJol. 23 94 Crecchio C, Ruggiero P & Pi zzigallo M DR, Biotechnol Bioel/g.
( 1990) 15. 48 ( 1995) 585.