1
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Carbohydrate microcapsules tailored and grafted for covalent immobilization of glucose isomerase for pharmaceutical and food industries. Biotechnol Lett 2023; 45:175-189. [PMID: 36482052 DOI: 10.1007/s10529-022-03323-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 10/31/2022] [Accepted: 11/15/2022] [Indexed: 12/14/2022]
Abstract
Carrageenan is one of the most common carbohydrates utilised in the entrapment industry to immobilise cells and enzymes. However, it lacks functionality. Carrageenan has been grafted to produce fructose by covalently immobilising glucose isomerase (GI). Fructose is one of the most widely used sweeteners in beverages, food production, and the pharmaceutical business. Up to 91.1 U g-1 gel beads are immobilised by the grafted beads. Immobilized GI has a Vmax of 13.8 times that of the free enzyme. pH of immobilized GI was improved from 6.5-7 to 6-7.5 that means more stability in wide pH range. Also, optimum temperature was improved and become 65-75 °C while it was at 70 °C for free enzyme. The immovability and tolerance of the gel beads immobilised with GI over 15 consecutive cycles were demonstrated in a reusability test, with 88 percent of the enzyme's original activity retained, compared to 60 percent by other authors. These findings are encouraging for high-fructose corn syrup producers.
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Gupta MN, Perwez M, Sardar M. Protein crosslinking: Uses in chemistry, biology and biotechnology. BIOCATAL BIOTRANSFOR 2020. [DOI: 10.1080/10242422.2020.1733990] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | - Mohammad Perwez
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | - Meryam Sardar
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
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3
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Highly sensitive amperometric biosensor based on alcohol dehydrogenase for determination of glycerol in human urine. Talanta 2019; 200:333-339. [DOI: 10.1016/j.talanta.2019.03.063] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/14/2019] [Accepted: 03/15/2019] [Indexed: 11/17/2022]
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4
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Cross-Linked Enzyme Aggregates of Feruloyl Esterase Preparations from Thermothelomyces thermophila and Talaromyces wortmannii. Catalysts 2018. [DOI: 10.3390/catal8050208] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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5
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Roy I, Mukherjee J, Gupta MN. Cross-Linked Enzyme Aggregates for Applications in Aqueous and Nonaqueous Media. Methods Mol Biol 2017; 1504:109-123. [PMID: 27770417 DOI: 10.1007/978-1-4939-6499-4_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Extensive cross-linking of a precipitate of a protein by a cross-linking reagent (glutaraldehyde has been most commonly used) creates an insoluble enzyme preparation called cross-linked enzyme aggregates (CLEAs). CLEAs show high stability and performance in conventional aqueous as well as nonaqueous media. These are also stable at fairly high temperatures. CLEAs with more than one kind of enzyme activity can be prepared, and such CLEAs are called combi-CLEAs or multipurpose CLEAs. Extent of cross-linking often influences their morphology, stability, activity, and enantioselectivity.
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Affiliation(s)
- Ipsita Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab, India
| | - Joyeeta Mukherjee
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110 016, India
| | - Munishwar N Gupta
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110 016, India.
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6
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Jiang Y, Wang Q, He Y, Zhou L, Gao J. Co-aggregation of Laccase and Nature Egg White: a Simple Method to Prepare Stable and Recyclable Biocatalyst. Appl Biochem Biotechnol 2014; 172:2496-506. [DOI: 10.1007/s12010-013-0697-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 12/25/2013] [Indexed: 11/29/2022]
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7
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Gupta MN, Mukherjee J, Malhotra D. Use of high activity enzyme preparations in neat organic solvents for organic synthesis. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2053-7670-1-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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8
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Conformation and Activity of Sol-Gels Encapsulated Cross-Linked Enzyme Aggregates of Lipase from Burkholderia cepacia. ACTA ACUST UNITED AC 2011. [DOI: 10.4028/www.scientific.net/amr.291-294.614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cross-linked enzyme aggregates (CLEAs) of lipase from Burkholderia cepacia (BCL) were explored using different precipitants and different amount of glutaraldehyde as cross-linkers. The ‘fresh’ and ‘mature’ CLEAs-BCL was successfully encapsulated with sol-gel support. The latter showed the highest specific enzyme activity, which was 1.7 and 13.2-fold over CLEAs-BCL before encapsulation with sol-gel and free BCL, respectively. It performed high transesterification activity with the biodiesel yield of 88.5%. The ‘mature’ CLEAs-BCL presented high stability in the ranges of temperature (30-70 ºС) and pH (pH = 5-10). Scanning electron microscopy (SEM) and circular dichroism (CD) studies showed that the morph secondary structure of ‘fresh’ and ‘mature’ CLEAs-BCL was variant to some extent, which may be responsible for the catalytic activity variance.
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García-García MI, Sola-Carvajal A, Sánchez-Carrón G, García-Carmona F, Sánchez-Ferrer A. New stabilized FastPrep-CLEAs for sialic acid synthesis. BIORESOURCE TECHNOLOGY 2011; 102:6186-6191. [PMID: 21376574 DOI: 10.1016/j.biortech.2011.02.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 02/04/2011] [Accepted: 02/05/2011] [Indexed: 05/30/2023]
Abstract
N-acetyl-D-neuraminic acid aldolase, a key enzyme in the biotechnological production of N-acetyl-D-neuraminic acid (sialic acid) from N-acetyl-D-mannosamine and pyruvate, was immobilized as cross-linked enzyme aggregates (CLEAs) by precipitation with 90% ammonium sulfate and crosslinking with 1% glutaraldehyde. Because dispersion in a reciprocating disruptor (FastPrep) was only able to recover 40% of the activity, improved CLEAs were then prepared by co-aggregation of the enzyme with 10mg/mL bovine serum albumin followed by a sodium borohydride treatment and final disruption by FastPrep (FastPrep-CLEAs). This produced a twofold increase in activity up to 86%, which is a 30% more than that reported for this aldolase in cross-linked inclusion bodies (CLIBs). In addition, these FastPrep-CLEAs presented remarkable biotechnological features for Neu5Ac synthesis, including, good activity and stability at alkaline pHs, a high K(M) for ManNAc (lower for pyruvate) and good operational stability. These results reinforce the practicability of using FastPrep-CLEAs in biocatalysis, thus reducing production costs and favoring reusability.
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Affiliation(s)
- María Inmaculada García-García
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, University of Murcia, Campus Espinardo, E-30100 Murcia, Spain
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10
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Šulek F, Fernández DP, Knez Ž, Habulin M, Sheldon RA. Immobilization of horseradish peroxidase as crosslinked enzyme aggregates (CLEAs). Process Biochem 2011. [DOI: 10.1016/j.procbio.2010.12.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Abstract
Extensive cross-linking of a precipitate of a protein by a cross-linking reagent (glutaraldehyde has been most commonly used) creates an insoluble enzyme preparation called cross-linked enzyme aggregates (CLEAs). CLEAs show high stability and performance in both conventional aqueous media as well as nonaqueous media. These are also stable at fairly high temperatures. CLEAs having more than one kind of enzyme activity can be prepared and such CLEAs are called combi-CLEAs or multipurpose CLEAs. Extent of cross-linking often influences their morphology, stability, activity, and enantioselectivity.
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Affiliation(s)
- Munishwar N Gupta
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
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12
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Affiliation(s)
- Roger A. Sheldon
- Department of Biotechnology, Laboratory of Biocatalysis and Organic Chemistry, Delft University of Technology, Julianalaan136, 2628 BL Delft, The Netherlands, and CLEA Technolgies, Delftechpark 134, 2628 XH Delft, The Netherlands
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13
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Castro GR, Knubovets T. Homogeneous Biocatalysis in Organic Solvents and Water-Organic Mixtures. Crit Rev Biotechnol 2010. [DOI: 10.1080/bty.23.3.195] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Matijošytė I, Arends IW, de Vries S, Sheldon RA. Preparation and use of cross-linked enzyme aggregates (CLEAs) of laccases. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2009.09.019] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Petritis BO, Qian WJ, Camp DG, Smith RD. A simple procedure for effective quenching of trypsin activity and prevention of 18O-labeling back-exchange. J Proteome Res 2009; 8:2157-63. [PMID: 19222237 DOI: 10.1021/pr800971w] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Trypsin-catalyzed stable isotope 16O/18O-labeling of the C-terminal carboxyl groups of peptides is increasingly used in shotgun proteomics for relative peptide/protein quantitation. However, precise quantitative measurements are often complicated by residual trypsin that can catalyze the back-exchange of 18O with 16O after labeling. Here, we demonstrate through a detailed evaluation that boiling the peptide sample for 10 min provides a simple means for completely quenching residual trypsin activity and preventing oxygen back-exchange in 18O-labeled samples. We also observed that the presence of organic solvents such as acetonitrile made boiling less efficient for inactivating trypsin. Finally, current 18O-labeling methods that typically employ immobilized trypsin result in significant sample losses due to nonspecific binding of peptides to the resin, making their application toward smaller biological samples increasingly impractical. We present here an improved 18O-labeling protocol that is more applicable to microscale biological samples by using solution-phase trypsin instead of immobilized trypsin. The ability to generate stably 18O-labeled samples without back-exchange should enable more effective applications of 18O-labeling toward large-scale biomarker discovery and validations where an 18O-labeled sample can be used as a common reference for quantitation.
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Fazary AE, Ismadji S, Ju YH. Biochemical studies on native and cross-linked aggregates of Aspergillus awamori feruloyl esterase. Int J Biol Macromol 2009; 44:240-8. [DOI: 10.1016/j.ijbiomac.2008.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 12/16/2008] [Accepted: 12/17/2008] [Indexed: 11/27/2022]
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18
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Cabana H, Jones JP, Agathos SN. Preparation and characterization of cross-linked laccase aggregates and their application to the elimination of endocrine disrupting chemicals. J Biotechnol 2007; 132:23-31. [PMID: 17884220 DOI: 10.1016/j.jbiotec.2007.07.948] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 07/02/2007] [Accepted: 07/20/2007] [Indexed: 11/25/2022]
Abstract
Laccase from the white rot fungus Coriolopsis polyzona was immobilized for the first time through the formation of cross-linked enzyme aggregates (CLEAs). Laccase CLEAs were produced by using 1000g of polyethylene glycol per liter of enzyme solution as precipitant and 200muM of glutaraldehyde as a cross-linking agent. These CLEAs had a laccase activity of 148Ug(-1) and an activity recovery of 60.2% when using 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as substrate. CLEAs formed by co-aggregation with bovine serum albumin (BSA) as a stabilizer showed lower laccase activity and affinity for ABTS than those without BSA. The CLEAs co-aggregated with BSA showed higher residual activity against a protease, NaN(3), EDTA, methanol and acetone. The thermoresistance was higher for CLEAs than for free laccase and also higher for CLEAs co-aggregated with BSA than for simple CLEAs when tested at a pH of 3 and a temperature of 40 degrees C. Finally, laccase CLEAs were tested for their capacity to eliminate the known or suspected endocrine disrupting chemicals (EDCs) nonylphenol, bisphenol A and triclosan in a fluidized bed reactor. A 100-ml reactor with 0.5mg of laccase CLEAs operated continuously at a hydraulic retention time of 150min at room temperature and pH 5 could remove all three EDCs from a 5mgl(-1) solution.
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Affiliation(s)
- Hubert Cabana
- Department of Chemical Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec, Canada J1K 2R1
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19
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Roy I, Mondal K, Gupta MN. Leveraging protein purification strategies in proteomics. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 849:32-42. [PMID: 17141589 DOI: 10.1016/j.jchromb.2006.11.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 11/03/2006] [Accepted: 11/09/2006] [Indexed: 11/25/2022]
Abstract
The proteomic studies, although, tend to be analytical in nature, yet many strategies of preparative protein purification can be usefully employed in such studies. This review points out the importance of purification techniques which are capable of dealing with samples which are suspensions rather than clear solution, e.g. aqueous two phase partitioning, three phase partitioning, expanded bed chromatography, etc. The review also outlines the potential of non-chromatographic techniques in dealing with fractionation of proteomes. Separation protocols which can deal with post-translationally modified (PTM) proteins are also considered.
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Affiliation(s)
- Ipsita Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, SAS Nagar, Punjab 160062, India
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20
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Wilson L, Fernández-Lorente G, Fernández-Lafuente R, Illanes A, Guisán JM, Palomo JM. CLEAs of lipases and poly-ionic polymers: A simple way of preparing stable biocatalysts with improved properties. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2005.12.011] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Shah S, Sharma A, Gupta MN. Preparation of cross-linked enzyme aggregates by using bovine serum albumin as a proteic feeder. Anal Biochem 2006; 351:207-13. [PMID: 16500610 DOI: 10.1016/j.ab.2006.01.028] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 01/13/2006] [Accepted: 01/16/2006] [Indexed: 10/25/2022]
Abstract
Addition of bovine serum albumin (BSA) as a proteic feeder facilitates obtaining cross-linked enzyme aggregates (CLEAs) in cases where the protein concentration in the enzyme preparation is low and/or the enzyme activity is vulnerable to the high concentration of glutaraldehyde required to obtain aggregates. CLEAs of Pseudomonas cepacia lipase and penicillin acylase were prepared. CLEA of lipase prepared in the presence of BSA retained 100% activity whereas CLEA prepared without BSA retained only 0.4% activity of the starting enzyme preparation. Lipase CLEA showed 12-fold increase in activity over free enzyme powder when the CLEA was used in transesterification of tributyrin. For the transesterification of Jatropha oil, while free enzyme powder required 8 h and 50 mg lipase to obtain 77% conversion, CLEA required only 6 h and 6.25 mg lipase to obtain 90% conversion. In the case of penicillin acylase, 86% activity could be retained in CLEA prepared with BSA whereas CLEA made without BSA retained only 50% activity. CLEA prepared without BSA lost 20% activity after 8 h at 45 degrees C whereas CLEA with BSA retained full activity. CLEA prepared with BSA showed Vmax/Km of 36.3 min-1 whereas CLEA prepared without BSA had Vmax/Km of 17.4 min-1 only. Scanning electron microscopy analysis showed that CLEAs prepared in the presence of BSA were less amorphous and closer in morphology to CLEAs of other enzymes described in the literature.
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Affiliation(s)
- Shweta Shah
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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22
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A comparison of the activities of three β-galactosidases in aqueous-organic solvent mixtures. Enzyme Microb Technol 2005. [DOI: 10.1016/j.enzmictec.2004.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Abstract
Enzyme catalysis in low water containing organic solvents is finding an increasing number of applications in diverse areas. This review focuses on some aspects which have not been reviewed elsewhere. Different strategies for obtaining higher activity and stability in such media are described. In this context, the damaging role of lyophilization and the means of overcoming such effects are discussed. Ultrasonication and microwave assistance are two emerging approaches for enhancing reaction rates in low water media. Control of water activity and medium engineering are two crucial approaches in optimization of catalytic behaviour in nonaqueous enzymology. Organometallics and synthesis/modification of polymers are two areas where nonaqueous enzymology can play a greater role in the coming years. The greater understanding of enzyme behaviour in nonaqueous media is expected to lead to larger and even more diverse kinds of applications.
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Affiliation(s)
- Munishwar N Gupta
- Chemistry Department, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, India.
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Wilson L, Illanes A, Pessela BCC, Abian O, Fernández-Lafuente R, Guisán JM. Encapsulation of crosslinked penicillin G acylase aggregates in lentikats: Evaluation of a novel biocatalyst in organic media. Biotechnol Bioeng 2004; 86:558-62. [PMID: 15129439 DOI: 10.1002/bit.20107] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The encapsulation of crosslinked enzyme aggregates (CLEA) of penicillin G acylase into a very rigid polymeric matrix based on polyvinyl alcohol (LentiKats) has been used successfully to improve the inadequate mechanical properties of CLEA. This encapsulation decreased CLEA activity by only around 40%. As compensation, a significant improvement in the stability of the CLEA in the presence of organic solvents was detected. This could be related to the highly hydrophilic environment inside the LentiKats biocatalysts: Partition experiments showed that the concentration of dioxane inside LentiKats was lower than in the reaction medium. In fact, thermal stability was about the same as in the corresponding CLEA. This permitted great improvement in the reaction rate for thermodynamically controlled synthesis of a model antibiotic (using phenylacetic acid and 7-amino-deacetoxycefalosporanic acid). Even more importantly, yields could be improved by using LentiKats-encapsulated CLEA, very likely by a favorable product/substrate partition. Thus, this very simple technique not only provides an efficient technique for solving the mechanical stability problem associated with CLEA, but also greatly improves the behavior of CLEA in organic media.
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Affiliation(s)
- Lorena Wilson
- Departamento de Biocatalisis, Instituto de Catalisis,Campus UAM Cantoblanco, 28049 Madrid, Spain
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Chand S, Mishra P. Research and application of microbial enzymes--India's contribution. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2003; 85:95-124. [PMID: 12930094 DOI: 10.1007/3-540-36466-8_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Enzymes have attracted the attention of scientists world over due to their wide range of physiological, analytical and industrial applications. Although enzymes have been isolated, purified and studied from microbial, animal and plant sources, microorganisms represent the most common source of enzymes due to their broad biochemical diversity, feasibility of mass culture and ease of genetic manipulation. With the advent of molecular biology techniques, a number of genes of industrially important enzymes has been cloned and expressed in order to improve the production of enzymes, substrate utilization and other commercially useful properties. Special attention has been focused on enzymes isolated from thermophiles due to their inherent stability and industrial applications. In addition, a variety of methods have been employed to modify enzymes for their industrial usage including strain improvement, chemical modifications, modification of reaction environment, immobilization and protein engineering. A wide range of applications of enzymes in different bioprocess industries is discussed.
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Affiliation(s)
- Subhash Chand
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-10016, India.
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26
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A local solvent structure study on 1,4-dioxane-water binary mixtures by total isotropic Rayleigh light scattering method. J Mol Liq 2001. [DOI: 10.1016/s0167-7322(01)00275-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Abstract
A microbial biosensor consists of a transducer in conjunction with immobilised viable or non-viable microbial cells. Non-viable cells obtained after permeabilisation or whole cells containing periplasmic enzymes have mostly been used as an economical substitute for enzymes. Viable cells make use of the respiratory and metabolic functions of the cell, the analyte to be monitored being either a substrate or an inhibitor of these processes. Bioluminescence-based microbial biosensors have also been developed using genetically engineered microorganisms constructed by fusing the lux gene with an inducible gene promoter for toxicity and bioavailability testing. In this review, some of the recent trends in microbial biosensors with reference to the advantages and limitations are been discussed. Some of the recent applications of microbial biosensors in environmental monitoring and for use in food, fermentation and allied fields have been reviewed. Prospective future microbial biosensor designs have also been identified.
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Affiliation(s)
- S F D'Souza
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
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Mateo C, Abian O, Fernandez-Lafuente R, Guisan JM. Increase in conformational stability of enzymes immobilized on epoxy-activated supports by favoring additional multipoint covalent attachment*. Enzyme Microb Technol 2000; 26:509-515. [PMID: 10771054 DOI: 10.1016/s0141-0229(99)00188-x] [Citation(s) in RCA: 288] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epoxy supports (Eupergit C) may be very suitable to achieve the multipoint covalent attachment of proteins and enzymes, therefore, to stabilize their three-dimensional structure. To achieve a significant multipoint covalent attachment, the control of the experimental conditions was found to be critical. A three-step immobilization/stabilization procedure is here proposed: 1) the enzyme is firstly covalently immobilized under very mild experimental conditions (e.g. pH 7.0 and 20 degrees C); 2) the already immobilized enzyme is further incubated under more drastic conditions (higher pH values, longer incubation periods, etc.) to "facilitate" the formation of new covalent linkages between the immobilized enzyme molecule and the support; 3) the remaining groups of the support are blocked to stop any additional interaction between the enzyme and the support. Progressive establishment of new enzyme-support attachments was showed by the progressive irreversible covalent immobilization of several subunits of multi-subunits proteins (all non-covalent structures contained in crude extracts of different microorganism, penicillin G acylase and chymotrypsin). This multipoint covalent attachment enabled the significant thermostabilization of two relevant enzymes, (compared with the just immobilized derivatives): chymotrypsin (5-fold factor) and penicillin G acylase (18-fold factor). Bearing in mind that this stabilization was additive to that achieved by conventional immobilization, the final stabilization factor become 100-fold comparing soluble penicillin G acylase and optimal derivative. These stabilizations were observed also when the inactivations were promoted by the enzyme exposure to drastic pH values or the presence of cosolvents.
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Affiliation(s)
- C Mateo
- Departamento de Biocatálisis, Instituto de Catalisis, CSIC, Campus Universidad Autonoma, Cantoblanco, 28049, Madrid, Spain
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