Abstract：
:By using very active and very stable penicillin G acylase (PGA)--agarose derivatives we have studied the industrial design of equilibrium-controlled synthesis of lactamic antibiotics. In the presence of high concentrations of organic cosolvents we have carried out the direct enzymatic condensation of phenylacetic acid and 6-aminopenicillanic acid to yield the model antibiotic penicillin G. We have mainly studied the integrated effect of different variables that define the reaction medium on a number of parameters of industrial interest:time course of antibiotic synthesis, highest synthetic yields, stability of the catalyst, and solubility and stability of substrates and products. The main variables tested were the nature and concentration of the organic cosolvent, pH, and temperature. The effects of the variables tested on different parameters were quite different and sometimes opposite. Hence, the optimal experimental conditions for antibiotic synthesis catalysed by PGA were established, as a compromise solution, in order to obtain good values for every parameter of industrial interest. These conditions seem to be important parameters for scale-up (e.g. we have been able to reach more than 95% of synthetic yields with productivities around 0.5 tons of model antibiotic per year per liter of catalyst).
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Fernandez-Lafuente R,Rosell CM,Guisán JMdoi
10.1016/0141-0229(91)90106-kkeywords:
subject
Has Abstractpub_date
1991-11-01 00:00:00pages
898-905issue
11eissn
0141-0229issn
1879-0909pii
0141-0229(91)90106-Kjournal_volume
13pub_type
杂志文章abstract：:Data and a semi-empirical model are presented that describe the affinity interaction of yeast cells with a Concanavalin A derivatised surface. The model uses 3 parameters to describe the time course of cell attachment from a flowing suspension of yeast cells, over a range of flow rates, and gives an effective global f...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(99)00161-1
更新日期：2000-02-01 00:00:00
abstract：:In this work, a biosensor using a glassy carbon electrode modified with gold nanoparticles (AuNPs) and tyrosinase (Tyr) within a dihexadecylphosphate film is proposed. Cystamine and glutaraldehyde crosslinking agents were used as a support for Tyr immobilization. The proposed biosensor was characterized by scanning el...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2015.12.004
更新日期：2016-03-01 00:00:00
abstract：:Effects of pulse and step changes in major metabolite concentrations such as glucose, glutamine, lactic acid, and ammonium on behavior of T-cell hybridomas in continuous culture were investigated in order to develop a strategy to maximize specific rate of lymphokine formation. Step increases in glucose, lactic acid, a...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90007-d
更新日期：1990-09-01 00:00:00
abstract：:This work presents the purification and characterization of an extracellular alpha-amylase (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1) produced by a new lactic acid bacterium: Lactobacillus manihotivorans able to produce L(+) lactic acid from starch. The molecular weight was found to be 135 kDa. The temperature ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00230-1
更新日期：2000-09-01 00:00:00
abstract：:The fatty acid methyl esters and fatty acid ethyl esters are known as biodiesels which are considered to be renewable, nontoxic and biodegradable biofuels. However, the conventional biodiesels show a high crystallization temperature which is one of the most critical obstacles against the widespread biodiesel usage. Th...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.03.012
更新日期：2017-07-01 00:00:00
abstract：:Myriococcum thermophilum cellobiose dehydrogenase (MtCDH) was expressed in Pichia pastoris using the pPICZαA expression vector under the control of methanol inducible AOX promoter. The purified recombinant MtCDH with a specific activity of 3.1 Umg(-1) was characterized to obtain kinetic constants for various carbohydr...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2012.10.007
更新日期：2013-01-10 00:00:00
abstract：:Three threonine aldolases (TAs) were cloned and overexpressed in Escherichia coli (Aeromonas jandaeil-allo-threonine aldolase, E. colil-threonine aldolase and Thermotoga maritimal-allo-threonine aldolase). A Design of Experiments strategy was used to identify optimal reaction conditions for each enzyme. These conditio...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2018.07.004
更新日期：2018-12-01 00:00:00
abstract：:Cytochrome P450 enzyme preparations were obtained from phenobarbital-treated rats. On immobilization in Romicon PM 10 polysulfone anisotropic hollow fibers, 20-25% of the original activity remained. The immobilization procedure did not significantly alter the Km of the preparations when 7-ethoxycoumarin was the substr...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(93)90031-v
更新日期：1993-02-01 00:00:00
abstract：:The cellulase and xylanase genes of filamentous Trichoderma fungi exist under carbon catabolite repression mediated by the regulator carbon catabolite repressor (CREI). Our objective was to find the role of CREI in a cellulase-hyperproducing mutant of Trichoderma koningii, and address whether enzyme production can be ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.04.007
更新日期：2013-07-10 00:00:00
abstract：:In the present investigation, the bacterium Escherichia coli (VM1) was isolated from a marine sediments of Ennore coastal water along southeast coast of India was exploited for its capability of Ag NPs synthesis. The derived nanoparticles were characterized employing ultraviolet-visible (UV-vis) spectroscopy, Fourier ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.09.008
更新日期：2016-12-01 00:00:00
abstract：:Industrial use of Novozym 435 in synthesis of structured lipids and biodiesel via alcoholysis is limited by mass transfer effects of the glycerides through immobilized enzymes and its low operational stability under operation conditions. To better understand this, differently modified Novozym 435 preparations, differi...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.04.007
更新日期：2016-08-01 00:00:00
abstract：:Glucose is the typical carbon source for producing microbial polyunsaturated fatty acids (PUFA) with single cell microorganisms such as thraustochytrids. We assessed the use of a fish oil derived glycerol by-product (raw glycerol), produced by a fish oil processing plant, as a carbon source to produce single cell oil ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2010.11.008
更新日期：2011-03-07 00:00:00
abstract：:l-asparaginase is a pharmaceutically and industrially important enzyme as it has potential to treat different cancers and inhibit acrylamide formation in fried and baked food products. In the present study, an attempt was made to screen for new and novel l-asparaginase producers using a widely applied phenol red and b...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.08.004
更新日期：2017-12-01 00:00:00
abstract：:The mechanical properties of TB/C3 hybridoma cells taken from a continuous culture were measured by micromanipulation. The culture conditions were constant except for the presence or absence of Pluronic F-68 in the medium. It was found that the mean bursting membrane tension and the mean elastic area compressibility m...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(92)90081-x
更新日期：1992-12-01 00:00:00
abstract：:An improved amperometric l-lactate biosensor was constructed based on covalent immobilization of lactate oxidase (LOx) from Pediococcus species onto carboxylated multiwalled carbon nanotubes (cMWCNT)/copper nanoparticles (CuNPs)/polyaniline (PANI) hybrid film electrodeposited on the surface of a pencil graphite electr...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.10.014
更新日期：2017-01-01 00:00:00
abstract：:Different whole-cell immobilization methods and conditions were tested for the delta 1-dehydrogenation of 6-alpha-methyl-hydrocortisone-21-acetate with Arthrobacter simplex cells, in n-decane-1-ol and chloroform. Among the entrapment methods, polyurethane foams gave the best productivity of n-decane-1-ol, but could no...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(92)90036-n
更新日期：1992-08-01 00:00:00
abstract：:Turanose is a natural isomer of sucrose. It is an emerging functional sweetener of the next generation. Turanose is catalytically synthesized from the sucrose biomass by employing amylosucrase enzyme. In this study, a novel gene encoding amylosucrase (Asmet) has been identified from the metagenome of a thermal aquatic...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109372
更新日期：2019-12-01 00:00:00
abstract：:The stabilization of fungal cellulases by spray drying, the thermal stability of Penicillium occitanis cellulases and the effect of some additives were studied. We observed that CMCase activity presents a good stability at 50 degrees C, even after 60 h of incubation. On the other hand, beta-glucosidase activity was mo...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00322-7
更新日期：2001-02-01 00:00:00
abstract：:Two GH43 β-xylosidases, RS223-BX from a rice straw metagenomic library, and BoXA from Bacteroides ovatus, that share similar amino acid sequences (81% identical) and 19 of 20 active-site residues, were compared by using site-directed mutagenesis of Asp and His residues implicated in metal binding. Thus, RS223-BX is st...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2018.03.007
更新日期：2018-07-01 00:00:00
abstract：:Bacterial chitinases recruited multiple accessory domains for the conversion of recalcitrant polysaccharides to simple soluble sugars/amino sugars. Here, we report detailed properties of a multi-domain GH18 chitinase from Enterobacter cloacae subsp. cloacae (EcChi2) that preferred β-chitin as substrate. EcChi2 exhibit...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2020.109702
更新日期：2021-02-01 00:00:00
abstract：:Growth conditions for mass production of luciferase-bacterial magnetic particles (BMPs) by a recombinant Magnetospirillum magneticum AMB-1 were investigated in a pH-regulated fed-batch culture system. Enrichment of growth medium with L-cysteine, yeast extract and polypeptone enhanced both bacterial growth and BMP prod...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(01)00343-x
更新日期：2001-07-05 00:00:00
abstract：:Kumamolisin from Alicyclobacillus sendaiensis strain NTAP-1 is a serine protease with collagenase activity. After molecular engineering, a kumamolisin mutant, named Kuma030, was obtained with high proteolytic activity against gluten, which might cause celiac disease. Kuma030 exhibited its potential application in indu...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.05.013
更新日期：2019-10-01 00:00:00
abstract：:Foaming, a proficient method for the recovery of surface active solutes from dilute solutions, was successfully applied for the concentration of the lipopeptide biosurfactant Surfactin from B. subtilis ATCC 21332 cell culture broths. Foaming was only partially successful in concentrating Surfactin when applied as a se...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00327-6
更新日期：2001-03-08 00:00:00
abstract：:During toluene hydroxylation, catalyzed by Pseudomonas putida UV4 one molecule of oxygen is added to the aromatic ring to produce the dihydroxylated (non-aromatic) ring structure, toluene cis-glycol. Toluene, which is toxic to the cells at aqueous phase concentration above ( approximately 2.4 mmol), is fed to the reac...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00289-1
更新日期：2001-02-01 00:00:00
abstract：:This study examined the potential of untreated and alkali-pretreated sugarcane bagasse (SCB) in cellulase, reducing sugar (RS) and fungal biomass production via solid state fermentation (SSF) using Pycnoporus sanguineus. The impact of the composition, structure and cellulase adsorption ability of SCB on the production...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.05.005
更新日期：2013-09-10 00:00:00
abstract：:This review focuses on the description of recently discovered esterase enzymes involved in xylan degradation (acetyl xylan, feruloyl, and p-coumaroyl esterases). The occurrence of these enzymes in various microorganisms, assays used for determination of their activity, induction and production on different substrates,...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章,评审
doi：10.1016/0141-0229(93)90078-g
更新日期：1993-06-01 00:00:00
abstract：:Effects of different microaerophilic conditions on cell growth, glucose consumption, hydrogen production and cellular metabolism of wild Enterobacter aerogenes strain and polyphosphate kinase (PPK) overexpressing strain were systematically studied in this paper, using NaH(2)PO(4) as the phosphate sources. Under differ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2010.09.015
更新日期：2011-02-08 00:00:00
abstract：:Global substitution of canonical amino acids (cAAs) with noncanonical (ncAAs) counterparts in proteins whose function is dependent on post-translational events such as cofactor binding is still a methodically challenging and difficult task as ncAA insertion generally interferes with the cofactor biosynthesis machinery...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.06.014
更新日期：2017-11-01 00:00:00
abstract：:Photothermal therapy (PTT) is a minimally invasive and effective cancer treatment method and has a great potential for innovating the conventional chemotherapy approaches. Copper sulfide (CuS) exhibits photostability, low cost, and high absorption in near infrared region, and is recognized as an ideal candidate for PT...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.04.002
更新日期：2016-12-01 00:00:00
abstract：:In the present work, NAD(+)-dependent formate dehydrogenase (FDH), encoded by fdh gene from Candida boidinii was successfully displayed on Escherichia coli cell surface using ice nucleation protein (INP) from Pseudomonas borealis DL7 as an anchoring protein. Localization of matlose binding protein (MBP)-INP-FDH fusion...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.06.002
更新日期：2016-09-01 00:00:00
