Abstract:
:Different lipases have been immobilized on octyl agarose beads at 1mg/g and at maximum loading, via physical interfacial activation versus the octyl layer on the support. The stability of the preparations was analyzed. Most biocatalysts had the expected result: the apparent stability increased using the highly loaded preparations, due to the diffusional limitations that reduced the initial observed activity. However, lipase B from Candida antarctica (CALB) was significantly more stable using the lowly loaded preparation than the maximum loaded one. This negative effect of the enzyme crowding on enzyme stability was found in inactivations at pH 5, 7 or 9, but not in inactivations in the presence of organic solvents. The immobilization using ethanol to reduce the immobilization rate had no effect on the stability of the lowly loaded preparation, while the highly loaded enzyme biocatalysts increased their stabilities, becoming very similar to that of the lowly loaded preparation. Results suggested that CALB molecules immobilized on octyl agarose may be closely packed together due to the high immobilization rate and this produced some negative interactions between immobilized enzyme molecules during enzyme thermal inactivation. Slowing-down the immobilization rate may be a solution for this unexpected problem.
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Fernandez-Lopez L,Pedrero SG,Lopez-Carrobles N,Gorines BC,Virgen-Ortíz JJ,Fernandez-Lafuente Rdoi
10.1016/j.enzmictec.2016.12.002subject
Has Abstractpub_date
2017-03-01 00:00:00pages
18-25eissn
0141-0229issn
1879-0909pii
S0141-0229(16)30253-8journal_volume
98pub_type
杂志文章abstract::We report a new colorimetric assay to quantify endo-polygalacturonase activity, which hydrolyzes polygalacturonic acid to produce smaller chains of galacturonate. Some of the reported polygalacturonase assays measure the activity by detecting the appearance of reducing ends such as the Somogyi-Nelson method. As a resu...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2010.04.004
更新日期:2011-02-08 00:00:00
abstract::Cystathionine γ-lyase (CGL) is a key enzyme in the methionine-cysteine cycle in all living organisms forming cysteine, α-ketobutyrate and ammonia via homocysteine and cystathionine intermediates. Although, human and plant CGLs have been extensively studied at the molecular and mechanistic levels, there has been little...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2015.08.004
更新日期:2015-12-01 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::The effect of intense pulsed light (IPL) irradiation on Chromobacterium viscosum lipase was investigated with a primary focus on catalytic activity and molecular structure. During IPL irradiation, lipase activity decreased significantly with increasing pulse fluence (Fp) and exposure time (te). IPL-induced deactivatio...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2019.02.001
更新日期:2019-05-01 00:00:00
abstract::In this work, porous biochar derived from sugarcane bagasse was prepared and then coated with different amounts of chitosan (C@CS) for cellulase immobilization. Cellulase was covalently immobilized on the support by using glutaraldehyde as a linker. The chemical characteristics and morphology of the samples were deter...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2020.109561
更新日期:2020-08-01 00:00:00
abstract::Water-insoluble nucleases were prepared by immobilizing the endonuclease from S. aureus onto the surface of nylon-66 and polystyrene spheres. The activation phase of the synthetic supports was optimized to define optimal conditions of pH, temperature, and Ca2+ concentration for using immobilized enzymes. The activity,...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/0141-0229(93)90140-w
更新日期:1993-03-01 00:00:00
abstract::Supercritical fluids offer environmental advantages over chemical solvents, while providing enhanced separation and chemical selectivity. The use of supercritical fluids for the recovery of products from biomass and the transformation of selected molecules (to add value) was studied. Free fatty acids were bio-catalyti...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2011.07.004
更新日期:2011-09-10 00:00:00
abstract::Conductive materials with attached biofilms, were used as membrane filtration biocathodes to filter the effluent and supply electrons for denitrification. Stainless steel mesh and carbon felt were employed to fabricate membrane modules, and the two MFC systems were termed as M1 and M2, respectively. High effluent qual...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2014.04.005
更新日期:2014-06-10 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::Trehalose diesters are Gemini-type surfactants that might have better surface activity than conventional surfactants. A one-step method for the preparation of trehalose unsaturated fatty acid diesters has been successfully developed. The yield of trehalose diester of different unsaturated fatty acids was between 78 % ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2020.109516
更新日期:2020-05-01 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::Biocatalytic peptide synthesis will benefit from enzymes that are active at low water levels in organic solvent compositions that allow good substrate and product solubility. To explore the use of proteases from thermophiles for peptide synthesis under such conditions, putative protease genes of the subtilase class we...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2015.03.003
更新日期:2015-06-01 00:00:00
abstract::The effect of hexoses (glucose and galactose) addition to the feed xylose mineral medium of Debaryomyces hansenii chemostat cultures grown at a constant dilution rate of 0.055 h(-1) was studied. Xylitol was the major product detected amongst all tested conditions. The maximal values for xylitol yield and volumetric pr...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00166-6
更新日期:2000-06-01 00:00:00
abstract::Catalase was covalently immobilized onto florisil via glutaraldehyde (GA) and glutaraldehyde+6-amino hexanoic acid (6-AHA) (as a spacer arm). Immobilizations of catalase onto modified supports were optimized to improve the efficiency of the overall immobilization procedures. The V(max) values of catalase immobilized v...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2011.09.002
更新日期:2011-12-10 00:00:00
abstract::Oxygen uptake rate and oxygen mass transfer rate have been studied during xanthan gum production process in stirred tank bioreactor. Empirical equations for the oxygen mass transfer coefficient have been obtained taking into account several variables such as air flow rate, stirrer speed and apparent viscosity. Oxygen ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00272-6
更新日期:2000-11-15 00:00:00
abstract::Non-productive cellulase adsorption onto lignin is a major inhibitory mechanism preventing enzymatic hydrolysis of lignocellulosic feedstocks. Therefore, understanding of enzyme-lignin interactions is essential for the development of enzyme mixtures and processes for lignocellulose hydrolysis. We have studied cellulas...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2013.07.003
更新日期:2013-10-10 00:00:00
abstract::Controlled hydrolysis of lactonic sophorolipids from Starmerella bombicola yields a previously undescribed sophorose analog that potently induces cellulase in Trichoderma reesei Rut-C30. Acid treatment of natural sophorolipids results in a mixture of monoacetylated, deacetylated, and diacetylated sophorolipids in acid...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2016.01.003
更新日期:2016-04-01 00:00:00
abstract::Musky macrolactones are an important group of compounds used in high-valued perfumery. An enzymatic cascade reaction including cytochrome P450 hydroxylase and lipase was explored to biosynthesize musky macrolactones. Firstly, fatty acids were hydroxylated by P450 hydroxylase to produce the corresponding ω-hydroxy fatt...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2019.109417
更新日期:2019-12-01 00:00:00
abstract::Operational stability under high temperature is required for enzyme application in industrial processes. Error-prone PCR and B-factor analysis were employed to enhance the thermostability of a xylanase from GH family 11 in this study. Based on the top 10 mutants screened from the random mutation libraries, mutant Xyn3...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2020.109720
更新日期:2021-02-01 00:00:00
abstract::The different physical and chemical properties of lignin might have various effects on the enzymatic hydrolysis of lignocellulosic substrates. In this study, the influence of lignin on enzymatic digestibility of cellulose was assessed. Addition of 20% (4g/L) isolated enzymatic lignin (lignin 2 and 3) and kraft lignin ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2017.03.001
更新日期:2017-06-01 00:00:00
abstract::Spodoptera frugiperda insect cells (IPLB-Sf21-AE) (Sf21), infected with baculovirus expression vectors during their exponential growth phase, are commonly used to produce a variety of heterologous recombinant proteins. In the present study the culture conditions of these insect cells were studied to establish high-den...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/0141-0229(94)90022-1
更新日期:1994-06-01 00:00:00
abstract::Kinetics of nitrification and denitrification of synthetic wastewater was investigated by using two reactors in series. An activated sludge unit was used for nitrification followed by a downflow biofilter for denitrification. Glucose solution was fed to the denitrification column to supply carbon source. Reactors were...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00145-9
更新日期:2000-07-01 00:00:00
abstract::beta-Xylosidase (1,4-beta-D-xylan xylohydrolase EC 3.2.1.37) and xylose isomerase (D-xylose ketol-isomerase EC 5.3.1.5) produced by Streptomyces sp. strain EC 10, were cell-bound enzymes induced by xylan, straw, and xylose. Enzyme production was subjected to a form of carbon catabolite repression by glycerol. beta-Xyl...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00182-4
更新日期:2000-07-01 00:00:00
abstract::Genetic engineering has been used to modify the proportion of different cellulases produced by a hypercellulolytic Trichoderma reesei mutant strain. A general expression vector, pAMH110, containing the promoter and terminator sequences of the strongly expressed main cellobiohydrolase 1 (cbh1) gene was used to overexpr...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/0141-0229(91)90133-u
更新日期:1991-03-01 00:00:00
abstract::The kinetic and thermodynamic parameters of wheat β-amylase (WBA) were characterized and various additives were evaluated for enhancing its activity and thermostability. WBA activity was examined by neocuproine method using soluble starch as substrate. The Michaelis constant (K(m)) and molecular activity (k(cat)) were...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2012.07.004
更新日期:2012-10-10 00:00:00
abstract::Two novel glycosyl hydrolase family 5 (GH5) β-mannanases (AoMan5A and AoMan5B) were identified from Aspergillus oryzae RIB40 by genome mining. The AoMan5A contains a predicted family 1 carbohydrate binding module (CBM-1), located at its N-terminal. The AoMan5A, AoMan5B and truncated mutant AoMan5AΔCL (truncating the N...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2016.08.003
更新日期:2016-11-01 00:00:00
abstract::The recombinant shuttle plasmid pCPPS-31, which confers carboxymethylcellulase (CMCase) production and neomycin resistance (Ner), was segregationally but not structurally unstable in both B. subtilis (50-60%) and Escherichia coli (80-90%) when grown in serial batch cultures for 72 h diluting 1:1,000 with fresh medium ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/0141-0229(94)90049-3
更新日期:1994-03-01 00:00:00
abstract::This study aimed to improve the thermostability of a newly cloned tyrosinase from Streptomyces kathirae SC-1. The POPMuSiC algorithm was applied to predict the folding free energy change (ΔDG) of amino acid substitution. Site-directed mutagenesis was used to construct mutants (Q7K, G234P, and Q7K/G234P), and the mutan...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2015.06.002
更新日期:2015-09-01 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::The D-amino acid oxidase cDNA gene (daao) of Trigonopsis variabilis was prepared by reverse transcriptase-polymerase chain reaction (PCR) and cloned into Escherichia coli expression vector, pTrc99A, under the control of tac promoter. Expression of daao gene significantly affected the growth and morphology of E. coli. ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00247-7
更新日期:2000-10-01 00:00:00