Abstract:
:When dissolved oxygen (DO) was maintained at saturation level during batch fermentations of Streptomyces clavuligerus (NRRL 3585), the accumulation of the intermediate penicillin N was lowered while formation of the end product cephamycin C was increased relative to fermentations without DO control. The specific activity of the penicillin ring-expansion enzyme deacetoxycephalosporin C synthase (DAOCS) was increased 2.3-fold under oxygen saturated conditions, whereas the penicillin ring-cyclizing enzyme isopenicillin N synthase (IPNS) showed only a 1.3-fold increase. Thus oxygen derepression of DAOCS appears to be an important regulatory mechanism in the conversion of penicillin N to cephamycin C in S. clavuligerus. IPNS, an early acting enzyme in cephamycin C biosynthesis, and DAOCS, which acts late in the pathway, both disappeared from cell extracts at 60 h, just prior to cessation of cephamycin production.
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Rollins MJ,Jensen SE,Wolfe S,Westlake DWdoi
10.1016/0141-0229(90)90178-skeywords:
subject
Has Abstractpub_date
1990-01-01 00:00:00pages
40-5issue
1eissn
0141-0229issn
1879-0909pii
0141-0229(90)90178-Sjournal_volume
12pub_type
杂志文章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::Bacterial spores maintain metabolic dormancy and have high resistance to external pressure. Germination requires degradation of the spore cortex and the participation of germination-specific cortex-lytic enzymes (GSLEs). Previously reported GSLEs have been identified in bacteria and facilitate germination. In this stu...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2020.109698
更新日期:2020-12-01 00:00:00
abstract::The xylanase R8 gene (xynR8) from uncultured rumen fungi was cloned and successfully expressed in Lactobacillus reuteri. A xylanase activity of 132.1 U/mL was found in the broth of L. reuteri R8, the transformant containing pNZ3004 vector with xynR8 gene insertion. Two distinct forms of recombinant xylanase with diffe...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2014.06.004
更新日期:2014-10-01 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::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::Production of laccase activity by nine strains of Chalara paradoxa isolated from olive mill wastewater disposal ponds were studied. Enzyme extracts obtained from cultured broths by adsorption on hydroxyapatite showed a single band of laccase activity on ABTS after polyacrylamide gel electrophoresis (PAGE). They showed...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(99)00197-0
更新日期:2000-04-01 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::A method to quantify the impact of proteolysis on accumulation of recombinant proteins in E. coli is described. A much smaller intracellular concentration of staphylococcal protein A (SpA) (14.7 mg. g(-1)) compared to the fusion protein SpA-betagalactosidase (138 mg. g(-1)) is explained by a very high proteolysis rate...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00294-5
更新日期:2000-12-01 00:00:00
abstract::In this study, we report the enzymatic production of glycerol acetate from glycerol and methyl acetate. Lipases are essential for the catalysis of this reaction. To find the optimum conditions for glycerol acetate production, sequential experiments were designed. Type of lipase, lipase concentration, molar ratio of re...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2014.11.004
更新日期:2015-02-01 00:00:00
abstract::Phenylalanine ammonia-lyase (PAL) gene plays an important role in the synthesis of flavones, lignin, and other bioactive compounds in living organisms. Inonotus baumii, the only known flavone-producing filamentous fungus, is of great importance in the investigation of flavone metabolic pathways. To study the function ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2017.10.010
更新日期:2018-05-01 00:00:00
abstract::An extracellular esterase from the actinomycetes Amycolatopsis orientalis was found by screening. It is capable of splitting the isomeric mixture (K/J) of (I, Scheme 1) into 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid, pivalic acid, and acetaldehyde with a high yield. The purified enzyme of 55.4 Kd by SDS-PAGE ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/0141-0229(95)00171-9
更新日期:1996-07-01 00:00:00
abstract::The primary aim of this study was to decipher the catalytic functions of the NHase with wide substrate spectra from Rhodococcus ruber CGMCC3090 by computer modeling and substrate docking. 3D structure model of the enzyme was built by computer modeling to obtain the optimal structure. The larger binding site cavity (55...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2012.11.004
更新日期:2013-02-05 00:00:00
abstract::NADPH is the key cofactor in L-isoleucine (Ile) biosynthetic pathway. To increase the Ile biosynthesis in Corynebacterium glutamicum ssp. lactofermentum JHI3-156, NADPH supply needs to be enhanced. Here NAD kinase, the key enzyme for the de novo biosynthesis of NADP(+) and NADPH, were cloned and expressed in JHI3-156,...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2012.04.003
更新日期:2012-07-15 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::Thiol dioxygenases are non-heme mononuclear-iron proteins and belong to the cupin superfamily. In 2014, mercaptosuccinate dioxygenase (Msdo) of Variovorax paradoxus B4 was identified as another bacterial cysteine dioxygenase (Cdo) homolog catalyzing the conversion of mercaptosuccinate (MS) into succinate and sulfite. ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2018.09.007
更新日期:2019-01-01 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::A solvent-mediated method (SMM) was used to prepare supersaturated sugar solutions in hydrophobic and mixture of hydrophilic/hydrophobic ionic liquids (ILs), namely, [Bmim][Tf2N] and [Bmim][TfO]/[Bmim][Tf2N], respectively. In this method, sugars were first solubilized in a mixture of organic solvent and water (i.e. me...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2019.03.004
更新日期:2019-07-01 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::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::Using bioinformatic homology search tools, this study utilized sequence phylogeny, gene organization and conserved motifs to identify members of the family of O-methyltransferases from lignin-degrading fungus Phanerochaete chrysosporium. The heterologous expression and characterization of O-methyltransferases from P. ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2015.08.016
更新日期:2016-01-01 00:00:00
abstract::Advantages in maltose fermentation at extremely low temperatures (5-10°C) using an alcohol resistant and cryotolerant yeast strain (Saccharomyces cerevisiae AXAZ-1) immobilized on porous cellulosic material (or tubular cellulose, TC), produced by delignification of wood sawdust, are reported. Pure maltose and glucose ...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2014.08.007
更新日期:2014-11-01 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::Crocin, one of the major carotenoid pigments of Crocus sativus (saffron), is responsible for antioxidant activity, neuroprotection, and the inhibition of tumor cell proliferation. In order to improve the functionality of crocin, α-glucosyl-(1→6)-trans-crocins (C-Gs) were synthesized using sucrose and dextransucrase fr...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2020.109630
更新日期:2020-10-01 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::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::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::Continuous culture and fed-batch fermentations were used to test the behavior of the system Bacillus subtilis DN1885(pCH7) that synthesizes a recombinant beta-1,4-endoglucanase. Continuous culture experiments were focused on the study of the instability aspects of the system as well as determination of the biomass gro...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00203-9
更新日期:2000-08-01 00:00:00
abstract::Flocculent yeast Saccharomyces cerevisiae YF234 (MATa ura3-52 trp1Delta2 his ade 2-1 can1-100 sta1 FLO8) cells overexpressing glyoxalase I and having strong flocculation ability were permeabilized with isopropyl alcohol and ethanol under various conditions. The treatment with 40% isopropyl alcohol significantly improv...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/s0141-0229(00)00304-5
更新日期:2000-12-01 00:00:00
abstract::The novel termite gut metagenomic-derived GH11 xylanase gene xyl7 was expressed in Escherichia coli BL21, and the purified XYL7 enzyme exhibited high specific activity (6340U/mg) and broad pH active range of 5.5-10.0. Directed evolution was employed to enhance the thermostability of XYL7; two mutants (XYL7-TC and XYL7...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2014.11.005
更新日期:2015-03-01 00:00:00
abstract::Direct cellobiose production from cellulose by a genetically modified fungus-Neurospora crassa, was explored in this study. A library of N. crassa sextuple beta-glucosidase (bgl) gene deletion strains was constructed. Various concentrations of cellobiose were detected in the culture broth of the N. crassa sextuple bet...
journal_title:Enzyme and microbial technology
pub_type: 杂志文章
doi:10.1016/j.enzmictec.2012.12.010
更新日期:2013-03-05 00:00:00