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 growth rate range at which the recombinant enzyme synthesis was improved. Fed-batch fermentations were carried out to study the possibility of enhancing recombinant enzyme synthesis through the control of medium addition. It was found that, in continuous culture fermentations, the culture is less unstable at low dilution rates (dilution rate < 0.1 h(-)(1)). Also, low dilution rates give a higher specific recombinant enzyme concentration (10 times more than that obtained at high dilution rates). In fed-batch fermentation, the final recombinant enzyme concentration can be manipulated through the medium addition strategy. To increase the recombinant enzyme concentration, the carbon source has to be fed slowly, otherwise enzyme synthesis is impaired due to catabolite repression. Therefore, an increase in the biomass concentration does not necessarily imply an increase in the recombinant enzyme concentration. Higher recombinant enzyme concentrations were found in fed-batch fermentations compared to those obtained in continuous culture.
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Shene C,Mir N,Andrews BA,Asenjo JAdoi
10.1016/s0141-0229(00)00203-9keywords:
subject
Has Abstractpub_date
2000-08-01 00:00:00pages
248-253issue
3-5eissn
0141-0229issn
1879-0909pii
S0141022900002039journal_volume
27pub_type
杂志文章abstract：:Nine proteins with lignin peroxidase activity were separated from cultures of Phanerochaete chrysosporium INA-12 in glycerol as carbon source and non-nitrogen limited. Four lignin peroxidase isozymes (4, 5, 8, 9) were purified and characterized. Although differences in kinetic parameters could be shown, antibody react...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90056-v
更新日期：1990-06-01 00:00:00
abstract：:Zygosaccharomyces rouxii is an important yeast in the formation of flavor in soy sauce. In this study, we investigated the separate effects of exogenous threonine, cystathionine, and the branched-chain amino acids on the metabolism of Z. rouxii. The addition of these amino acids had significant effects on both Z. roux...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(99)00165-9
更新日期：2000-02-01 00:00:00
abstract：:GH11 xylanase XynJ from Bacillus sp. strain 41M-1 has a β-jellyroll fold composed of eight β strands with a deep active-site cleft. We hypothesized that the thermostability of XynJ will increase if the flexibility of the β strands in the jellyroll structure is decreased without impairing activity. To verify this hypot...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109363
更新日期：2019-11-01 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：:Based on a differential pre-screening of 44 white-rot fungi on a lignocellulose-supplemented minimal medium, four basidiomycetes were selected for further study: Ganoderma lucidum, Polyporus brumalis, Polyporus ciliatus and Trametes versicolor. Only G. lucidum was able to grow vividly on malt extract or minimal media ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.08.003
更新日期：2013-12-10 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：:Marine microbes have gained significant attention as potential biofactories for broad spectrum bioactive compounds. In the recent years, bioactive biosurfactants have warranted renewed interest from both environmental and clinical sectors as anti-biofilm agents due to their excellent properties of dispersing microbial...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2018.09.008
更新日期：2019-01-01 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：:This study examines a novel method to reduce the probability of disulfide mismatches during the refolding process by the replacement of cysteines within a protein. Specifically, Cys383 of recombinant rat procarboxypeptidase B was replaced by other amino acids to increase the refolding efficiency in vitro. Mutants C383...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2011.04.018
更新日期：2011-07-10 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：:A chemiluminescence fiber optic system coupled to flow injection analysis (FIA) and ion exchange chromatography has been developed for determining glucose in blood and urine. Immobilized glucose oxidase acted on beta-D-glucose to produce hydrogen peroxide, which was then reacted with luminol in the presence of ferricy...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(93)90130-t
更新日期：1993-05-01 00:00:00
abstract：:Escherichia coli B/pTG201 recombinant cells were immobilized by entrapment in a carrageenan gel and cultivated in nonselective media to investigate the effect of agitation rate on plasmid stability, biomass concentration, and enzyme productivity. These parameters were studied in continuous cultures for free and immobi...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90112-4
更新日期：1990-12-01 00:00:00
abstract：:We have examined the chain length selectivity for a series of acyl donors by lipase B from Candida antarctica (CalB). CalB accepted aliphatic diesters of C4, C6 and C12 chain lengths equally. The introduction of a carbon-carbon double bond into the C4 esters dramatically lowered the rate constant associated with polym...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2014.03.006
更新日期：2014-05-10 00:00:00
abstract：:The selected thermotolerant, lactose-utilizing yeast strain Kluyveromyces marxianus NBIMCC 8362 possesses high specific d-amino acid oxidase activity (60Ug(-1)), which was increased nine-fold (545Ug(-1)) by design of the growth medium and conditions for d-amino oxidase induction. Applying an optimized simple and rapid...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2007.08.010
更新日期：2008-01-01 00:00:00
abstract：:Enzymatic production of cephalexin using immobilized penicillin G acylase was studied. The factors that affect the conversion of 7-amino-3-deacetoxycephalosporanic acid (7-ADCA) to cephalexin, such as pH; temperature; concentrations of 7-ADCA, D(-)-phenylglycine methyl ester (PGME), and immobilized penicillin G acylas...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(94)90095-7
更新日期：1994-08-01 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：: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：:Amoxicillin can be produced in an enzymatic suspension-to-suspension reaction in which the substrate(s) and product(s) are mainly present as solid particles, while the reaction takes place in the liquid phase. During these suspension-to-suspension reactions different subprocesses take place, such as dissolution/crysta...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00245-3
更新日期：2000-11-01 00:00:00
abstract：:An approach was developed to enhance the efficiency for the bioconversion of 1-(3-hydroxyphenyl)-2-(methyamino)-ethanone to (R)-phenylephrine. The strain Serratia marcescens N10612, giving the benefit of 99% enantiomeric excess in (R)-PE conversion, was used. The fermentation was devised to harvest cells with high hyd...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2015.11.004
更新日期：2016-05-01 00:00:00
abstract：:A three-phase fluidized bed reactor (TPFBR) was designed to evaluate the potential of CoQ(10) production by gel-entrapped Sphingomonas sp. ZUTE03 via a conversion-extract coupled process. In the reactor, the CoQ(10) yield reached 46.99 mg/L after 8 h of conversion; a high-level yield of about 45 mg/L was maintained ev...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2011.11.006
更新日期：2012-02-10 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：:A novel magnetic Fe3O4 nanoparticles (MNPs) coupled with agarose (AMNPs) was synthesized using co-precipitation via alkaline condition and span-80 surfactants in organic solvent. Iminodiacetate was first attached to the MNPs through epichlorohydrin agent and then chelated with metal ions. The morphology and chemical p...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2014.05.008
更新日期：2014-09-01 00:00:00
abstract：:Filamentous fungal secretomes comprise highly dynamic sets of proteins, including multiple carbohydrate active enzymes (CAZymes) which are able to hydrolyze plant biomass polysaccharides into products of biotechnological interest such as fermentable sugars. In recent years, proteomics has been used to identify and qua...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章,评审
doi：10.1016/j.enzmictec.2017.08.007
更新日期：2018-02-01 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：:Numerous studies have focused on how to obtain high yield of sophorolipids using low-cost materials as substrates, and there has been various work on the experimental methods for purifying lactonic sophorolipids. These studies have not yet obtained satisfied results in combining a low-cost fermentation process and the...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2012.08.002
更新日期：2012-12-10 00:00:00
abstract：:The family B DNA polymerase gene from the euryarchaeon Thermococcus barophilus Ch5 (Tba5) contains an open reading frame of 6198 base pairs that encodes 2065 amino acid residues. The gene is split by three inteins that must be spliced out to form the mature DNA polymerase. A Tba5 DNA polymerase gene without inteins (g...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.02.004
更新日期：2016-05-01 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：:Direct esterifications using a nylon-immobilized lipase from Candida cylindracea were carried out in batch and continuous-flow reactors. The immobilized enzyme was effective in catalyzing the synthesis of ethylpropionate, isoamylpropionate, and isoamylbutyrate. With ethanol dissolved in hexane as a substrate, the maxi...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(92)90054-r
更新日期：1992-11-01 00:00:00
abstract：:Nitrification kinetics of synthetic saline wastewater was investigated by using an activated sludge unit. Initial experiments were performed with salt-free wastewater to obtain baseline information. Experiments with 3% salt concentration were performed at different sludge ages in order to investigate the system perfor...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(01)00312-x
更新日期：2001-05-07 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
