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 separate semi-batch unit downstream of the cell culture stage. Surfactin partitioned strongly into the foam during the latter stages of the semi-batch process, where enrichments of over 50 could be obtained. However, simultaneous high enrichments and recoveries of Surfactin could not be obtained as the majority of Surfactin (around 70% of the total recovered) was produced at a low concentration during the early stages of foaming. Foam fractionation was considered for both cell free and cell containing broths; the presence of cells increased the foamability of the solution and therefore yielded more dilute Surfactin preparations. More favourable recovery and enrichment of Surfactin occurred when foaming was integrated with the cell culture stage. The use of low stirrer speeds was essential in producing foam at a controlled rate. By collecting fractions of the foam produced between 10 and 30 hours, from systems stirred at 166 and 146 rpm, a highly concentrated Surfactin extract could be obtained. The Surfactin concentration in the foam was 1.22 and 1.67 g l(-1) respectively, which represented enrichments and percent recoveries of over 60. This study points to the utility of foaming as a method for the recovery of surface-active fermentation products, particularly when used in an integrated production/recovery system.
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Davis DA,Lynch HC,Varley Jdoi
10.1016/s0141-0229(00)00327-6keywords:
subject
Has Abstractpub_date
2001-03-08 00:00:00pages
346-354issue
4-5eissn
0141-0229issn
1879-0909pii
S0141022900003276journal_volume
28pub_type
杂志文章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：: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：: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：:The characterization of the S' subsite specificity of native and ethylated alpha-chymotrypsin has been studied via acyl transfer reaction in acetonitrile containing 10 vol% of water. Using Ac-Tyr-OEt as acyl donor, we investigated the partitioning of acyl-chymotrypsins between water and amino acid and peptide-derived ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(94)90125-2
更新日期：1994-07-01 00:00:00
abstract：:The present work describes a novel central pathway engineering method that has been designed with the aim to increase the carbon conversion rates under oxidizing conditions in L. lactis fermentations. The nisin producer L. lactis ATCC11454 strain has been genetically engineered by cloning a truncated version of the ph...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2012.04.007
更新日期：2012-08-10 00:00:00
abstract：:A colorimetric platform based on enzyme-inorganic hybrid nanoflowers was used for ultraviolet-visible detection of hydrogen peroxide (H2O2). The hybrid nanoflowers were prepared via incubation at room temperature using horseradish peroxidase (HRP) and copper phosphate (Cu3(PO4)2) as the organic and inorganic component...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2020.109620
更新日期：2020-10-01 00:00:00
abstract：:Biosensors have been extensively studied during the last 20 years, and a myriad of laboratory biosensors have been developed. Improvements are required in biosensor design and performance before they become widely accepted in industrial process monitoring. However, as the biotechnology industry expands, biosensors may...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章,评审
doi：10.1016/0141-0229(91)90115-q
更新日期：1991-12-01 00:00:00
abstract：:This work describes for the first time the green synthesis of neopentyl glycol diheptanoate in a solvent-free medium via an enzymatic pathway. The process has been carried out in an open-air reactor in order to ease water removal through evaporation and shift the chemical equilibrium towards product formation. The inh...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109400
更新日期：2020-01-01 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：:Recently, we reported a highly sensitive immunoassay using Escherichia coli cells with autodisplayed Z-domains. In this work, E. coli cells with autodisplayed Z-domains were applied to the flow-cytometry-based simultaneous detection of multiple analytes. The E. coli cells were doubly transfected to express a fluoresce...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.03.018
更新日期：2013-08-15 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：:The mass distribution regularity in substrate of solid-state fermentation (SSF) has rarely been reported due to the heterogeneity of solid medium and the lack of suitable instrument and method, which limited the comprehensive analysis and enhancement of the SSF performance. In this work, the distributions of water, bi...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2014.02.007
更新日期：2014-05-10 00:00:00
abstract：:A novel endoglucanase active on 1,3-1,4-beta-D-glucans was purified to apparent homogeneity from submerged cultures of the moderately thermophilic aerobic fungus Talaromyces emersonii CBS 814.70. The enzyme is a single subunit glycoprotein with M(r) and pI values of 40.7 +/- 0.3 kDa and 4.4, respectively, and an estim...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(01)00354-4
更新日期：2001-07-05 00:00:00
abstract：:We have designed an electrochemical DNA biosensor based on stem-loop structured probes for enzymatic detection of Pseudomonas aeruginosa 16S ribosomal RNA (rRNA) in composting degradation. The probe modified with a thiol at its 5' end and a biotin at its 3' end was immobilized on a gold electrode through self-assembly...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2011.06.011
更新日期：2011-08-10 00:00:00
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 activ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90178-s
更新日期：1990-01-01 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：: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
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：:Di-, tri-, and tetra-tyrosine peptides with angiotensin I-converting enzyme inhibitory activity were synthesized by papain-catalyzed polymerization of L-tyrosine ethyl ester in aqueous media at 30 °C. Varying the reaction pH from 6.0 to 7.5 and the initial concentration of the ester substrate from 25 to 100 mM, the hi...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2015.03.007
更新日期：2015-07-01 00:00:00
abstract：:The effect of treatment with various intercalating dyes on the ability to produce antibiotics in Micromonospora rosaria and Micromonospora purpurea was studied. Treatment with acriflavine resulted in a high frequency loss of antibiotic productivity in both species. In M. rosaria, the loss of antibiotic-producing abili...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90128-d
更新日期：1990-08-01 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：:Recombinant plasmid pCED3 [confers beta-galactosidase production (LacZ+) and kanamycin resistance (Kmr)] in Bacillus subtilis was found to be both segregationally and structurally unstable. Since many solutions to segregational instability are already available, the problem of structural instability was specifically a...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90160-r
更新日期：1990-05-01 00:00:00
abstract：:2,5-Bis(hydroxymethyl)furan (BHMF) is a versatile building block in the synthesis of polymers, fuels, and macrocycle polyethers. In this work, alcohol dehydrogenases (ADHs) were identified from Meyerozyma guilliermondii SC1103 and were heterologously expressed in Saccharomyces cerevisiae for the synthesis of BHMF from...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109491
更新日期：2020-03-01 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：:Mycobacterium tuberculosis acetohydroxyacid synthase (M. tuberculosis AHAS) has been proposed to bean essential target for novel herbicide- and chemical-based antibacterial agents. Therefore, here we investigated the roles of multiple conserved herbicide-binding site residues (R318, A146, Q148, M512, and V513) in M. t...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2015.06.009
更新日期：2015-10-01 00:00:00
abstract：:Even though many enzyme processes occur at the interface of an insoluble substrate, these reactions are generally much less studied than homogenous enzyme reactions in the aqueous bulk. Interfacial (or heterogeneous) enzyme reactions involve several reaction steps, and the established experimental approach to elucidat...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.06.009
更新日期：2017-10-01 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：: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：: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：:Phytate is the major storage form of phosphorus in plants. It is present in cereals and raw materials of vegetable origin used in animal and human diets. However, non-ruminant animals have little phytase activity in their guts and, therefore, cannot digest phytate. As a result, almost all dietary phytate is discharged...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2020.109533
更新日期：2020-06-01 00:00:00
