共查询到20条相似文献,搜索用时 31 毫秒
1.
Joseph Selvin S. Shanmughapriya R. Gandhimathi G. Seghal Kiran T. Rajeetha Ravji K. Natarajaseenivasan T. A. Hema 《Applied microbiology and biotechnology》2009,83(3):435-445
The sponge-associated actinomycetes were isolated from the marine sponge Dendrilla nigra, collected from the southwest coast of India. Eleven actinomycetes were isolated depending upon the heterogeneity and stability
in subculturing. Among these, Nocardiopsis dassonvillei MAD08 showed 100% activity against the multidrug resistant pathogens tested. The culture conditions of N. dassonvillei MAD08 was optimized under submerged fermentation conditions for enhanced antimicrobial production. The unique feature of
MAD08 includes extracellular amylase, cellulase, lipase, and protease production. These enzymes ultimately increase the scope
of optimization using broad range of raw materials which might be efficiently utilized. The extraction of the cell free supernatant
with ethyl acetate yielded bioactive crude extract that displayed activity against a panel of pathogens tested. Analysis of
the active thin layer chromatography fraction by Fourier transform infrared and gas chromatography-mass spectrometry evidenced
11 compounds with antimicrobial activity. The ammonium sulfate precipitation of the culture supernatant at 80% saturation
yielded an anticandidal protein of molecular weight 87.12 kDa. This is the first strain that produces both organic solvent
and water soluble antimicrobial compounds. The active extract was non-hemolytic and showed surface active property envisaging
its probable role in inhibiting the attachment of pathogens to host tissues, thus, blocking host–pathogen interaction at an
earlier stage of pathogenesis. 相似文献
2.
The lipases of Rhizopus spp. share a high 1,3-regiospecificity toward triacylglycerols, which makes them important enzymes in lipid modification.
In the present study, the extracellularly active production of recombinant Rhizopus arrhizus lipase was carried out with genes encoding the mature region (mRAL) and the mRAL having the prosequence (ProRAL) in Pichia pastoris. Two transformed P. pastoris clones containing the multicopy of mRAL and ProRAL genes were separately selected for the production of recombinant enzymes.
In a fed-batch cultivation, where methanol feeding was controlled by an on-line methanol analyzer, the supernatant contained
91 mg/L recombinant pro-form lipase (rProRAL) and 80 mg/L recombinant mature lipase (rRAL) after 92 h of cultivation. rProRAL
and rRAL were purified by ultrafiltration, SP-Sepharose Rast Flow chromatography, and Butyl-Sepharose Fast Flow chromatography.
Molecular weights of rProRAL and rRAL are 32 kDa and 29 kDa, respectively. The amino-terminal analysis showed that the 32-kDa
protein was mRAL attached with 28 amino acids of the carboxy-terminal part of the prosequence (rPro28RAL). The specific lipase
activities of mRAL attached with 28 amino acids of the carboxy-terminal part of the prosequence (rPro28RAL) and rRAL were
1543 U/mg and 2437 U/mg. The rPro28RAL was more stable than rRAL at pH 4.0–7.0, whereas rRAL was more stable at pH 7.0–10.0.
The rPro28RAL had the highest lipase activity toward tributyrin (C4), whereas rRAL had the highest lipase activity toward tricaprylin (C8). 相似文献
3.
Sánchez-Otero MG Valerio-Alfaro G García-Galindo HS Oliart-Ros RM 《Journal of industrial microbiology & biotechnology》2008,35(12):1687-1693
A partially purified lipase produced by the thermophile Geobacillus thermoleovorans CCR11 was immobilized by adsorption on porous polypropylene (Accurel EP-100) in the presence and absence of 0.1% Triton X-100.
Lipase production was induced in a 2.5% high oleic safflower oil medium and the enzyme was partially purified by diafiltration
(co. 500,000 Da). Immobilization conditions were established at 25 °C, pH 6, and a protein concentration of 0.9 mg/mL in the
presence and absence of 0.1% Triton X-100. Immobilization increased enzyme thermostability but there was no change in neither
the optimum pH nor in pH resistance irrelevant to the presence of the detergent during immobilization. Immobilization with
or without Triton X-100 allowed the reuse of the lipase preparation for 11 and 8 cycles, respectively. There was a significant
difference between residual activity of immobilized and soluble enzyme after 36 days of storage at 4 °C (P < 0.05). With respect to chain length specificity, the immobilized lipase showed less activity over short chain esters than
the soluble lipase. The immobilized lipase showed good resistance to desorption with phosphate buffer and NaCl; minor loses
with detergents were observed (less than 50% with Triton X-100 and Tween-80), but activity was completely lost with SDS. Immobilization
of G. thermoleovorans CCR11 lipase in porous polypropylene is a simple and easy method to obtain a biocatalyst with increased stability, improved
performance, with the possibility for re-use, and therefore an interesting potential use in commercial conditions. 相似文献
4.
Agaricus bisporous tyrosinase was immobilized on commercial available epoxy-resin Eupergit®C250L and then coated by the Layer-by-Layer method (LbL). The two novel heterogeneous biocatalysts were characterized for their morphology, pH and storage stability, kinetic properties (Km, Vmax, Vmax/Km) and reusability. These biocatalysts were used for the efficient and selective synthesis of bioactive catechols under mild and environmental friendly experimental conditions. Ascorbic acid was added in the reaction medium to inhibit the formation of ortho-quinones, thus avoiding the known enzyme suicide inactivation process. Catechols were obtained mostly in quantitative yields and conversion of substrate. Tyrosinase immobilized on Eupergit®C250L and coated by the LbL method showed better catalytic activities, higher pH and storage stability, and reusability with respect to immobilized uncoated tyrosinase. Since chemical procedures to synthesize catechols are often expensive and with high environmental impact, the use of immobilized tyrosinase represents an efficient alternative for the preparation of this family of bioactive compounds. 相似文献
5.
Enzyme extraction from solid matrix is as important step in solid-state fermentation to obtain soluble enzymes for further immobilization and application in biocatalysis. A method for the recovery of a pool of lipases from Penicillium simplicissimum produced by solid-state fermentation was developed. For lipase recovery different extraction solution was used and phosphate buffer containing Tween 80 and NaCl showed the best results, yielding lipase activity of 85.7 U/g and 65.7 U/g, respectively. The parameters with great impacts on enzyme extraction detected by the Plackett-Burman analysis were studied by Central Composite Rotatable experimental designs where a quadratic model was built showing maximum predicted lipase activity (160 U/g) at 25°C, Tween 80 0.5% (w/v), pH 8.0 and extraction solution 7 mL/g, maintaining constant buffer molarity of 0.1 M and 200 rpm. After the optimization process a 2.5 fold increase in lipase activity in the crude extract was obtained, comparing the intial value (64 U/g) with the experimental design (160 U/g), thus improving the overall productivity of the process. 相似文献
6.
Deise Juliana Kolling Jean Borges Bertoldo Fábio Cristiano Angonesi Brod Javier Vernal Hernán Terenzi Ana Carolina Maisonnave Arisi 《Molecular biotechnology》2010,46(2):168-175
Staphylococcus xylosus AF208229 lipase was expressed in E. coli containing an histidine-tag (WT-Val). In the present work, in order to check the importance of the residue 309 in the specific
activity, the amino acid side chain residue valine 309 was substituted by aspartate or lysine through site-directed mutagenesis.
Both mutant lipases (MUT-Lys and MUT-Asp) were expressed in E. coli and the recombinant histidine-tagged lipases were purified by immobilized metal ion affinity chromatography. The enzyme activity
was determined using p-nitrophenyl butyrate as substrate and secondary structure content was evaluated by circular dichroism. MUT-Lys and MUT-Asp
presented significant increase of lipase activity (P < 0.05) in comparison to WT-Val, although highest activities for the three enzymes were observed at the same pH and temperature
(pH 9.0 and 42°C). The wild type and mutant lipases presented high thermal stability, after 30 min of incubation at 80°C all
enzymes retained their initial activities. 相似文献
7.
Lipase from Pseudomonas aeruginosa LP602, a bacterial strain isolated from a domestic wastewater sample, was preliminarily characterized. The enzyme exhibited
maximum lipolytic activity at pH 8.0 where it was also stably maintained. At 55°C, the lipase had the highest activity but
not stability. The enzyme was insensitive to EDTA and to many ions tested except Zn2+. It was sensitive to SDS but not to Tween-20, Tween-80 or Triton X-100. The enzyme was active towards a number of commercial
food grade fats and oils. A suitable medium formula for lipase production was MMP containing 6.25% whey as a carbon source,
1% soybean oil as inducer and 0.5% yeast extract supplement. The culture was fed with glucose to a final concentration of
0.1% at the 15th hour of incubation. Lipase production under this condition was 3.5 U ml−1. Both P. aeruginosa LP602 cells and the lipase were shown to be usable for lipid-rich wastewater treatment.
Received 21 April 1998/ Accepted in revised form 6 August 1998 相似文献
8.
Microbial lipases are widely diversified in their enzymatic properties and substrate specificities, which make them very attractive
for industrial application. Partially purified lipase from Bjerkandera adusta R59 was immobilized on controlled porous glass (CPG) and its properties were compared with those of the free enzyme. The free
and immobilized lipases showed optimal activities at 45 and 50°C, respectively. Both enzyme forms were highly thermostable
up to 60°C. The enzymes were stable at pH from 6.0 to 9.0 and their optimal pH for activity was 7.0. The free lipase was more
thermostable in n-hexane than in aqueous environment. Both lipase preparations had good stabilities in non-polar solvents and were capable
of hydrolysing a variety of synthetic and natural fats. Non-immobilized lipase activity was inhibited by disulphide bond reagents,
serine and thiol inhibitors, while EDTA and eserine had no effect on enzyme activity. All anionic detergents tested in experiments
inhibited lipase activity. The free lipase showed good stability in the presence of commercial detergents at laundry pH and
temperatures. Applications of free and immobilized lipases for esterification were also presented. 相似文献
9.
《Biocatalysis and Biotransformation》2013,31(4):315-329
Three novel lipase-producing microorganisms have been isolated from 526 actinomycete strains by employing screening techniques on solid media. Time-course and scale-up of enzyme production were analyzed. The lipases, produced by microorganisms belonging to the Streptomyces genus, were tested in several reactions in organic medium using unnatural substrates. The lyophilized crude lipases are stable at least for 1 month at 4°C (100% recovered activity). The lipase activity per milliliter of cell culture broth was higher than described in the literature for other lipases from actinomycetes. The three selected lipases displayed better activity than commercial lipase from Candida rugosa in the resolution of chiral secondary alcohols. The lipase from S. halstedii also displayed very good activity in the synthesis of carbamates. 相似文献
10.
Evaluation of diatomaceous earth as a support for sol–gel immobilized lipase for transesterification
Enzymatic production of biodiesel by triglyceride transesterification is a promising alternative to chemically catalyzed biodiesel production despite the challenges involved with using enzymes. Celite® supported lipase sol–gels were investigated as an option for solving some of the challenges associated with the use of enzymes for biodiesel production addressing such problems as activity, stability and reusability of the enzyme. Three types of Celite® were considered (R633, R632, and R647) and compared to unsupported lipase sol–gels. Various factors were considered with regard to comparing the support materials. They included surface morphology characterized using surface area analysis and scanning electron microscopy, physical properties including adhesion of the sol–gel to the Celite® and the protein loading on the Celite®, and finally enzymatic properties based on the conversion of methanol to methyl oleate and the enzymatic activity of lipase. All the sol–gels showed good conversion and initial lipase activity, and all the Celite® supports had similar sol–gel adhesion and protein loading. Sol–gel immobilized lipase supported on Celite® R632 had an average 6-h percent conversion of approximately 60%, and an average initial lipase activity comparable to that of the unsupported sol–gel formulation. 相似文献
11.
Olfa Ghorbel-Bellaaj Kemel Jellouli Hana Maalej 《Biocatalysis and Biotransformation》2017,35(4):287-297
Protein hydrolysates were prepared from shrimp processing by-products (SPBP) using five proteolytic enzymes: trypsin, Alcalase®, crude enzyme extract from sardinelle (Sardinella aurita) viscera and enzyme preparations from Bacillus licheniformis NH1 and Aspergillus clavatus ES1. The obtained hydrolysates exhibited different degrees of antioxidant activities evaluated through three main tests: 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity, reducing power and β-carotene bleaching assays. Hydrolysates were also tested as nitrogen source for microbial growth and proteases production by Escherichia coli, Saccharomyces cerevisiae, B. mojavensis A21 and B. subtilis A26. The reached results showed that the SPBP protein hydrolysates (SPBPPHs) could be a promising alternative to currently available commercial nitrogen sources of other origins. 相似文献
12.
AbstractThe present study aims to exploit microbial potential from colder region to produce lipase enzyme stable at low temperatures. A newly isolated bacterium GBPI_508 from Himalayan environment, was investigated for the production of cold-active lipase emphasizing on its aggregation properties. Plate based assays followed by quantitative production of enzyme was estimated under different culture conditions. Further characterization of partially purified enzyme was done for molecular weight determination and activity and stability under varying conditions of pH, temperature, and in presence of organic solvents, inhibitors, and metal ions. The psychrotolerant bacterium was identified as Pseudomonas palleroniana following 16S rRNA gene sequencing. Maximum lipase production by GBPI_508 was recorded in 7?days at 25?°C utilizing yeast extract as nitrogen source and olive oil as substrate in the lipase production medium. Triton X-100 (1%) in the medium as emulsifier significantly enhanced the lipase production. Lipase produced by bacterium showed aggregation which was confirmed by dynamic light scattering and native PAGE. SDS-PAGE followed by zymogram analysis of partially purified enzyme showed two active bands of ~50?kDa and ~54?kDa. Optimum activity of partially purified enzymatic preparation was recorded at 40?°C while the activity remained nearly consistent from pH 7.0 to 12.0, whereas, maximum stability was recorded at pH values 7.0 and 11.0 at 25?°C. Interestingly, lipase in the partially purified fraction retained 60% enzyme activity at 10?°C. Medium chain pNP ester (C10) was the most preferred substrate for the lipase of GBPI_508. The lipase possessed >50% residual activity when incubated with different organic solvents (25% v/v) except toluene and dichloromethane which inhibited the activity below 50%. Partially purified enzyme was also stable in the presence of metal ions and inhibitors. The study suggests applicability of GBPI_508 lipase in low temperature conditions such as cold-active detergent formulations and cold bioremediation. 相似文献
13.
Independent production of two molecular forms of a recombinant Rhizopus oryzae lipase by KEX2-engineered strains of Saccharomyces cerevisiae 总被引:1,自引:0,他引:1
A mixture of rProROL having the full-length prosequence (97 amino acids) for a recombinant lipase of Rhizopus oryzae (rROL) and r28ROL having 28 amino acids of the same prosequence has been produced as active forms by Saccharomyces cerevisiae [Takahashi et al. (1998) J Ferment Bioeng 86: 164–168]. However, the separation of rProROL and r28ROL has not been successful
due to their identical behavior on column chromatographs, presumably because of the similarity of their surface properties.
The independent production of two different molecular forms of rROL was carried out using KEX2-engineered strains of S. cerevisiae, since r28ROL was predicted to be a product from rProROL by a Kex2-like protease. rProROL was successfully obtained by expression
of the ROL gene in the S. cerevisiae kex2 strain in which the KEX2 gene encoding Kex2p was disrupted, while r28ROL was obtained by co-expression of the gene (KEX2Δ613) encoding the soluble form of the C-terminal truncated Kex2 protease (sKex2p). The specific lipase activities of rProROL
and r28ROL were 92.9 U/mg and 140 U/mg, respectively. rProROL was stable at pH 2.2–8.0, and showed the optimal reaction temperature
to be 30–35 °C with a T
50 of 55 °C (T
50 is the temperature resulting in 50% loss of activity). The values for r28ROL were pH 3.0–10.0, 25–30 °C, and 40 °C, respectively.
rProROL was an N-linked glycosylated form, but r28ROL was not. The enhanced thermostability of rProROL did not seem to be
due to the N-linked glycosylation, as judged by the results of the Endo H treatment. rProROL had the highest esterase activity
toward p-nitrophenyl laurate (C12), whereas r28ROL had the highest esterase activity toward p-nitrophenyl caprylate (C8) and stearate (C18). These results suggest that the distinct properties of these two forms of lipase are caused by the different length of the
ROL prosequence.
Received: 26 January 1999 / Received last revision: 24 May 1999 / Accepted: 4 June 1999 相似文献
14.
The extracellular lipase structural gene was isolated from cDNA of Aureobasidium pullulans HN2-3 by using SMARTTM RACE cDNA amplification kit. The gene had an open reading frame of 1245 bp long encoding a lipase. The coding region of the
gene was interrupted by only one intron (55 bp). It encodes 414 amino acid residues of a protein with a putative signal peptide
of 26 amino acids. The protein sequence deduced from the extracellular lipase structural gene contained the lipase consensus
sequence (G-X-S-X-G) and three conserved putative N-glycosylation sites. According to the phylogenetic tree of the lipases,
the lipase from A. pullulans was closely related to that from Aspergillus fumigatus (XP_750543) and Neosartorya fischeri (XP_001257768) and the identities were 50% and 52%, respectively. The mature peptide encoding cDNA was subcloned into pET-24a
(+) expression vector. The recombinant plasmid was expressed in Escherichia coli BL21(DE3). The expressed fusion protein was analyzed by SDS-PAGE and western blotting and a specific band with molecular
mass of about 47 kDa was found. Enzyme activity assay verified the recombinant protein as a lipase. A maximum activity of
0.96 U/mg was obtained from cellular extract of E. coli BL21(DE3) harboring pET-24a(+)LIP1. Optimal pH and temperature of the crude recombinant lipase were 8.0 and 35 °C, respectively and the crude recombinant lipase
had the highest hydrolytic activity towards peanut oil. 相似文献
15.
The adsorption capacity and immobilization rate of two Eupergit® supports for acid urease was studied by varying the ionic strength and enzyme preparation concentration in the immobilizing solution at pH 7. Eupergit® C250 L yielded a series of derivatives with enzyme loadings (YP/B) ranging from 48 to 171 mg of bovine serum albumin equivalent (BSAE) per gram of dry support (ds). Use of drastic postimmobilization conditions at pH 9 for 3–9 days yielded a slight decrease (8–14%) in the initial activity of immobilized enzymes and a limited increase in the stabilization factor (1.1–1.5), as assessed by accelerated aging tests at 65°C. Further storage tests at 4°C in the wet state showed that the activity of several derivatives either stabilized or not was practically constant for as long as 547 days. Both free enzyme and immobilized acid urease derivatives exhibited a kinetic pattern of the Michaelis–Menten type. Using the Eadie–Hofstee diagram, the specific ammonia formation rate constant for free (kcat) or immobilized (k′cat) enzyme resulted to be little affected by immobilization (kcat ≈ k′cat ≈ 18.86 ± 0.34 IU/mg BSAE), whereas the apparent Michaelis constant for immobilized enzymes exhibited a statistically significant increase at P < 0.05 from the intrinsic value (2.55 ± 0.14 mM) for free enzyme to 5.38 ± 0.87 mM as YP/B increased to 171 mg BSAE/g ds. By estimating the observable Thiele modulus (?obs), the activity of the biocatalyst with the greatest enzyme loading at the lowest urea concentrations tested (0.833 mM) was reduced by a factor of about 2 due to internal diffusional limitations. By operating in the pseudofirst‐order regime with immobilized derivatives at YP/B about 126 mg BSAE/g ds, their activity after grinding was no more limited by intraparticle diffusion and approached the value for free enzyme. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012 相似文献
16.
Kato M Fuchimoto J Tanino T Kondo A Fukuda H Ueda M 《Applied microbiology and biotechnology》2007,75(3):549-555
To prepare a whole-cell biocatalyst of a stable lipase at a low price, mutated Candida antarctica lipase B (mCALB) constructed on the basis of the primary sequences of CALBs from C. antarctica CBS 6678 strain and from C. antarctica LF 058 strain was displayed on a yeast cell surface by α-agglutinin as the anchor protein for easy handling and stability
of the enzyme. When mCALB was displayed on the yeast cell surface, it showed a preference for short chain fatty acids, an
advantage for producing flavors; although when Rhizopus oryzae lipase (ROL) was displayed, the substrate specificity was for middle chain lengths. When the thermal stability of mCALB on
the cell surface was compared with that of ROL on a cell surface, T
1/2, the temperature required to give a residual activity of 50% for heat treatment of 30 min, was 60°C for mCALB and 44°C for
ROL indicating that mCALB displayed on cell surface has a higher thermal stability. Furthermore, the activity of the displayed
mCALB against p-nitrophenyl butyrate was 25-fold higher than that of soluble CALB, as reported previously. These findings suggest that mCALB-displaying
yeast is more practical for industrial use as the whole-cell biocatalyst. 相似文献
17.
New cold-adapted lipase from Photobacterium lipolyticum sp. nov. that is closely related to filamentous fungal lipases 总被引:1,自引:0,他引:1
Ryu HS Kim HK Choi WC Kim MH Park SY Han NS Oh TK Lee JK 《Applied microbiology and biotechnology》2006,70(3):321-326
A Photobacterium strain, M37, showing lipolytic activity, was previously isolated from an intertidal flat of the Yellow Sea in Korea and identified as Photobacterium lipolyticum sp. nov. In the present study, the corresponding gene was cloned using the shotgun method. The amino acid sequence deduced from the nucleotide sequence (1,023 bp) corresponded to a protein of 340 amino acid residues with a molecular weight of 38,026. No sequence similarity was found with any known bacterial lipases/esterases; instead, the most similar enzymes were several filamentous fungal lipases. Although the similarity was very low (less than 16%), there were many conserved regions over the entire sequence and N-terminal oxyanion hole (RG) region, a signature sequence of filamentous fungal lipases. The novel protein M37 was produced in both a soluble and insoluble form when the Escherichia coli cells harboring the gene were cultured at 18°C. The soluble protein exhibited lipase activity in a pH-stat assay using an olive oil emulsion. The M37 lipase also displayed a maximum activity at 25°C and maintained its activity at a low temperature range (5–25°C) with an activation energy (E
a) of 2.07 kcal/mol. Accordingly, these results indicate that the M37 lipase from P. lipolyticum sp. nov. is a new cold-adapted enzyme. 相似文献
18.
Lipase (Glycerol ester hydrolase E.G. 3.1.1.3) from a Brazilian strain of Penicillium citrinum free of the mycotoxin citrinin has been investigated. Citrinin production was inhibited by using culture medium containing olive oil, soybean oil and corn oil as carbon sources. Potassium concentration and pH play an important role in citrinin production. Potassium concentration lower than 30 mM and pH below 4.5 inhibited the mycotoxin production. P. citrinum produced lipase free of extraneous proteins and citrinin when cultured using, as nitrogen source, ammonium sulphate (lipase activity of 7.88 U/mg) and yeast extract (lipase activity of 4.95 U/mg) with olive oil as carbon source. This data is relevant to the larger scale production of lipases for food technology applications, from Penicillium citrinum. 相似文献
19.
Lozada-Ramírez JD Sánchez-Ferrer A García-Carmona F 《Applied microbiology and biotechnology》2012,93(6):2317-2325
Recombinant S-adenosylhomocysteine hydrolase from Corynebacterium glutamicum (CgSAHase) was covalently bound to Eupergit® C. The maximum yield of bound protein was 91% and the catalytic efficiency was 96.9%. When the kinetic results for the immobilized enzyme were compared with those for the soluble enzyme, no decrease in the catalytic efficiency of the former was detected. Both soluble and immobilized enzymes showed similar optimum pH and temperature ranges. The reuse of immobilized CgSAHase caused a loss of synthetic activity due to NAD+ release, although the binding to the support was sufficiently strong for up to 5 cycles with 95% conversion efficiency. The immobilized enzyme was incubated every 3 cycles with 100 μM NAD+ to recover the loss of activity after 5 cycles. This maintained the activity for another 50 cycles. The purification of S-adenosylhomocysteine (SAH) provided an overall yield of 76% and 98% purity as determined by HPLC and NMR analyses. The results indicate the suitability of immobilized CgSAHase for synthesizing SAH and other important S-nucleosidylhomocysteine. 相似文献
20.
Fernando R.R. Teles Joaquim M.S. Cabral José A.L. Santos 《Biotechnology letters》2001,23(14):1159-1163
The lipolytic activity of cutinase produced by a recombinant Saccharomyces cerevisiae strain was compared with Defat 50, a commercial lipase solution, for their degreasing abilities on a lipidic concentrate of sheep fleshing, a solid by-product of the leather industry. The specific activities obtained were 2749 and 938 U mg–1 of lipase for cutinase and Defat 50, respectively. 相似文献