共查询到20条相似文献,搜索用时 500 毫秒
1.
Leda M. F. Gottschalk Jacyara M. B. Macedo Elba P. S. Bon 《Applied biochemistry and biotechnology》1999,79(1-3):771-778
Lignin peroxidase (LiP) production cost should be reduced to justify its use in the control of environmental pollution. In
this work, we studied the enzyme production by Streptomyces viridosporus T7A using glucose or corn oil as a carbon source having 0.65% yeast extract as a nitrogen source. Enzyme activity, observed
using either 0.65% glucose or corn oil at 0.1, 0.5, and 1.0% concentration, was 300, 150, 300, and 200 U/L, respectively.
Although higher enzyme activity was obtained in both media containing 0.65% glucose and 0.5% corn oil, the use of corn oil
resulted in a better LiP stability. When combined carbon sources were used, higher values of enzyme activity (360, 350, and
225 U/L) were observed in media with 0.65% glucose and supplemented with 0.1, 0.5, and 1.0% corn oil, respectively. Although
the presence of both glucose and 0.5% corn oil is favorable for LiP production, satisfactory results in terms of enzyme production
and stability could be also observed using 0.5% corn oil as a sole carbon source, which may lead to reduced production costs
of the LiP enzyme. 相似文献
2.
Fernanda Germano Alves Francisco Maugeri Filho Janaína Fernandes de Medeiros Burkert Susana Juliano Kalil 《Applied biochemistry and biotechnology》2010,160(5):1528-1539
In this work, the agitation and aeration effects in the maximization of the β-galactosidase production from Kluyveromyces marxianus CCT 7082 were investigated simultaneously, in relation to the volumetric enzyme activity and the productivity, as well as
the analysis of the lactose consumption and production of glucose, and galactose of this process. Agitation and aeration effects
were studied in a 2 L batch stirred reactor. A central composite design (22 trials plus three central points) was carried out. Agitation speed varied from 200 to 500 rpm and aeration rate from 0.5
to 1.5 vvm. It has been shown in this study that the volumetric enzyme production was strongly influenced by mixing conditions,
while aeration was shown to be less significant. Linear models for activity and productivity due to agitation and aeration
were obtained. The favorable condition was 500 rpm and 1.5 vvm, which lead to the best production of 17 U mL−1 for enzymatic activity, 1.2 U mL−1 h−1 for productivity in 14 h of process, a cellular concentration of 11 mg mL−1, and a 167.2 h−1 volumetric oxygen transfer coefficient. 相似文献
3.
de Lima CJ Ribeiro EJ Sérvulo EF Resende MM Cardoso VL 《Applied biochemistry and biotechnology》2009,152(1):156-168
Pseudomonas aeruginosa PACL strain, isolated from oil-contaminated soil taken from a lagoon, was used to investigate the efficiency and magnitude
of biosurfactant production, using different waste frying soybean oils, by submerged fermentation in stirred tank reactors
of 6 and 10 l capacities. A complete factorial experimental design was used, with the goal of optimizing the aeration rate
(0.5, 1.0, and 1.5 vvm) and agitation speed (300, 550, and 800 rpm). Aeration was identified as the primary variable affecting
the process, with a maximum rhamnose concentration occurring at an aeration rate of 0.5 vvm. At optimum levels, a maximum
rhamnose concentration of 3.3 g/l, an emulsification index of 100%, and a minimum surface tension of 26.0 dynes/cm were achieved.
Under these conditions, the biosurfactant production derived from using a mixture of waste frying soybean oil (WFSO) as a
carbon source was compared to production when non-used soybean oil (NUSO), or waste soybean oils used to fry specific foods,
were used. NUSO produced the highest level of rhamnolipids, although the waste soybean oils also resulted in biosurfactant
production of 75–90% of the maximum value. Under ideal conditions, the kinetic behavior and the modeling of the rhamnose production,
nutrient consumption, and cellular growth were established. The resulting model predicted data points that corresponded well
to the empirical information. 相似文献
4.
Production of an extracellular lipase from Serratia marcescens ECU1010, which is an industrially important biocatalyst for the stereospecific synthesis of Diltiazem precusor, was carefully
optimized in both shake flasks and a fermenter, using Tween-80 as the enzyme inducer. Dextrin and beef extract combined with
ammonium sulfate were indicated to be the best carbon and nitrogen sources, respectively. With the increase of Tween-80 from
0 to 10 g l−1, the lipase production was greatly enhanced from merely 250 U l−1 to a maximum of 3,340 U l−1, giving the highest lipase yield of ca 640 U g−1 dry cell mass (DCW), although the maximum biomass (6.0 g DCW l−1) was achieved at 15 g l−1 of Tween-80. When the medium loading in shake flasks was reduced from 20 to 10% (v / v), the lipase production was significantly enhanced. The increase in shaking speed also resulted in an improvement of the
lipase production, although the cell growth was slightly repressed, suggesting that the increase of dissolved oxygen (DO)
concentration contributed to the enhancements of lipase yield. When the lipase fermentation was carried out in a 5-l fermenter,
the lipase production reached a new maximum of 11,060 U l−1 by simply raising the aeration rate from 0.5 to 1.0 vvm, while keeping the dissolved oxygen above 20% saturation via intermittent
adjustment of the agitation speed (≥400 rpm), in the presence of a relatively low concentration (2 g l−1) of Tween-80 to prevent a potential foaming problem, which is easy to occur in the intensively aerated fermenter. 相似文献
5.
Valeria F. Soares Leda R. Castilho Elba P. S. Bon Denise M. G. Freire 《Applied biochemistry and biotechnology》2005,121(1-3):311-319
A Bacillus subtilis isolate was shown to be able to produce extracellular protease in solid-state fermentations (SSF) using soy cake as culture
medium. A significant effect of inoculum concentration and physiological age on protease production was observed. Maximum
activities were obtained for inocula consisting of exponentially growing cells at inoculum concentrations in the range of
0.7–2.0 mg g−1. A comparative study on the influence of cultivation temperature and initial medium pH on protease production in SSF and
in submerged fermentation (SF) revealed that in SSF a broader pH range (5–10), but the same optimum temperature (37°C), is
obtained when compared to SF. A kinetic study showed that enzyme production is associated with bacterial growth and that enzyme
inactivation begins before biomass reaches a maximum level for both SF and SSF. Maximum protease activity and productivity
were 960 U g−1 and 15.4 U g−1 h−1 for SSF, and 12 U mL−1 and 1.3 U mL−1 h−1 for SF. When SSF protease activity was expressed by volume of enzyme extract, the enzyme level was 10-fold higher and the
enzyme productivity 45% higher than in SF. These results indicate that this bacterial strain shows a high biotechnological
potential for protease production in solid-state fermentation. 相似文献
6.
Sene Luciane Felipe Maria G. A. Silva Silvio S. Vitolo Michele 《Applied biochemistry and biotechnology》2001,91(1-9):671-680
Candida guilliermondii FTI 20037 was cultured in sugarcane bagasse hydrolysate supplemented with 2.0 g/L of (NH4)2SO4, 0.1 g/L of CaCl2·2H2O, and 20.0 g/L of rice bran at 35°C; pH 4.0; agitation of 300 rpm; and aeration of 0.4, 0.6, or 0.8 vvm. The high xylitol
production (20.0 g/L) and xylose reductase (XR) activity (658.8 U/mg of protein) occurred at an aeration of 0.4 vvm. Under
this condition, the xylitol dehydrogenase (XD) activity was low. The apparent K
M for XR and XD against substrates and cofactors were as follows: for XR, 6.4×10−2
M (xylose) and 9.5×10−3 mM (NADPH); for XD, 1.6×10−1
M (xylitol) and 9.9×10−2 mM (NAD+). Because XR requires about 10-fold less xylose and cofactor than XD for the condition in which the reaction rate is
half of the V
max, some interference on the overall xylitol production by the yeast could be expected. 相似文献
7.
Polygalacturonases are part of the group of enzymes involved in pectin degradation. The aim of this work was to investigate
some of the factors affecting polygalacturonase production by an Aspergillus giganteus strain and to characterize this pectinolytic activity. Several carbon sources, both pure substances and natural substrates,
were tested in standing cultures, and the best results were obtained with orange bagasse and purified citrus pectin. On citrus
pectin as sole carbon source, the highest extracellular activity (9.5 U/ml and 40.6 U/mg protein) was obtained in 4.5-day-old
cultures shaken at 120 rpm, pH 3.5 and 30°C, while on orange bagasse, the highest extracellular activity (48.5 U/ml and 78.3 U/mg
protein) was obtained in 3.5-day-old cultures shaken at 120 rpm, pH 6.0 and 30°C. Optimal polygalacturonase activity was observed
in assays conducted at pH 5.5–6.5 and 55–60°C. The activity showed good thermal stability, with half-lives of 90 and 30 min
when incubated at 55 and 60°C, respectively. High stability was observed from pH 4.5 to 8.5; more than 90% of the activity
remained after 24 h in this pH range. 相似文献
8.
The effects of different aeration conditions on xylitol production from corncob hemicellulose hydrolysate by Candida sp. ZU04 were investigated. Batch fermentations were carried out in a 3.7-L fermentor at 30°C, pH5.5, and agitation of 300
rpm. It was found that the two-phase aeration process was more effective than the one-phase aeration process in xylitol production.
In the first 24h of the aerobic phase, a high aeration rate was applied, glucose was soon consumed, and biomass increased
quickly. In the second fermentation phase, aeration rate was reduced and an improved xylitol yield was obtained. The maximum
xylitol yield (0.76 g/g) was obtained with an aeration rate of 1.5 vvm (KLa of 37 h−1) for the first 24 h and 0.3 vvm (KLa of 6 h−1) from 24 to 96 h. 相似文献
9.
Liakopoulou-Kyriakides M Psomas SK Kyriakidis DA 《Applied biochemistry and biotechnology》1999,82(3):175-183
Xanthomonas campestris w.t. was used for production of xanthan gum in fermentations with chestnut flour for the first time. Fermentations were carried
out with either chestnut flour or its soluble sugars (33.5%) and starch (53.6%), respectively, at 28°C and 200 rpm at initial
pH 7.0 in flasks. The effect of agitation rate (at 200, 400, and 600 rpm) on xanthan gum production was also studied in a
2-L batch reactor. It was found that xanthan production reaches a maximum value of 3.3 g/100 mL at 600 rpm and 28°C at 45
h. 相似文献
10.
Ashok Pandey Simon Joseph L. Ashakumary P. Selvakumar Carlos R. Soccol 《Applied biochemistry and biotechnology》1999,82(2):103-114
A newly isolated mesophilic bacterial strain from dahlia rhizosphere, identified as Staphylococcus sp. and designated as RRL-M-5, was evaluated for inulinase synthesis in submerged cultivation using different carbon sources
individually or in combination with inulin as substrate. Inulin appeared as the most favorable substrate at a 0.5–1.0% concentration.
Media pH influenced the enzyme synthesis by the bacterial strain, which showed an optimum pH at 7.0–7.5. Supplementation of
fermentation medium with external nitrogen (organic and inorganic) showed a mixed impact on bacterial activity of enzyme synthesis.
The addition of soybean meal and corn steep solid resulted in about an 11% increase in enzyme titers. Among inorganic nitrogen
sources, ammonium sulfate was found to be the most suitable. Maximum enzyme activities (446 U/L) were obtained when fermentation
was carried out at 30°C for 24 h with a medium containing 0.5% inulin as a sole carbon source and 0.5% soybean meal as the
nitrogen source. Bacterial inulinase could be a good source for the hydrolysis of inulin for the production of d-fructose. 相似文献
11.
Emilia Curotto Marisol Concha Victoriano Campos Adriane M. F. Milagres Nelson Duran 《Applied biochemistry and biotechnology》1994,48(2):107-116
Xylanase production byPenicillium janthinellum using 10–100 mM of 2,2-dimethylsuccinate (DMS) buffer, in a range of pH 4.5-6.0 was studied. The enzyme activity was enhanced
using oat xylan as the carbon source. Under these conditions a culture produced 1.14 Μmol/ min (11.4 U/mL or 84.4 U/mg) of
Β-xylanase after 5 d of growth in a 10-mM buffer solution at pH 4.5. Protease was absent in the DMS buffer except when 100
mM phosphate buffer at pH 6.0 was used (4 U/mL). Β-Xylosidase was only found at a pH of 4.5 in all the buffer concentrations.
At a 50 mM DMS buffer concentration at pH 4.5 Β- xylanases were induced by both oat and birch xylans, having a greater effect with oat spelt xylans.
Electrophoretic analyses showed that the birchwood xylan induction exhibited different proteins profiles. No Β-xylosidase
or Β- glucosidase was induced until d 5. The Β-xylanases were rapidly inactivated at 50‡C, however, birch xylanase appeared to
be more stable than oat xylanase.
Using oat xylan as an inductor, theΒ-xylosidase andΒ-glucosidase were 85 and 91 U/L, respectively, on d 7. The xylanase produced by induction from sugar cane bagasse hydrolyzate
was used for pulp biobleaching. A 20% decrease on the Kappa value in Kraft pulp using the culture extract was obtained. These
selective growth conditions led us to modulate the xylanase production for pulp delignification. 相似文献
12.
Synthesis of Cyclodextrin Glucosyl Transferase byBacillus cereus for the production of cyclodextrins
R. Jamuna N. Saswathi R. Sheela S. V. Ramakrishna 《Applied biochemistry and biotechnology》1993,43(3):163-176
A potent indigenous bacillus isolate identified asBacillus cereus (RJ-30) was found to produce Cyclodextrin Glucosyl Transferase (CGTase) extracellularly. Process optimization of various
fermentation parameters has been established for optimal growth of bacillus and the maximum enzyme synthesis. The organism
had the highest specific growth rate (0.7μ) with a generation time of 1 h in glucose containing medium at the conditions of
pH 7.0, 37°C at 300 rpm, 1.5 vvm of agitation, and aeration. At these conditions, it exhibited the maximum activity of 54
U/mL at the synthesis rate of 2.7 U/L/h. CGTase was produced from the early exponential growth and peaked during the midsporulating
stage of about 16 h thereafter maintained at the same level of 50 U/mL. Saccharides containing media were better inducers
than starch, and the influence of carbohydrate substrates has shown that enzyme synthesis is promoted by xylose (65 U/mL)
and, more remarkably, by the supplementation of wheat bran extract in glucose medium (106 U/mL). This organism produced CGTase
stably in a chemostat culturing over a period of 400 h with a maximum productivity of 5.4 kU/L/h (threefold higher than obtained
in batch culturing [1.75 kU/L/h]). Comparatively, CGTase was produced by immobilized cells in a continuous fluidized bed reactor
for over approx 360 h, at a relatively high dilution rate of 0.88 h−1 resulting in the productivity of 23.0 kU/L/h. 相似文献
13.
Streptomyces SP.N 14, isolated from soil samples, produced extracellular L-glutamate oxidase (GOD) in liquid culture. After
a two-step ammonium sulfate purification and dextran G-150 chromatography, the specific activity was reached at 28.2 U/mg.
The partial purified enzyme and horseradish peroxidase (HRP) were covalently coupled to alkylamine controlled pore glass (CPG)
by means of glutaraldehyde. About 200–300 U/g of immobilized GOD and 300–400 U/g of immobilized HRP were obtained. The immobilized
enzymes were packed into a teflon tube and used in flow injection analysis (FIA) for glutamate in broth. A good linear range
was observed for this immobilized enzyme system at 0.1–2.0 mM, and the precision was 2.8% (n = 25). More than 80 samples were measured within an hour. One enzyme column with about 4 U of immobilized GOD and 5 U of
immobilized HRP, applied for 50 assays/d, has been used for more than 50 d. The concentration of L-glutamate remaining lower
than 2.0 mM, the determination of glutamate in this system was not affected by pH and temperature within the range of 6.0–7.0
and 25–35‡C, respectively. The system was applied to determine L-glutamate in broth samples during L-glutamate fermentation,
and good correlation was achieved between results obtained with the system and with the Warburg’s method. 相似文献
14.
An extracellular lipase was purified from the fermentation broth of Penicillium expansum PED-03 by DEAE-Sepharose chromatography, followed by sephacryl S-200 chromatography. The enzyme was purified 81.8-fold with
19.8% recovery and a specific activity of 85.94 U/mg. The molecular weight of the homogeneous enzyme was about 28 kDa, determined
by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The enzymatic resolution of racemic ibuprofen was carried
out by the lipase from P. expansum PED-03, and the conversion reached 46% with excellent enantioselectivity(E > 200 ), which showed a good application potential in the production of optically pure ibuprofen. 相似文献
15.
Purification and partial characterization of a lipase from Bacillus coagulans ZJU318 总被引:1,自引:0,他引:1
An extracellular lipase was purified from the fermentation broth of Bacillus coagulans ZJU318 by CM-Sepharose chromatography, followed by Sephacryl S-200 chromatography. The lipase was purified 14.7-fold with
18% recovery and a specific activity of 141.1 U/mg. The molecular weight of the homogeneous enzyme was (32 kDa), determined
by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The enzyme activity was maximum at pH 9.0 and was stable
over a pH range of 7.0–10.0, and the optimum temperature for the enzyme reaction was 45°C. Little activity loss (6.2%) was
observed after 1 h of incubation at 40°C. However, the stability of the lipase decreased sharply at 50 and 60°C. The enzyme
activity was strongly inhibited by Ag+ and Cu2+, whereas EDTA caused no inhibition. SDS, Brij 30, and Tween-80 inhibited lipase, whereas Triton X-100 did not significantly
inhibit lipase activity. 相似文献
16.
Heloiza Ferreira Alves-Prado Eleni Gomes Roberto Da Silva 《Applied biochemistry and biotechnology》2006,129(1-3):234-246
Cyclodextrin glycosyltransferase (CGTase) is an enzyme that produces cyclodextrins from starch by an intramolecular transglycosylation
reaction. Cyclodextrins have been shown to have a number of applications in the food, cosmetic, pharmaceutical, and chemical
industries. In the current study, the production of CGTase by Paenibacillus campinasensis strain H69-3 was examined in submerged and solid-state fermentations. P. campinasensis strain H69-3 was isolated from the soil, which grows at 45°C, and is a Gramvariable bacterium. Different substrate sources
such as wheat bran, soybean bran, soybean extract, cassava solid residue, cassava starch, corn starch, and other combinations
were used in the enzyme production. CGTase activity was highest in submerged fermentations with the greatest production observed
at 48–72 h. The physical and chemical properties of CGTase were determined from the crude enzyme produced from submerged fermentations.
The optimum temperature was found to be 70–75°C, and the activity was stable at 55°C for 1 h. The enzyme displayed two optimum
pH values, 5.5 and 9.0 and was found to be stable between a pH of 4.5 and 11.0. 相似文献
17.
Silvana T. Silveira Melissa S. Oliveira Jorge A. V. Costa Susana J. Kalil 《Applied biochemistry and biotechnology》2006,128(2):131-139
Glucoamylase production by Aspergillus niger in solid-state fermentation was optimized using factorial design and response surface techniques. The variables evaluated
were pH and bed thickness in tray, having as response enzyme production and productivity. The bed thickness in tray was the
most significant variable for both responses. The highest values for glucoamylase production occurred using pH 4.5 and bed
thickness in the inferior limits at 2.0–4.2 cm. For productivity, the optimal conditions were at pH 4.5 as well and bed thickness
from 4.4 to 7.5 cm. The optimal conditions for glucoamylase production while obtaining high activity without loss of productivity
were pH 4.5 and bed thickness in tray from 4.0 to 4.5 cm, which resulted in an enzyme production of 695 U/g and productivity
of 5791 U/h. 相似文献
18.
K. T. Normurodova Sh. Kh. Nurmatov B. Kh. Alimova O. M. Pulatova Z. R. Akhmedova A. A. Makhsumkhanov 《Chemistry of Natural Compounds》2007,43(4):454-457
Partially purified enzyme preparation with specific activities of 153.7 U/mg for α-amylase and 0.15 U/mg for protease was
produced by selective adsorption on starch. Enzymes were purified until homogeneous electrophoretically by gel-filtration
over HW-55 TSK-gel with specific activities of 245 U/mg for α-amylase and 1.44 U/mg for protease. The optimum temperature
and pH for purified α-amylase activity are 40–50°C and pH 6.0. The effects of various metal ions on the activity and stability
of the enzyme were studied.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 374–376, July–August, 2007. 相似文献
19.
O. García-Kirchner M. Segura-Granados P. Rodríguez-Pascual 《Applied biochemistry and biotechnology》2005,121(1-3):347-359
The hydrolytic activity of fungal originated β-glucosidase is exploited in several biotechnological processes to increase
the rate and extent of saccharification of several cellulosic materials by hydrolyzing the cellobiose which inhibits cellulases.
In a previous presentation, we reported the screening and liquid fermentation with Aspergillus niger, strain C-6 for β-glucosidase production at shake flask cultures in a basal culture medium with mineral salts, corn syrup liquor, and
different waste lignocellulosic materials as the sole carbon source obtaining the maximum enzymatic activity after 5–6 d of
8.5 IU/mL using native sugar cane bagasse. In this work we describe the evaluation of fermentation conditions: growth temperature,
medium composition, and pH, also the agitation and aeration effects for β-glucosidase production under submerged culture using
a culture media with corn syrup liquor (CSL) and native sugar cane bagasse pith as the sole carbon source in a laboratory
fermenter. The maximum enzyme titer of 7.2 IU/mL was obtained within 3 d of fermentation. This indicates that β-glucosidase
productivity by Aspergillus niger
C-6 is function of culture conditions, principally temperature, pH, culture medium conditions, and the oxygen supply given in
the bioreactor. Results obtained suggest that this strain is a potential microorganism that can reach a major level of enzyme
production and also for enzyme characterization. 相似文献
20.
Four myrosinase (β-thioglucosidase EC. 3.2.3.1) and seven disaccharase (β-fructofuranosidase, EC. 3.2.1.26) isoenzymes were isolated from turnip leaves. The most active enzymes were isolated in pure
form. Myrosinase and disaccharase mol wt was 62.0 × 103 and 69.5 × 103 dalton, respectively, on the basis of gel filtration on Sephadex G-200.
Myrosinase pH profile showed high activity between pH 5 and 7 with the optimum at pH 5.5. The purified enzyme was heat-stable
for 60 min at 30°C with only loss of 24% of activity. Its activity is strongly inhibited (100%) by Pb2+, Ba2+, Cu2+ and Ca2+ ions, and activated (70%) by EDTA at 0.04M. The pure enzyme failed to hydrolyze amylose, glycogen, lactose, maltose, and
sucrose. TheK
m andV
max values of myrosinase using sinigrin as specific substrate was 0.045 mM and 2.5 U, respectively.
The maximal activity of disaccharase enzyme was obtained at pH 4–5 and 35–37°C. The enzyme was heat-stable at 30°C for 30
min with only 10% loss of its activity. Its activity is strongly activated (70–240%) by Ca2+, Ba2+, Cu2+, and EDTA at 0.01M. The enzyme activity is specific to the disaccharide sucrose and failed to hydrolyze other disaccharides (maltose and lactose).
TheK
m andV
max of disaccharase were 0.123 mM and 3.33 U, respectively. 相似文献