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1.
Luciana A. I. de Azeredo Leda R. Castilho Selma G. F. Leite Rosalie R. R. Coelho Denise M. G. Freire 《Applied biochemistry and biotechnology》2003,108(1-3):749-755
Streptomyces are important microorganisms because of their capacity to produce numerous bioactive molecules. In the present work protease
production, by Streptomyces sp. 594 isolated from a Brazilian Cerrado soil, was maximized by optimizing a low-cost culture medium composition (casitone
and sugarcane molasses) using statistical experimental design. The final protease activity (56 U/mL) was 2.8-fold and 58-fold
higher than that obtained in the beginning of this study, and in a previous work, using an actinomycete selection medium,
respectively. Protease production, not growth associated, appeared to be modulated by an inducer system, whereby the C/N ratio
seemed to play a significant role. 相似文献
2.
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
3.
The Pichia pastoris clone producing streptokinase (SK) was optimized for its nutritional requirements to improve intracellular expression using
statistical experimental designs and response surface methodology. The skc gene was ligated downstream of the native glyceraldehyde 3-phosphate dehydrogenase promoter and cloned in P. pastoris. Toxicity to the host was not observed by SK expression using YPD medium. The transformant producing SK at level of 1,120 IU/ml
was selected, and the medium composition was investigated with the aim of achieving high expression levels. The effect of
various carbon and nitrogen sources on SK production was tested by using Plackett–Burman statistical design and it was found
that dextrose and peptone are the effective carbon and nitrogen sources among all the tested. The optimum conditions of selected
production medium parameters were predicted using response surface methodology and the maximum predicted SK production of
2,136.23 IU/ml could be achieved with the production medium conditions of dextrose (x1), 2.90%; peptone (x2), 2.49%; pH, 7.2 (x3), and temperature, 30.4 (x4). Validation studies showed a 95% increase in SK production as compared to that before optimization at 2,089 IU/ml. SK produced
by constitutive expression was found to be functionally active by plasminogen activation assay and fibrin clot lysis assay.
The current recombinant expression system and medium composition may enable maximum production of recombinant streptokinase
at bioreactor level. 相似文献
4.
Zaghloul Taha I. Abdel Wahab Abir E. Mostafa Mostafa H. 《Applied biochemistry and biotechnology》2000,84(1-9):319-327
Bacillus subtilis Bios 11 strain was previously isolated and identified. This strain naturally produces a high level of α-amylase. The multicopy
(pS1) plasmid that carries the complete alkaline protease aprA gene was introduced to this host strain by transformation. The newly constructed strain was found to express the aprA gene and produces a high level of alkaline protease. The level of α-amylase production was not affected compared with the
parent strain. The pS1 plasmid in the new host was proved to be segregationally and structurally stable, and the multicopy
aprA gene was expressed at the stationary phase. This expression did not affect growth rate and sporulation frequency. Moreover,
the level of α-amylase was maintained. Both alkaline protease and α-amylase enzymes were purified using a single-step affinity
chromatography column. The use of the newly constructed strain would be valuable to the enzyme industry and would promote
recycling of some food-processing wastes. 相似文献
5.
Sanjay Kumar Venkata Dasu Veeranki Kannan Pakshirajan 《Applied biochemistry and biotechnology》2011,163(3):327-337
Statistically based experimental design was applied to maximize the production of glutaminase-free L-asparaginase from Pectobacterium carotovorum MTCC 1428. The effect of physical process parameters (initial pH of the medium, temperature, rpm of the shaking incubator,
and inoculum size) on the production of L-asparaginase from P. carotovorum MTCC 1428 was studied using central composite design technique. The individual optimum levels of initial pH of the medium,
temperature, rpm of shaking incubator, and inoculum size were found to be 6.90, 29.8 °C, 157 rpm, and 2.61% (v/v), respectively, for the production of L-asparaginase. After physical process parameters optimization, the production and
productivity of L-asparaginase was enhanced by 26.39% (specific activity) and 10.19%, respectively. Maximization of L-asparaginase
production was achieved at 12 h under optimal levels of physical process parameters in shake flask level. 相似文献
6.
Subba Rao Ch Madhavendra SS Sreenivas Rao R Hobbs PJ Prakasham RS 《Applied biochemistry and biotechnology》2008,150(1):65-83
This study uses an overall evaluation criterion for improving the immobilized bead reusability and extracellular enzyme production by immobilized cells by assigning relative weightage to bead reusability, enzyme production, and cell leakage. Initially, alkaline protease production by alginate-immobilized Bacillus circulans (MTCC 6811) was analyzed using L18 orthogonal array (OA). The resultant optimized parameters were further fine-tuned with L9 OA experimentation. At L18-OA analysis, inoculum level and CaCl(2) had least influence at individual level. At the interactive level, incubation time revealed maximum and minimum interaction with sodium alginate and glucose concentration, respectively. L9 experimentation indicated that glucose concentration contributed the major influence on protease production followed by matrix material and incubation time at the individual level, and at the interactive level, matrix concentration played a vital role by interacting with incubation time, inoculum, and CaCl(2) concentration. All selected input parameters showed significance either at individual level or interactive in both OAs. Scanning electron microscopy analysis showed bacterial morphology variation with variation of matrix concentration. Overall, glucose concentration depicted a major influence at the individual level for the enzyme production. Significant improvement, approximately 147%, in enzyme yield was observed. Economic enzyme production by immobilized B. circulans is regulated by interactive influence of fermentation parameters, which influence the immobilized bead stability, reusability, and enzyme yield. 相似文献
7.
Thermostable phytase production by Thermoascus aurantiacus in submerged fermentation 总被引:2,自引:0,他引:2
Nampoothiri KM Tomes GJ Roopesh K Szakacs G Nagy V Soccol CR Pandey A 《Applied biochemistry and biotechnology》2004,118(1-3):205-214
Phytases act on phytic acid, an antinutrient factor present in animal feeds, and release inorganic phosphate. We optimized
the production parameters for phytase production using Thermoascus aurantiacus (TUB F 43), a thermophilic fungal culture, by submerged fermentation. A semisynthetic medium containing glucose, starch,
peptone, and minerals supplemented with 3.75% (w/v) wheat bran particles was found to be the best production medium among
the various combinations tried. Further supplementation of this medium with surfactants such as Tween-20 and Tween-80 considerably
enhanced the enzyme yield. A maximum phytase activity (468.22 U/mL) was obtained using this production medium containing 2%
(v/v) Tween-20 after 72 h of fermentation at 45°C in shake-flask cultures with a rotation of 150 rpm. Herein we present details
of a few of the process parameter optimizations. The phytase enzyme was found to be thermostable, and the optimal temperature
for phytase activity was found to be 55°C. However, 80% of the activity still remained when the temperature was shifted to
70°C. 相似文献
8.
Munish Puri Aneet Kaur Ram Sarup Singh Anubhav Singh 《Applied biochemistry and biotechnology》2010,162(1):181-191
Response surface methodology was used to optimize the fermentation medium for enhancing naringinase production by Staphylococcus xylosus. The first step of this process involved the individual adjustment and optimization of various medium components at shake
flask level. Sources of carbon (sucrose) and nitrogen (sodium nitrate), as well as an inducer (naringin) and pH levels were
all found to be the important factors significantly affecting naringinase production. In the second step, a 22 full factorial
central composite design was applied to determine the optimal levels of each of the significant variables. A second-order
polynomial was derived by multiple regression analysis on the experimental data. Using this methodology, the optimum values
for the critical components were obtained as follows: sucrose, 10.0%; sodium nitrate, 10.0%; pH 5.6; biomass concentration,
1.58%; and naringin, 0.50% (w/v), respectively. Under optimal conditions, the experimental naringinase production was 8.45 U/mL. The determination coefficients
(R
2) were 0.9908 and 0.9950 for naringinase activity and biomass production, respectively, indicating an adequate degree of reliability
in the model. 相似文献
9.
Palma Marcia B. Pinto Annette L. Gombert Andreas K. Seitz Karina H. Kivatinitz Silvia C. Castilho Leda R. Freire Denise M. G. 《Applied biochemistry and biotechnology》2000,84(1-9):1137-1145
Lipase, protease, and amylase production by Penicillium restrictum in solid-state fermentation was investigated. The basal medium was an industrial waste of babassu oil (Orbignya oleifera) production. It was enriched with peptone, oliveoil, and Tween-80. The supplementation positively influenced both enzyme
production and fungal growth. Media enriched with Tween-80 provided the highest protease activity (8.6 U/g), whereas those
enriched with peptone and olive oil led to the highest lipase (27.8 U/g) and amylase (31.8 U/g) activities, respectively. 相似文献
10.
A statistical approach, response surface methodology (RSM), was used to study the production of extracellular protease fromBacillus sp., which has properties of immense industrial importance. The most influential parameters for protease production obtained
through the method of testing the parameters one at a time were starch, soybean meal, CaCl2, agitation rate, and inoculum density. This method resulted in the production of 2543 U/mL of protease in 48 h fromBacillus sp. Based on these results, face-centered central composite design falling under RSM was employed to further enhance protease
activity. The interactive effect of the most influential parameters resulted in a 1.50-fold increase in protease production,
yielding 3746 U/mL in 48 h. Analysis of variance showed the adequacy of the model and verification experiments confirmed its
validity. On subsequent scale-up in a 30-L bioreactor using conditions optimized through RSM, 3978 U/mL of protease was produced
in 18 h. This clearly indicated that the model remained valid even on a large scale. RSM is a quick process for optimization
of a large number of variables and provides profound insight into the interactive effect of various parameters involved in
protease production. 相似文献
11.
The Effects of Wheat Bran Composition on the Production of Biomass-Hydrolyzing Enzymes by Penicillium decumbens 总被引:1,自引:0,他引:1
The effects of the starch, protein, and soluble oligosaccharides contents in wheat bran on the extracellular biomass-hydrolyzing
enzymes activities released by Penicillium decumbens mycelia grown in batch fermentations have been examined. The results showed increased starch content correlated directly
with an increase in released amylase activity but inversely with the levels of secreted cellulase and xylanase. High amounts
of protein in wheat bran also reduced the activities of cellulase, xylanase and protease in the culture medium. The effects
of the soluble and insoluble components of wheat bran and cello-oligosaccharides supplements on production of extracellular
cellulase and xylanase were compared. The soluble cello-oligosaccharides compositions in wheat bran were proved to be one
of the most significant factors for cellulase production. According to the results of this research, determining and regulating
the composition of wheat bran used as a fermentation supplement may allow for improved induction of cellulase and xylanase
production. 相似文献
12.
A. L. F. Porto G. M. Campos-Takaki J. L. Lima Filho 《Applied biochemistry and biotechnology》1996,60(2):115-122
The influence of nitrogen and phosphate sources on the production of extracellular protease activity byStreptomyces clavuligerus has been investigated. The experiments were carried out in batch fermentation using soy-bean flour as nitrogen source and
potassium phosphate dibasic as phosphate source. High protease yield was obtained after 24 h of fermentation with an initial
pH of 7.0. The maximal protease activity (112.68 and 88.72 U/mg) was obtained the phosphate concentration of the 21 and 29
mM for strains 3585 and 644, respectively. With regard to the nitrogen concentration in both strains, the maximal protease
activity was achieved with 0.5% (154.89 U/mg and 228.36 U/mg for 3585 and 644 strains, respectively). Enzyme production appeared
to be modulated by an inducer system where ammonia, complex nitrogen, and phosphate sources might have been involved. 相似文献
13.
A cassava flour-processing effluent (manipueira) was evaluated as a substrate for surfactant production by two Bacillus subtilis strains. B. subtilis ATCC 21332 reduced the surface tension of the medium to 25.9 mN/m, producing a crude biosurfactant concentration of 2.2 g/L.
The wild-type strain, B. subtilis LB5a, reduced the surface tension of the medium to 26.6 mN/m, giving a crude biosurfactant concentration of 3.0 g/L. A decrease
in surfactant concentration observed for B. subtilis ATCC 21332 seemed to be related to an increase in protease activity. The biosurfactant produced on cassava effluent medium
by B. subtilis LB5a was similar to surfactin. 相似文献
14.
Aguilar CN Favela-Torres E Viniegra-González G Augur C 《Applied biochemistry and biotechnology》2002,102(1-6):407-414
Undesirable protease production by Aspergillus niger Aa-20 in submerged culture and solid-state culture was evaluated using different concentrations of tannic acid as sole carbon
source in a model system designed for tannase production. Protease production was found to be dependent on the culture system
used (submerged culture or solid-state culture) and on the initial tannic acid concentration. Expression of protease activity
in submerged culture was higher (up to 10 times) than activity obtained in solid-state culture, using identical culture medium
composition. In submerged culture, the lowest final protease activity (0.13 IU) was obtained with the highest tannic acid
concentration, while in solid-state culture protease activity was not affected by changes in initial substrate concentration.
Absence of detectable proteolytic activity in solid-state culture is related to high production of tannase enzyme. Hence,
the use of solid-state culture for fungal enzyme production may allow for higher and more stable enzyme titers present in
culture extracts. 相似文献
15.
The major constraint in the enzymatic saccharification of biomass for ethanol production is the cost of cellulase enzymes.
Production cost of cellulases may be brought down by multifaceted approaches which includes the use of cheap lignocellulosic
substrates for fermentation production of the enzyme, and the use of cost efficient fermentation strategies like solid state
fermentation (SSF). The current study investigated the production of cellulase by Trichoderma reesei RUT C30 on wheat bran under SSF. Process parameters important in cellulase production were identified by a Plackett and Burman
design and the parameters with significant effects on enzyme production were optimized for maximal yield using a central composite
rotary design (CCD). Higher initial moisture content of the medium had a negative effect on production whereas incubation
temperature influenced cellulase production positively in the tested range. Optimization of the levels of incubation temperature
and initial moisture content of the medium resulted in a 6.2 fold increase in production from 0.605 to 3.8 U/gds of cellulase.
The optimal combination of moisture and temperature was found to be 37.56% and 30 °C, respectively, for maximal cellulase
production by the fungus on wheat bran. 相似文献
16.
As a potential anticarcinogenic agent, polysaccharides from Cordyceps sinensis have been demonstrated to possess strong antioxidation activity. The aim of the present research was to study the optimal
medium to produce polysaccharides of C. sinensis by using response surface methodology (RSM). The composition of optimized medium for polysaccharide production calculated
from the regression model of RSM was 6.17% sucrose, 0.53% corn steep powder, 0.5% (NH4)2HPO4, and 0.15% KH2PO4 at pH 4.44, with a predicted maximum polysaccharide production of 3.17 g/L. When applying this optimal medium, the maximum
polysaccharide production was 3.05 and 3.21 g/L in a shake flask and a 5-L jar fermentor, respectively. When the pH was controlled
at a higher level such as pH 5.0, both cell growth and polysaccharide production were inhibited. A low pH of 2.85 was required
for maximum production of polysaccharides. 相似文献
17.
Laccase production by solid-state fermentation (SSF) using an indigenously isolated white rot basidiomycete Ganoderma sp. was studied. Among the various agricultural wastes tested, wheat bran was found to be the best substrate for laccase
production. Solid-state fermentation parameters such as optimum substrate, initial moisture content, and inoculum size were
optimized using the one-factor-at-a-time method. A maximum laccase yield of 2,400 U/g dry substrate (U/gds) was obtained using
wheat bran as substrate with 70% initial moisture content at 25°C and the seven agar plugs as the inoculum. Further enhancement
in laccase production was achieved by supplementing the solid-state medium with additional carbon and nitrogen source such
as starch and yeast extract. This medium was optimized by response surface methodology, and a fourfold increase in laccase
activity (10,050 U/g dry substrate) was achieved. Thus, the indigenous isolate seems to be a potential laccase producer using
SSF. The process also promises economic utilization and value addition of agro-residues. 相似文献
18.
Vandana Saini Amrik Bhattacharya Anshu Gupta 《Applied biochemistry and biotechnology》2013,170(8):1896-1908
The present study is an attempt to demonstrate the feasibility of sal (Shorea robusta) deoiled cake—a forest-based industrial by-product—as a cheaper media supplement for augmented protease production from Aeromonas sp. S1 and application of protease in the treatment of kitchen wastewater. Under optimized conditions, protease production could successfully be enhanced to 5.13-fold (527.5 U mL?1) on using sal deoiled seed cake extract (SDOCE), as medium additive, compared to an initial production of 102.7 U mL?1 in its absence. The culture parameters for optimum production of protease were determined to be incubation time (48 h), pH (7.0), SDOCE concentration (3 % (v/v)), inoculum size (0.3–0.6 % (v/v)), and agitation rate (100 rpm). The enzyme was found to have an optimum pH and temperature of 8.0 and 60 °C, respectively. The protease preparation was tested for treatment of organic-laden kitchen wastewater. After 96 h of wastewater treatment under static condition, enzyme preparation was able to reduce 74 % biological oxygen demand, 37 % total suspended solids, and 41 % oil and grease. The higher and improved level of protease obtained using sal deoiled seed cake-based media hence offers a new approach for value addition to this underutilized biomass through industrial enzyme production. The protease produced using this biomass could also be used as pretreatment tool for remediation of organic-rich food wastewater. 相似文献
19.
Culture conditions for pullulan production by Aureobasidium pullulans were optimized using response surface methodology at shake flask level without pH control. In the present investigation,
a five-level with five-factor central composite rotatable design of experiments was employed to optimize the levels of five
factors significantly affecting the pullulan production, biomass production, and sugar utilization in submerged cultivation.
The selected factors included concentration of sucrose, ammonium sulphate, yeast extract, dipotassium hydrogen phosphate,
and sodium chloride. Using this methodology, the optimal values for concentration of sucrose, ammonium sulphate, yeast extract,
dipotassium hydrogen phosphate, and sodium chloride were 5.31%, 0.11%, 0.07%, 0.05%, and 0.15% (w/v), respectively. This optimized medium has projected a theoretically production of pullulan of 4.44%, biomass yield of 1.03%,
and sugar utilization of 97.12%. The multiple correlation coefficient ‘R’ was 0.9976, 0.9761 and 0.9919 for pullulan production, biomass production, and sugar utilization, respectively. The value
of R being very close to one justifies an excellent correlation between the predicted and the experimental data. 相似文献
20.
Chattopadhyay S Srivastava AK Bisaria VS 《Applied biochemistry and biotechnology》2002,102(1-6):381-393
The root explants of the germinated seedlings of Podophyllum hexandrum were grown in MS medium supplemented with indole acetic acid (IAA) (2 mg/L) and activated charcoal (0.5%), and healthy callus
culture was obtained after incubation for 3 wk at 20°C. The cultivation of plant cells in shake flask was associated with
problems such as clumping of cells and browning of media, which were solved by the addition of pectinase and polyvinylpyrrolidone.
The effect of major media components and carbon source was studied on the growth and podophyllotoxin production in suspension
culture. It was found that glucose was a better carbon source than sucrose and that NH4
+:NO3
− ratio (total nitrogen concentration of 60 mM) and PO4
3− did not have much effect on the growth and product formation. The relative effect of culture parameters (inoculum level,
pH, IAA, glucose, NH4
+:NO3
− ratio, and PO4
3−) on the overall growth and product response of the plant cell suspension culture was further investigated by Plackett-Burman
design. This indicated that inoculum level, glucose, IAA, and pH had significant effects on growth and production of podophyllotoxin.
To identify the exact optimum concentrations of these parameters on culture growth and podophyllotoxin production, central
composite design experiments were formulated. The overall response equations with respect to growth and podophyllotoxin production
as a function of these culture parameters were developed and used to determine the optimum concentrations of these parameters,
which were pH 6.0, 1.25 mg/L of IAA, 72 g/L of glucose, and inoculum level of 8 g/L. 相似文献