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1.
A novel phytase producing thermophilic strain of Bacillus laevolacticus insensitive to inorganic phosphate was isolated from the rhizosphere soil of leguminous plant methi (Medicago falacata). The culture conditions for production of phytase by B. laevolacticus under shake flask culture were optimized to obtain high levels of phytase (2.957 ± 0.002 U/ml). The partially purified phytase from B. laevolacticus strain was optimally active at 70 °C and between pH 7.0 and pH 8.0. The enzyme exhibited thermostability with ∼80% activity at 70 °C and pH 8.0 for up to 3 h in the presence/absence of 5 mM CaCl2. The phytase from B. laevolacticus showed high specificity for phytate salts of Ca+ > Na+. The enzyme showed an apparent K
m 0.526 mM and V
max 12.3 μmole/min/mg of activity against sodium phytate. 相似文献
2.
A strain of Thermomyces lanuginosus, isolated from hot spring water in Turkey, was studied for optimization of phytase production using solid-state fermentation. Effects on fermentation of different production parameters such as substrate type, moisture, culture time, and inoculum size were investigated using a one-factor-at-a-time approach. Central composite design (CCD) of response surface methodology was applied for the optimization of four factors (culture temperature, initial pH, aeration area, age of seeding culture) that were affecting phytase production by Thermomyces lanuginosus in rice bran. Maximum phytase activity was achieved by using rice bran. The optimum levels of variables that supported maximum enzyme activity were moisture 70%, culture time 7 days, inoculum size 40%, culture temperature 55°C, initial pH 7.5, aeration area 30%, age of seeding culture 5 days, sucrose 1%, and ZnSO4 2.5 mM. An overall 10.83-fold enhancement in phytase activity (0.30 to 3.248 U) was attained due to the optimization. 相似文献
3.
Bhavsar K Kumar VR Khire JM 《Journal of industrial microbiology & biotechnology》2011,38(9):1407-1417
Phytase production by Aspergillus niger NCIM 563 was optimized by using wheat bran in solid state fermentation (SSF). An integrated statistical optimization approach
involving the combination of Placket–Burman design (PBD) and Box–Behnken design (BBD) was employed. PBD was used to evaluate
the effect of 11 variables related to phytase production, and five statistically significant variables, namely, glucose, dextrin,
NaNO3, distilled water, and MgSO4·7H2O, were selected for further optimization studies. The levels of five variables for maximum phytase production were determined
by a BBD. Phytase production improved from 50 IU/g dry moldy bran (DMB) to 154 IU/g DMB indicating 3.08-fold increase after
optimization. A simultaneous reduction in fermentation time from 7 to 4 days shows a high productivity of 38,500 IU/kg/day.
Scaling up the process in trays gave reproducible phytase production overcoming industrial constraints of practicability and
economics. The culture extract also had 133.2, 41.58, and 310.34 IU/g DMB of xylanase, cellulase, and amylase activities,
respectively. The partially purified phytase was optimally active at 55°C and pH 6.0. The enzyme retained ca. 75% activity
over a wide pH range 2.0–9.5. It also released more inorganic phosphorus from soybean meal in a broad pH range from 2.5 to
6.5 under emulated gastric conditions. Molecular weight of phytase on Sephacryl S-200 was approximately 87 kDa. The K
m and V
max observed were 0.156 mM and 220 μm/min/mg. The SSF phytase from A. niger NCIM 563 offers an economical production capability and its wide pH stability shows its suitability for use in poultry feed. 相似文献
4.
Priyanka Buddhiwant Kavita Bhavsar V. Ravi Kumar 《Preparative biochemistry & biotechnology》2016,46(6):531-538
This investigation deals with the use of agro-industrial waste, namely groundnut oil cake (GOC), for phytase production by the fungi Aspergillus niger NCIM 563. Plackett–Burman design (PBD) was used to evaluate the effect of 11 process variables and studies here showed that phytase production was significantly influenced by glucose, dextrin, distilled water, and MgSO4 · 7H2O. The use of response surface methodology (RSM) by Box–Behnken design (BBD) of experiments further enhanced the production by a remarkable 36.67-fold from the original finding of 15 IU/gds (grams of dry substrate) to 550 IU/gds. This is the highest solid-state fermentation (SSF) phytase production reported when compared to other microorganisms and in fact betters the best known by a factor of 2. Experiments carried out using dried fermented koji for phosphorus and mineral release and also thermal stability have shown the phytase to be as efficient as the liquid enzyme extract. Also, the enzyme, while exhibiting optimal activity under acidic conditions, was found to have significant activity in a broad range of pH values (1.5–6.5). The studies suggest the suitability of the koji supplemented with phytase produced in an SSF process by the “generally regarded as safe” (GRAS) microorganism A. niger as a cost-effective value-added livestock feed when compared to that obtained by submerged fermentation (SmF). 相似文献
5.
Phytase (myo-inositol-hexakisphosphate phosphohydrolase) is an enzyme, which breaks down phytate to inositol and orthophosphoric acid. Phytase has been used as feed additive, and in some medical applications for years. To date, phytase production has been usually performed as a solid-state fermentation with small production volumes. Therefore, the aim of this study was to increase the phytase activity in submerged fermentations by screening several microorganism strains based on the literature to select the most productive phytase producer and optimizing growth parameters such as temperature, pH, and aeration level using response surface methodology (RSM). As a result, among the four different microorganisms evaluated, Aspergillus ficuum (NRRL 3135) was selected as the most productive strain. Optimum temperature, pH, and aeration values were determined as 33 °C, 4.5, and 0.9 vvm, respectively, for A. ficuum in 2-l batch submerged phytase productions. Under these conditions, phytase activity was measured as 2.27 U/ml. Therefore, this is a unique study showing the production of phytase with A. ficuum successfully in submerged fermentation as opposed to the traditional solid-state fermentation. 相似文献
6.
Pandee P Summpunn P Wiyakrutta S Isarangkul D Meevootisom V 《Journal of microbiology (Seoul, Korea)》2011,49(2):257-264
A phytase gene was cloned from Neosartorya spinosa BCC 41923. The gene was 1,455 bp in size, and the mature protein contained a polypeptide of 439 amino acids. The deduced
amino acid sequence contains the consensus motif (RHGXRXP) which is conserved among phytases and acid phosphatases. Five possible
disulfide bonds and seven potential N-glycosylation sites have been predicted. The gene was expressed in Pichia pastoris KM71 as an extracellular enzyme. The purified enzyme had specific activity of 30.95 U/mg at 37°C and 38.62 U/mg at 42°C.
Molecular weight of the deglycosylated recombinant phytase, determined by SDS-PAGE, was approximately 52 kDa. The optimum
pH and temperature for activity were pH 5.5 and 50°C. The residual phytase activity remained over 80% of initial activity
after the enzyme was stored in pH 3.0 to 7.0 for 1 h, and at 60% of initial activity after heating at 90°C for 20 min. The
enzyme exhibited broad substrate specificity, with phytic acid as the most preferred substrate. Its K
m and V
max for sodium phytate were 1.39 mM and 434.78 U/mg, respectively. The enzyme was highly resistant to most metal ions tested,
including Fe2+, Fe3+, and Al3+. When incubated with pepsin at a pepsin/phytase ratio of 0.02 (U/U) at 37°C for 2 h, 92% of its initial activity was retained.
However, the enzyme was very sensitive to trypsin, as 5% of its initial activity was recovered after treating with trypsin
at a trypsin/phytase ratio of 0.01 (U/U). 相似文献
7.
myo-Inositol mono-, di-, tri-, tetra-, and pentaphosphate were prepared by enzymic hydrolysis of myo-inositol hexaphosphate with a 1,500-fold purified phytase preparation from wheat bran and the subsequent Dowex 1 column chromatography. Relative initial rates of hydrolysis of these inositol phosphates by phytase were nearly the same each other and the activation energy of hydrolysis was about 11,000 cal. per mole for all these substrates. Km values did not vary widely with the substrates. The hydrolysis of inositol phosphates proceeded in a complicated way, except inositol monophosphate, where the reaction was of the first order. The enzyme hydrolyzed the substrates in the manner that removed phosphate group of them one by one. When mixed substrate was used the enzyme showed a preferential attack on the highest member of the phosphates present. From the mixed substrate test, it was concluded that wheat bran phytase is a single enzyme. 相似文献
8.
Microbial phytase is used to reduce the environmental loading of phosphorus from animal production facilities. The limiting
factors in the use of this enzyme in animal feeds can be overcome by solid-state fermentation (SSF), which is a promising
technology for commercial enzyme production with lower production costs. Inoculum quality and the influence of inoculum quality
on phytase production are important factors which need in-depth investigation before scaling-up of high-yielding fermentation
process. A full factorial experimental design for 240 h with sampling at every 24 h was used to determine the effects of the
treatments, inoculum age (plate and liquid culture), media composition and the duration of SSF on the production of fungal
biomass and phytase in SSF systems using Aspergillus niger. The optimal treatment combination for maximal phytase production was determined by statistically comparing all treatments
at each sampling time. Both 7- and 14-day plate cultures and M1+ medium composition with 72-h-old liquid inoculum treatments
resulted in optimal phytase production at 144 h of SSF, which was the shortest duration observed for maximal phytase production.
This resulted in maximal phytase production with a mean of 884±121 U/g substrate, while the maximal phytase production observed
at 216 h of SSF (mean phytase activity of 1008±121 U/g substrate), with the same treatment combinations, was not statistically
significant from that at 144 h of SSF. Phytase production was strongly growth-associated with younger inocula. The significant
treatment variables, age of liquid inoculum and the duration of SSF, were used to predict the system response for phytase
production using response surface methodology. From the response surface model, the optimal response of the experiment was
predicted and the reliability of the prediction was checked with the verification experiment. Journal of Industrial Microbiology & Biotechnology (2001) 26, 161–170.
Received 06 June 2000/ Accepted in revised form 14 October 2000 相似文献
9.
Aims: To isolate, clone and express a novel phytase gene (phy) from Bacillus sp. in Escherichia coli; to recover the active enzyme from inclusion bodies; and to characterize the recombinant phytase. Methods and Results: The molecular weight of phytase was estimated as 40 kDa on SDS-polyacrylamide gel electrophoresis. A requirement of Ca2+ ions was found essential both for refolding and activity of the enzyme. Bacillus phytase exhibited a specific activity of 16 U mg−1 protein; it also revealed broad pH and temperature ranges of 5·0 to 8·0 and 25 to 70°C, respectively. The Km value of phytase for hydrolysis of sodium phytate has been determined as 0·392 mmol l−1. The activity of enzyme has been inhibited by EDTA. The enzyme exhibited ample thermostability upon exposure to high temperatures from 75 to 95°C. After 9 h of cultivation of transformed E. coli in the bioreactor, the cell biomass reached 26·81 g wet weight (ww) per l accounting for 4289 U enzyme activity compared with 1·978 g ww per l producing 256 U activity in shake-flask cultures. In silico analysis revealed a β-propeller structure of phytase. Conclusions: This is the first report of its kind on the purification and successful in vitro refolding of Bacillus phytase from the inclusion bodies formed in the transformed E. coli. Significance and Impact of the Study: Efficient and reproducible protocols for cloning, expression, purification and in vitro refolding of Bacillus phytase enzyme from the transformed E. coli have been developed. The novel phytase, with broad pH and temperature range, renaturation ability and substrate specificity, appears promising as an ideal feed supplement. Identification of site between 179th amino acid leucine and 180th amino acid asparagine offers scope for insertion of small peptides/domains for production of chimeric genes without altering enzyme activity. 相似文献
10.
A novel thermostable phytase gene was cloned from Aspergillus fumigatus WY-2. It was 1459 bp in size and encoded a polypeptide of 465 amino acids. The gene was expressed in Pichia pastoris GS115 as an extracellular enzyme. The expressed enzyme was purified to homogeneity and biochemically characterized. The purified
enzyme had a specific activity of 51 U/mg with an approximate molecular mass of 88 kDa. The optimum pH and temperature for
activity were pH 5.5 and 55°C, respectively. After incubation at 90°C for 15 min, it still remained at 43.7% of the initial
activity. The enzyme showed higher affinity for sodium phytate than other phosphate conjugates, and the Km and Kcat for sodium phytate were 114 μM and 102 s−1, respectively. Incubated with pepsin at 37°C for 2 h at the ratio (pepsin/phytase, wt/wt) of 0.1, it still retained 90.1%
residual activity. These exceptional properties give the newly cloned enzyme good potential in animal feed applications. 相似文献
11.
Characterization,Gene Cloning,and Sequencing of a Fungal Phytase,PhyA, From Penicillium oxalicum PJ3
Seung Ho Lee Jaiesoon Cho Jinduck Bok Seungha Kang Yunjaie Choi 《Preparative biochemistry & biotechnology》2013,43(4):336-347
A phytase from Penicillium oxalicum PJ3, PhyA, was purified near to homogeneity with 427-fold increase in specific phytase activity by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatographies. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram analysis of the purified enzyme indicated an estimated molecular mass of 65 kD. The optimal pH and temperature of the purified enzyme were pH 4.5 and 55°C, respectively. The enzyme activity was strongly inhibited by Ca2+, Cu2+, Zn2+, and phenylmethylsulfonyl fluoride (PMSF). The Km value for sodium phytate was 0.545 mM with a Vmax of 600 U/mg of protein. The phyA gene was cloned, and it contains an open reading frame of 1,383 with a single intron (118 bp), and encodes a protein of 461 amino acids. 相似文献
12.
Gunashree BS Venkateswaran G 《Journal of industrial microbiology & biotechnology》2008,35(12):1587-1596
The present article deals with the studies on the effect of media ingredients, such as carbon, nitrogen, inorganic phosphates,
surfactants, and metal salts, on phytase enzyme production by Aspergillus niger CFR 335 in submerged (SmF) and solid-state fermentations (SSF). The results obtained showed a 1.5-fold higher enzyme yield
in the presence of sucrose in both SmF and SSF, while peptone was found to be a favorable nitrogen source for SmF. Sodium
dihydrogen phosphate (NaH2PO4) favored 34% higher enzyme yield than the control, which was followed by 19% higher activity in potassium dihydrogen phosphate
(KH2PO4) in SSF at 0.015% w/v. The addition of Tween-20 in SmF showed a maximum yield of 12.6 U/mL while, SDS suppressed the growth
of the fungus. None of the surfactants favored the enzyme yield in SSF. Calcium chloride (CaCl2) was extensively efficient in stimulating more than 55% higher phytase production in SmF at 0.01% v/v. In SSF, none of the
metal salts stimulated phytase production. 相似文献
13.
Jaecheon Lee Yunjaie Choi Peter-Changwhan Lee Seungha Kang Jinduck Bok Jaiesoon Cho 《World journal of microbiology & biotechnology》2007,23(3):443-446
The 1,332 bp phytase gene of Penicillium
oxalicum PJ3 was inserted into the expression vector, pPICZαA and expressed in the methylotrophic yeast, Pichia pastoris as an active, extracellular phytase. The recombinant phytase reached a maximum yield of 12 U/ml of medium at 120 h of cultivation
after methanol induction under shake-flask conditions. The enzyme was glycosylated, with a molecular mass of about 62.5 kDa.
The Michaelis constant (K
m) and maximum reaction rate (V
max) for sodium phytate was 0.37 mM and 526.3 U/mg of protein, respectively. The optimal activity occurred at pH 4.5 and 55°C.
Jaecheon Lee and Yunjaie Choi contributed equally to this work. 相似文献
14.
B.S. Chadha Gulati Harmeet Minhas Mandeep H.S. Saini N. Singh 《World journal of microbiology & biotechnology》2004,20(1):105-109
A thermophilic fungus, Rhizomucor pusillus, isolated from composting soil, was studied for phytase production using solid-state fermentation. The optimization of phytase production was carried out by Box–Behnken design of experiments, using three independent variables (pH of medium, culture age and incubation period), resulting in a maximal level of phytase (9.18 units/g substrate). The partially purified phytase was optimally active at 70 °C and pH 5.4, though the enzyme showed 80% activity over a wide pH range, 3.0–8.0. The phytase was found to have broad substrate specificity. 相似文献
15.
K. Bhavsar P. Gujar P. Shah V. Ravi Kumar J. M. Khire 《Applied microbiology and biotechnology》2013,97(2):673-679
Combination of statistical optimization and mutagenesis to isolate hypersecretory strains is studied to maximize phytase production from Aspergillus niger NCIM 563 under submerged fermentation. The overall results obtained show a remarkable 5.98-fold improvement in phytase production rates when compared to that using basal medium. Optimization of culture conditions from parent strain is studied first by the Plackett–Burman technique to evaluate the effects of 11 variables for phytase production. The results showed that glucose, MgSO4, KCl, incubation period, and MnSO4 are the most significant variables affecting enzyme production. Further optimization in these variables, using a central composite design technique, resulted in 3.74-fold increase in the yield of phytase production to 254,500 U/l when compared with the activity observed with basal media (68,000 U/l) in shake flask. Our experiments show that the phytase from A. niger NCIM 563 exhibits desirable activity in simulated gastric fluid conditions with low pH and also improved thermostability when compared to commercial phytase. The improved yield demonstrates the potential applicability of phytase enzyme as a source of phytase supplement for phosphorus nutrition and environmental protection in animal feed industry. Physical and chemical mutagenesis experiments were carried out in parallel to isolate hypersecretory mutants that could possibly further enhance the enzyme production. Using optimized media conditions of the parent strain, our results show that mutant strain A. niger NCIM 1359 increased the phytase activity by another 1.6-fold to 407,200 U/l. 相似文献
16.
The effect of diets differing in enzyme supplements, mineral phosphorus (P) and microwave wheat treatment on phytate hydrolysis and lower inositol phosphate isomers (InsPs) appearance in broiler crops was studied. The broilers (16- and 15-day-old) were assigned to 48 pens of 15 or 20 birds each (n = 8 pens per treatment) in Experiments 1 and 2, respectively. In Experiment 1, birds received a low-P wheat-soybean meal diet where the wheat was either microwave treated or not. These diets were offered without further supplementation or with added phytase (500 FTU/kg diet), alone or in combination with a xylanase (16,000 BXU/kg diet). In Experiment 2, two maize-soybean meal-based diets were fed, without or with monocalcium phosphate supplementation. Furthermore, these diets were offered without further supplementation or with phytase at 500 or 12,500 FTU/kg diet. On day 23 or 24 (Experiments 1 and 2, respectively), crop digesta were pooled per pen, freeze-dried and analysed for InsPs and the marker TiO2. Microwaving reduced the intrinsic phytase activity and InsP6 hydrolysis, but increased the concentration of Ins(1,2,3,4,5)P5 and Ins(1,2,4,5,6)P5 in the digesta of crop (Experiment 1). Microwave treatment significantly interacted with enzyme supplementation for Ins(1,2,5,6)P4 concentration, indicating a synergistic effect of intrinsic and supplied phytase in the crop. Xylanase tended to support phytase hydrolysis in diets with microwave-treated wheat. Phytase addition increased InsP6 hydrolysis up to 79% (Experiment 2). Thus, wheat phytase activity can cause high InsP6 hydrolysis in the crop. Treatment differences in lower InsPs indicated that hydrolysis of the first InsP6 phosphate group is not the only step in the degradation cascade in the crop of broilers that is influenced by dietary factors. 相似文献
17.
A phytase gene from Aspergillus niger was isolated and two Escherichia coli expression systems, based on T7 RNA polymerase promoter and tac promoter, were used for its recombinant expression. Co-expression of molecular chaperone, GroES/EL, aided functional cytosolic expression of the phytase in E. coli BL21 (DE3). Untagged and maltose-binding protein-tagged recombinant phytase showed an activity band of ~49 and 92 kDa, respectively, on a zymogram. Heterologously-expressed phytase was fractionated from endogenous E. coli phytase by (NH4)2SO4 precipitation. The enzyme had optimum activity at 50 °C and pH 6.5. 相似文献
18.
Aims: Phytase production by Sporotrichum thermophile in a cost‐effective cane molasses medium in submerged fermentation and its application in bread. Methods and Results: The production of phytase by a thermophilic mould S. thermophile was investigated using free and immobilized conidiospores in cane molasses medium in shake flasks, and stirred tank and air‐lift fermenters. Among surfactants tested, Tweens (Tween‐20, 40 and 80) and sodium oleate increased phytase accumulation, whereas SDS and Triton X‐100 inhibited the enzyme production. The mould produced phytase optimally at aw 0·95, and it declined sharply below this aw value. The enzyme production was comparable in air‐lift and stirred tank reactors with a marked reduction in fermentation time. Among the matrices tried, Ca‐alginate was the best for conidiospore immobilization, and fungus secreted sustained levels of enzyme titres over five cycles. The phytic acid in the dough was efficiently hydrolysed by the enzyme accompanied by the liberation of soluble phosphate in the bread. Conclusions: The phytase production by S. thermophile was enhanced in the presence of Tween‐80 in cane molasses medium. A peak in enzyme production was attained in 48 h in the fermenter when compared with that of 96 h in shake flasks. Ca‐alginate immobilized conidiospores germinated to produce fungal growth that secreted sustained levels of phytase over five cycles. The bread made with phytase contained reduced level of phytic acid and a high‐soluble phosphate. Significance and Impact of the Study: The phytase accumulation by S. thermophile was increased by the surfactants. The sustainability of enzyme production in stirred tank and air‐lift fermenters suggested the possibility for scaling up of phytase. The bread made with phytase contained low level of antinutrient, i.e. phytic acid. 相似文献
19.
Tanami Roy Goutam Banerjee Suhas Kumar Dan Arun Kumar Ray 《Proceedings of the Zoological Society》2013,66(1):27-35
The culture conditions for extracellular production of phytase by two strains of Bacillus licheniformis (LF1 and LH1) isolated from the proximal and distal intestine of rohu (Labeo rohita) were optimized to obtain maximum level of phytase. Both the strains were cultured TSA broth for 24 h at 37 ± 2 °C, when average viable count of 9.75 × 107 cells ml?1 culture broth was obtained. This was used as the inoculum for the production medium. Sesame (Sesamum indicum) oilseed meal was used as the source of phytic acid (substrate). The effects of moisture, pH, temperature, fermentation period, inoculum size, different nitrogen sources, vitamins and surfactants on phytase production by these two strains were evaluated. Phytase yield was highest (1.87 U in LF1 and 1.57 U in LH1) in solid-state fermentation. Enzyme production in both the isolates increased in an optimum pH range of 5.5–6.5. Minimum phytase production was observed at 50 °C, while maximum production was obtained at 40 °C. To standardize the fermentation period for phytase production, production rate was measured at 12-h intervals up to 120 h. Enzyme production increased for 72 h of fermentation in both strains, and decreased thereafter. The enzyme production increased with increased inoculum size up to 3.0 percentage points for the strain LF1 and up to 2.0 % for the strains LH1. Ammonium sulphate as the nitrogen source was most effective in LF1, while beef extract proved useful to maximize enzyme production by LH1. 相似文献
20.
Yoshiyuki Takasaki 《Bioscience, biotechnology, and biochemistry》2013,77(4):435-440
The equilibrium constant of the isomerization reaction between d-mannose and d-fructose which is catalyzed by a mannose isomerase from Streptomyces aerocolorigenes was obtained by using three methods over the temperature range from 1 to 40°C.It was found that the equilibrium constant was scarcely dependent on temperature, ΔH, the heat of the formation of d-fructose from d-mannose, being approximately zero.The standard free energy change, ΔG, and the standard entropy change, ΔS, of the reaction were calculated from the equilibrium constants at various temperatures and ΔH. The values of ΔG and ΔS at 25°C were ?650 cal/mole and + 2.2 cal/deg·mole, respectively.By combining these thermodynamic data with those obtained for the isomerization reaction between d-glucose and d-fructose reported in the previous paper, ΔH, ΔG and ΔS for the isomerization between d-mannose and d-glucose were indirectly obtained to be +2220 cal/mole, +830 cal/mole and +4.6 cal/deg·mole at 25°C, respectively. 相似文献