共查询到20条相似文献,搜索用时 0 毫秒
1.
Mohammed A. Farid Eglal A. Ghoneimy Maie A. El-Khawaga Asmaa Negm-Eldein Ghada E. A. Awad 《Annals of microbiology》2013,63(2):523-531
Response surface methodology (RSM), employing the fractional factorial design (FFD) was used to optimize the fermentation medium for the production of glucose oxidase (GOD) from a marine isolate (NRC9) of Aspergillus niger under submerged fermentation. The design was employed by selecting glucose, CaCO3, ammonium phosphate and MgSO4 concentrations as model factors by ‘one variable at a time’ experiment. A second-order quadratic model and response surface method showed that the optimum concentrations (g/l) glucose, 100; CaCO3, 25; (NH4)2HPO4, 1.8 and 0.4 of MgSO4, resulted in an improvement of GOD production (170?±?0.88 U/ml) as compared to the initial level (109.81?±?1.38 U/ml) after four days of incubation at 200 rpm and 30 °C, whereas its predicted value obtained by the quadratic model was 164.36 U/ml. Analysis of variance (ANOVA) showed a high coefficient of determination value (R 2) of 0.967, ensuring a satisfactory adjustment of the quadratic model with the experimental data. This is the first report on production of glucose oxidase from a marine fungal isolate, Aspergillus niger NRC9, using statistical experimental design and response surface methodology in optimization of its production under submerged fermentation. 相似文献
2.
Three Aspergillus nigerstrains were grown in submerged and solid state fermentation systems with sucrose at 100 g l–1. Average measurements of all strains, liquid vs solid were: final biomass (g l–1), 11 ± 0.3 vs 34 ± 5; maximal enzyme titres (U l–1) 1180 ± 138 vs 3663 ± 732; enzyme productivity (U l–1h–1) 20 ± 2 vs 87 ± 33 and enzyme yields (U/gX) 128 ± 24 vs 138 ± 72. Hence, better productivity in solid-state was due to a better mould growth. 相似文献
3.
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
4.
N+注入选育黑曲霉益生菌及其突变菌株产酶条件的研究 总被引:13,自引:0,他引:13
以益生菌株黑曲霉AN01为材料,经N 多次诱变得突变益生菌株AN03。结果表明,出发益生菌株AN01酸性蛋白酶、纤维素酶和果胶酶的酶活分别由原来的71.6Ug、141.7Ug和264.8Ug相继提高到996.5Ug、940.4Ug和906.5Ug。突变益生菌株AN03经传5代培养,产酶特性稳定。试验还研究了变突变益生菌株AN03最佳产酶条件,培养基为每升含麸皮105g,玉米芯105g,豆粕105g,氯化铵16g,pH5.0。30℃培养4d。 相似文献
5.
Sarvesh Kumar Soni Jayant Malhar Khire 《World journal of microbiology & biotechnology》2007,23(11):1585-1593
Novel extracellular phytase was produced by Aspergillus niger NCIM 563 under submerged fermentation conditions at 30 °C in medium containing dextrin and glucose as carbon sources along
with sodium nitrate as nitrogen source. Maximum phytase activity (41.47 IU/mL at pH 2.5 and 10.71 IU/mL at pH 4.0) was obtained
when dextrin was used as carbon source along with glucose and sodium nitrate as nitrogen source. Nearly 13 times increase
in phytase activity was observed when phosphate in the form of KH2PO4 (0.004 g/100 mL) was added in the fermentation medium. Physic-chemical properties of partially purified enzyme indicate the
possibility of two distinct forms of phytases, Phy I and Phy II. Optimum pH and temperature for Phy I was 2.5 and 60 °C while
Phy II was 4.0 and 60 °C, respectively. Phy I was stable in the pH range 1.5–3.5 while Phy II was stable in the wider pH range,
2.0–7.0. Molecular weight of Phy I and Phy II on Sephacryl S-200 was approximately 304 kDa and 183 kDa, respectively. Phy
I activity was moderately stimulated in the presence of 1 mM Mg2+, Mn2+, Ca2+ and Fe3+ ions and inhibited by Zn2+ and Cd2+ ions while Phy II activity was moderately stimulated by Fe3+ ions and was inhibited by Hg2+, Mn2+ and Zn2+ ions at 1 mM concentration in reaction mixture. The Km for Phy I and II was 3.18 and 0.514 mM while Vmax was 331.16 and 59.47 μmols/min/mg protein, respectively. 相似文献
6.
A multi-objective optimization formulation that reflects the multi-substrate optimization in a multi-product fermentation
is proposed in this work. This formulation includes the application of ε-constraint to generate the trade-off solution for
the enhancement of one selective product in a multi-product fermentation, with simultaneous minimization of the other product
within a threshold limit. The formulation has been applied to the fed-batch fermentation of Aspergillus niger that produces a number of enzymes during the course of fermentation, and of these, catalase and protease enzyme expression
have been chosen as the enzymes of interest. Also, this proposed formulation has been applied in the environment of three
control variables, i.e. the feed rates of sucrose, nitrogen source and oxygen and a set of trade-off solutions have been generated
to develop the pareto-optimal curve. We have developed and experimentally evaluated the optimal control profiles for multiple
substrate feed additions in the fed-batch fermentation of A. niger to maximize catalase expression along with protease expression within a threshold limit and vice versa. An increase of about
70% final catalase and 31% final protease compared to conventional fed-batch cultivation were obtained. Novel methods of oxygen
supply through liquid-phase H2O2 addition have been used with a view to overcome limitations of aeration due to high gas–liquid transport resistance. The
multi-objective optimization problem involved linearly appearing control variables and the decision space is constrained by
state and end point constraints. The proposed multi-objective optimization is solved by differential evolution algorithm,
a relatively superior population-based stochastic optimization strategy. 相似文献
7.
Exopectinases produced by Aspergillus niger in solid-state and submerged fermentation: a comparative study 总被引:1,自引:0,他引:1
Díaz-Godínez G Soriano-Santos J Augur C Viniegra-González G 《Journal of industrial microbiology & biotechnology》2001,26(5):271-275
Exopectinase production by Aspergillus niger was compared in submerged fermentation (SmF) and solid-state fermentation (SSF). SSF was carried out using polyurethane foam
(PUF) as the solid support. The purpose was to study the effect of sucrose addition (0 or 40 g/l) and water activity level
(A
w=0.99 or 0.96) on the level of enzyme activity induced by 15 g/l of pectin. Mycelial growth, as well as extracellular protease
production, was also monitored. Sucrose addition in SmF resulted in catabolite repression of exopectinase activity. However,
in SSF, an enhancement of enzyme activity was observed. Protease levels were minimal in SSF experiments with sucrose and maximal
in SmF without sucrose. Exopectinase yields (IU/g X) were negligible in SmF with sucrose. The high levels of exopectinase with sucrose and high A
w in SSF can be explained by a much higher level of biomass production without catabolite repression and with lower protease
contamination. Journal of Industrial Microbiology & Biotechnology (2001) 26, 271–275.
Received 05 July 2000/ Accepted in revised form 27 January 2001 相似文献
8.
O. Schmidt H. Angermann I. Frommhold-Treu K. Hoppe 《Applied microbiology and biotechnology》1995,43(3):424-430
The growth of the microorganism and the production of the pectinolytic enzyme complex in a stirred 30-l biofermentor using the Aspergillus niger Rehbrücke strain were studied. The time courses of fermentation parameters (formation of biomass, consumption of carbon and inorganic nitrogen source, formation of pectinolytic enzymes) were measured. The formation of biomass showed a distinct lag phase, followed by a log phase with exponential growth and finally a stationary period when cell lysis was beginning. The uptake of the carbon source and inorganic nitrogen source by the A. niger cells corresponded to the time course of growth. The formation of pectinolytic enzymes took place in two steps. The first one was growth-bounded and finished with the end of the log phase of biomass growth. The second step of pectinolytic enzyme formation took place after the end of the catabolite repression of the carbon source and was not growth-bounded. On the basis of the experimental data a mathematical model of the fermentation process was developed. Comparison of the kinetics of the measured fermentation curves and the solution curves of the model showed qualitatively good agreement. 相似文献
9.
Kavita Bhavsar Priyanka Buddhiwant Sarvesh K. Soni Dilip Depan Sampa Sarkar Jayant M. Khire 《Process Biochemistry》2013,48(11):1618-1625
Aspergillus niger NCIM 563 produces dissimilar phytase isozymes under solid state and submerged fermentation conditions. Biochemical characterization and applications of phytase Phy III and Phy IV in SSF and their comparison with submerged fermentation Phy I and Phy III were studied. SSF phytases have a higher metabolic potential as compared to SmF. Phy I is tetramer and Phy II, III and IV are monomers. Phy I and IV have pH optima of 2.5 and Phy II and III have pH optima of 5.0 and 5.6, respectively. Phy I, III and IV exhibited very broad substrate specificity while Phy II was more specific for sodium phytate. SSF phytase is less thermostable as compared to SmF phytase. Phy I and II show homology with other known phytases while Phy III and IV show no homology with SmF phytases and any other known phytases from the literature suggesting their unique nature. This is the first report about differences among phytase produced under SSF and SmF by A. niger and this study provides basis for explanation of the stability and catalytic differences observed for these enzymes. Exclusive biochemical characteristics and multilevel application of SSF native phytases determine their efficacy and is exceptional. 相似文献
10.
N+注入选育产蛋白酶益生菌及其生物学效应研究 总被引:3,自引:0,他引:3
试验研究了N+注入选育产蛋白酶益生菌及其生物学效应.经N+反复注入诱变筛选,突变高产菌株的酶活由出发菌株的75.8IU.g-1提高到631.6IU.g-1;利用中心组合设计原理摸索出了突变菌株最佳产酶条件即麸皮24.83%,豆粕23.68%,水50%,硫酸铵1.49%,发酵温度30℃,发酵时间66h,培养基pH 5.5.生物学效应研究发现真空处理对活细胞有明显伤害;孢子存活率先是随着注入剂量加大而迅速降低,当注入剂量加大到50×2.6×1013 ions/cm2时存活率出现平缓回升,注入剂量超过100×2.6×1013ions/cm2时存活率又再次开始下降;注入剂量越大,孢子突变率越高,中等注入剂量30×2.6×1013N+/cm3~80×2.6×1013N+/cm2可引起较高的正突变率;ESR谱研究结果表明,N+注入前和注入后都有自由基ESR波谱单一峰,随着注入剂量的增大,孢子内的自由基ESR波谱的强度也逐渐增大;SEM观察发现,未经N+注入的孢子较为完整、饱满且表面光滑,而经注入后的孢子表面粗糙,可见明显的刻蚀损伤和破壁现象,并且注入剂量越大,伤痕也越深宽.试验结果提示N+注入是一种有效的动物益生菌选育方法. 相似文献
11.
Aspergillus niger ORS-4.410, a mutant of Aspergillus niger ORS-4 was produced by repeated irradiation with UV rays. Treatments with chemical mutagnes also resulted into mutant strains. The mutants differed from the parent strain morphologically and in gluconic acid production. The relationship between UV treatment dosage, conidial survival and frequency of mutation showed the maximum frequency of positive mutants (25%) was obtained along with a conidial survival of 59% after second stage of UV irradiation. Comparison of gluconic acid production of the parent and mutant ORS-4.410 strain showed a significant increase in gluconic acid production that was 87% higher than the wild type strain. ORS-4.410 strain when transferred every 15 days and monitored for gluconic acid levels for a total period of ten months appeared stable. Mutant ORS-4.410 at 12% substrate concentration resulted into significantly higher i.e. 85-87 and 94-97% yields of gluconic acid under submerged and solid state surface conditions respectively. Further increase in substrate concentration appeared inhibitory. Maximum yield of gluconic acid was obtained after 6 days under submerged condition and decreased on further cultivation. Solid state surface culture condition on the other hand resulted into higher yield after 12 days of cultivation and similar levels of yields continued thereafter. 相似文献
12.
A. Nowakowska-Waszczuk E. Rubaj B. Matusiak E. Kosiek 《Applied microbiology and biotechnology》1984,20(6):416-418
Summary Two strains of Aspergillus niger showed a 57% and 40% reduction in growth in a shaken mineral medium with 5% glucose, at the initial pH 6.5–6.0 where ammonium acetate (0.25% and 0.2%) was a source of nitrogen. Uptake of glucose was not inhibited and mycelium kept its acid-forming activity. Growth inhibition was abolished in the presence of 12% glucose or increased content of ammonium and sodium acetate up to 765 mg acetate anion per 100 cm3.This work was a part of Project MR II, 17, topic no. 2.3.2. 相似文献
13.
Acid protease production by solid-state fermentation using Aspergillus oryzae MTCC 5341: optimization of process parameters 总被引:1,自引:0,他引:1
K. S. Vishwanatha A. G. Appu Rao Sridevi Annapurna Singh 《Journal of industrial microbiology & biotechnology》2010,37(2):129-138
Aspergillus oryzae MTCC 5341, when grown on wheat bran as substrate, produces several extracellular acid proteases. Production of the major
acid protease (constituting 34% of the total) by solid-state fermentation is optimized. Optimum operating conditions obtained
are determined as pH 5, temperature of incubation of 30°C, defatted soy flour addition of 4%, and fermentation time of 120 h,
resulting in acid protease production of 8.64 × 105 U/g bran. Response-surface methodology is used to generate a predictive model of the combined effects of independent variables
such as, pH, temperature, defatted soy flour addition, and fermentation time. The statistical design indicates that all four
independent variables have significant effects on acid protease production. Optimum factor levels are pH 5.4, incubation temperature
of 31°C, 4.4% defatted soy flour addition, and fermentation time of 123 h to yield a maximum activity of 8.93 × 105 U/g bran. Evaluation experiments, carried out to verify the predictions, reveal that A. oryzae produces 8.47 × 105 U/g bran, which corresponds to 94.8% of the predicted value. This is the highest acid protease activity reported so far,
wherein the fungus produces four times higher activity than previously reported [J Bacteriol 130(1): 48–56, 1977]. 相似文献
14.
Darah Ibrahim Haritharan Weloosamy Sheh-Hong Lim 《World journal of biological chemistry》2015,6(3):265-271
AIM: To investigate the impact of agitation speed on pectinase production and morphological changing of Aspergillus niger(A. niger) HFD5A-1 in submerged fermentation. METHODS: A. niger HFM5A-1 was isolated from a rotted pomelo. The inoculum preparation was performed by adding 5.0 m L of sterile distilled water containing 0.1% Tween 80 to a sporulated culture. Cultivation was carried out with inoculated 1 × 107 spores/m L suspension and incubated at 30 ℃ with different agitation speed for 6 d. The samples were withdrawn after 6 d cultivation time and were assayed for pectinase activity and fungal growth determination. The culture broth was filtered through filter paper(Whatman No. 1, London) to separate the fungal mycelium. The cell-free culture filtrate containing the crude enzyme was then assayed for pectinase activity. The biomass was dried at 80 ℃ until constant weight. The fungal cell dry weight was then expressed as g/L. The 6 d old fungal mycelia were harvested from various agitation speed, 0, 50, 100, 150, 200 and 250 rpm. The morphological changing of samples was then viewed under the light microscope and scanning electron microscope.RESULTS: In the present study, agitation speed was found to influence pectinase production in a batch cultivation system. However, higher agitation speeds than the optimal speed(150 rpm) reduced pectinase production which due to shear forces and also collision among the suspended fungal cells in the cultivation medium. Enzyme activity increased with the increasing of agitation speed up to 150 rpm, where it achieved its maximal pectinase activity of 1.559 U/m L. There were significant different(Duncan, P 0.05) of the pectinase production with the agitation speed at static, 50, 100, 200 and 250 rpm. At the static condition, a well growth mycelial mat was observed on the surface of the cultivation medium and sporulation occurred all over the fungal mycelial mat. However with the increased in agitation speed, the mycelial mat turned slowly to become a single circular pellet. Thus, it was found that agitation speed affected the morphological characteristics of the fungal hyphae/mycelia of A. niger HFD5A-1 by altering their external as well as internal cell structures.CONCLUSION: Exposure to higher shear stress with an increasing agitation speed could result in lower biomass yields as well as pectinase production by A. niger HFD5A-1. 相似文献
15.
In view of the often-cited theory that citric acid accumulation is caused by an inhibition of aconitase activity, the equilibrium of the reaction of aconitase was investigated by comparing in vivo steady-state concentrations of citrate and isocitrate in Aspergillus niger grown under various citric acid-producing conditions. With the equilibrium catalyzed by the A. niger enzyme in vitro, similar values were obtained. The validity of our in vivo measurements was verified by the addition of the aconitase inhibitor fluorocitrate, which appreciably elevated the citrate:isocitrate ratio. The results strongly argue against an inhibition of aconitase during citric acid fermentation. 相似文献
16.
Kelly S Grimm LH Hengstler J Schultheis E Krull R Hempel DC 《Bioprocess and biosystems engineering》2004,26(5):315-323
Product formation of mycelial organisms, like Aspergillus niger, is intimately connected with their morphology. Pellet morphology is often requested for product formation. Therefore, it is important to reveal the influence of the hydrodynamic conditions on the morphological development. In the present study, pellet morphology and glucoamylase formation were studied under different agitation intensities of A. niger AB1.13. For pellet formation inside the bioreactor, without the use of precultures, it is necessary to work at low energy dissipation rates. Biomass growth and glucoamylase activity were correlated with energy dissipation. Furthermore, product yield was analysed in dependence of pellet size and concentration. The present work shows that simple equations based on Monod-kinetics can describe growth and product formation, in general, also in mycelian organisms. All measured morphological data, like pellet concentration, as well as glucoamylase formation, strongly depend on the hydrodynamic conditions. 相似文献
17.
Production of tannase by Aspergillus niger Aa-20 in submerged and solid-state fermentation: influence of glucose and tannic acid 总被引:1,自引:0,他引:1
Aguilar CN Augur C Favela-Torres E Viniegra-González G 《Journal of industrial microbiology & biotechnology》2001,26(5):296-302
Tannase production by Aspergillus niger Aa-20 was studied in submerged (SmF) and solid-state (SSF) fermentation systems with different tannic acid and glucose concentrations.
Tannase activity and productivity were at least 2.5 times higher in SSF than in SmF. Addition of high tannic acid concentrations
increased total tannase activity in SSF, while in SmF it was decreased. In SmF, total tannase activity increased from 0.57
to 1.03 IU/mL, when the initial glucose concentration increased from 6.25 to 25 g/L, but a strong catabolite repression of
tannase synthesis was observed in SmF when an initial glucose concentration of 50 g/L was used. In SSF, maximal values of
total tannase activity decreased from 7.79 to 2.51 IU when the initial glucose concentration was increased from 6.25 to 200
g/L. Kinetic results on tannase production indicate that low tannase activity titers in SmF could be associated to an enzyme
degradation process which is not present in SSF. Tannase titers produced by A. niger Aa-20 are fermentation system-dependent, favoring SSF over SmF. Journal of Industrial Microbiology & Biotechnology (2001) 26, 296–302.
Received 07 July 2000/ Accepted in revised form 15 February 2001 相似文献
18.
通过对木聚糖酶高产菌株EIM-30基于形态学和18SrDNA序列的系统发育进化分析,鉴定为里氏木霉Trichoder撇reesei。在单因子实验确定EIM-30产木聚糖酶的最适碳源和氮源的基础上,通过Plackett—Burman实验对影响其产酶的相关因素进行评估并筛选出3个显著效应因子,然后应用最陡爬坡实验和响应面分析确定最适产酶培养基配方为:酵母浸膏1.50%,蛋白胨1.00%,NaC10.50%,PPG-20000.10%,MgS041.20%,CaC20.18%,(NH4)2S040.45%,甘油4.18%,乳糖3.05%,K2唧041.59%。优化后TrichodermareeseiEIM-30的液体发酵产木聚糖酶的活力可达9.857×105V/mL,较优化前提高1.98倍。 相似文献
19.
YANG Zhang-ping CAI Shao-li KE Chong-rong HUANG Ping LIU Xiao-lin YU Qing-mei ZHUANG Xiu-hong CHEN Lin LIN Guo-yan HUANG Jian-zhong 《工业微生物》2012,42(3)
通过对木聚糖酶高产菌株EIM-30基于形态学和18S rDNA序列的系统发育进化分析,鉴定为里氏木霉Trichoderma reesei.在单因子实验确定EIM-30产木聚糖酶的最适碳源和氮源的基础上,通过Plackett-Burman实验对影响其产酶的相关因素进行评估并筛选出3个显著效应因子,然后应用最陡爬坡实验和响应面分析确定最适产酶培养基配方为:酵母浸膏1.50%,蛋白胨1.00%,NaCl 0.50%,PPG-2000 0.10%,MgSO4 1.20%,CaCl2 0.18%,(NH4)2 SO4 0.45%,甘油4.18%,乳糖3.05%,K2HPO41.59%.优化后Trichoderma reesei EIM-30的液体发酵产木聚糖酶的活力可达9.857×105 U/mL,较优化前提高1.98倍. 相似文献