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1.
We have cloned a gene (papA) that encodes a prolyl aminopeptidase from Aspergillus niger. Homologous genes are present in the genomes of the Eurotiales A. nidulans, A. fumigatus and Talaromyces emersonii, but the gene is not present in the genome of the yeast Saccharomyces cerevisiae. Cell extracts of strains overexpressing the gene under the control of its own promoter showed a fourfold to sixfold increase in prolyl aminopeptidase activity, but no change in phenylalanine or leucine aminopeptidase activity. The overexpressed enzyme was subsequently purified and characterised. The enzyme specifically removes N-terminal proline and hydroxyproline residues from peptides. It is the first enzyme of its kind from a eukaryotic organism that has been characterised. 相似文献
2.
Xiao-Wei Yu Yong-Quan Li Shi-Miao Zhou Yu-Yi Zheng 《World journal of microbiology & biotechnology》2007,23(8):1091-1098
Aspergillus niger with mycelium-bound tannase activity was employed to investigate the synthesis of propyl gallate from gallic acid and 1-propanol
in organic solvents. The effects of various organic solvents (log P: −1.0 to 6.6) on the enzymatic reactions showed that benzene (log P: 2.0) was the most suitable solvent. The water content and protonation state of mycelium-bound enzyme both had significant
effects on the activity of tannase. The maximum molar conversion (65%) was achieved with 7.3% (v/v) 1-propanol and 5.56 mM
gallic acid at stirring speeds of 200 rev/min, 40 °C in presence of anhydrous sodium sulfate and PEG-10,000. Enzyme specificity
for the alcohol portion (C1–C8) of the ester showed that the optimum synthesis was observed with alcohols ranging from C3 to C5. 相似文献
3.
In vitro colonization of hydrophilic contact lenses by Aspergillus niger was investigated. Five strains of the fungus, four polymers, two culture media and four incubation periods were considered
for analysis. Only the 2700 strain colonized the lenses. The degrees of adhesion and invasion varied significantly according
to the characteristics of the culture under investigation. Journal of Industrial Microbiology & Biotechnology (2002) 29, 6–9 doi:10.1038/sj.jim.7000255
Received 06 August 2001/ Accepted in revised form 23 March 2002 相似文献
4.
Fermentation conditions were statistically optimized for producing extracellular xylanase by Aspergillus niger SL-05 using apple pomace and cotton seed meal. The primary study shows that culture medium with a 1:1 ratio of apple pomace and cotton seed meal (carbon and nitrogen sources) yielded maximal xylanase activity. Three significant factors influencing xylanase production were identified as urea, KH(2)PO(4), and initial moisture content using Plackett-Burman design study. The effects of these three factors were further investigated using a design of rotation-regression-orthogonal combination. The optimized conditions by response surface analysis were 2.5% Urea, 0.09% KH(2)PO(4), and 62% initial moisture content. The analysis of variance indicated that the established model was significant (P < 0.05), "while" or "and" the lack of fit was not significant. Under the optimized conditions, the model predicted 4,998 IU/g dry content, whereas validation experiments produced an enzymatic activity of xylanase at 5,662 IU/g dry content after 60 h fermentation. This study innovatively developed a fermentation medium and process to utilize inexpensive agro-industrial wastes to produce a high yield of xylanase. 相似文献
5.
P. Shah K. Bhavsar S. K. Soni Jayant Malhar Khire 《Journal of industrial microbiology & biotechnology》2009,36(3):373-380
Combination of physical and chemical mutagenesis was used to isolate hyper secretory strains of Aspergillus niger NCIM 563 for phytase production. Phytase activity of mutant N-1 and N-79 was about 17 and 47% higher than the parent strain.
In shake flask the productivity of phytase in parent, mutant N-1 and N-79 was 6,181, 7,619 and 9,523 IU/L per day, respectively.
Up scaling of the fermentation from shake flask to 3 and 14 L New Brunswick fermenter was studied. After optimizing various
fermentation parameters like aeration, agitation and carbon source in fermentation medium the fermentation time to achieve
highest phytase activity was reduced considerably from 14 days in shake flask to 8 days in 14 L fermenter. Highest phytase
activity of 80 IU/ml was obtained in 1% rice bran–3.5% glucose containing medium with aeration 0.2 vvm and agitation 550 rpm
at room temperature on 8th day of fermentation. Addition of either bavistin (0.1%), penicillin (0.1%), formalin (0.2%) and
sodium chloride (10%) in fermented broth were effective in retaining 100% phytase activity for 8 days at room temperature
while these reagents along with methanol (50%) and ethanol (50%) confer 100% stability of phytase activity at 4°C till 20 days.
Among various carriers used for application of phytase in feed, wheat bran and rice bran were superior to silica and calcium
carbonate. Thermo stabilization studies indicate 100% protection of phytase activity in presence of 12% skim milk at 70°C,
which will be useful for its spray drying. 相似文献
6.
Papagianni M Joshi N Moo-Young M 《Journal of industrial microbiology & biotechnology》2002,29(5):259-263
The effects of cell immobilization on the secretion of extracellular proteases and glucoamylase production by Aspergillus niger were investigated under a variety of immobilization techniques and culture conditions. Immobilization was achieved by means
of cell attachment on metal surfaces or spore entrapment and subsequent growth on porous Celite beads. Free-suspension cultures
were compared with immobilized mycelium under culture conditions that included growth in shake flasks and an airlift bioreactor.
Cell attachment on metal surfaces minimized the secretion of proteases while enhancing glucoamylase production by the fungus.
Growth on Celite beads in shake-flask cultures reduced the specific activity of the secreted proteases from 128 to 61 U g−1, while glucoamylase specific activity increased from 205 to 350 U g−1. The effect was more pronounced in bioreactor cultures. A reduction of six orders of magnitude in protease specific activities
was observed when the fungus grew immobilized on a rolled metal screen, which served as the draft tube of an airlift bioreactor.
Received 29 October 2001/ Accepted in revised form 14 June 2002 相似文献
7.
Hesham A. El Enshasy Elsayed Ahmed Elsayed Noorhamizah Suhaimi Roslinda Abd Malek Mona Esawy 《BMC biotechnology》2018,18(1):71
Background
Pectinase enzymes present a high priced category of microbial enzymes with many potential applications in various food and oil industries and an estimated market share of $ 41.4 billion by 2020.Results
The production medium was first optimized using a statistical optimization approach to increase pectinase production. A maximal enzyme concentration of 76.35 U/mL (a 2.8-fold increase compared with the initial medium) was produced in a medium composed of (g/L): pectin, 32.22; (NH4)2SO4, 4.33; K2HPO4, 1.36; MgSO4.5H2O, 0.05; KCl, 0.05; and FeSO4.5H2O, 0.10. The cultivations were then carried out in a 16-L stirred tank bioreactor in both batch and fed-batch modes to improve enzyme production, which is an important step for bioprocess industrialization. Controlling the pH at 5.5 during cultivation yielded a pectinase production of 109.63 U/mL, which was about 10% higher than the uncontrolled pH culture. Furthermore, fed-batch cultivation using sucrose as a feeding substrate with a rate of 2 g/L/h increased the enzyme production up to 450 U/mL after 126 h.Conclusions
Statistical medium optimization improved volumetric pectinase productivity by about 2.8 folds. Scaling-up the production process in 16-L semi-industrial stirred tank bioreactor under controlled pH further enhanced pectinase production by about 4-folds. Finally, bioreactor fed-batch cultivation using constant carbon source feeding increased maximal volumetric enzyme production by about 16.5-folds from the initial starting conditions.8.
Meng-Hao Cai Xiang-Shan Zhou Xue-Qian Sun Ke-Jing Tao Yuan-Xing Zhang 《Journal of industrial microbiology & biotechnology》2009,36(3):381-389
Statistical methodologies were employed to optimize submerged culture medium for the production of a novel antineoplastic
compound aspergiolide A by a marine-derived fungus Aspergillus glaucus HB1-19 for the first time. Orthogonal design was preformed to determine the initial composition. Then Plackett–Burman design
was applied to evaluate the influence of related nutrients, and yeast extract paste, soybean powder and sodium glutamate were
confirmed as critical factors in the medium. Response surface methodology (RSM) was finally taken as an effective approach
to optimize the combination of the obtained three significant factors. The predicted maximal aspergiolide A production of
62.4 mg/L appeared at the region where the concentrations of sodium glutamate, soybean powder, and yeast extract paste were
2, 1, and 1.07 g/L, respectively. Under the proposed optimized conditions, the experimental aspergiolide A production reached
71.2 mg/L. The correlation between predicted value and measured value of these experiments proved the validity of the response
model. After optimization, aspergiolide A production increased 4.22 times compared to that of the original medium. Elemental
analysis was finally taken into consideration, and carbon–nitrogen ratio in the medium increased from 20.1:1 to 86.6:1. This
great difference was inferred as the most important reason for production enhancement by metabolic pathway analysis. 相似文献
9.
Lovastatin, an inhibitor of HMG-CoA reductase, was produced by submerged fermentation using Monascus purpureus MTCC 369. Five nutritional parameters screened using Plackett–Burman experimental design were optimized by Box–Behnken factorial
design of response surface methodology for lovastatin production in shake flask cultures. Maximum lovastatin production of
351 mg/l were predicted in medium containing 29.59 g/l dextrose, 3.86 g/l NH4Cl, 1.73 g/l KH2PO4, 0.86 g/l MgSO4·7H2O, and 0.19 g/l MnSO4·H2O using response surface plots and point prediction tool of DESIGN EXPERT 7.0 (Statease, USA) software. 相似文献
10.
K. Parvathi R. Naresh Kumar R. Nagendran 《World journal of microbiology & biotechnology》2007,23(5):671-676
Summary Biosorption of manganese from its aqueous solution using yeast biomass Saccharomyces cerevisiae and fungal biomass Aspergillus niger was carried out. Manganese biosorption equilibration time for A. niger and S. cerevisiae were found to be 60 and 20 min, with uptakes of 19.34 and 18.95 mg/g, respectively. Biosorption increased with rise in pH,
biomass, and manganese concentration. The biosorption equilibrium data fitted with the Freundlich isotherm model revealed
that A. niger was a better biosorbent of manganese than S. cerevisiae. 相似文献
11.
Y. P. Vinetsky A. M. Rozhkova A. M. Chulkin A. D. Satrutdinov O. A. Sinitsyna E. A. Fedorova A. O. Bekkarevich O. N. Okunev A. P. Sinitsyn 《Biochemistry. Biokhimii?a》2009,74(8):882-887
The gene encoding the xlnR xylanolytic activator of the heterologous fungus Aspergillus niger was incorporated into the Penicillium canescens genome. Integration of the xlnR gene resulted in the increase in a number of activities, i.e. endoxylanase, β-xylosidase, α-L-arabinofuranosidase, α-galactosidase, and feruloyl esterase, compared to the host P. canescens PCA 10 strain, while β-galactosidase, β-glucosidase, endoglucanase, and CMCase activities remained constant. Two different expression constructs were developed. The first consisted of the nucleotide sequence containing the mature P. canescens phytase gene under control of the axhA promoter region gene encoding A. niger (1,4)-β-D-arabinoxylan-arabinofuranohydrolase. The second construct combined the P. canescens phytase gene and the bgaS promoter region encoding homologous β-galactosidase. Both expression cassettes were transformed into P. canescens host strain containing xlnR. Phytase synthesis was observed only for strains with the bgaS promoter on arabinose-containing culture media. In conclusion, the bgaS and axhA promoters were regulated by different inducers and activators in the P. canescens strain containing a structural tandem of the axhA promoter and the gene of the xlnR xylanolytic activator. 相似文献
12.
Two new effective microbial producers of inulinases were isolated from Jerusalem artichoke tubers grown in Thailand and identified
as Aspergillus niger TISTR 3570 and Candida
guilliermondii TISTR 5844. The inulinases produced by both these microorganisms were appropriate for hydrolysing inulin to fructose as the
principal product. An initial inulin concentration of ∼100 g l−1 and the enzyme concentration of 0.2 U g−1 of substrate, yielded 37.5 g l−1 of fructose in 20 h at 40°C when A. niger TISTR 3570 inulinase was the biocatalyst. The yield of fructose on inulin was 0.39 g g−1. Under identical conditions, the yeast inulinase afforded 35.3 g l−1 of fructose in 25 h. The fructose yield was 0.35 g g−1 of substrate. The fructose productivities were 1.9 g l−1 h−1 and 1.4 g l−1 h−1 for the mold and yeast enzymes, respectively. After 20 h of reaction, the mold enzyme hydrolysate contained 53% fructose
and more than 41% of initial inulin had been hydrolysed. Using the yeast enzymes, the hydrolysate contained nearly 38% fructose
at 25 h and nearly 36% of initial inulin had been hydrolysed. The A. niger TISTR 3570 inulinases exhibited both endo-inulinase and exo-inulinase activities. In contrast, the yeast inulinases displayed
mainly exo-inulinase activity. The mold and yeast crude inulinases mixed in the activity ratio of 5:1 proved superior to individual
crude inulinases in hydrolysing inulin to fructose. The enzyme mixture provided a better combination of endo- and exo-inulinase
activities than did the crude extracts of either the mold or the yeast individually. 相似文献
13.
Bo Young Jeon Soo Jin Kim Dae Hee Kim Byung Kwan Na Doo Hyun Park Hung Thuan Tran Ruihong Zhang Dae Hee Ahn 《Biotechnology and Bioprocess Engineering》2007,12(5):566-573
Aspergillus niger hyphae were found to grow with unliquefied potato starch under aerobic conditions, but did not grow under anaerobic conditions.
The raw culture ofA. niger catalyzed saccharification of potato starch to glucose, producing approximately 12 g glucose/L/day/ The extracellular enzyme
activity was decreased in proportion to incubation time, and approximately 64% of initial activity was maintained after 3
days. At 50°C,A. niger hyphae growth stopped, while the extracellular enzyme activity peaked. On the basis of theA. niger growth property and enzyme activity, we designed a serial bioreactor system composed of four different reactors. Fungal hyphae
were cultivated in reactor I at 30°C, uniquefied starch was saccharified to glycose by a fungal hyphae culture in reactors
II and III at 50°C, and glucose was fermented to ethanol bySaccharomyces cerevisiae in reactor IV. The total glucose produced by fungal hyphae in reactor I and saccharification in reactor II was about 42 g/L/day.
Ethanol production in reactor IV was approximately 22 g/L/day, which corresponds to about 79% of the theoretical maximum produced
from 55 g starch/L/day. 相似文献
14.
黑曲霉固态发酵生产单宁酶的条件优化 总被引:1,自引:0,他引:1
研究采用响应面法优化黑曲霉固态发酵生产单宁酶的培养条件。应用Plackett—Burman试验筛选出重要影响因子:五倍子粉含量、(NH4)2SO4浓度以及接种孢子量,最陡爬坡试验逼近最大响应区域。应用Box.Behnken响应面试验对重要影响因子进一步优化。得到最佳培养条件:每250mL三角瓶中装入1.0g五倍子粉、4.4g稻壳和0.5g麸皮、液固比(mL/g)2:1且营养盐溶液组成为(NH4)2s0421g/L、MgSO4·7H2O1g/L、NaCl1g/L,培养基pH自然,接种5.7×10^7个孢子后在30℃温度下培养4d。在此条件下,单宁酶产量从40U/g提高到114U/g,3次重复验证性试验平均值为115U/g,验证了模型的可靠性。 相似文献
15.
The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for
the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity
assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes
AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle. 相似文献
16.
A constitutive level of a mycelium-bound lipolytic activity from Aspergillus niger MYA 135 was strongly increased by 97% in medium supplemented with 2% olive oil. The constitutive lipase showed an optimal
activity in the pH range of 3.0–6.5, while the mycelium-bound lipase activity produced in the presence of olive oil had two
pH optima at pH 4 and 7. Interestingly, both lipolytic sources were cold-active showing high catalytic activities in the temperature
range of 4–8°C. These mycelium-bound lipase activities were also very stable in reaction mixtures containing methanol and
ethanol. In fact, the constitutive lipase maintained almost 100% of its activity after exposure by 1 h at 37°C in ethanol.
A simple methodology to evaluate suitable transesterification activities in organic solvents was also reported. 相似文献
17.
18.
Vania Castriani Fernandes da Silva Fabiano Jares Contesini Patrícia de Oliveira Carvalho 《Journal of industrial microbiology & biotechnology》2009,36(7):949-954
Considering the extraordinary microbial diversity and importance of fungi as enzyme producers, the search for new biocatalysts
with special characteristics and possible applications in biocatalysis is of great interest. Here, we report the performance
in the resolution of racemic ibuprofen of a native enantioselective lipase from Aspergillus niger, free and immobilized in five types of support (Accurel EP-100, Amberlite MB-1, Celite, Montmorillonite K10 and Silica gel).
Amberlite MB-1 was found to be the best support, with a conversion of 38.2%, enantiomeric excess of 50.7% and enantiomeric
ratio (E value) of 19 in 72 h of reaction. After a thorough optimization of several parameters, the E value of the immobilized Aspergillus niger lipase was increased (E = 23) in a shorter reaction period (48 h) at 35°C. Moreover, the immobilized Aspergillus niger lipase maintained an esterification activity of at least 80% after 8 months of storage at 4°C and could be reused at least
six times. 相似文献
19.
Certain cost-effective carbohydrate sources in crude as well as after purification were utilized as the sole sources of carbon for gluconic acid production using Aspergillus niger ORS-4.410 under submerged fermentation. Crude grape must (GM) and banana-must (BM) resulted into significant levels of gluconic acid production i.e. 62.6 and 54.6 g/l, respectively. The purification of grape and banana-must led to a 20–21% increase in gluconic acid yield. Molasses as such did not favour gluconate production (12.0 g/l) but a significant increase in production (60.3 g/l) was observed following hexacyanoferrate (HCF) treatment of the molasses. Rectified grape must (RGM) appeared to be best suitable substrate which after 144 h resulted in 73.2 g of gluconic acid/l with 80.6% yield followed by the yield obtained from the rectified banana must (RBM) (72.4%) and treated cane molasses (TM) (61.3%). Abundant growth of mould A. niger ORS-4.410 was observed with crude grape (0.131 g/l/h) and banana must (0.132 g/l/h). 相似文献
20.
M. Subhosh Chandra Buddolla Viswanath B. Rajasekhar Reddy 《Indian journal of microbiology》2007,47(4):323-328
The production of cellulolytic enzymes by Aspergillus niger on lignocellulosic substrates groundnut fodder, wheat bran, rice bran and sawdust in solid state fermentation in a laboratory
scale was compared. Czapek Dox liquid broth amended with cellulose (0.5%) was used to moisten lignocellulosic solid supports
for cultivation of Aspergillus niger. The production of filter paperase, carboxymethyl cellulase and -glucosidase were monitored at daily intervals for 5 days.
The peak production of the enzymes occurred within 3 days of incubation. Among solid supports used in the study, wheat bran
was the best solid matrix followed by groundnut fodder in production of cellulolytic enzymes in solid state fermentation.
Groundnut fodder supported significant production of FPase (2.09 FPU/g), CMCase (1.36 U/g) and -glucosidase activity (0.0117
U/g) in solid state fermentation. Considerable secretion of protein (5.10 mg/g) on groundnut fodder at peak time interval
1st day of incubation was recorded. 相似文献