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1.
α-Amylase activity during pullulan production and α-amylase gene analyses of <Emphasis Type="Italic">Aureobasidium pullulans</Emphasis> 总被引:1,自引:0,他引:1
Manitchotpisit P Skory CD Leathers TD Lotrakul P Eveleigh DE Prasongsuk S Punnapayak H 《Journal of industrial microbiology & biotechnology》2011,38(9):1211-1218
2.
Effects of different sugars on pullulan production, UDP-glucose level, and activities of α-phosphoglucose mutase, UDPG-pyrophosphorylase and glucosyltransferase in Aureobasidium pullulans Y68 were examined. It was found that more pullulan was produced when the yeast strain was grown in the medium containing glucose than when it was cultivated in the medium supplementing other sugars. Our results demonstrate that when more pullulan was synthesized, less UDP-glucose was left in the cells of A. pullulans Y68. However, it was observed that more pullulan was synthesized, the cells had higher activities of α-phosphoglucose mutase, UDPG-pyrophosphorylase and glycosyltransferase. Therefore, high pullulan yield is related to high activities of α-phosphoglucose mutase, UDPG-pyrophosphorylase and glucosyltransferase in A. pullulans Y68 grown on different sugars. A pathway of pullulan biosynthesis in A. pullulan Y68 was proposed based on the results of this study and those from other researchers. This study will be helpful to metabolism-engineer the yeast strain to further enhance pullulan yield. 相似文献
3.
Guoqiang Chen Jiming Wang Yulong Su Youshuang Zhu Ge Zhang Hongwei Zhao 《Preparative biochemistry & biotechnology》2017,47(10):963-969
Pullulan with different molecular-weight could be applied in various fields. A UV-induced mutagenesis Aureobasidium pullulans UVMU6-1 was obtained from the strain A. pullulans CGMCC3.933 for the production of low-molecular-weight pullulan. First, the obtained polysaccharide from A. pullulans UVMU6-1 was purified and identified to be pullulan with thin-layer chromatography, Fourier transform infrared, and nuclear magnetic resonance. Then, culture medium and conditions for this strain were optimized by flask fermentation. Based on the optimized medium and culture conditions (pH 4, addition of 4?g/L Tween 80 for 96?hr of cultivation), continuously fermentation was performed. The highest pullulan production and dry biomass was 109 and 125?g/L after fermentation for 114?hr, respectively. The average productivity was about 1?g/L/hr, which was intensively higher than the previous reported. This study would lay foundations for the industrial production of pullulan. 相似文献
4.
Bing-xue Li Ning Zhang Qing Peng Tie Yin Fei-fei Guan Gui-li Wang Ying Li 《Applied microbiology and biotechnology》2009,84(2):293-300
A black yeast strain “NG” was isolated from strawberry fruit and identified as Aureobasidium pullulans. Strain NG displayed yeast-like cell (YL), swollen cell (SC), septate swollen cell (SSC), meristematic structure (MS), and
chlamydospore (CH) morphologies. pH was the key factor regulating cell morphogenesis of strain NG. Differentiation of YL controlled
by extracellular pH had no relationship with nutrition level. YL was maintained at pH >6.0, but was transformed into SC at
pH ∼4.5. SC, a stable cell type of A. pullulans, could bud, septate, or transform into MS or CH, in response to nutrition level and low pH. SC produced swollen cell blastospores
(SCB) at pH 2.1 with abundant nutrition, and could transform into MS at lower pH (1.5). SC was induced to form CH by low level
nutrition and pH <3, and this transition was suppressed by adjusting pH to ∼4.5. Crude polysaccharides without pigment (melanin)
were produced by SC of strain NG. Pullulan content of the polysaccharides was very high (98.37%). Fourier-transform infrared
spectroscopy confirmed that chemical structures of the polysaccharides and standard pullulan were identical. Swollen cells
produced 2.08 mg/ml non-pigmented polysaccharides at 96 h in YPD medium. Controlling pH of fermentation is an effective and
convenient method to harvest SC for melanin-free pullulan production. 相似文献
5.
Summary Byproducts of fuel ethanol production from wet-milled corn, were tested as substrates for growth and pullulan production byAureobasidium sp. strain NRRL Y-12,974. The strain grew well on corn fiber and corn condensed distiller's solubles (CCDS), and fermented CCDS to pullulan. CCDS compared favorably with starch as a substrate for pullulan production.The use of brand or trade names may be necessary to report factually on available data. The USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable. All programs and services of the USDA are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status, or handicap. 相似文献
6.
Purification and characterization of pullulanase from Aureobasidium pullulans. Pullulanase was purified by using gel—filtration column then on ion exchange using Q-sepharose column yielding a single
peak. Purification was further carried out on SP-sepharose column. Molecular weight of pullulanase from A. pullulans was found to be about 73 KDa on the SDS-PAGE 10%. Native-PAGE 10% showed the activity of pullulanase, using polyacrylamide
gel containing pullulan. Hydrolysis products from pullulanase activity with soluble starch, glycogen and pullulan on thin
layer chromatography appeared as one band which is maltotriose, while α-amylase with soluble starch and glycogen showed two
bands which are maltose and maltotriose but α-amylase gave negative result with pullulan on TLC chromatography only. Pullulanase
could degrade α-1,6 glycosidic linkage of the previous substrates, while amylase could degrade α-1,4 glycosidic linkage of
glycogen, soluble starch and pullulan. MALDI-Ms was employed to deduce protein sequence of pullulanase. 相似文献
7.
R. Gaur R. Singh S. Tiwari S.K. Yadav N.S. Daramwal 《Journal of applied microbiology》2010,109(3):1035-1043
Aims: To isolate the novel nonmelanin pullulan‐producing fungi from soil and to optimize the physico‐chemical and nutritional parameters for pullulan production. Methods and Results: A selective enrichment method was followed for the isolation, along with development of a suitable medium for pullulan production, using shake flask experiments. Pullulan content was confirmed using pure pullulan and pullulanase hydrolysate. Eurotium chevalieri was able to produce maximum pullulan (38 ± 1·0 g l?1) at 35°C, pH 5·5, 2·5% sucrose, 0·3% ammonium sulfate and 0·2% yeast extract in a shake flash culture medium with an agitation rate of 30 rev min?1 for 65 h. Conclusions: The novel pullulan‐producing fungus was identified as E. chevalieri (MTCC no. 9614), which was able to produce nonmelanin pullulan at from poorer carbon and nitrogen sources than Aureobasidium pullulans and may therefore be useful for the commercial production of pullulan. Significance and Impact of the Study: Eurotium chevalieri could produce pullulan in similar amounts to A. pullulans. Therefore, in future, this fungus could also be used for commercial pullulan production, because it is neither polymorphic nor melanin producing, hence its handling during pullulan fermentation will be easier and more economical. 相似文献
8.
A strain Aureobasidium pullulans AP329, was used for the production of pullulan by employing hydrolysed sweet potato as cultivation media. Hydrolysis with α-amylase alone resulted in the lowest yields of pullulan. In contrast continuous hydrolysis with pullulanase and the β-amylase in sweet potato itself gave higher yields, but prolonged hydrolysis with amyloglucosidase decreased the yield. The maximum pullulan yield (29.43 g/l) was achieved at the dextrose equivalent value of 45 and pH of 5.5 for 96 h. As a substitute of sucrose, hydrolysed sweet potato was found to be hopeful and the yield of pullulan was higher than that of glucose and sucrose. The molecular weight of pullulan obtained from hydrolysed sweet potato media was much higher than that of sucrose and glucose media. Results of this work indicated that sweet potato was a promising substrate for the economical production of pullulan. 相似文献
9.
Isolation of New Aureobasidium Strains That Produce High-Molecular-Weight Pullulan with Reduced Pigmentation 总被引:4,自引:0,他引:4
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New isolates of Aureobasidium pullulans were obtained from plant leaf surfaces gathered in San Diego County. The new fungal isolates were identified as A. pullulans on the basis of the appearance of polymorphic colonies formed on agar plates, the electrophoretic profiles of repeated genomic DNA sequences, and the production of pullulan in shake flask cultures. The isolates showed different degrees of pigmentation. One of the natural isolates was nonpigmented under mock production conditions in liquid culture, but was still able to synthesize a reduced amount of pigment on agar plates at late times. A mutagenic treatment with ethidium bromide produced derivatives of normally pigmented natural isolates that exhibited an increased tendency toward yeastlike growth and reduced pigmentation. Additionally, some of the new isolates and mutant derivatives accumulated pullulan of relatively high molecular weight in the culture broths. 相似文献
10.
Leuconostoc mesenteroides strain NRRL B-1355 produces the soluble exopolysaccharides alternan and dextran in planktonic cultures. Mutants of this strain
are available that are deficient in the production of alternan, dextran, or both. Our recent work demonstrated that biofilms
from mutant strains contained insoluble polysaccharides. We now find that the insoluble polysaccharides are composed of d-glucose polymers with contiguous sequences of α(1→3) and α(1→6) linkages. In addition, planktonic cultures of the wild type
also produce this insoluble mixture in association with the cell mass. This material is similar to the insoluble glucan matrix
known as mutan formed by cariogenic strains of streptococci. The production of insoluble mutan-like glucans may be more widespread
among Leuconostoc spp. than previously recognized.
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献
11.
Ji-Hyun Lee Jeong-Hwa Kim Il-Hui Zhu Xiao-Bei Zhan Jin-Woo Lee Dong-Hoon Shin Sung-Koo Kim 《Biotechnology letters》2001,23(10):817-820
Aureobasidium pullulans had a maximum yield coefficient of pullulan (Y
p/s=0.24) with an initial pH of the culture broth of 6.5 in a shake-flask culture. In a batch culture, the maximum pullulan yield coefficient of 0.30 was obtained at the aeration rate of 0.5 vvm. A yeast-like form and mycelial form of cells were found at the culture broth with pH controlled at 4.5 with a maximum yield coefficient of pullulan of 0.27. However, a high portion (35%) of high molecular weight pullulan (M
w>2 000 000) was produced at pH 6.5 with a yeast-like morphology of the cells. 相似文献
12.
Poly(β-L-malic acid) production by diverse phylogenetic clades of Aureobasidium pullulans 总被引:1,自引:0,他引:1
Manitchotpisit P Skory CD Peterson SW Price NP Vermillion KE Leathers TD 《Journal of industrial microbiology & biotechnology》2012,39(1):125-132
Poly(β-L-malic acid) (PMA) is a natural biopolyester that has pharmaceutical applications and other potential uses. In this study,
we examined PMA production by 56 strains of the fungus Aureobasidium pullulans representing genetically diverse phylogenetic clades. Thirty-six strains were isolated from various locations in Iceland
and Thailand. All strains from Iceland belonged to a newly recognized clade 13, while strains from Thailand were distributed
among 8 other clades, including a novel clade 14. Thirty of these isolates, along with 26 previously described strains, were
examined for PMA production in medium containing 5% glucose. Most strains produced at least 4 g PMA/L, and several strains
in clades 9, 11, and 13 made 9–11 g PMA/L. Strains also produced both pullulan and heavy oil, but PMA isolated by differential
precipitation in ethanol exhibited up to 72% purity with no more than 12% contamination by pullulan. The molecular weight
of PMA from A. pullulans ranged from 5.1 to 7.9 kDa. Results indicate that certain genetic groups of A. pullulans are promising for the production of PMA. 相似文献
13.
Leuconostoc mesenteroides strain NRRL B-1355 produces the soluble exopolysaccharides alternan and dextran in planktonic cultures. Mutants of this strain
are available that are deficient in the production of alternan, dextran, or both. Another mutant of NRRL B-1355, strain R1510,
produces an insoluble glucan in place of alternan and dextran. To test the effect of exopolysaccharide production on biofilm
formation, these strains were cultured in a biofilm reactor. All strains grew well as biofilms, with comparable cell densities,
including strain NRRL B-21414, which produces neither alternan nor dextran in planktonic cultures. However, the exopolysaccharide
phenotype clearly affected the appearance of the biofilms and the sloughed-off biofilm material produced by these biofilms.
For all strains, soluble glucansucrases and soluble polysaccharides produced by biofilm cultures appeared to be similar to
those produced by planktonic cultures. Biofilms from all strains also contained insoluble polysaccharides. Strain R1510 biofilms
contained an insoluble polysaccharide similar to that produced by planktonic cultures. For most other strains, the insoluble
biofilm polysaccharides resembled a mixture of alternan and dextran.
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献
14.
Byung-Kwan Kang Hee-Jong Yang Nack-Shick Choi Keug-Hyun Ahn Chan-Sun Park Byung-Dae Yoon Min-Soo Kim 《Biotechnology letters》2010,32(1):137-142
By disruption of the pullulan synthetase gene (pul) of Aureobasidium pullulans IMS822 KCTC11179BP, we constructed a mutant strain, A. pullulans NP1221, which produced a pure β-glucan exopolysaccharide. The mutant NP1221 was white, whereas the wild-type strain produced
a black dye. When we compared fermentation kinetics between wide-type and mutant strains, the mutant NP1221 did not produce
pullulan. Substrate uptake rate and β-glucan production were similar in both strains. However, the biomass yield of mutant
NP1221 was 2.3-fold (9.2 g l−1) greater than that of wild-type. 相似文献
15.
Effects of different pH and carbon sources on pullulan production, UDP-glucose level and pullulan-related synthases activity inAureobasidium pullulans Y68 were examined. It was found that more pullulan was produced when the yeast strain was grown in the medium with initial pH 7.0 than when it was grown in the same medium with constant pH 6.0. The results also show that higher pullulan yield was obtained when the cells were grown in the medium containing glucose than when they were cultivated in the medium supplementing other carbon sources. Our results demonstrate that the more pullulan was synthesized, the less UDP-glucose was left in the cells ofA. pullulans Y68. However, it was observed that more pullulan was synthesized; the cells had higher pullulan-related synthase activity. Therefore, high pullulan yield was related to low UDP-glucose level and high pullulan-related synthases activity inAureobasidium pullulans Y68. 相似文献
16.
Summary Pullulan is a polysaccharide produced by Aureobasidium pullulans. In this study, the effect of pH on the molecular weight of pullulan was investigated. High concentration of pullulan was obtained when initial pH was 6. Pullulan having molecular weight of 500,000–600,000 was produced at initial pH of 3.0, while pullulan with molecular weight of 200,000–300,000 was produced at pH above 4.5. To obtain high molecular weight pullulan with high concentration, pH was initially controlled at pH 6, followed by pH shift from pH 6 to pH 3. Transition of pH at 2 days of fermentation was observed to be optimum. Higher molecular weight pullulan was also obtained when sucrose concentration was 50 g/l compared to the result obtained at initial sucrose concentration of 20 g/l. Sucrose concentration and pH of the fermentation broth seem to be important parameters in obtaining high molecular weight of pullulan. 相似文献
17.
Biofilm is a natural form of cell immobilization in which microorganisms attach onto solid support. In this study, a pigment-reduced
pullulan-producing strain, Aureobasidium pullulans (ATCC 201253), was used for continuous pullulan fermentation in a plastic composite support (PCS) biofilm reactor. Optimal
conditions for the continuous pullulan production were determined by evaluating the effects of the feeding medium with various
concentrations of ammonium sulfate and sucrose and dilution rate. Pullulan concentration and production rate reached maximum
(8.3 g/l and 1.33 g/l/h) when 15 g/l of sucrose, 0.9 g/l of ammonium sulfate, and 0.4 g/l of yeast extract were applied in
the medium, and the dilution rate was at 0.16 h−1. The purity of produced pullulan was 93.0%. The ratio of hyphal cells of A. pullulans increased when it was grown on the PCS shaft. Overall, the increased pullulan productivity can be achieved through biomass
retention by using PCS biofilm reactor. 相似文献
18.
Pullulan: biosynthesis,production, and applications 总被引:1,自引:0,他引:1
Pullulan is a linear glucosic polysaccharide produced by the polymorphic fungus Aureobasidium pullulans, which has long been applied for various applications from food additives to environmental remediation agents. This review
article presents an overview of pullulan’s chemistry, biosynthesis, applications, state-of-the-art advances in the enhancement
of pullulan production through the investigations of enzyme regulations, molecular properties, cultivation parameters, and
bioreactor design. The enzyme regulations are intended to illustrate the influences of metabolic pathway on pullulan production
and its structural composition. Molecular properties, such as molecular weight distribution and pure pullulan content, of
pullulan are crucial for pullulan applications and vary with different fermentation parameters. Studies on the effects of
environmental parameters and new bioreactor design for enhancing pullulan production are getting attention. Finally, the potential
applications of pullulan through chemical modification as a novel biologically active derivative are also discussed. 相似文献
19.
Wa Gao Yi-Joon Kim Chung-Han Chung Jianhong Li Jin-Woo Lee 《Biotechnology and Bioprocess Engineering》2010,15(5):837-845
Based on intuitive analyses and statistical calculations using data from orthogonal array experiments, the optimal concentrations
of K2HPO4, NaCl, MgSO4·7H2O, and (NH4)2SO4 in cell growth medium of Aureobasidium pullulans HP-2001 were measured as 7.5, 1.0, 0.1, and 2.4 g/L, respectively, whereas those for the production of pullulan were 2.5,
0.25, 0.8, and 0.3 g/L, respectively. The most important factor for cell growth and production of pullulan by A. pullulans HP-2001 was identified as K2HPO4. Optimal concentrations of glucose and yeast extract, along with the initial pH of the cell growth medium of A. pullulans HP-2001 containing optimized salt concentrations, were found to be 100.0, 10.0, and 6.0 g/L, respectively, whereas those
for the production of pullulan were 100.0, 2.5, and 6.0 g/L, respectively. Conversion rates of pullulan from 10.0, 25.0, 50.0,
75.0, and 100.0 g/L of glucose in the presence of optimized salt concentrations were 26.0, 25.2, 22.4, 17.9, and 14.1%, respectively,
whereas those in the presence of previously reported salt concentrations were 26.6, 25.2, 19.9, 14.3, and 11.7%, respectively.
Optimal salt concentrations for the production of pullulan by A. pullulans HP-2001 varied according to the concentrations of the carbon and nitrogen sources, especially at higher concentrations. 相似文献
20.
Influence of impeller speed upon the pullulan fermentation 总被引:4,自引:0,他引:4
Summary The effect of impeller speed on pullulan production and the morphology ofAureobasidium
pullulans in batch culture was studied. Pullulan production and the percentage of yeast cells in the culture rose with impeller speed, as did molecular weight of the polysaccharide. 相似文献