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1.
From 42 different hot springs in six provinces belonging to distinct geographical regions of Turkey, 451 thermophilic bacilli
were isolated and 67 isolates with a high amylase activity were selected to determine the α-glucosidase production capacities
by using pNPG as a substrate. α-Glucosidase production capacities of the isolates varied within the range from 77.18 to 0.001 U/g. Eleven
of our thermophilic bacilli produced α-glucosidase at significant levels comparable with that of the reference strains tested;
thus, five strains, F84b (77.18 U/g), A333 (48.64 U/g), F84a (36.64 U/g), E134 (32.09 U/g), and A343 (10.79 U/g), were selected
for further experiments. 16S rDNA sequence analysis revealed that these selected isolates all belonged to thermophilic bacilli
16S rDNA genetic group 5, four of them representing the genus Geobacillus, while strain A343 had an uncultured bacterium as the closest relative. Changes in α-glucosidase levels in the intracellular
and extracellular fractions were determined during 48-h cultivation of A333, A343, F84a, F84b, E134, and the reference strain
G. stearothermophilus ATCC 12980. According to α-glucosidase production type and enzyme levels in intracellular and extracellular fractions, Geobacillus spp. A333, F84a, and F84b were defined as extracellular enzyme producers, whereas the thermophilic bacterium A343 was found
to be an intracellular α-glucosidase producer, similar to ATCC 12980 strain. Geobacillus sp. E134 differed in α-glucosidase production type from all tested isolates and the reference strain; it was described as
a membrane-associated cell-bound enzyme producer. In this study, apart from screening a great number of new thermophilic bacilli
from the hot springs of Turkey, which have not yet been thoroughly studied, five new thermostable α-1,4-glucosidase-producing
bacilli that have biotechnological potential with α-glucosidases located at different cell positions were obtained.
The text was submitted by the authors in English. 相似文献
2.
In this study, a new α-glucosidase gene from Thermoanaerobacter ethanolicus JW200 was cloned and expressed in Escherichia coli by a novel heat-shock vector pHsh. The recombinant α-glucosidase exhibited its maximum hydrolytic activity at 70°C and pH 5.0∼5.5. With p-nitrophenyl-α-D-glucoside as a substrate and under the optimal condition (70°C, pH 5.5), K
m and V
max of the enzyme was 1.72 mM and 39 U/mg, respectively. The purified α-glucosidase could hydrolyze oligosaccharides with both α-1,4 and α-1,6 linkages. The enzyme also had strong transglycosylation activity when maltose was used as sugar donor. The transglucosylation
products towards maltose are isomaltose, maltotriose, panose, isomaltotriose and tetrasaccharides. The enzyme could convert
400 g/L maltose to oligosaccharides with a conversion rate of 52%, and 83% of the oligosaccharides formed were prebiotic isomaltooligosaccharides
(containing isomaltose, panose and isomaltotriose). 相似文献
3.
Arzu Coleri Cihan Birgul Ozcan Cumhur Cokmus 《World journal of microbiology & biotechnology》2009,25(12):2205-2217
We have partially purified and characterized two new thermostable exo-α-1,4-glucosidases (E.C.3.2.1.20) isolated from Geobacillus sp. A333 and thermophilic bacterium A343 strains. A333 α-glucosidase showed optimum activity at 60°C, pH 6.8 and had a value
of 1.38 K
m for the pNPG substrate, whereas these results were found to be 65°C, 7.0 and 0.85, respectively for A343 enzyme. Specificity for 20
different substrates and thin layer chromatography studies demonstrated that the A333 enzyme had high transglycosylation activity,
and A343 had wide substrate specificity. The substrate specificity of A333 α-glucosidase was determined as maltose, dextrin,
turanose, maltotriose, maltopentaose, meltotetraose, maltohexaose and phenyl-α-d-glycopyranoside. On the other hand, the A343 α-glucosidase mostly hydrolyzed dextrin, turanose, maltose, phenyl-α-d-glucopyranoside, maltotriose, maltotetraose, maltopentaose, isomaltose, saccharose and kojibiose by acting α-1,2, α-1,3,
α-1,4 and α-1,6 bonds of these substrates. The relative activites of A333 and A343 enzymes were determined to be 83 and 92%
when incubated at 60°C for 5 h whereas, the pH of 50% inactivation at 60°C for 15 h were determined to be pH 4.5/10.0 and
pH 5.0/10.0, respectively. In addition, the results not only showed that both of the α-glucosidases were stable in a wide
range of pH and temperatures, but were also found to be resistant to most of the denaturing agents, inhibitors and metal ions
tested. With this study, thermostable exo-α-1,4-glucosidases produced by two new thermophilic strains were characterized as
having biotechnological potential in transglycosylation reactions and starch hydrolysis processes. 相似文献
4.
In this study, using the API-ZYM system, we have reported the enzyme profile of 42 soil strains and 2 clinical strains of
Nocardia asteroides isolated locally. Of the 19 enzymes tested, only 7 were demonstrable in over 90% of the soil isolates.
These included alkaline phosphatase, esterase lipase, leucine arylamidase, acid phosphatase, phosphohydrolase, α-glucosidase
and β-glucosidase. In addition, β-galactosidase activity was demonstrated in all the strains by the O-nitrophenyl-β-D-galactopyranoside
(ONPG) test. The enzymes which were not demonstrable in >95% of the strains included valine arylamidase, cystine arylamidase,
trypsin, chymotrypsin, α-galactosidase, β-glucoronidase, N-acetyl-β-glucosaminidase, α-mannosidase and α-fucosidase. With
the exception of valine arylamidase, which was lacking in all but one isolate, the enzyme profiles of the soil isolates were
comparable with the clinical isolates of N. asteroides reported in previous studies. The reasons for this difference in the
two sets of isolates is not clear. The study reinforces the view that specific differences in the enzymatic profiles of Nocardia
species could be used for their rapid identification. However, more extensive studies are needed to establish the reproducibility
of this method. To the best of our knowledge, this is the first study of the enzymatic profile of soil isolates of N. asteroides
originating from a single geographic region.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
5.
Christina Bohlin Eigil Praestgaard Martin J. Baumann Kim Borch Jens Praestgaard Rune N. Monrad Peter Westh 《Applied microbiology and biotechnology》2013,97(1):159-169
β-glucosidases (BGs) from Aspergillus fumigatus, Aspergillus niger, Aspergillus oryzae, Magnaporthe grisea, Neurospora crassa, and Penicillium brasilianum were purified to homogeneity, and investigated for their (simultaneous) hydrolytic and transglycosylation activity in samples with high concentrations of either cellobiose or glucose. The rate of the hydrolytic process (which converts one cellobiose to two glucose molecules) shows a maximum around 10–15 mM cellobiose and decreases with further increase in the concentration of substrate. At the highest investigated concentration (100 mM cellobiose), the hydrolytic activity for the different enzymes ranged from 10% to 55% of the maximum value. This decline in hydrolysis was essentially compensated by increased transglycosylation (which converts two cellobiose to one glucose and one trisaccharide). Hence, it was concluded that the hydrolytic slowdown at high substrate concentrations solely relies on an increased flow through the transglycosylation pathway and not an inhibition that delays the catalytic cycle. Transglycosylation was also detected at high product (glucose) concentrations, but in this case, it was not a major cause for the slowdown in hydrolysis. The experimental data was modeled to obtain kinetic parameters for both hydrolysis and transglycosylation. These parameters were subsequently used in calculations that quantified the negative effects on BG activity of respectively transglycosylation and product inhibition. The kinetic parameters and the mathematical method presented here allow estimation of these effects, and we suggest that this may be useful for the evaluation of BGs for industrial use. 相似文献
6.
Baba Yutaro Sumitani Jun-ichi Tanaka Kiyotaka Tani Shuji Kawaguchi Takashi 《Applied microbiology and biotechnology》2016,100(24):10495-10507
Applied Microbiology and Biotechnology - Aspergillus aculeatus β-glucosidase 1 (AaBGL1) is one of the best cellobiose hydrolytic enzymes without transglycosylation products, among... 相似文献
7.
Family 18 chitinases hydrolyze chitin through a substrate-assisted catalytic mechanism and are to a variable extent able to
catalyze transglycosylation reactions. Previously Aspergillus fumigatus AfChiB1 was found to be able to catalyze transglycosylation reactions. Structural analysis reveals that AfChiB1 consists
of an eight-stranded β/α-barrel. Like other members of the family 18 hydrolases, AfChiB1 has conserved substrate binding site
and catalytic acid, while a suitable nucleophile is missing. In this study, Trp137, Asp246, and Met243, which are close to
the glycosidic cleavage site, were mutated to glutamate individually. As a result, the W137E remained its hydrolytic activity
and was completely devoid of transglycosyl activity, while the D246E reduced its chitinolytic activity and increased its transglycosyl
activity. And the M243E showed a remarkable reduction of chitinolytic activity and complete loss of transglycosyl activity.
These results suggested that the transglycosyl reaction catalyzed by the AfChiB1 is due to lacking of nucleophile.
Enzymes: exochitinases (EC 3.2.1.14) 相似文献
8.
Quantification of glycosidase activities in selected yeasts and lactic acid bacteria 总被引:4,自引:0,他引:4
H McMahon B W Zoecklein K Fugelsang Y Jasinski 《Journal of industrial microbiology & biotechnology》1999,23(3):198-203
Using a model system, the activities of α-L-arabinofuranosidase, β-glucosidase, and α-L-rhamonopyranosidase were determined
in 32 strains of yeasts belonging to the genera Aureobasidium, Candida, Cryptococcus, Hanseniaspora, Hansenula, Kloeckera, Metschnikowia, Pichia, Saccharomyces, Torulaspora and Brettanomyces (10 strains); and seven strains of the bacterium Leuconostoc oenos. Only one Saccharomyces strain exhibited β-glucosidase activity, but several non-Saccharomyces yeast species showed activity of this enzyme. Aureobasidium pullulans hydrolyzed α-L-arabinofuranoside, β-glucoside, and α-L-rhamnopyranoside. Eight Brettanomyces strains had β-glucosidase activity. Location of enzyme activity was determined for those species with enzymatic activity.
The majority of β-glucosidase activity was located in the whole cell fraction, with smaller amounts found in permeabilized
cells and released into the growth medium. Aureobasidium pullulans hydrolyzed glycosides found in grapes.
Received 02 February 1999/ Accepted in revised form 26 June 1999 相似文献
9.
I. D. Georgieva 《Biologia Plantarum》1991,33(5):337-344
Changes in the activity and localization of nonspecific esterase, acid phosphatase, α-galactosidase and β-glucosidase inL. regale pistils after pollination with μ-irradiated pollen were studied. In the embryo sac and in the ovule reduction of AS-esterase
and α-galactosidase and, at the same time, enhancement of α-esterase, acid phosphatase and β-glucosidase activities were observed.
The changes in hydrolytic enzyme activities are discussed as manifestations of lethal factors resulting from structural disturbances
of DNA in the generative nucleus and in sperms caused by irradiation. 相似文献
10.
α-Glucosidase from a strain of deep-sea Geobacillus: a potential enzyme for the biosynthesis of complex carbohydrates 总被引:1,自引:0,他引:1
Hung VS Hatada Y Goda S Lu J Hidaka Y Li Z Akita M Ohta Y Watanabe K Matsui H Ito S Horikoshi K 《Applied microbiology and biotechnology》2005,68(6):757-765
An α-glucosidase from Geobacillus sp. strain HTA-462, one of the deepest sea bacteria isolated from the sediment of the Mariana Trench, was purified to homogeneity
and estimated to be a 65-kDa protein by SDS-PAGE. At low ion strength, the enzyme exists in the homodimeric form (130 kDa).
It is a thermo- and alkaline-stable enzyme with a half-life of 13.4 h and a maximum hydrolytic activity at 60°C and pH 9.0
in 15 mM glycine–NaOH buffer. The enzyme exclusively hydrolyzed α-1,4-glycosidic linkages of oligosaccharides in an exo-type
manner. The enzyme had an overwhelming transglycosylation activity and glycosylated various non-sugar molecules when maltose
was used as a sugar donor. It converted maltose to isomaltose. The gene encoding the enzyme was cloned and sequenced. The
recombinant enzyme could be extracellularly overproduced by Bacillus subtilis harboring its gene and preserved the primary properties of the native enzyme. Site-directed mutagenesis experiments showed
that Asp98 is essential for the enzyme activity in addition to Asp199, Asp326, and Glu256. 相似文献
11.
Kaya M Ito J Kotaka A Matsumura K Bando H Sahara H Ogino C Shibasaki S Kuroda K Ueda M Kondo A Hata Y 《Applied microbiology and biotechnology》2008,79(1):51-60
For efficient production of isoflavone aglycones from soybean isoflavones, we isolated three novel types of β-glucosidase
(BGL1, BGL3, and BGL5) from the filamentous fungi Aspergillus oryzae. Three enzymes were independently displayed on the cell surface of a yeast Saccharomyces cerevisiae as a fusion protein with α-agglutinin. Three β-glucosidase-displaying yeast strains hydrolyzed isoflavone glycosides efficiently
but exhibited different substrate specificities. Among these β-glucosidases, BGL1 exhibited the highest activity and also
broad substrate specificity to isoflavone glycosides. Although glucose released from isoflavone glycosides are generally known
to inhibit β-glucosidase, the residual ratio of isoflavone glycosides in the reaction mixture with BGL1-displaying yeast strain
(Sc-BGL1) reached approximately 6.2%, and the glucose concentration in the reaction mixture was maintained at lower level.
This result indicated that Sc-BGL1 assimilated the glucose before they inhibited the hydrolysis reaction, and efficient production
of isoflavone aglycones was achieved by engineered yeast cells displaying β-glucosidase. 相似文献
12.
Temporal changes in α-and β-glucosidase activities, dissolved organic matter content, and bacterial biomass were studied in
the superficial sediment layer of a eutrophic lake during the period of anoxia. The mean α-and β-glucosidase activities were
30.7±11.0 and 15.1±6.2 nmol h−1 g−1 of dry sediment, respectively. The specifc β-glucosidase activity seemed to be stimulated by carbohydrates (r=0.80, P<0.05), whereas the specifc α-glucosidase activity was negatively correlated with the dissolved protein concentration (r=−0.72, P<0.10). To test the effect of organic matter on hydrolytic activities under controlled conditions, changes in specific activities
were studied in relation to the concentrations of different types of organic matter: phytoplankton, polymers (proteins, cellobiose,
and starch) and monomers (glucose and amino acids). The specifc α-and β-glucosidase activities were strongly induced by their
natural substrates (starch and cellobiose, respectively) (P<0.05) and were not inhibited by glucose. Proteins inhibited these activities (P<0.05), whereas supplementation with amino acids had no effect on specifc glycolytic activities. 相似文献
13.
Tramice A Giordano A Andreotti G Mollo E Trincone A 《Marine biotechnology (New York, N.Y.)》2006,8(5):448-452
We recently succeeded in the identification and purification of an interesting marine exo-α-glucosidase (EC 3.2.1.20) from
the anaspidean mollusc Aplysia fasciata. The enzyme was characterized by good transglycosylation activity toward different acceptors using maltose as donor. High-yielding
enzymatic α-glycosylation of pyridoxine using this marine enzyme is reported here; the reaction has been optimized, reaching
80% molar yield of products (pyridoxine monoglucosides 24 g/l; pyridoxine isomaltoside 35 g/l). High selectivity toward the
5′ position is observed for both monoglucoside and disaccharide formation. This is the first report describing the enzymatic
production of pyridoxine isomaltoside. 相似文献
14.
A selection of different glycosidases was screened for the glycosylation of 1-propanethiol. The g -glucosidases from almond, Aspergillus niger and Caldocellum saccharolyticum were capable of 1-propanethioglucoside (1-PTG) formation. The almond g -glucosidase showed the highest activity in this reversed hydrolysis type of reaction using glucose as glucosyl donor. Besides 1-propanethiol, also thioglucosides of 2-propanethiol and furfuryl mercaptan were formed by the almond g -glucosidase. The substrate specificity of the almond g -glucosidase with respect to thioglucosylation is restricted to primary and secondary aliphatic thiols. Once the thioglucosides are formed, they are not hydrolyzed at a significant rate by almond g -glucosidase. As a consequence the synthesis of 1-PTG could be observed at very low aglycone concentrations (0.5% v/v based on the reaction solution) and high yields (68% based on 1-PT and 41% based on glucose) were obtained. An excess of aglycone, otherwise frequently applied in reversed hydrolysis glycosylation, is therefore not necessary in the glucosylation of 1-PT. 相似文献
15.
Six wild fungal strains, Trichoderma viride, T. harzianum, Gliocladium virens, Aspergillus terreus, A. niger and Tiarosporella phaseolina , isolated from decomposed jute stacks and diseased jute stem, were tested for their cellulolytic and hemicellulolytic activities and compared with T. reesei MCG 77. Filter paper cellulase production by all these wild strains were lower than those produced by T. reesei while some strains ( T. viride, T. harzianum and G. virens ) possessed carboxymethyl cellulase, β-glucosidase, xylanase and β-xylosidase activities comparable to T. reesei. A. terreus and A. niger produced 3·2 and 1·2 times respectively, greater β-glucosidase activity compared to T. reesei when grown on microcrystalline cellulose. 相似文献
16.
Naoki Kato Sachie Suyama Masao Shirokane Masashi Kato Tetsuo Kobayashi Norihiro Tsukagoshi 《Applied microbiology》2002,68(3):1250-1256
Aspergillus nidulans possessed an α-glucosidase with strong transglycosylation activity. The enzyme, designated α-glucosidase B (AgdB), was purified and characterized. AgdB was a heterodimeric protein comprising 74- and 55-kDa subunits and catalyzed hydrolysis of maltose along with formation of isomaltose and panose. Approximately 50% of maltose was converted to isomaltose, panose, and other minor transglycosylation products by AgdB, even at low maltose concentrations. The agdB gene was cloned and sequenced. The gene comprised 3,055 bp, interrupted by three short introns, and encoded a polypeptide of 955 amino acids. The deduced amino acid sequence contained the chemically determined N-terminal and internal amino acid sequences of the 74- and 55-kDa subunits. This implies that AgdB is synthesized as a single polypeptide precursor. AgdB showed low but overall sequence homology to α-glucosidases of glycosyl hydrolase family 31. However, AgdB was phylogenetically distinct from any other α-glucosidases. We propose here that AgdB is a novel α-glucosidase with unusually strong transglycosylation activity. 相似文献
17.
Thierry Dintinger Delphine Dutheil-Bouëdec Michel Bouchonneau Charles Tellier 《Biotechnology letters》1994,16(7):689-692
Summary The synthetic potential ofAlmond β-glucosidase andJack bean α-mannosidase in the presence of high amounts of β-mercaptoethanol as glycosyl acceptor for the synthesis of β-mercaptoethyl-glycosides
was studied. The regioselectivity, O-glycosylation and/or S-glycosylation, and the stereoselectivity were analyzed with the
reverse hydrolysis and the transglycosylation methods. With both enzymes, high yields of condensation are obtained without
the use of chemical protective groups. 相似文献
18.
Konishi MA Fukuoka T Shimane Y Mori K Nagano Y Ohta Y Kitamoto D Hatada Y 《Biotechnology letters》2011,33(1):139-145
Purpose of work
To explore a novel glycolipid, we performed biochemical reactions using a recombinant α-glucosidase from Geobacillus sp. which shows excellent transglycosylation reaction to hydroxyl groups in a variety of compounds. 相似文献19.
To evaluate the potential of the production of the ectomycorrhizal fungus Tricholoma matsutake to produce carbohydrases, (1) the distribution of carbohydrase activities among the different strains (18 strains) was investigated
and (2) the abilities of T. matsutake and saprophytic fungi to produce β-glucosidase were compared. The results showed that the carbohydrase productions patterns
of T. matsutake still resemble one another. Moreover, this fungus exhibited markedly higher β-glucosidase than did the saprophytic mushrooms.
Tricholoma matsutake showed weak production of α-amylase and α-glucosidase in a static cultur filtrate. On the other hand, glucoamylase activity
was not observed. Surprisingly, we discovered that β-glucosidase demonstrated strong activity. This finding suggests that
this fungus has saprotrophic abilities. The carbohydrase production systems in T. matsutake were characterized from our experimental results. Also, we point out some weak points in the carbohydrase production systems
of T. matsutake. 相似文献
20.
苍术挥发油的提取及其抑菌活性研究 总被引:9,自引:0,他引:9
采用水蒸气蒸馏法、微波萃取法和索氏提取法3种方法提取苍术挥发油。平板法涂布研究了3种苍术挥发油对3种细菌和4种真菌的最低抑菌浓度(MIC),滤纸片固相扩散法研究了苍术挥发油对供试菌体的抑菌活性。结果表明,3种方法提取的苍术挥发油对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、酵母、青霉、黑曲霉、黄曲霉的MIC分别为:水蒸气蒸馏法为5.00、150.00、150.00、5.00、5.00、5.00、20.00 mL/L;索氏提取法的为10.00、150.00、200.00、20.00、5.00、60.00、40.00 mL/L;微波萃取法的为10.00、150.00、150.00、20.00、20.00、20.00、20.00 mL/L。3种苍术挥发油对供试细菌和真菌都具有相当强的抑菌活性,且浓度越高效果越好。抑菌实验表明3种方法提取的苍术挥发油对金黄色葡萄球菌、酵母、青霉、黑曲霉、黄曲霉的抑菌圈直径都比对大肠杆菌、枯草芽孢杆菌的抑菌圈直径大。不同提取方法得到的苍术挥发油对同一种菌的最低抑制浓度和抑菌效果不相同,同一种方法提取的苍术挥发油对不同菌的最低抑制浓度和抑菌效果也不相同。 相似文献