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engineering of polyploid saccharomyces cerevisiae for secretion of large amounts of fungal glucoamylase.we engineered saccharomyces cerevisiae cells that produce large amounts of fungal glucoamylase (gai) from aspergillus awamori var. kawachi. to do this, we used the delta-sequence-mediated integration vector system and the heat-induced endomitotic diploidization method. delta-sequence-mediated integration is known to occur mainly in a particular chromosome, and the copy number of the integration is variable. in order to construct transformants carrying the gai gene on several chromosomes, haploid ...200212406766
glucoamylase from thermoanaerobacterium thermosaccharolyticum: sequence studies and analysis of the macromolecular architecture of the enzyme.a chromosomal dna fragment with a length of 2,025 bp, carrying the structural gene coding for glucoamylase in thermoanaerobacterium thermosaccharolyticum, was cloned and sequenced. it coded for 695 amino acids, representing a polypeptide with a predicted molecular mass of 77.5 kda. the deduced amino acid sequence exhibited high homologies with the glucoamylase sequence of another bacterial glucoamylase (clostridium sp. g0005) and with fungal glucoamylases. the catalytic domain (amino acids 271 t ...199812501412
molecular dynamics simulations of the unfolding mechanism of the catalytic domain from aspergillus awamori var. x100 glucoamylase.in this study, 200 ps molecular dynamics simulations were conducted to investigate the unfolding mechanism of the catalytic domain of glucoamylase from aspergillus awamori var. x100. the unfolding of this domain was suggested to follow a putative hierarchical manner, in which the heavily o-glycosylated belt region from residues t440 to a471 acted as the initiation site, followed by the alpha-helix secondary structure destruction, and then the collapse of the catalytic center pocket. the o-glycos ...200312529155
[characterization and transformation of anti-foa strain of aspergillus awamori].a suspension of freshly harvested spores of aspergillus awamori sg1 strain was exposed to uv light. the irradiated spores with survival rate of 10%-15% were plated directly on minimal medium (mm) agar plates containing 10 mmol/l uridine and 5-fluoro-orotic acid (foa 1 mg/ml). five stable anti-foa colonies with the reversed rate below 10(-9) were obtained. all anti-foa strains, can grow on uridine or uricil-containing minimal medium agar plate but not on orotic acid-containing mm plate, indicatin ...200012548939
protein engineering to improve the thermostability of glucoamylase from aspergillus awamori based on molecular dynamics simulations.twelve mutations were constructed to improve the thermostability of glucoamylase from aspergillus awamori based on the results of molecular dynamics simulations. the thermal unfolding of the catalytic domain followed a putative hierarchical behavior. in addition, the unfolding of the 13 alpha-helices obeyed the random ordered mechanism, in which the alpha-helices 8, 1 and 11 unfolded more rapidly than the others. the catalytic center was well protected by the (alpha/alpha)(6)-barrel at simulatio ...200312646689
a novel circulating loop bioreactor with cells immobilized in loofa ( luffa cylindrica) sponge for the bioconversion of raw cassava starch to ethanol.a circulating loop bioreactor (clb) with cells immobilized in loofa sponge was constructed for simultaneous aerobic and anaerobic processes. the clb consists of an aerated riser and a non-aerated downcomer column connected at the top and bottom by cylindrical pipes. ethanol production from raw cassava starch was investigated in the clb. aspergillus awamori iam 2389 and saccharomyces cerevisiae ir2 immobilized on loofa sponge were placed, respectively, in the aerated riser column and non-aerated ...200312664145
[effect of various sources of nitrogen and carbon on the biosynthesis of proteolytic enzymes in a culture of aspergillus awamori 21/96].effects of various conditions of nitrogen and carbon nutrition on the biosynthesis of proteolytic enzymes in a selected culture of aspergillus awamori 21/96 were studied. this strain was shown to produce proteolytic enzymes constitutively. in the presence of mineral sources of nitrogen, the synthesis of the enzymes under study was not induced by proteinaceous substrates. optimum conditions of the enzyme biosynthesis were achieved with casein as a source of nitrogen and starch or dulcitol as a so ...200312722657
expression of a synthetic copy of the bovine chymosin gene in aspergillus awamori from constitutive and ph-regulated promoters and secretion using two different pre-pro sequences.a copy of the bovine chymosin gene (chy) with a codon usage optimized for its expression in aspergillus awamori was constructed starting from synthetic oligonucleotides. to study the ability of this filamentous fungus to secrete bovine prochymosin, two plasmids were constructed in which the transcriptional, translational, and secretory control regions of the a. nidulans gpda gene and pepb genes were coupled to either preprochymosin or prochymosin genes. secretion of a protein enzymatically and i ...200312783481
efficient production of arthromyces ramosus peroxidase by aspergillus awamori.the heterologous production of arthromyces ramosus peroxidase (arp) was analysed in the filamentous fungus aspergillus awamori under control of the inducible endoxylanase promoter. secretion of active arp was achieved up to 800 mg l(-1) in shake flask cultures. western blot analysis showed that an rarp product of the correct molecular weight was produced. in contrast to several other studies about heterologous production of heme containing peroxidases, our results suggest that in a. awamori no h ...200312814876
l-lactic acid production from raw cassava starch in a circulating loop bioreactor with cells immobilized in loofa (luffa cylindrica).l-lactic acid was produced from raw cassava starch, by simultaneous enzyme production, starch saccharification and fermentation in a circulating loop bioreactor with aspergillus awamori and lactococcus lactis spp. lactis immobilized in loofa sponge. a. awamori was immobilized directly in cylindrical loofa sponge while the l. lactis was immobilized in a loofa sponge alginate gel cube. in the loofa sponge alginate gel cube, the sponge serves as skeletal support for the gel with the cells. the algi ...200312889820
evaluation of alternative reporter genes for the yeast two-hybrid system.the yeast two-hybrid system is a powerful tool for screening protein-protein interactions and has also been used for large-scale studies. we evaluated two protein-coding sequences as reporter genes for the yeast two-hybrid system, to determine if it was suitable as an alternative screening strategy. aspergillus awamori glucoamylase activity results in clear haloes around colonies producing this enzyme after growth on starch plates and staining with iodine vapors. however, transcription activatio ...200312917809
biochemical characterization of aspergillus awamori exoinulinase: substrate binding characteristics and regioselectivity of hydrolysis.1h-nmr analysis was applied to investigate the hydrolytic activity of aspergillus awamori inulinase. the obtained nmr signals and deduced metabolite pattern revealed that the enzyme cleaves off only fructose from inulin and does not possess transglycosylating activity. kinetics for the enzyme hydrolysis of inulooligosaccharides with different degree of polymerization (d.p.) were recorded. the enzyme hydrolyzed both beta2,1- as well as beta2,6-fructosyl linkages in fructooligosaccharides. from th ...200312922166
cloning and expression of fungal phytases in genetically modified strains of aspergillus awamori.in an effort to produce phytases cost-effectively, and to determine the efficiency of a novel expression system, the genes for aspergillus awamori ( phya) phytase and aspergillus fumigatus ( phya) phytase (a putative thermostable enzyme) were cloned and overexpressed in a. awamori. regulation of phytase expression was achieved by separately placing the genes under the transcriptional control of the glucoamylase a ( glaa) promoter of a. awamori. a gene fusion strategy was employed that involved t ...200314513384
predicted unfolding order of the 13 alpha-helices in the catalytic domain of glucoamylase from aspergillus awamori var. x100 by molecular dynamics simulations.the unfolding mechanism of the 13 alpha-helices in the catalytic domain of aspergillus awamori var. x100 glucoamylase was investigated by 200 ps molecular dynamics simulations in explicit water with temperature jump technique. rather than a simultaneous event, the unfolding of these 13 alpha-helices followed a random ordered mechanism as alpha8-->alpha1-->alpha11-->alpha7-->alpha10-->alpha3-->alpha12-->alpha13-->alpha4-->alpha5-->alpha9-->alpha6-->alpha2. no significant relationships were found ...200314524723
growth and pectinase production by aspergillus mexican strain protoplast regenerated under acidic stress.protoplasts from aspergillus sp. fp-180 and aspergillus awamori nrrl- 3112 were released and regenerated at extreme acidic conditions. the best conditions for protoplast release were 0.8 m kci, ph 5.8, and 3 h of digestion using mycelia from 12- to 16-h cultures from either aspergillus sp. fp-180 or a. awamori nrrl-3112. the addition of fresh mycelia to an ongoing digestion after 1 h increased protoplast 4.5-5 times. a regeneration efficiency of 90% was attained at ph 6.0, and it was possible to ...200314566066
genetically modified soybeans: false-positive detection in fermented natural soybean (tempe).tempe was prepared using mixtures of natural soybean and genetically modified roundup ready (rur) soybean fermented with natural rhizopus sp. the amount of rur soybean was quantified using an elisa plate test. the rur signal decreased during fermentation. in the control experiments on fermentation of non-rur soybean, the tempe gave a false-positive rur signal. the cross-reacting substance was generated only in non-rur soybean during fermentation by rhizopus sp., rhizopus oligosporus, r. oryzae, ...200314571970
influence of carbon, nitrogen and phosphorous sources on glucoamylase production by aspergillus awamori in solid state fermentation.it was the objective of the present study to increase the production of glucoamylase by aspergillus awamori through solid state fermentation, using wheat bran as the main carbon source and (nh4)2so4, urea, kh2po4, glucose, maltose and starch as additional nitrogen, phosphorus, and carbon sources. the production of glucoamylase is strongly influenced by n and c sources. a 100% increase was observed when the (nh4)2so4 was replaced by urea, with c/n = 4.8, using maltose as the additional carbon sou ...200314577636
improvement of foreign-protein production in aspergillus niger var. awamori by constitutive induction of the unfolded-protein response.unfolded-protein response (upr) denotes the upregulation of endoplasmic reticulum (er)-resident chaperone and foldase genes and numerous other genes involved in secretory functions during the accumulation of unfolded proteins into the er. overexpression of individual foldases and chaperones has been used in attempts to improve protein production in different production systems. we describe here a novel strategy to improve foreign-protein production. we show that the constitutive induction of the ...200314660339
characterization of secretory genes ypt1/ypta and nsf1/nsfa from two filamentous fungi: induction of secretory pathway genes of trichoderma reesei under secretion stress conditions.two genes involved in protein secretion, encoding the rab protein ypt1/ypta and the general fusion factor nsfi/nsfa, were characterized from two filamentous fungi, trichoderma reesei and aspergillus niger var. awamori. the isolated genes showed a high level of conservation with their saccharomyces cerevisiae and mammalian counterparts, and t. reesei ypt1 was shown to complement yeast ypt1p depletion. the transcriptional regulation of the t. reesei ypt1, nsf1, and sar1 genes, involved in protein ...200414711675
a one-step method to convert vectors into binary vectors suited for agrobacterium-mediated transformation.bacterial artificial chromosomes (bacs) are widely used for the construction of physical maps, positional-cloning and whole-genome sequencing strategies. unfortunately, their use for functional genomics is limited, as currently there is no efficient method to use bacs directly for complementation. we describe a novel strategy for one-step conversion of any bac into a binary bac (bibac). using agrobacterium tumefaciens, these bibacs can be efficiently transformed to virtually all organisms, inclu ...200414745506
restructuring upstream bioprocessing: technological and economical aspects for production of a generic microbial feedstock from wheat.restructuring and optimization of the conventional fermentation industry for fuel and chemical production is necessary to replace petrochemical production routes. guided by this concept, a novel biorefinery process has been developed as an alternative to conventional upstream processing routes, leading to the production of a generic fermentation feedstock from wheat. the robustness of aspergillus awamori as enzyme producer is exploited in a continuous fungal fermentation on whole wheat flour. vi ...200414760693
proliferation of lactobacillus plantarum in solid-state fermentation of oats.in an attempt to introduce probiotic functionalities to breakfast cereals and similar food products, the technique of solid-state fermentation (ssf) was applied to cultivate lactobacillus plantarum (ncimb 8826) on oat bran and spent oats after lipid extraction by supercritical co(2) extraction. when compared to the frequently favored submerged processes for bacterium incubation, ssf presents not only the potential of simple downstream processing but also a more natural growth environment for the ...200414763831
agrobacterium-mediated transformation of aspergillus awamori in the absence of full-length vird2, virc2, or vire2 leads to insertion of aberrant t-dna structures.reductions to 2, 5, and 42% of the wild-type transformation efficiency were found when agrobacterium mutants carrying transposon insertions in vird2, virc2, and vire2, respectively, were used to transform aspergillus awamori. the structures of the t-dnas integrated into the host genome by these mutants were analyzed by southern and sequence analyses. the t-dnas of transformants obtained with the vire2 mutant had left-border truncations, whereas those obtained with the vird2 mutant had truncated ...200415028687
the aspergillus nidulans amds gene as a marker for the identification of multicopy t-dna integration events in agrobacterium-mediated transformation of aspergillus awamori.the aspergillus nidulans amds selection marker was used for the identification of multicopy t-dna insertions in agrobacterium-mediated transformation of asp. awamori. the selection of transformants on agar plates containing acetamide as sole nitrogen source and hygromycin resulted in a six-fold decrease in the transformation frequency, compared with the transformation frequency obtained after hygromycin selection alone. however, it was found that 47% of the transformants obtained after hygromyci ...200415045526
role of bacterial virulence proteins in agrobacterium-mediated transformation of aspergillus awamori.the agrobacterium-mediated transformation of aspergillus awamori was optimized using defined co-cultivation conditions, which resulted in a reproducible and efficient transformation system. optimal co-cultivation conditions were used to study the role of agrobacterium tumefaciens virulence proteins in t-dna transfer. this study revealed that inactivation of either of the regulatory proteins (vira, virg), any of the transport pore proteins (virb), proteins involved in generation of the t-strand ( ...200415050546
thr/ser-rich domain of aspergillus glucoamylase is essential for secretion.the recombinant aspergillus awamori strain carrying the mutant glucoamylase-encoding gene in which the entire thr/ser-rich gp-i domain was deleted abolished secretion of mutant glucoamylase. the transcription of the bip-encoding bipa was low in the wild type (wt) strain, but elevated in the recombinant strain under the condition of glaa expression. the results indicate that the gp-i domain is vital for glucoamylase secretion.200415118335
calcium measurement in living filamentous fungi expressing codon-optimized aequorin.calcium signalling is little understood in filamentous fungi largely because easy and routine methods for calcium measurement in living hyphae have previously been unavailable. we have developed the recombinant aequorin method for this purpose. high levels of aequorin expression were obtained in neurospora crassa, aspergillus niger and aspergillus awamori by codon optimization of the aequorin gene. three external stimuli (mechanical perturbation, hypo-osmotic shock and high external calcium) wer ...200415165245
modulation of aspergillus awamori thaumatin secretion by modification of bipa gene expression.two different strains, aspergillus awamori tgdth-4 and a. awamori tgp-3 overexpressing a synthetic gene encoding the plant sweet protein thaumatin, showed an unfolded protein response. to facilitate protein secretion, the chaperone bipa gene was expressed in a. awamori under control of the strong constitutive promoter of the gpda gene. a good correlation was observed between the level of the bipa transcript in different strains and the amount of thaumatin secreted. thaumatin secretion was increa ...200415345393
survey of mycoflora and ochratoxin a in dried vine fruits from argentina markets.the aims of this work were to identify the mycoflora and to evaluate the natural occurrence of oa in dried vine fruits. likewise, the capacity to produce oa by aspergillus section nigri was studied.200415355533
expression and production of llama variable heavy-chain antibody fragments (v(hh)s) by aspergillus awamori.we report the expression and production of llama variable heavy-chain antibody fragments (v(hh)s) by aspergillus awamori. fragments encoding v(hh)s were cloned in a suitable aspergillus expression vector and transformants secreting v(hh) fragments were analysed for integrated gene copy-numbers, mrna levels and protein production. functional v(hh)s were detected in the culture medium, indicating the feasibility of producing this type of protein in a fungal expression system. secreted v(hh)s were ...200515378291
degradation of raw starch granules by alpha-amylase purified from culture of aspergillus awamori kt-11.raw-starch-digesting alpha-amylase (amyl iii) was purified to an electrophoretically pure state from the extract of a koji culture of aspergillus awamori kt-11 using wheat bran in the medium. the purified amyl iii digested not only soluble starch but also raw corn starch. the major products from the raw starch using amyl iii were maltotriose and maltose, although a small amount of glucose was produced. amyl iii acted on all raw starch granules that it has been tested on. however, it was consider ...200415469729
molecular cloning and determination of the nucleotide sequence of raw starch digesting alpha-amylase from aspergillus awamori kt-11.complementary dnas encoding alpha-amylases (amyl i, amyl iii) and glucoamylase (ga i) were cloned from aspergillus awamori kt-11 and their nucleotide sequences were determined. the sequence of amyl iii that was a raw starch digesting alpha-amylase was found to consist of a 1,902 bp open reading frame encoding 634 amino acids. the signal peptide of the enzyme was composed of 21 amino acids. on the other hand, the sequence of amyl i, which cannot act on raw starch, consisted of a 1,500 bp orf enco ...200415469730
crystal structure of exo-inulinase from aspergillus awamori: the enzyme fold and structural determinants of substrate recognition.exo-inulinases hydrolyze terminal, non-reducing 2,1-linked and 2,6-linked beta-d-fructofuranose residues in inulin, levan and sucrose releasing beta-d-fructose. we present the x-ray structure at 1.55a resolution of exo-inulinase from aspergillus awamori, a member of glycoside hydrolase family 32, solved by single isomorphous replacement with the anomalous scattering method using the heavy-atom sites derived from a quick cryo-soaking technique. the tertiary structure of this enzyme folds into two ...200415522299
agrobacterium-mediated transformation leads to improved gene replacement efficiency in aspergillus awamori.in this study, the efficiency of gene replacement in aspergillus awamori between agrobacterium-mediated transformation and cacl(2)/peg-mediated transformation was compared. for the genes, pyrg and gfaa, it was found that the homologous recombination frequencies obtained by agrobacterium-mediated transformation were 3- to 6-fold higher than the frequencies obtained with cacl(2)/peg protoplast transformation. for the pyrg gene, it was found that agrobacterium-mediated transformation allowed an eff ...200515588992
phenolic composition and radical scavenging activity of sweetpotato-derived shochu distillery by-products treated with koji.phenolic composition and radical scavenging activity in the shochu distillery by-products of sweetpotato (ipomoea batatas l.) treated with koji (aspergillus awamori mut.) and cellulase (cellulosin t2) were investigated to develop new uses. koji and cellulosin t2 treatment of shochu distillery by-products from sweetpotatoes, rice, and barley increased phenolic content. caffeic acid was identified as a dominant phenolic component in the shochu distillery by-products of the sweetpotato. adding koji ...200415618617
[analysis of the ca2+ response of mycelial fungi to external effects by the recombinant aequorin method].using the mutant strain aspergillus awamori 66a producing a recombinant ca2+-dependent photosensitive protein aequorin, the dynamics of ca2+ was studied for the first time in the cytosol of the micromycetes exposed to stressful factors, such as an increase in extracellular ca2+ to 50 mm, hypoosmotic shock, and mechanical shock. cell response to stress proved to involve an increase in the ca2+ concentration in the cytosol, which was determined from the amplitude of aequorin luminescence and the t ...200415688931
[effect of a chemical analogue of autoinducers of microbial anabiosis on the ca2+ response of mycelial fungi].the microbial alkylhydroxybenzenes (ahb), autoinducers of anabiosis, or d1 factors, participate in stress response of mycelial fungi, as determined from changes in intracellular ca2+ concentration. by using the genetically modified strain aspergillus awamori 66a, which produces a recombinant ca2+-dependent protein aequorin, the dynamics of ca2+ was studied in the cytosol of cells exposed to mechanical shock in the presence of the protective doses (0.001-0.01% w/vol) of a chemical ahb analogue, 4 ...200415688932
mutational analysis of a feruloyl esterase from aspergillus awamori involved in substrate discrimination and ph dependence.we cloned the feruloyl esterase a gene from aspergillus awamori (awfaea) and engineered it to study substrate specificity and ph dependence of catalysis. based on the crystal structures of two type-a feruloyl esterases (fae-iii and anfaea) from aspergillus niger, residues located in the flap region of awfaea (asp71, thr72, asp77, and tyr80) were replaced with corresponding amino acid residues (ile, arg, asn, and phe), respectively, found in the lid of lipases from rhizomucor miehei (rmlip) and h ...200515716038
survey of coastal mangrove fungi for xylanase production and optimized culture and assay conditions.xylanase activity was detected among 34 of 77 fungal isolates derived from decaying wood, debris and soil samples collected in coastal mangrove environment of hong kong. of those, three isolates cy2809 (staganospora sp.), cy4786 and cy5040 were chosen for comparison of xylanase production in parallel to hu5048 (aspergillus awamori), a terrestrial, highly productive isolate. based on the assessment of mycelial biomass, xylanase activity and content of xylose-equivalent reducing sugars in their li ...200515847171
biochemical characterization of recombinant acetyl xylan esterase from aspergillus awamori expressed in pichia pastoris: mutational analysis of catalytic residues.we engineered an acetyl xylan esterase (awaxea) gene from aspergillus awamori into a heterologous expression system in pichia pastoris. purified recombinant awaxea (rawaxea) displayed the greatest hydrolytic activity toward alpha-naphthylacetate (c2), lower activity toward alpha-naphthylpropionate (c3) and no detectable activity toward acyl-chain substrates containing four or more carbon atoms. putative catalytic residues, ser(119), ser(146), asp(168) and asp(202), were substituted for alanine b ...200515848131
allosteric nadp-glutamate dehydrogenase from aspergilli: purification, characterization and implications for metabolic regulation at the carbon-nitrogen interface.nadp-dependent glutamate dehydrogenase (nadp-gdh) mediates fungal ammonium assimilation through reductive synthesis of glutamate from 2-oxoglutarate. by virtue of its position at the interface of carbon and nitrogen metabolism, biosynthetic nadp-gdh is a potential candidate for metabolic control. in order to facilitate characterization, a new and effective dye-affinity method was devised to purify nadp-gdh from two aspergilli, aspergillus niger and aspergillus nidulans. the a. niger nadp-gdh was ...200515870451
a new short-term toxicity assay using aspergillus awamori with recombinant aequorin gene.most currently available short-term toxicity assays are based on bacterial cells. therefore there is a need for novel eukaryotic microbial bioassays that will be relevant to higher eukaryotes such as animals and plants. ca2+ is a universal intracellular signalling molecule found in all organisms from prokaryotes to highly specialized animal cells. in fungi calcium has been demonstrated to be involved in control of many important processes. the recombinant aequorin gene from the jellyfish aequore ...200515992407
production of bifunctional proteins by aspergillus awamori: llama variable heavy chain antibody fragment (v(hh)) r9 coupled to arthromyces ramosus peroxidase (arp).the arthromyces ramosus peroxidase gene (arp) was genetically fused to either the 5'- or 3'-terminal ends of the gene encoding llama variable heavy chain antibody fragment v(hh) r9, resulting in the fusion expression cassettes arp-r9 or r9-arp. aspergillus awamori transformants were obtained which produced up to 30 mgl(-1) fusion protein in the culture medium. both fusion proteins showed peroxidase activity in an abts activity test. considerable amounts of fusion protein were detected intracellu ...200516169108
enzymatic production of caffeic acid by koji from plant resources containing caffeoylquinic acid derivatives.the effect of a koji (aspergillus awamori mut.) extract on the caffeoylquinic acid derivatives purified from sweetpotato (ipomoea batatas l.) leaves was examined to develop the mass production of caffeic acid. a koji extract hydrolyzed the caffeoylquinic acid derivatives, chlorogenic acid, 3,4-di-o-caffeoylquinic acid, 3,5-di-o-caffeoylquinic acid, 4,5-di-o-caffeoylquinic acid and 3,4,5-tri-o-caffeoylquinic acid, to caffeic acid. furthermore, the koji extract also converted the major polyphenoli ...200516195601
characteristics of transxylosylation by beta-xylosidase from aspergillus awamori k4.the aspergillus awamori k4 beta-xylosidase gene (xaw1) sequence was deduced by sequencing rt-pcr and pcr products. the orf was 2,412 bp and the predicted peptide was 804 amino acids long, corresponding to a molecular weight of 87,156 da. the mature protein was 778 amino acids long with a molecular weight of 84,632 da. a homology search of the amino acid sequence revealed that it was very similar to the aspergillus niger beta-xylosidase gene with only five amino acid differences. k4 beta-xylosida ...200516202538
role of two alpha-l-arabinofuranosidases in arabinoxylan degradation and characteristics of the encoding genes from shochu koji molds, aspergillus kawachii and aspergillus awamori.two different alpha-l-arabinofuranosidases from aspergillus kawachii were purified and characterized. the two enzymes acted synergically with xylanase in the degradation of arabinoxylan and resulted in an increase in the amount of ferulic acid release by feruloyl esterase. both enzymes were acidophilic and acid stable enzymes which had an optimum ph of 4.0 and were stable at ph 3.0-7.0. the general properties of the enzymes including ph optima and ph stability were similar to those of aspergillu ...200316233515
molecular cloning and characterization of an exoinulinase gene from aspergillus niger strain 12 and its expression in pichia pastoris.a genomic dna segment and cdnas encoding an extracellular exoinulinase from aspergillus niger strain 12 were cloned and sequenced. southern blot analysis indicated that the exoinulinase gene (inue) was present as a single copy in the genome. an open reading frame of 1611 by was interrupted by a single intron of 60 bp, and encoded a 19-amino acid signal peptide and a 518-amino acid mature protein. the mature protein contained a single cys residue and nine potential n-linked glycosylation sites. t ...200316233531
purification and physico-chemical characterisation of genetically modified phytases expressed in aspergillus awamori.two heterologous phytases from aspergillus awamori and aspergillus fumigatus obtained from submerged cultures of genetically modified fungal strains in addition to two commercially available phytase preparations (allzyme and natuphos phytases) were purified to homogeneity using a combination of ultrafiltration, gel filtration and ion exchange. the purified preparations were used in subsequent characterisation studies, in which western immunoblot analysis, ph and temperature optima, thermal stabi ...200616243522
computer-aided analysis of spatial structure of some hydrolytic enzymes.using the molscript version 2.1 computer program for protein molecule modeling and x-ray structure analysis data the spatial structures of several hydrolytic enzymes have been compared. these include glucoamylase from aspergillus awamori and saccharomycopsis fibuligera and lipases from rhizopus japonicus. results on homology of amino acid sequences and topology of secondary structure elements were obtained. 3d models of these enzymes with positioning of functionally important groups in the activ ...200516271023
protein o-mannosyltransferase a of aspergillus awamori is involved in o-mannosylation of glucoamylase i.industrially important extracellular enzymes from filamentous fungi are often o-mannosylated. the structure and function of the pmta (aapmta) gene encoding the protein o-d-mannosyltransferase of aspergillus awamori were characterized. the aapmta disruptant, designated aapmta, was constructed by homologous recombination. the strain aapmta exhibited fragile cell morphology with respect to hyphal extension, as well as swollen hyphae formation and conidia formation in potato dextrose medium. moreove ...200516272387
production and characteristics of raw starch-digesting glucoamylase o from a protease-negative, glycosidase-negative aspergillus awamori var. kawachi mutant.production of a raw starch-digesting glucoamylase o (ga o) by protease-negative, glycosidase-negative mutant strain hf-15 of aspergillus awamori var. kawachi was undertaken under submerged culture conditions. the purified ga o was electrophoretically homogeneous and similar to the parent glucoamylase i (ga i) in the hydrolysis curves toward gelatinized potato starch, raw starch, and glycogen and in its thermostability and ph stability, but it was different in molecular weight and carbohydrate co ...198316346254
production and characteristics of raw starch-digesting glucoamylase o from a protease-negative, glycosidase-negative aspergillus awamori var. kawachi mutant.[this corrects the article on p. 906 in vol. 45.].198316346379
production of malformin by aspergillus awamori. 196716349787
enzymatic degradation of oligosaccharides in pinto bean flour.the use of dry edible beans is limited due to the presence of flatulence factors, the raffinose oligosaccharides. our objective was to investigate the process for the removal of oligosaccharides from pinto bean using enzymatic treatment and to compare it to removal by soaking and cooking methods. crude enzyme preparation was produced by six fungal species on wheat bran- and okara-based substrates with soy tofu whey. the loss of raffinose oligosaccharides after soaking pinto beans for 16 h at the ...200616478251
distribution profiles of isoflavone isomers in black bean kojis prepared with various filamentous fungi.this study was conducted to compare the transformation of both isoflavone derivatives (aglycones, beta-glucosides, and acetyl and malonyl gluclucosides) and beta-glucosidase activity in kojis fermented with various generally recognized as safe filamentous fungi including aspergillus awamori, aspergillus oryzae, aspergillus sojae, rhizopus azygosporus, and rhizopus sp. no. 2. solid fermentation was performed to prepare the kojis by inoculating the steamed black beans with starter organism and cul ...200616478253
evidence of rip (repeat-induced point mutation) in transposase sequences of aspergillus oryzae.a dna methyl-binding column was used to isolate genomic fragments enriched for dna-methylation from aspergillus parasiticus. one of the isolated sequences presented 67% identity at the protein level with the transposase from the transposable element tan1 of aspergillus niger var. awamori, and was found to be present in at least 20 copies in the aspergillus oryzae database. analysis of four copies showed evidence of c:g to t:a transitions in at least 98.2% of the mutations found over a 1,032-1,18 ...200616531081
rock phosphate enriched compost: an approach to improve low-grade indian rock phosphate.in this study, rock phosphate enriched composts (rp-compost) were prepared by mixing four low-grade indian rock phosphates with rice straw with and without aspergillus awamori. rp-compost had higher total p, citrate soluble p (csp), organic p (org.p), acid and alkaline phosphatase activities, and lower water soluble p (wsp) and microbial biomass c (mbc) than normal compost. inoculation with a. awamori increased total p, wsp, csp, org.p, mbc and acid phosphatase activity. rp-compost recorded lowe ...200616545954
microbial biomass, p-nutrition, and enzymatic activities of wheat soil in response to phosphorus enriched organic and inorganic manures.compost was prepared from wheat straw enriched with rajasthan rock phosphate and aspergillus awamori. the resulting phospho-compost along with phosphorus enriched fym, mineral fertilizer (rock phosphate) and super phosphate were evaluated for their individual contribution in improving organic matter status, p availability, and enzymatic activities of soil under wheat crop grown in a micro plot. the results showed that total organic carbon, nitrogen, microbial biomass, and humus content (an index ...200616578904
suppression on the mutagenicity of 4-nitroquinoline-n-oxide by the methanol extracts of soybean koji prepared with various filamentous fungi.in this study, solid fermentation of soybean with various gras filamentous fungi including aspergillus sojae bcrc 30103, aspergillus oryzae bcrc 30222, aspergillus awamori, actinomucor taiwanesis and rhizopus sp. was performed to prepare various soybean kojis. toxicity, mutagenicity and suppression on the mutagenesis induced by a direct mutagen, 4-nitroquinoline-n-oxide (4-nqo) on salmonella typhimurium ta 100, by the various methanol extracts of the prepared soybean koji and unfermented soybean ...200616580082
digestion of dna regions to discriminate ochratoxigenic and non-ochratoxigenic strains in the aspergillus niger aggregate.aspergillus strains belonging to the aspergillus niger aggregate, either isolated from italian grapes or received from public collections, were analysed in order to discriminate between the ochratoxin a (ota) producing and the non-producing strains by means of the analysis of internal transcribed spacers (its), intergenic spacers (igs) and of a beta-tubulin gene portion. a. niger and aspergillus awamori were identified observing the macro- and microscopic features of the colonies and the strains ...200616735072
[the effect of acid proteinases on the activity and stability of glucoamylase preparations].it was demonstrated that the presence of acid proteinases in the preparation isolated from aspergillus awamori decreased the activity and stability of glucoamylase. patterns of changes in the enzymatic activity and stability of glucoamylase at increased temperature and various ph values were studied over a long-term storage. a biospecific sorbent for removal of acid proteinases was synthesized, and glucoamylase preparations free of proteolytic activity were produced.200616761575
free energy perturbation calculations on glucosidase-inhibitor complexes.free energy perturbation studies have been performed on glucoamylase ii (471) from aspergillus awamori var. x100 complexed with three different inhibitors: (+)lentiginosine, (+)(1s,2s,7r,8as) 1,2,7-trihydroxyindolizidine, (+)(1s,2s,7s,8as) 1,2,7-trihydroxyindolizidine and the inactive compound (+)(1s,7r,8as)-1,7-dihydroxyindolizidine. molecular dynamic simulations were carried out using a recently developed procedure for fast free energy perturbation calculations. in this procedure only a sphere ...200516787329
a novel system of genetic transformation allows multiple integrations of a desired gene in saccharomyces cerevisiae chromosomes.increasing industrial competitiveness and productivity demand that recombinant yeast strains, used in many different processes, be constantly adapted and/or genetically improved to suit changing requirements. among yeasts, saccharomyces cerevisiae is the best-studied organism, and the most frequently employed yeast in industrial processes. in the present study, laboratory strains and industrial s. cerevisiae strains were stably transformed with a novel vector containing the glucoamylase cdna of ...200616831478
enhanced antioxidative activity of soybean koji prepared with various filamentous fungi.in the present study, soybean koji fermented with various gras filamentous fungi, including aspergillus sojae bcrc 30103, aspergillus oryzae bcrc 30222, aspergillus awamori, actinomucor taiwanensis and rhizopus sp. these organisms are commonly used as starters in the fermentation of many traditional, oriental food products. the growth of starter organisms, total phenolic content, and antioxidative activities of the methanol extract of these kojis are compared with specific reference to alpha-dip ...200616943061
cereal-based biorefinery development: integrated enzyme production for cereal flour hydrolysis.restructuring the traditional fermentation industry into viable biorefineries for the production of fuels, chemicals and plastics is essential in order to replace (petro)chemical processing. this work presents engineering aspects of aspergillus awamori submerged fermentation for on-site production of an enzymatic consortium that contains glucoamylase, protease and phosphatase. the crude broth filtrate was used for the production of wheat flour hydrolysates. improvements on traditional starch hyd ...200717009318
apho1 from the yeast arxula adeninivorans encodes an acid phosphatase of broad substrate specificity.the extracellular acid phosphatase-encoding arxula adeninivorans apho1 gene was isolated using degenerated specific oligonucleotide primers in a pcr screening approach. the gene harbours an orf of 1449 bp encoding a protein of 483 amino acids with a calculated molecular mass of 52.4 kda. the sequence includes an n-terminal secretion sequence of 17 amino acids. the deduced amino acid sequence exhibits 54% identity to phytases from aspergillus awamori, asp. niger and asp. ficuum and a more distant ...200717016743
n-linked oligosaccharides of aspergillus awamori feruloyl esterase are important for thermostability and catalysis.a unique n-linked glycosylation motif (asn(79)-tyr-thr) was found in the sequence of type-a feruloyl esterases from aspergillus spp. to clarify the function of the flap, the role of n-linked oligosaccharides located in the flap region on the biochemical properties of feruloyl esterase (awfaea) from aspergillus awamori expressed in pichia pastoris was analyzed by removing the n-linked glycosylation recognition site by site-directed mutagenesis. n79 was replaced with a or q. n-glycosylation-free n ...200617031032
biochemical and kinetic analysis of the gh3 family beta-xylosidase from aspergillus awamori x-100.the beta-xylosidase from aspergillus awamori x-100 belonging to the family 3 glycoside hydrolase revealed a distinctive transglycosylating ability to produce xylooligosaccharides with degree of polymerization more than 7. in order to explain this fact, the enzyme has been subjected to the detailed biochemical study. the enzymatic hydrolysis of p-nitrophenyl beta-d-xylopyranoside was found to occur with overall retention of substrate anomeric configuration suggesting cleavage of xylosidic bonds t ...200717145041
enhancement of acid amylase production by an isolated aspergillus awamori.evaluation of the influence of fermentation components on extracellular acid amylase production by an isolated fungal strain aspergillus awamori.200717184336
mutagenic and antimutagenic effects of methanol extracts of unfermented and fermented black soybeans.in this study, solid fermentation of steamed black soybean with various gras (generally recognized as safe) filamentious-fungi including aspergillus awamori, aspergillus oryzae bcrc 30222, aspergillus sojae bcrc 30103, rhizopus azygosporus bcrc 31158 and rhizopus sp. no. 2 was performed. mutagenicity and antimutagenicity of the methanol extracts of unfermented and fermented steamed black soybeans against 4-nitroquinoline-n-oxide (4-nqo), a direct mutagen and benzo[a]pyrene (b[a]p), an indirect m ...200717628128
expression, glycosylation, and secretion of an aspergillus glucoamylase by saccharomyces cerevisiae.a strain of saccharomyces cerevisiae capable of simultaneous hydrolysis and fermentation of highly polymerized starch oligosaccharides was constructed. the aspergillus awamori glucoamylase enzyme, form gai, was expressed in saccharomyces cerevisiae by means of the promoter and termination regions from a yeast enolase gene. yeast transformed with plasmids containing an intron-free recombinant glucoamylase gene efficiently secreted glucoamylase into the medium, permitting growth of the transforman ...198517811549
kinetics of phosphorus and potassium release from rock phosphate and waste mica enriched compost and their effect on yield and nutrient uptake by wheat (triticum aestivum).an attempt was made to study the efficient use of rice straw and indigenous source of phosphorus and potassium in crop production through composting technology. various enriched composts were prepared using rice straw, rock phosphate (rp), waste mica and bioinoculant (aspergillus awamori) and kinetics of release of phosphorus and potassium from enriched composts and their effect on yield and nutrient uptake by wheat (triticum aestivum) were carried out. results showed sharp increases in release ...200817905580
application of statistical experimental design to optimize culture requirements of aspergillus sp. zh-26 producing xylanase for degradation of arabinoxylans in mashing.the objective of this study was to isolate and characterize a strain of aspergillus capable of producing xylanase. according to the morphology and comparison of its (internal transcribed spacer) rdna gene sequence, the strain aspergillus sp. zh-26 was identified as a strain of aspergillus awamori. statistically based experimental designs were applied for the optimization of xylanase production from a. awamori zh-26. the considered medium components included 17 components as follows: yeast extrac ...200717995733
solid-state fermentation with fungi to enhance the antioxidative activity, total phenolic and anthocyanin contents of black bean.in the present study, solid-state fermentation of black bean with various gras filamentous fungi including aspergillus awamori, aspergillus oryzae, aspergillus sojae, rhizopus azygosporus and rhizopus sp. no. 2 was preformed to prepared koji. mycelial propagation of starter organisms and antioxidative activity, including alpha-alpha-diphenyl-2-picyl-hydoxyl (dpph) radicals, fe2+-chelating ability, and reducing activity, were examined. depending upon the starter organism, various amounts of mycel ...200818031859
biodegradation dynamics of high catechol concentrations by aspergillus awamori.the biodegradation process of high catechol concentrations by aspergillus awamori was investigated. the values of the kinetic constants for a model of specific growth rate at different initial conditions were determined. at 1.0 g/l catechol concentration, the biodegradation process proceeded in the conditions of substrate limitation. at higher catechol concentrations (2.0 and 3.0 g/l) a presence of substrate inhibition was established. the dynamics of the specific catechol degradation rate was s ...200818037238
recombinant human lactoferrin and iron transport across caco-2 monolayers: effect of heat treatment on the binding to cells.recombinant human lactoferrin (rhlf) from aspergillus awamori bound to caco-2 cell membranes in a saturable manner. the dissociation constant for the apo form was (kd)=2.2 x 10(-7) m; however, the specific binding of the iron-saturated rhlf and of lactoferrin from human milk (hlf) was too low to calculate the binding parameters. recombinant human lactoferrin subjected to heat treatment did not lose the ability to bind to cell membranes except at high temperature and long time treatments (85 and ...200818355020
udp-xylose-stimulated glucuronyltransferase activity in wheat microsomal membranes: characterization and role in glucurono(arabino)xylan biosynthesis.microsomal membranes from etiolated wheat (triticum aestivum) seedlings cooperatively incorporated xylose (xyl), arabinose, and glucuronic acid residues from their corresponding uridine 5'-diphosphosugars into an ethanol-insoluble glucurono(arabino)xylan (gax)-like product. a glucuronyltransferase activity that is enhanced by the presence of udp-xyl was also identified in these microsomes. wheat glucuronyltransferase activity was optimal at ph 7 and required manganese ions, and several lines of ...200818359844
heterologous expression of aspergillus niger beta-d-xylosidase (xlnd): characterization on lignocellulosic substrates.the gene encoding a glycosyl hydrolase family 3 xylan 1,4-beta-xylosidase, xlnd, was successfully cloned from aspergillus niger strain atcc 10864. the recombinant product was expressed in aspergillus awamori, purified by column chromatography, and verified by matrix-assisted laser desorption ionization, tandem time of flight (maldi-tof/tof) mass spectroscopy of tryptic digests. the t (max) was determined using differential scanning microcalorimetry (dsc) to be 78.2 degrees c; the k (m) and k (ca ...200818421587
heterologous expression of two ferulic acid esterases from penicillium funiculosum.two recombinant ferulic acid esterases from penicillium funiculosum produced in aspergillus awamori were evaluated for their ability to improve the digestibility of pretreated corn stover. the genes, faea and faeb, were cloned from p. funiculosum and expressed in a. awamori using their native signal sequences. both enzymes contain a catalytic domain connected to a family 1 carbohydrate-binding module by a threonine-rich linker peptide. interestingly, the carbohydrate binding-module is n-terminal ...200818421589
a wheat biorefining strategy based on solid-state fermentation for fermentative production of succinic acid.in this study, a novel generic feedstock production strategy based on solid-state fermentation (ssf) has been developed and applied to the fermentative production of succinic acid. wheat was fractionated into bran, gluten and gluten-free flour by milling and gluten extraction processes. the bran, which would normally be a waste product of the wheat milling industry, was used to produce glucoamylase and protease enzymes via ssf using aspergillus awamori and aspergillus oryzae, respectively. the r ...200818434138
implications of cellobiohydrolase glycosylation for use in biomass conversion.the cellulase producing ascomycete, trichoderma reesei (hypocrea jecorina), is known to secrete a range of enzymes important for ethanol production from lignocellulosic biomass. it is also widely used for the commercial scale production of industrial enzymes because of its ability to produce high titers of heterologous proteins. during the secretion process, a number of post-translational events can occur, however, that impact protein function and stability. another ascomycete, aspergillus niger ...200818471276
antioxidative pyranonigrins in rice mold starters and their suppressive effect on the expression of blood adhesion molecules.antioxidants having a 1,1-diphenyl-2-picrylhydrazyl (dpph) radical scavenging capacity in rice mold starters, which are used for the preparation of various japanese fermented foods, and their effectiveness against the expression of blood adhesion molecules were examined. an antioxidant was isolated from the rice mold starters used for shochu and identified as pyranonigrin-s (pg-s) by (1)h-nmr, (13)c-nmr, and fab-ms analyses. it was a derivative of pyranonigrin-a (pg-a), which has been isolated a ...200818540108
continuous production of high-glucose syrup by chitin-immobilized amylase.a simple method of preparing a chitin-immobilized alpha-amylase and glucoamylase from the protease- and glycosidase-less mutant hf-15 of aspergillus awamori var. kawachi was developed and used for the production of high-glucose syrup. the glucoamylase was tightly bound onto chitin without the aid of a crosslinking agent because the enzyme contained a specific binding site for chitin. continuous production of high glucose concentrate from a highly concentrated alpha-amylasetreated gelatinized sta ...198318551543
ethanol production from starch by a coimmobilized mixed culture system of aspergillus awamori and zymomonas mobilis.the production of ethanol from starch by a coimmobilized mixed culture system of aerobic and anaerobic microorganisms in ca-alginate gel beads was investigated. the mold aspergillus awamori was used as an aerobic amylolytic microorganism and an anaerobic bacterium, zymomonas mobilis, as an ethanol producer. by controlling the mixing ratio of the microorganisms in the inoculum size, a desirable coimmobilized mixed culture system, in which the aerobic mycelia grew on and near the oxygen-rich surfa ...198618555292
extracellular proteolytic processing of aspergillus awamori gai into gaii is supported by physico-chemical evidence.the proportion of glucoamylases, gai and gaii, in the culture supernatant of aspergillus awamori fermentations depends on the medium c/n ratio in such a way that the transformation of gai into gaii is favored by the existence of a surplus of the carbon source in the growth medium. this condition also favors the appearance of the proteolytic activity. the authors report the observation that the shift in the isoenzyme proportion was concomitant to the peak of proteolytic activity. a peptide that m ...199818576028
glucoamylase isoenzymes tailoring through medium composition.two major glucoamylase isoenzymes (gai and gaii) have been identified in culture supernatants of aspergillus awamori. it has been suggested that a stepwise degradation of a native enzyme during the fermentation by proteases and/or glucosidases results in the formation of isoenzymes that have different characteristics concerning substrate specificity and stability to ph and temperature. in this study, the glucoamylase isoenzymes produced by aspergillus awamori using liquid media with c/n 10 (2.0% ...199718576072
l-lactic acid production from starch by coimmobilized mixed culture system of aspergillus awamori and streptococcus lactis. 198818581580
fermentation of corn starch to ethanol with genetically engineered yeast.expression of the glucoamylase gene from aspergillus awamori by laboratory and distiller's strains of saccharomyces cerevisiae allowed them to ferment soluble starch. approximately 95% of the carbohydrates in the starch were utilized. glycerol production was significantly decreased when soluble starch was used instead of glucose. ethanol yield on soluble starch was higher than that on glucose. the rate of starch fermentation was directly related to the level of glucoamylase activity. strains wit ...198818584739
ethanol production from starch by a coimmobilized mixed culture system of aspergillus awamori and saccharomyces cerevisiae.the development of a coimmobilized mixed culture sys tem of aerobic and facultative anaerobic microorganisms in ca-alginate gel beads and the production of useful metabolites by the system were investigated. a coimmobilized mixed culture system of aspergillus awamori (obligate aerobe) and saccharomyces cerevisiae (facultative anaerobe) in ca-alginate gel beads was used as a model system, and ethanol production from starch by the system was used as a model production. mold asp. awamori is an amyl ...198918587973
oxygen diffusivity in gel beads containing viable cells.this article proposes a simple steady-state method for measuring the effective diffusion coefficient of oxygen (d(e)) in gel beads entrapping viable cells. we applied this method to the measurement of d(e) in ca- and ba-alginate gel beads entrapping saccharomyces cerevisiae and pseudomonas ovalis. the diffusivity of oxygen through gel beads containing viable cells was measured within an accuracy of +/-7% and found not to be influenced by cell density (0-30 g/l gel), cell type, and cell viability ...198918588184
expression of a fungal glucoamylase in transgenic rice seeds.glucoamylase, which catalyses the hydrolysis of the alpha-1,4 glycosidic bonds of starch, is an important industrial enzyme used in starch enzymatic saccharification. in this study, a glucoamylase gene from aspergillus awamori, under the control of the promoter of seed storage protein gt1, was introduced into rice by agrobacterium-mediated transformation. significant glucoamylase activity was detected specifically in the seeds but not other tissues of the transgenic rice lines. the highest enzym ...200818588984
xylanase production by aspergillus awamori. development of a medium and optimization of the fermentation parameters for the production of extracellular xylanase and beta-xylosidase while maintaining low protease production.a growth medium was developed for maximal production in batch culture of extracellular xylanase and beta-xylosidase by aspergillus awamori cmi 142717 and a mutant (aantg 43) derived from the wild-type strain. the optimum ph for the production of xylanase and beta-xylosidase was 4.0. the best temperature of xylanase production was 30 degrees c; 35 degrees c was optimal for beta-xylosidase. protease production was never completely suppressed under any of the conditions tested. however, protease ti ...199118600845
microencapsulation selection for isolation of yeast mutants with increased secretion of aspergillus awamori glucoamylase.we have developed a microencapsulation selection method which allows the rapid and quantitative screening of >10(6) yeast cells for enhanced secretion of aspergillus awamori glucoamylase. the method provides a 400-fold single-pass enrichment for high-secreting mutants, and can be straightforwardly adapted for application to growth-based selection schemes with other microorganisms and enzymes.199318613019
increased thermostability of asn182 --> ala mutant aspergillus awamori glucoamylase.asn182 --> ala aspergillus awamori glucoamylase expressed in saccharomyces cerevisiae had a first-order thermodeactivation coefficient 40% that of wild-type glucoamylase at ph 4.5 between 60 degrees and 65 degrees c, caused by the elimination of an asn-gly sequence subject to deamidation and eventual chain breakage. above 70 degrees c, and at phs 3.5 and 5.5, thermodeactivation coefficients of wild-type and mutant enzymes were roughly equal, because the fastest deactivation mechanism was no long ...199418613315
domain e of bacillus macerans cyclodextrin glucanotransferase: an independent starch-binding domain.the starch-binding domains of glucoamylase i (sbd of ga-i) from aspergillus awamori and of cyclodextrin glucanotransferase (domain e of cgtase) from bacillus macerans were fused to the c-terminus of beta-galactosidase (beta-gal) the majority of the fusion proteins produced in escherichia coli were found as inclusion bodies. active fusion proteins were purified by partial solubilization of the inclusion bodies with 2 m urea followed by affinity chromatography. adsorption isotherms of purified fus ...199518623437
kinetic characterization of o-phospho-l-tyrosine phosphohydrolase activity of two fungal phytases.fungal phytases belonging to "histidine acid phosphatase" or hap class of phosphohydrolases that catalyze the hydrolysis of phytic acid could also hydrolyze o-phospho-l-tyrosine, which is also called phosphotyrosine. two phytases from aspergillus niger and aspergillus awamori with ph optima 2.5 were tested for phosphotyrosine hydrolase activity; both enzymes cleaved the phosphomonoester bond of phosphotyrosine efficiently at acidic ph. the km for phosphotyrosine ranged from 465 to 590 microm as ...200818627164
protein production using recombinant yeast in an immobilized-cell-film airlift bioreactor.a recombinant saccharomyces cerevisiae c468/pgac9 (atcc 20690), which expresses aspergillus awamori glucoamylase gene under the control of the yeast enolase i (eno1) promoter and secretes glucoamylase into the extracellular medium, was used as a model system to investigate the effect of cell immobilization on bioreactor culture performance. free suspension cultures in stirred-tank and airlift bioreactors confirmed inherent genetic instability of the recombinant yeast. an immobilized-cell-film ai ...199718636482
effect of agitation intensities on fungal morphology of submerged fermentation.both parallel fermentations with aspergillus awamori (cbs 115.52) and a literature study on several fungi have been carried out to determine a relation between fungal morphology and agitation intensity. the studied parameters include hyphal length, pellet size, surface structure or so-called hairy length of pellets, and dry mass per-wet-pellet volume at different specific energy dissipation rates. the literature data from different strains, different fermenters, and different cultivation conditi ...199718636582
characteristics of glucose uptake by glucose- and nh4-limited grown penicillium ochrochloron at low, medium and high glucose concentration.glucose uptake by penicillium ochrochloron (formerly penicillium simplicissimum) was studied from 0.01 to 400 mm glucose using chemostat culture and bioreactor batch culture. the characteristics of glucose uptake varied considerably with the conditions of growth, harvest and uptake assay. glucose-limited grown mycelium showed one saturable transport system [k(s) below 0.01 mm; v(max) 1.1-1.2 mmol (g dry weight)(-1)h(-1)] plus a first order process (permeability p=1.2x10(-7)cm s(-1)). ammonium-li ...200818722543
production, partial purification and characterization of feruloyl esterase by aspergillus awamori in submerged fermentation.microbial feruloyl esterases acting on plant cell wall polymers represent key tools for the degradation of plant cell wall. in this paper, we describe in detail the microbial production, partial purification and characterization of feruloyl esterase from a culture medium of aspergillus awamori strain ifo4033 obtained from a crude hemicellulose preparation of wheat straw, corncobs and wheat germ. feruloyl esterase was extracted using centrifugation and dialysis, and then purified by ion exchange ...200818830967
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