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Publications (13)22.86 Total impact

  • Arja Miettinen-Oinonen · Marja Paloheimo · Raija Lantto · Pirkko Suominen
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    ABSTRACT: In the search for suitable cellulase combinations for industrial biofinishing of cotton, five different types of Trichoderma reesei strains were constructed for elevated cellobiohydrolase production: CBHI overproducers with and without endoglucanase I (EGI), CBHII overproducers with and without endoglucanase II (EGII) and strains overproducing both CBHI and CBHII without the major endoglucanases I and II. One additional copy of cbh1 gene increased production of CBHI protein 1.3-fold, and two copies 1.5-fold according to ELISA (enzyme-linked immunosorbent assay). The level of total secreted proteins was increased in CBHI transformants as compared to the host strain. One copy of the cbh2 expression cassette in which the cbh2 was expressed from the cbh1 promoter increased production of CBHII protein three- to four-fold when compared to the host strain. T. reesei strains producing elevated amounts of both CBHI and CBHII without EGI and EGII were constructed by replacing the egl1 locus with the coding region of the cbh1 gene and the egl2 locus with the coding region of cbh2. The cbh1 was expressed from its own promoter and the cbh2 gene using either the cbh1 or cbh2 promoter. Production of CBHI by the CBH-transformants was increased up to 1.6-fold and production of CBHII up to 3.4-fold as compared with the host strain. Approximately similar amounts of CBHII protein were produced by using cbh1 or cbh2 promoters. When the enzyme preparation with elevated CBHII content was used in biofinishing of cotton, better depilling and visual appearance were achieved than with the wild type preparation; however, the improvement was not as pronounced as with preparations with elevated levels of endoglucanases (EG).
    No preview · Article · Apr 2005 · Journal of Biotechnology
  • R. Lantto · E. Heine · G. Freddi · A. Lappalainen · A. Miettinen-Oinonen · M-L. Niku-Paavola · J. Buchert
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    ABSTRACT: The capabilities of tyrosinase and peroxidase to activate tyrosine residues of wool fibres and to catalyze crosslink formation between peptides derived from a wool protein hydrolyzate were investigated. Peroxidases were able to catalyse oxidation of wool fibres corresponding to 35–40% of the tyrosine residues located on the wool surface or 2% of the tyrosine residues in the wool fibre. Similar fibre surface modification was detected with tyrosinase and a fungal peroxidase using x-ray photoelectron spectroscopy. Tyrosinase did not show detectable activation of fibres measured as oxygen consumption. Tyrosinase was, however, able to crosslink peptides of 3–10 kDa derived from enzymatically hydrolysed wool fibres. Surprisingly, no crosslinking was detected with peroxidase.
    No preview · Article · Mar 2005 · Journal of the Textile Institute
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    Full-text · Article · May 2004 · Enzyme and Microbial Technology
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    ABSTRACT: Culture supernatants from strains of Melanocarpus albomyces, Myceliophthora thermophila, Chaetomium thermophilum, and Sporotrichum thermophilum were tested for their ability to release dye in neutral pH conditions from indigo-dyed cotton-containing fabric in biostoning applications. The supernatants from M. albomyces worked well in biostoning, with low backstaining. Three cellulases were purified to homogeneity from the culture medium of this species. Two of the cellulases were endoglucanases with apparent molecular masses of 20 and 50 kDa. The 20 kDa endoglucanase was a relatively heat-stable cellulase with high pH optimum. The partially purified enzyme crystallized spontaneously at pH 4.0 and 7 °C. The 50 kDa endoglucanase also had activity against 4-methylumbelliferyl-β-d-lactoside (MUL) and was active over a wide range of pH values. The third purified cellulase was the 50 kDa cellobiohydrolase with low MUL activity at acidic pH and detectable activity towards filter paper and acid swollen Solca Floc-cellulose, but no endoglucanase activity. The purified 20 kDa endoglucanase performed well in biostoning of denim fabric at neutral pH. Addition of the purified 50 kDa endoglucanase or the 50 kDa cellobiohydrolase to the 20 kDa endoglucanase decreased backstaining in biostoning.
    No preview · Article · Mar 2004 · Enzyme and Microbial Technology
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    ABSTRACT: In our previous study, three purified cellulases of Melanocarpus albomyces proved to be effective in biostoning application at neutral pH [Enzyme Microb. Technol., accepted for publication]. We cloned and sequenced three genes of M. albomyces, which encode a 20 kDa and two 50-kDa polypeptides. The 20-kDa protein (Cel45A) and one of the 50-kDa proteins (Cel7A) are endoglucanases of the glycosyl hydrolase families 45 and 7, respectively. The other 50-kDa protein (Cel7B) is a family 7 cellobiohydrolase. None of the cellulases harbors a cellulose binding domain (CBD). These genes were expressed in Trichoderma reesei under the control of the T. reesei cbh1 promoter and the proteins detected in the culture medium. The endoglucanase production levels of the cel45A- and cel7A-transformants were several times higher than those of the parental M. albomyces strain. The sizes of Cel45A, Cel7A and Cel7B proteins produced by the transformants were the same as the sizes of the corresponding proteins purified from M. albomyces. Cellulase preparations produced by the cel45A transformants performed well at neutral pH in stone-washing of denim fabric and caused considerably less backstaining as compared to the acid cellulase product of T. reesei.
    No preview · Article · Feb 2004 · Enzyme and Microbial Technology
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    Arja Miettinen-Oinonen
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    ABSTRACT: Trichoderma reesei is a biotechnically important filamentous fungus used commercially in enzyme production. T. reesei is also one of the best known cellulolytic organisms, producing readily and in large quantities a complete set of extracellular cellulases for the degradation of crystalline cellulose. In addition to T. reesei, a wide variety of other bacteria and fungi also produce cellulolytic enzymes. Cellulases originating from various organisms and having different characteristics are used industrially in many applications, such as in the textile industry in finishing of denim fabric to impart a stonewashed appearance (biostoning) and in biofinishing of cotton. In this work T. reesei strains producing significant amounts of homologous and heterologous cellulases and having defined cellulase profiles were constructed for specific industrial applications, i.e. biostoning and biofinishing of cotton. The production of T. reesei endoglucanase II (EGII), cellobiohydrolases I and II (CBHI and CBHII) was improved in separate strains. Strains producing high amounts of EGI and EGII without CBHs or CBHI and CBHII without the main EGs were also constructed. The cellulase genes were expressed under the powerful T. reesei cbh1 promoter; in a transformant overproducing both CBHI and CBHII, the cbh2 promoter was also used for cbh2 expression. The level of endoglucanase activity produced by the EGII-overproducing transformants correlated with the copy number of the egl2 expression cassette. Production of the major secreted cellulase CBHI was increased up to 1.5-fold and production of CBHII fourfold compared with the parent strain. In transformants overproducing both CBHI and CBHII, production of CBHI was increased up to 1.6-fold and production of CBHII up to 3.4-fold as compared with the host strain and approximately similar amounts of CBHII protein were produced by using the cbh1 or cbh2 promoters. The enzyme preparation with elevated EGII content most clearly improved the biostoning of denim fabric and the biofinishing of cotton fabric. Better depilling and visual appearance were achieved with the enzyme preparation having an elevated CBHII content compared to the wild type preparation in biofinishing of cotton, but the improvement was not as pronounced as in the case of the EGII preparation. Novel neutral cellulases were demonstrated to have potential in biostoning. The cellulase preparation of the thermophilic fungus Melanocarpus albomyces was found to be effective in releasing dye from indigo-dyed denim and to cause low backstaining at neutral pH. M. albomyces produces at least three cellulases and these cellulases with an effect on biostoning were purified and the genes encoding them were cloned and sequenced. Ma 20 kDa EGV (Ma Cel45A) belongs to the glycosyl hydrolase family 45 and the 50 kDa EGI (Ma Cel7A) and CBHI (Ma Cel7B) to family 7. None of the cellulases harbours a cellulose binding domain. Especially purified Ma Cel45A performed well in biostoning. The Ma cellulases were produced in T. reesei under the T. reesei cbh1 promoter for biostoning applications. The endoglucanase production levels of Ma cel45A- and cel7A-transformants were several times higher than those of the parental M. albomyces strain. The cellulase preparation produced by the recombinant Ma cel45A transformant performed well at neutral pH in the finishing of denim fabric and caused considerably less backstaining than the acid cellulase product of T. reesei.
    Preview · Article · Jan 2004 · VTT Publications
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    Lea Heikinheimo · Arja Miettinen-Oinonen · Artur Cavaco-Paulo · Johanna Buchert
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    ABSTRACT: The mode of action of monocomponent purified Trichoderma reesei cellobiohydrolases (CBHI and CBHII) and endoglucanases (EGI and EGII) on cotton fabrics was studied by analyzing the weight loss of the fabric, the reducing sugars, the soluble oligosaccharides and the molecular weight of the cotton powder formed. The impact of mechanical action on these factors was also evaluated. EGI and EGII released the highest amounts of reducing sugars and soluble oligosaccharides in both treatments with or without additional mechanical action. After cellulase treatment without additional mechanical action, all of the cellulases were found to have reduced the molecular weight of cotton poplin powder. When mechanical action was combined with enzyme treatments, only EGII reduced the molecular weight. The weight loss of EG-treated fabrics was clearly higher than the weight loss of CBH-treated fabrics with both low and high mechanical action levels. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1917–1922, 2003
    Full-text · Article · Nov 2003 · Journal of Applied Polymer Science
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    Arja Miettinen-Oinonen · Pirkko Suominen
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    ABSTRACT: Trichoderma reesei strains were constructed for production of elevated amounts of endoglucanase II (EGII) with or without cellobiohydrolase I (CBHI). The endoglucanase activity produced by the EGII transformants correlated with the copy number of the egl2 expression cassette. One copy of the egl2 expression cassette in which the egl2 was under the cbh1 promoter increased production of endoglucanase activity 2.3-fold, and two copies increased production about 3-fold above that of the parent strain. When the enzyme with elevated EGII content was used, an improved stonewashing effect on denim fabric was achieved. A T. reesei strain producing high amounts of EGI and -II activities without CBHI and -II was constructed by replacing the cbh2 locus with the coding region of the egl2 gene in the EGI-overproducing CBHI-negative strain. Production of endoglucanase activity by the EG-transformant strain was increased fourfold above that of the host strain. The filter paper-degrading activity of the endoglucanase-overproducing strain was lowered to below detection, presumably because of the lack of cellobiohydrolases.
    Full-text · Article · Sep 2002 · Applied and Environmental Microbiology
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    ABSTRACT: Knitted and woven cotton fabrics were treated with a monocomponent Trichoderma reesei endoglucanase II (EGII) and with experimental Trichoderma cellulase mixtures containing different cellulase profiles. The cellulase action was evaluated by measuring weight loss, pilling, and bursting strength. Of the experimental mixtures, Cellulase F, being an EGII-enriched preparation, was the best mixture to obtain the highest pilling reduction with the lowest strength and weight losses on cotton knitted fabric. The monocomponent EGII was, however, even more efficient with respect to good depilling with minimal negative effect on the knitted fabric. The results obtained with the different cellulases were found to depend on the fabric type. In the case of ring-spun, woven fabric, purified EGII was the best enzyme in depilling with the lowest weight loss. Cellulase B (containing CBHIand EGII) reduced the pilling tendency, but the weight loss was higher as compared to that obtained with the monocomponent EGII. In the case of open end-spun woven fabric, Cellulase B and Cellulase E (EGII enriched, CBHI negative) resulted in improved depilling, but at the same time they caused relatively high weight loss.
    Full-text · Article · Jan 2001 · Aatcc Review
  • L. Heikinheimo · J. Buchert · A. Miettinen-Oinonen · P. Suominen
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    ABSTRACT: Cellulases are widely used to age denim fabrics. In this work the effects of three purified monocomponent cellulases, EG I, EG II, and CBH I, and two different cellulase mixtures produced by genetically modified strains of Trichoderma reesei are compared for stone washing denim fabrics. Stone washing effects are evaluated by analyzing the soluble reducing sugars, absorbance, and lightness values of the treatment solutions. The prop erties of denim swatches are evaluated by reflectance units and by a panel. Purified cellulase EG II is most effective at removing color from denim, producing a good stone washing effect with the lowest hydrolysis level. Treatment with CBH I does not produce any stone washing effect, even at high enzyme dosages. The commercial cellulase Ecostone® L produces a good stone washing effect, but the experimental cellulase mixture Cellulase B removes color only with the highest enzyme dosage, i.e., when the amount of EGS in the mixture is high enough.
    No preview · Article · Nov 2000 · Textile Research Journal
  • Arja Miettinen-Oinonen · Tuula Torkkeli · Marja Paloheimo · Helena Nevalainen
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    ABSTRACT: An Aspergillus gene coding for a pH 2.5 acid phosphatase enzyme was successfully overexpressed in Trichoderma reesei under the strong main cellobiohydrolase I (cbh 1) promoter. The best transformants produced up to 240 times more of the acid phosphatase than the Aspergillus strain from which the phosphatase gene was originally isolated. The recombinant enzyme was effectively secreted into the culture medium both by its own and the cbh 1 secretion signal. The heterologous pH 2.5 acid phosphatase enzyme produced by the Trichoderma transformants was seen as four protein bands of about 55-66 kD resulting from variable glycosylation in Trichoderma. The activity of the recombinant enzyme was not affected. Enzyme preparations rich in both cellulose and phytate hydrolysing enzymes are of interest in the animal feed industry.
    No preview · Article · Nov 1997 · Journal of Biotechnology
  • R. Lantto · A. Miettinen-Oinonen · P. Suominen
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    ABSTRACT: Neutral cellulases, which are active in the pH range 5-7, are used in indigo dyed denim processing parallel with acid cellulases because of little or no backstaining and more suitable washing conditions. Backstaining means a tendency of the released indigo dye to redeposit on the surface of the fibers. In the literature it is claimed that backstaining is dependent on pH and /or the type of enzyme. According to the authors results backstaining depends only indirectly on pH. This article studies two spent culture media containing neutral cellulase activity (A and B) and a commercial neutral (C) and a commercial acid (D) cellulase product both biochemically and in small scale denim wash with an equal enzyme dosage at pH 5 and pH 7. Cellulases A, B, C, and D each come from a different fungal origin.
    No preview · Article · Aug 1996
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    ABSTRACT: The genes encoding phytase (EC 3.1.3.8) and pH 2.5-optimum acid phosphatase (EC 3.1.3.2) have been cloned and sequenced from Aspergillus niger var. awamori. The translated nucleotide sequences yielded polypeptides of 467 and 479 amino acids (aa) for phytase and acid phosphatase, respectively. The genes were isolated using oligodeoxyribonucleotide probes based on the aa sequences of the purified proteins. Recombinant A. niger var. awamori strains carrying additional copies of the gene sequences demonstrated elevated enzyme activities.
    No preview · Article · Nov 1993 · Gene