T. Tzanov - Academia.edu (original) (raw)

Papers by T. Tzanov

Research paper thumbnail of Cellobiose dehydrogenase functionalized urinary catheter as novel antibiofilm system

Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2015

Urinary catheters expose patients to a high risk of acquiring nosocomial infections. To prevent t... more Urinary catheters expose patients to a high risk of acquiring nosocomial infections. To prevent this risk of infection, cellobiose dehydrogenase (CDH), an antimicrobial enzyme able to use various oligosaccharides as electron donors to produce hydrogen peroxide using oxygen as an electron acceptor, was covalently grafted onto plasma-activated urinary polydimethylsiloxane (PDMS) catheter surfaces. Successful immobilization of CDH on PDMS was confirmed by Fourier transformed-infrared spectrometry and production of H2 O2 . The CDH functionalized PDMS surfaces reduced the amount of viable Staphylococcus aureus by 60%, total biomass deposited on the surface by 30% and 70% of biofilm formation. The immobilized CDH was relatively stable in artificial urine over 16 days, retaining 20% of its initial activity. The CDH coated PDMS surface did not affect the growth and physiology of HEK 239 and RAW 264,7 mammalian cells. Therefore this new CDH functionalized catheter system shows great potential for solving the current problems associated with urinary catheters. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2015.

Research paper thumbnail of DOI 10.1007/s10311-005-0004-3 ORIGINAL PAPER

A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show tha... more A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show that laccases of this organism were responsible for oxidation of the flavonoids morin, luteolin, rutin and quercetin. Out of two laccases produced by T. hirsuta (60.7 and 51.0 kDa) the more prominent 60.7 kDa laccase was purified and showed Km and kcat values of 75.5, 20.9 and 49.4 µM and 72.5, 96.3 and 32.7 s−1, hours on ABTS, syringaldazide and DMP, respectively. Pretreatment of cotton with the T. hirsuta laccase resulted in a whiteness increase of 8.5%.

Research paper thumbnail of Making the hospital a safer place by sonochemical coating of all its textiles with antibacterial nanoparticles

Ultrasonics sonochemistry, 2015

The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparti... more The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparticles is demonstrated in the current paper. A roll-to-roll pilot installation to coat textiles was built taking into consideration the requirements of the sonochemical process. A long-run experiment was conducted in which 2500m of fabric were coated with antibacterial ZnO nanoparticles (NPs). The metal oxide NPs were deposited from an ethanol:water solution. In this continuous process a uniform concentration of coated NPs over the length/width of the fabric was achieved. The antibacterial efficiency of the sonochemically-coated textiles was validated in a hospital environment by a reduction in the occurrence of nosocomial infections. NP-coated bed sheets, patient gowns, pillow cover, and bed covers were used by 21 patients. For comparison 16 patients used regular textiles. The clinical data indicated the reduced occurrence of hospital-acquired infections when using the metal oxide NP-coat...

Research paper thumbnail of Size and Aging Effects on Antimicrobial Efficiency of Silver Nanoparticles Coated on Polyamide Fabrics Activated by Atmospheric DBD Plasma

ACS Applied Materials & Interfaces, 2015

Research paper thumbnail of Progress on enzymatic preparation of flax and flax wool blends

Aatcc Review, 2005

This paper is outcome from a European Commission funded project under the FAIR programme and unde... more This paper is outcome from a European Commission funded project under the FAIR programme and under COST ACTION 847 “Textile Quality and Biotechnology”. It demonstrated the high level of international collaboration with VTT Biotechnology in Finland and Minho University in Portugal. The outcome of the paper brought in significant knowledge of traditional and novel enzymatic preparation for flax and flax blends to meet the cost effective production. The paper showed the leading research in the enzymatic treatment using laccases or laccases/mediator systems for degradation of lignin for producing high quality of flax textile materials. J Shen also published another two papers in the subject of evaluation of physical and chemical properties of flax fibres from stand-retted crops in JTI 2006 and Industrial Crops & Products 2005.

Research paper thumbnail of Contributor contact details

Advances in Textile Biotechnology, 2010

Research paper thumbnail of Tannic acid NPs – Synthesis and immobilization onto a solid surface in a one-step process and their antibacterial and anti-inflammatory properties

Ultrasonics Sonochemistry, 2014

Research paper thumbnail of Enzymatic pre-treatment as a means of enhancing the antibacterial activity and stability of ZnO nanoparticles sonochemically coated on cotton fabrics

Journal of Materials Chemistry, 2012

ABSTRACT Zinc oxide nanoparticles (ZnO NP's) are known for their excellent antibacter... more ABSTRACT Zinc oxide nanoparticles (ZnO NP's) are known for their excellent antibacterial properties. This paper describes a method for enhancing the stability and the antibacterial activity of ZnO NPs synthesized and embedded sonochemically on cotton fabrics, by pre-treating the fabric surface with cellulase enzyme. The enzymatic pre-treatment resulted in the deposition of smaller sized NPs with improved adhesion. The reduction in particle size brought about better antibacterial performance against several types of bacteria. The sonochemically produced ZnO coating withstood 10 laundry cycles at 92 °C retaining its antibacterial activity.

Research paper thumbnail of Voltammetric monitoring of laccase-catalysed mediated reactions

Bioelectrochemistry, 2002

Research paper thumbnail of Voltammetric monitoring of laccase-catalysed mediated reactions

Bioelectrochemistry, 2002

Research paper thumbnail of Mediators-boosted enzymatic bleaching of eucalyptus kraft pulp

Research paper thumbnail of Chitosan and chitosan–ZnO-based complex nanoparticles: formation, characterization, and antibacterial activity

Journal of Materials Chemistry B, 2013

Research paper thumbnail of Thermo-alkali-stable catalases from newly isolated Bacillus sp. for the treatment and recycling of textile bleaching effluents

Journal of Biotechnology, 2001

Research paper thumbnail of Bio-preparation of cotton fabrics

Enzyme and Microbial Technology, 2001

Research paper thumbnail of Immobilization of catalases from Bacillus SF on alumina for the treatment of textile bleaching effluents

Enzyme and Microbial Technology, 2001

Research paper thumbnail of Studies of stabilization of native catalase using additives

Enzyme and Microbial Technology, 2002

Research paper thumbnail of Predicting Dye Biodegradation from Redox Potentials

Biotechnology Progress, 2004

Research paper thumbnail of Bio-catalyzed coloration of cellulose fibers

Biocatalysis and Biotransformation, 2007

Cotton fabrics were dyed with dyes generated in situ by laccase-catalyzed oxidative coupling of t... more Cotton fabrics were dyed with dyes generated in situ by laccase-catalyzed oxidative coupling of the colorless 2, 5-diaminobenzenesulfonic acid (2, 5-DABSA) and 1-hydroxyphenol (catechol). The enzymatic oxidation of the dye intermediates led to cross-...

Research paper thumbnail of Effect of Some Process Parameters in Enzymatic Dyeing of Wool

Applied Biochemistry and Biotechnology, 2003

Research paper thumbnail of Decolorization and Detoxification of Textile Dyes with a Laccase from Trametes hirsuta

Applied and Environmental Microbiology, 2000

Trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, i... more Trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, indigoid, azo, and anthraquinonic dyes. Initial decolorization velocities depended on the substituents on the phenolic rings of the dyes. Immobilization of theT. hirsuta laccase on alumina enhanced the thermal stabilities of the enzyme and its tolerance against some enzyme inhibitors, such as halides, copper chelators, and dyeing additives. The laccase lost 50% of its activity at 50 mM NaCl while the 50% inhibitory concentration (IC50) of the immobilized enzyme was 85 mM. Treatment of dyes with the immobilized laccase reduced their toxicities (based on the oxygen consumption rate of Pseudomonas putida) by up to 80% (anthraquinonic dyes). Textile effluents decolorized with T. hirsuta or the laccase were used for dyeing. Metabolites and/or enzyme protein strongly interacted with the dyeing process indicated by lower staining levels (K/S) values than obtained with a blank using water. Howeve...

Research paper thumbnail of Cellobiose dehydrogenase functionalized urinary catheter as novel antibiofilm system

Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2015

Urinary catheters expose patients to a high risk of acquiring nosocomial infections. To prevent t... more Urinary catheters expose patients to a high risk of acquiring nosocomial infections. To prevent this risk of infection, cellobiose dehydrogenase (CDH), an antimicrobial enzyme able to use various oligosaccharides as electron donors to produce hydrogen peroxide using oxygen as an electron acceptor, was covalently grafted onto plasma-activated urinary polydimethylsiloxane (PDMS) catheter surfaces. Successful immobilization of CDH on PDMS was confirmed by Fourier transformed-infrared spectrometry and production of H2 O2 . The CDH functionalized PDMS surfaces reduced the amount of viable Staphylococcus aureus by 60%, total biomass deposited on the surface by 30% and 70% of biofilm formation. The immobilized CDH was relatively stable in artificial urine over 16 days, retaining 20% of its initial activity. The CDH coated PDMS surface did not affect the growth and physiology of HEK 239 and RAW 264,7 mammalian cells. Therefore this new CDH functionalized catheter system shows great potential for solving the current problems associated with urinary catheters. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2015.

Research paper thumbnail of DOI 10.1007/s10311-005-0004-3 ORIGINAL PAPER

A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show tha... more A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show that laccases of this organism were responsible for oxidation of the flavonoids morin, luteolin, rutin and quercetin. Out of two laccases produced by T. hirsuta (60.7 and 51.0 kDa) the more prominent 60.7 kDa laccase was purified and showed Km and kcat values of 75.5, 20.9 and 49.4 µM and 72.5, 96.3 and 32.7 s−1, hours on ABTS, syringaldazide and DMP, respectively. Pretreatment of cotton with the T. hirsuta laccase resulted in a whiteness increase of 8.5%.

Research paper thumbnail of Making the hospital a safer place by sonochemical coating of all its textiles with antibacterial nanoparticles

Ultrasonics sonochemistry, 2015

The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparti... more The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparticles is demonstrated in the current paper. A roll-to-roll pilot installation to coat textiles was built taking into consideration the requirements of the sonochemical process. A long-run experiment was conducted in which 2500m of fabric were coated with antibacterial ZnO nanoparticles (NPs). The metal oxide NPs were deposited from an ethanol:water solution. In this continuous process a uniform concentration of coated NPs over the length/width of the fabric was achieved. The antibacterial efficiency of the sonochemically-coated textiles was validated in a hospital environment by a reduction in the occurrence of nosocomial infections. NP-coated bed sheets, patient gowns, pillow cover, and bed covers were used by 21 patients. For comparison 16 patients used regular textiles. The clinical data indicated the reduced occurrence of hospital-acquired infections when using the metal oxide NP-coat...

Research paper thumbnail of Size and Aging Effects on Antimicrobial Efficiency of Silver Nanoparticles Coated on Polyamide Fabrics Activated by Atmospheric DBD Plasma

ACS Applied Materials & Interfaces, 2015

Research paper thumbnail of Progress on enzymatic preparation of flax and flax wool blends

Aatcc Review, 2005

This paper is outcome from a European Commission funded project under the FAIR programme and unde... more This paper is outcome from a European Commission funded project under the FAIR programme and under COST ACTION 847 “Textile Quality and Biotechnology”. It demonstrated the high level of international collaboration with VTT Biotechnology in Finland and Minho University in Portugal. The outcome of the paper brought in significant knowledge of traditional and novel enzymatic preparation for flax and flax blends to meet the cost effective production. The paper showed the leading research in the enzymatic treatment using laccases or laccases/mediator systems for degradation of lignin for producing high quality of flax textile materials. J Shen also published another two papers in the subject of evaluation of physical and chemical properties of flax fibres from stand-retted crops in JTI 2006 and Industrial Crops & Products 2005.

Research paper thumbnail of Contributor contact details

Advances in Textile Biotechnology, 2010

Research paper thumbnail of Tannic acid NPs – Synthesis and immobilization onto a solid surface in a one-step process and their antibacterial and anti-inflammatory properties

Ultrasonics Sonochemistry, 2014

Research paper thumbnail of Enzymatic pre-treatment as a means of enhancing the antibacterial activity and stability of ZnO nanoparticles sonochemically coated on cotton fabrics

Journal of Materials Chemistry, 2012

ABSTRACT Zinc oxide nanoparticles (ZnO NP's) are known for their excellent antibacter... more ABSTRACT Zinc oxide nanoparticles (ZnO NP's) are known for their excellent antibacterial properties. This paper describes a method for enhancing the stability and the antibacterial activity of ZnO NPs synthesized and embedded sonochemically on cotton fabrics, by pre-treating the fabric surface with cellulase enzyme. The enzymatic pre-treatment resulted in the deposition of smaller sized NPs with improved adhesion. The reduction in particle size brought about better antibacterial performance against several types of bacteria. The sonochemically produced ZnO coating withstood 10 laundry cycles at 92 °C retaining its antibacterial activity.

Research paper thumbnail of Voltammetric monitoring of laccase-catalysed mediated reactions

Bioelectrochemistry, 2002

Research paper thumbnail of Voltammetric monitoring of laccase-catalysed mediated reactions

Bioelectrochemistry, 2002

Research paper thumbnail of Mediators-boosted enzymatic bleaching of eucalyptus kraft pulp

Research paper thumbnail of Chitosan and chitosan–ZnO-based complex nanoparticles: formation, characterization, and antibacterial activity

Journal of Materials Chemistry B, 2013

Research paper thumbnail of Thermo-alkali-stable catalases from newly isolated Bacillus sp. for the treatment and recycling of textile bleaching effluents

Journal of Biotechnology, 2001

Research paper thumbnail of Bio-preparation of cotton fabrics

Enzyme and Microbial Technology, 2001

Research paper thumbnail of Immobilization of catalases from Bacillus SF on alumina for the treatment of textile bleaching effluents

Enzyme and Microbial Technology, 2001

Research paper thumbnail of Studies of stabilization of native catalase using additives

Enzyme and Microbial Technology, 2002

Research paper thumbnail of Predicting Dye Biodegradation from Redox Potentials

Biotechnology Progress, 2004

Research paper thumbnail of Bio-catalyzed coloration of cellulose fibers

Biocatalysis and Biotransformation, 2007

Cotton fabrics were dyed with dyes generated in situ by laccase-catalyzed oxidative coupling of t... more Cotton fabrics were dyed with dyes generated in situ by laccase-catalyzed oxidative coupling of the colorless 2, 5-diaminobenzenesulfonic acid (2, 5-DABSA) and 1-hydroxyphenol (catechol). The enzymatic oxidation of the dye intermediates led to cross-...

Research paper thumbnail of Effect of Some Process Parameters in Enzymatic Dyeing of Wool

Applied Biochemistry and Biotechnology, 2003

Research paper thumbnail of Decolorization and Detoxification of Textile Dyes with a Laccase from Trametes hirsuta

Applied and Environmental Microbiology, 2000

Trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, i... more Trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, indigoid, azo, and anthraquinonic dyes. Initial decolorization velocities depended on the substituents on the phenolic rings of the dyes. Immobilization of theT. hirsuta laccase on alumina enhanced the thermal stabilities of the enzyme and its tolerance against some enzyme inhibitors, such as halides, copper chelators, and dyeing additives. The laccase lost 50% of its activity at 50 mM NaCl while the 50% inhibitory concentration (IC50) of the immobilized enzyme was 85 mM. Treatment of dyes with the immobilized laccase reduced their toxicities (based on the oxygen consumption rate of Pseudomonas putida) by up to 80% (anthraquinonic dyes). Textile effluents decolorized with T. hirsuta or the laccase were used for dyeing. Metabolites and/or enzyme protein strongly interacted with the dyeing process indicated by lower staining levels (K/S) values than obtained with a blank using water. Howeve...