Laboratoř environmentální chemie a enzymologie

@article{nokey,

title = {Valorization of brewer's spent grain using biological treatments and its application in feeds for European seabass (Dicentrarchus labrax)},

author = {Fernandes Helena, and Salgado José Manuel, and Ferreira Marta, and Vršanská Martina, and Fernandes Nélson, and Castro Carolina, and Oliva-Teles Aires, and Peres Helena, Belo Isabel},

url = {https://www.frontiersin.org/article/10.3389/fbioe.2022.732948},

doi = {10.3389/fbioe.2022.732948   },

issn = {2296-4185  },

year  = {2022},

date = {2022-05-03},

journal = {Frontiers in Bioengineering and Biotechnology},

volume = {10},

abstract = {Brewer’s spent grain (BSG) is the main brewery industry by-product, with potential applications in the feed and food industries due to its carbohydrate composition. In addition, the lignocellulosic nature of BSG makes it an adequate substrate for carbohydrases production. In this work, solid-state fermentation (SSF) of BSG was performed with Aspergillus ibericus, a non-mycotoxin producer fungus with a high capacity to hydrolyze the lignocellulosic matrix of the agro-industrial by-products. SSF was performed at different scales to produce a crude extract rich in cellulase and xylanase. The potential of the crude extract was tested in two different applications: -(1) - the enzymatic hydrolysis of the fermented BSG and (2) - as a supplement in aquafeeds. SSF of BSG increased the protein content from 25% to 29% (w/w), while the fiber content was reduced to 43%, and cellulose and hemicellulose contents were markedly reduced to around 15%. The scale-up of SSF from 10 g of dry BSG in flasks to 50 g or 400 g in tray-type bioreactors increased 55% and 25% production of cellulase and xylanase, up to 323 and 1073 U g^{−1} BSG, respectively. The optimum temperature and pH of maximal activities were found to be 55°C and pH 4.4 for xylanase and 50°C and pH 3.9 for cellulase, cellulase being more thermostable than xylanase when exposed at temperatures from 45°C to 60°C. A Box–Behnken factorial design was applied to optimize the hydrolysis of the fermented BSG by crude extract. The crude extract load was a significant factor in sugars release, highlighting the role of hydrolytic enzymes, while the load of fermented BSG, and addition of a commercial β-glucosidase were responsible for the highest phenolic compounds and antioxidant activity release. The lyophilized crude extract (12,400 and 1050 U g^{−1} lyophilized extract of xylanase and cellulase, respectively) was also tested as an enzyme supplement in aquafeed for European seabass (Dicentrarchus labrax) juveniles. The dietary supplementation with the crude extract significantly improved feed and protein utilization. The processing of BSG using biological treatments, such as SSF with A. ibericus, led to the production of a nutritionally enriched BSG and a crude extract with highly efficient carbohydrases capable of hydrolyzing lignocellulosic substrates, such as BSG, and with the potential to be used as feed enzymes with remarkable results in improving feed utilization of an important aquaculture fish species.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Laminated PAA nanofibers as a practical support for crude laccase: A new perspective for biocatalytic treatment of micropollutants in wastewaters},

author = {Milena Maryskova, and Martina Vrsanska, and Alena Sevcu, and Vit Novotny, and Andrea Blahutova, and Stanislava Voberkova,},

doi = {https://doi.org/10.1016/j.eti.2022.102316},

isbn = {2352-1864},

year  = {2022},

date = {2022-01-17},

urldate = {2022-01-17},

journal = {Environmental Technology & Innovation},

volume = {26},

abstract = {Increasing concentrations of endocrine disrupting pollutants from countless human activities represent an increasingly serious threat to the environment. However, crude microbial enzymes that are easily obtained from nature may serve as eco-friendly and cost-effective biocatalysts for polluted wastewater treatment. In this work, crude laccase, obtained from white-rot fungi Trametes versicolor, was covalently immobilized onto laminated poly(acrylic acid) nanofibers and its biocatalytic activity and stability tested on real wastewater effluent. The immobilized crude laccase retained almost 80% of its initial activity after 35 days of storage in wastewater, with no significant inhibition of enzymatic activity caused by the high concentrations of inorganic salts or cations. Most importantly, immobilized laccase proved highly effective in degrading a mixture of bisphenol A, 17α-ethinylestradiol, triclosan and diclofenac in wastewater effluent over 14 days. Based on these results, crude laccase from T. versicolor could represent an important new perspective for wastewater treatment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Antioxidant and Antibacterial Properties of Norway Spruce (Picea abies H. Karst.) and Eastern Hemlock (Tsuga canadensis (L.) Carrière) Cone Extracts},

author = {HOFMANN, T. and ALBERT, L. and NEMETH, L. and VRSANSKA, M. and SCHLOSSEROVA, N. and VOBERKOVA, S. and VISI-RAJCZI, E.},

doi = { https://doi.org/10.3390/f12091189},

year  = {2021},

date = {2021-09-01},

urldate = {2021-09-01},

journal = {Forests},

volume = {12},

issue = {9},

abstract = {According to recent studies, Norway spruce cones and eastern hemlock cones possess exceptionally high antioxidant capacities; however, the antioxidant efficiency of extractives and their bioactive effects have yet to be investigated in detail. The present article utilizes state-of-the art analytical chemical methodology and chemometric evaluation to reveal cone extractives with the highest antioxidant potential, accounting for possible bioactive effects. Antioxidant properties were determined by the Ferric reducing antioxidant power (FRAP) assay and the Folin–Ciocalteu’s total phenol content (TPC) assay. Structure and relative polyphenol concentrations were determined using liquid chromatography/diode array detection/tandem mass spectrometry. The antibacterial testing was conducted using Staphylococcus aureus and Escherichia coli strains. Using correlation analysis and factor analysis, a scoring evaluation was implemented to determine and compare the antioxidant efficiency of extractives. In Norway spruce, piceatannol-O-hexoside and coumaric acid derivatives were found to be the most powerful antioxidants, while in eastern hemlock, kaempferol glycosides were the most powerful. The antibacterial test did not show any promising antimicrobia},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {In vitro antioxidant and antibacterial activities with polyphenolic profiling of wild cherry, the European larch and sweet chestnut tree bark},

author = {Agarwal, C., and Hofmann, T., and Vrsanska, M., and Schlosserova, N., and Visi-Rajczi, E., and Voberkova, S., and Pasztory, Z.},

doi = {https://doi.org/10.1007/s00217-021-03796-w},

issn = {2355-2370},

year  = {2021},

date = {2021-01-12},

urldate = {2021-01-12},

journal = {European Food Research and Technology},

abstract = {This study is a comparative investigation of antioxidant and antibacterial properties of tree bark extracts of three common European species, Prunus avium L., Larix decidua Mill. and Castanea sativa Mill. The bioactive compounds present in the bark were recovered in 80% aqueous ethanol using ultrasound as the green extraction method. The antioxidant potential of the extracts was assessed with multiple biochemical assays: total phenol content (TPC) expressed in gallic acid equivalent (GAE), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) expressed in trolox equivalent (TE), and ferric reducing ability of plasma (FRAP) expressed in ascorbic acid equivalent (AAE). Sweet chestnut bark extract showed the highest antioxidant activity with TPC of 174.25 ± 16.95 mg GAE/g dry weight, DPPH (IC50) of 2.69 ± 0.03 μg/mL, ABTS of 739.65 ± 24.41 mg TE/g dry weight and FRAP of 207.49 ± 3.62 mg AAE/g dry weight. The antibacterial activity of the extracts was evaluated by disk diffusion test, minimal inhibitory concentration (MIC) assay and bacterial growth curves. Sweet chestnut bark extract gave IC50 values of 0.25 mg/mL and 1.00 mg/mL against E. coli and S. aureus, respectively. The polyphenolic profiling of the bark extracts was performed to identify the major compounds responsible for the bioactivities using high-performance liquid chromatography/tandem mass spectrometry (HPLC–MS/MS). The bark extracts were rich in natural antioxidants, thus holding tremendous potential for use as natural additives in food industry.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32224413b,

title = {Food waste composting - Is it really so simple as stated in scientific literature? - A case study},

author = {Stanislava Voběrková and Alžbeta Maxianová and Nikola Schlosserová and Dana Adamcová and Martina Vršanská and Lukáš Richtera and Milica Gagić and Jan Zloch and Magdalena Daria Vaverková},

doi = {10.1016/j.scitotenv.2020.138202},

issn = {1879-1026},

year  = {2020},

date = {2020-06-01},

journal = {Sci Total Environ},

volume = {723},

pages = {138202},

abstract = {Food waste has recently gained much worldwide interest due to its influence on the environment, economy and society. Gathering and recycling of food waste is the essential issue in the waste management and the interest in processing food waste arises mainly out of influence of the processes of food putrefaction on the environment. Composting of food waste encounters a number of technical challenges, arising weak physical structure of food waste with weak porosity, high content of water, low carbon-to-nitrogen relation and fast hydrolysis and accumulation of organic acids during composting. Therefore, the aim of this study was to investigate the challenges facing installations intended for food waste composting, with the purpose to their optimization with use of appropriate additives. Physico-chemical, biochemical characteristics and phytotoxicity of the produced compost has been measured. Two additives (20% biochar and 20% sawdust) were chosen from experimental variants I-XII containing different additives (biochar, Devonian sand, sawdust) in diverse concentration. The use of selected additives seems to slightly increase potential of hydrogen value and carbon-to-nitrogen ratio, while decreasing electrical conductivity in comparison with control sample. The results obtained also show that the addition of biochar leads to an increase dehydrogenase, phosphatase and arylsulphatase activities and addition of sawdust has a positive effect on beta-D-glucosidase, protease, phosphatase and arylsulphatase activities. The phytotoxicity test shows that the compost made of food waste (control sample) and with addition of biochar is toxic to plants. By contrast, the addition of sawdust shows that the compost was not phytotoxic. In conclusion, the addition of additives does not provide unambiguous results in terms of the quality of the final product in all monitored parameters. Therefore, we can state that food waste was reduced and hygienized, and that the final product does not meet conditions for mature compost.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32224413,

title = {Food waste composting - Is it really so simple as stated in scientific literature? - A case study},

author = {Stanislava Voběrková and Alžbeta Maxianová and Nikola Schlosserová and Dana Adamcová and Martina Vršanská and Lukáš Richtera and Milica Gagić and Jan Zloch and Magdalena Daria Vaverková},

doi = {10.1016/j.scitotenv.2020.138202},

issn = {1879-1026},

year  = {2020},

date = {2020-06-01},

journal = {Sci Total Environ},

volume = {723},

pages = {138202},

abstract = {Food waste has recently gained much worldwide interest due to its influence on the environment, economy and society. Gathering and recycling of food waste is the essential issue in the waste management and the interest in processing food waste arises mainly out of influence of the processes of food putrefaction on the environment. Composting of food waste encounters a number of technical challenges, arising weak physical structure of food waste with weak porosity, high content of water, low carbon-to-nitrogen relation and fast hydrolysis and accumulation of organic acids during composting. Therefore, the aim of this study was to investigate the challenges facing installations intended for food waste composting, with the purpose to their optimization with use of appropriate additives. Physico-chemical, biochemical characteristics and phytotoxicity of the produced compost has been measured. Two additives (20% biochar and 20% sawdust) were chosen from experimental variants I-XII containing different additives (biochar, Devonian sand, sawdust) in diverse concentration. The use of selected additives seems to slightly increase potential of hydrogen value and carbon-to-nitrogen ratio, while decreasing electrical conductivity in comparison with control sample. The results obtained also show that the addition of biochar leads to an increase dehydrogenase, phosphatase and arylsulphatase activities and addition of sawdust has a positive effect on beta-D-glucosidase, protease, phosphatase and arylsulphatase activities. The phytotoxicity test shows that the compost made of food waste (control sample) and with addition of biochar is toxic to plants. By contrast, the addition of sawdust shows that the compost was not phytotoxic. In conclusion, the addition of additives does not provide unambiguous results in terms of the quality of the final product in all monitored parameters. Therefore, we can state that food waste was reduced and hygienized, and that the final product does not meet conditions for mature compost.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32222681,

title = {Composting versus mechanical-biological treatment: Does it really make a difference in the final product parameters and maturity},

author = {Magdalena Daria Vaverková and Jakub Elbl and Stanislava Voběrková and Eugeniusz Koda and Dana Adamcová and Zygmunt Mariusz Gusiatin and Abd Al Rahman and Maja Radziemska and Zbigniew Mazur},

doi = {10.1016/j.wasman.2020.03.030},

issn = {1879-2456},

year  = {2020},

date = {2020-04-01},

journal = {Waste Manag},

volume = {106},

pages = {173--183},

abstract = {One of crucial waste management problems is the management of organic waste. This activity employs the composting. In case of green waste, its application seems reasonable, whereas the use of selected mixed waste raises problems related to the compost quality. Across countries, the non-sterile organic fraction of municipal solid waste is being separated through the mechanical-biological treatment. The technology is a solution of waste treatment and meets objectives set out in the Landfill Directive. There are many problems associated with the use of output products. The use of compost as a fertilizer requires determination of its impact on the environment. Compost quality can be assessed using analytical methods and phytotoxicity tests. Therefore, the aim of this study was to describe changes in physico-chemical, enzymatic, phytotoxicity and vegetation parameters occurring in composts from two systems - a prismatic installation for green waste, and a mechanical-biological treatment installation. The compost from green waste exhibited greater stability. Values of dehydrogenase activity were lower if compared with the mechanically and biologically treated compost, which indicates lower compost maturity. The biomass production of Brassica napus L. and Fetuca rubra L. was higher in the variant with the application of green compost. The influence on Hordeum vulgare L., Cannabis sativa L., and Sinapis alba L. depended on the plant type and the compost used. Nevertheless, the compost from green waste was less toxic. The evidence from this study suggests that the mechanical-biological treatment had problems associated with the maturation and quality of the final product.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32540568,

title = {Soil protein as a potential antimicrobial agent against methicillin -resistant Staphylococcus aureus},

author = {Hanadi Ananbeh and Miguel Angel Merlos Rodrigo and Pavlina Jelinkova and Vladislav Strmiska and Zbynek Splichal and Nico Jehmlich and Hana Michalkova and Marko Stojanović and Stanislava Voberkova and Vojtech Adam and Amitava Moulick},

doi = {10.1016/j.envres.2020.109320},

issn = {1096-0953},

year  = {2020},

date = {2020-01-01},

journal = {Environ Res},

volume = {188},

pages = {109320},

abstract = {Recently, the interest is increasing to find alternatives to replace the usage of antibiotics since their massive and improper usage enhance the antibiotic resistance in human pathogens. In this study, for the first time we showed that the soil proteins have very high antibacterial activity (98% of growth inhibition) against methicillin resistant Staphylococcus aureus (MRSA), one of the most threatening human pathogens. We found that the protein extract (C3) from the forest with past intensive management showed higher antibacterial activity than that of unmanaged forest. The MIC and IC were found to be 30 and 15.0 μg protein g dry soil respectively. C3 was found to kill the bacteria by cell wall disruption and genotoxicity which was confirmed by optical and fluorescent microscopy and comet assay. According to qPCR study, the mecA (the antibiotic resistant gene) expression in MRSA was found to be down-regulated after C3 treatment. In contrast, C3 showed no hemolytic toxicity on human red blood cells which was confirmed by hemolytic assay. According to ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), 144 proteins were identified in C3 among which the majority belonged to Gram negative bacteria (45.8%). Altogether, our results will help to develop novel, cost-effective, non-toxic and highly efficient antibacterial medicines from natural sources against antibiotic resistant infections.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31398647,

title = {Use of soil enzyme activities to assess the recovery of soil functions in abandoned coppice forest systems},

author = {Hanadi Ananbeh and Marko Stojanović and Antonio Pompeiano and Stanislava Voběrková and Carmen Trasar-Cepeda},

doi = {10.1016/j.scitotenv.2019.133692},

issn = {1879-1026},

year  = {2019},

date = {2019-12-01},

journal = {Sci Total Environ},

volume = {694},

pages = {133692},

abstract = {Coppicing consists of periodically cutting back tree stems to ground level to stimulate the growth of multiple stems from the stool. In Central Europe, many coppiced forests were abandoned at the beginning of the last century owing to a decline in the demand for charcoal and wood. This was assumed to enable the forests to recover and the properties to become similar to those of unmanaged forest (high forest). Most studies on abandoned coppiced forest have focused on forest recovery, while soil recovery has generally been overlooked. With the aim of filling this gap, this study investigated the effect of coppicing abandonment on soil recovery by analysing the changes in soil enzyme activities (dehydrogenase, β-glucosidase, invertase, urease, acid phosphatase and arylsulphatase). Two differently managed sessile oak (Quercus petraea) forests were selected for study: a former coppice forest, abandoned >90 years ago, and an undisturbed forest. The analytical data were compared to assess the degree of recovery of the soil in the abandoned coppice forest. The soil organic matter content was two times lower in the abandoned coppice than in the high forest, suggesting that organic matter depletion due the past coppicing is a long-term effect. All of the absolute enzyme activities were also two times lower in the abandoned coppice forest soil than in the high forest soil. However, the specific enzyme activities were similar in both types of soil. This indicates that metabolic activity is similar in both soil types, suggesting that it either recovers faster than organic matter and soil enzyme activity or that, despite the depletion in organic matter and enzyme activities, metabolic activity was sustained in coppiced forest soil. However, in the latter case this would imply that organic matter and soil enzymes were lost in exactly the same proportion, which is highly improbable.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29602102,

title = {Immobilization of ligninolytic enzymes from white-rot fungi in cross-linked aggregates},

author = {Stanislava Voběrková and Veronika Solčány and Martina Vršanská and Vojtěch Adam},

doi = {10.1016/j.chemosphere.2018.03.088},

issn = {1879-1298},

year  = {2018},

date = {2018-07-01},

journal = {Chemosphere},

volume = {202},

pages = {694--707},

abstract = {Ligninolytic enzymes from white-rot fungi are widely used in biotechnological processes. However, the application of these enzymes as free enzymes is limited due to their instability and lack of reusability. Enzyme stabilization is therefore a major challenge in biocatalytic process research, and immobilization methods are desirable. Using cross-linked enzyme aggregates (CLEAs) such as magnetic CLEAs, porous-CLEAs and combi-CLEAs is a promising technique for overcoming these issues. Cross-linking methods can stabilize and immobilize enzymes by interconnecting enzyme molecules via multiple bonds using cross-linking agents such as glutaraldehyde. The high catalyst density and microporous assembly of CLEAs guarantee high catalyst activity, which, together with their long shelf life, operational stability, and reusability, provide a cost-efficient alternative to matrix-assisted immobilization approaches. Here, we review current progress in ligninolytic enzyme immobilization and provide a comprehensive review of CLEAs. Moreover, we summarize the use of these CLEAs for biocatalysis processes, bioremediation such as dye decolourization, wastewater treatment or pharmaceutically active compound elimination.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Enzyme Production During Composting of Aliphatic–Aromatic Copolyesters in Organic Wastes},

author = {Stanislava Voběrková, and Magdalena Dária Vaverková, and Dana Adamcová.},

doi = {http://doi.org/10.1089/ees.2015.0445},

year  = {2017},

date = {2017-03-01},

urldate = {2017-03-01},

journal = {Environmental Engineering Science},

volume = {34},

issue = {3},

abstract = {Monitoring of various enzymes' production throughout the process provides useful information on the dynamics of composting and is beneficial for understanding the transformations occurring during composting. In this study, aliphatic–aromatic copolyesters with different polyethylene terephthalate/poly(lactic) acid ratios were subjected to laboratory-scale and full-scale composting conditions. Activities of hydrolase (urease, protease, lipase, and cellulase) and dehydrogenase were monitored during 21 days to better understand the effect of polymer presence on enzyme production. After 7 days, a significant increase in lipase, protease, and cellulase activities in compost soil with polymer indicates qualitative and quantitative changes in the content of particular organic polymers, probably due to polymer degradation. This observation was more pronounced for copolyesters A and B and also for reference material—model aromatic oligomer. This result is in correlation with dehydrogenase activity, which reflected a higher microbial growth in compost soil containing polymer. Production of all monitored enzymes was significantly higher in a real compost pile when compared to laboratory composting conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28065548,

title = {Effect of inoculation with white-rot fungi and fungal consortium on the composting efficiency of municipal solid waste},

author = {Stanislava Voběrková and Magdalena D Vaverková and Alena Burešová and Dana Adamcová and Martina Vršanská and Jindřich Kynický and Martin Brtnický and Vojtěch Adam},

doi = {10.1016/j.wasman.2016.12.039},

issn = {1879-2456},

year  = {2017},

date = {2017-03-01},

journal = {Waste Manag},

volume = {61},

pages = {157--164},

abstract = {An investigation was carried out on the effect of inoculation methods on the compost of an organic fraction of municipal solid waste. Three types of white-rot fungi (Phanerochaete chrysosporium, Trametes versicolor and Fomes fomentarius), and a consortium of these fungi, were used. The study assessed their influence on microbial enzymatic activities and the quality of the finished compost. It was found that the addition of white-rot fungi to municipal solid waste (after 37days of composting) could be a useful strategy for enhancing the properties of the final compost product. In comparison with the control sample (compost without inoculation), it accelerates degradation of solid waste as indicated by changes in C/N, electrical conductivity and pH. However, the effectiveness of waste degradation and compost maturation depends on the type of microorganism used for inoculation. The presence of inoculants, such as Trametes versicolor and Fomes fomentarius, led to a higher degrading ratio and a better degree of maturity. This resulted in an increase of enzymatic activities (especially dehydrogenase and protease) and a germination index in comparison with inoculation using Phanerochaete chrysosporium or a consortium of fungi.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Enzyme Production During Composting of Aliphatic–Aromatic Copolyesters in Organic Wastes},

author = {Stanislava Voběrková and Magdalena Dária Vaverková and Dana Adamcová},

doi = {https://doi.org/10.1089/ees.2015.0445},

year  = {2017},

date = {2017-03-01},

journal = {Environmental Engineering Science},

volume = {34},

number = {3},

abstract = {Monitoring of various enzymes' production throughout the process provides useful information on the dynamics of composting and is beneficial for understanding the transformations occurring during composting. In this study, aliphatic–aromatic copolyesters with different polyethylene terephthalate/poly(lactic) acid ratios were subjected to laboratory-scale and full-scale composting conditions. Activities of hydrolase (urease, protease, lipase, and cellulase) and dehydrogenase were monitored during 21 days to better understand the effect of polymer presence on enzyme production. After 7 days, a significant increase in lipase, protease, and cellulase activities in compost soil with polymer indicates qualitative and quantitative changes in the content of particular organic polymers, probably due to polymer degradation. This observation was more pronounced for copolyesters A and B and also for reference material—model aromatic oligomer. This result is in correlation with dehydrogenase activity, which reflected a higher microbial growth in compost soil containing polymer. Production of all monitored enzymes was significantly higher in a real compost pile when compared to laboratory composting conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29295505,

title = {Preparation and Optimisation of Cross-Linked Enzyme Aggregates Using Native Isolate White Rot Fungi Trametes versicolor and Fomes fomentarius for the Decolourisation of Synthetic Dyes},

author = {Martina Vršanská and Stanislava Voběrková and Ana María Jiménez Jiménez and Vladislav Strmiska and Vojtěch Adam},

doi = {10.3390/ijerph15010023},

issn = {1660-4601},

year  = {2017},

date = {2017-01-01},

journal = {Int J Environ Res Public Health},

volume = {15},

number = {1},

abstract = {The key to obtaining an optimum performance of an enzyme is often a question of devising a suitable enzyme and optimisation of conditions for its immobilization. In this study, laccases from the native isolates of white rot fungi  and/or , obtained from Czech forests, were used. From these, cross-linked enzyme aggregates (CLEA) were prepared and characterised when the experimental conditions were optimized. Based on the optimization steps, saturated ammonium sulphate solution (75 wt.%) was used as the precipitating agent, and different concentrations of glutaraldehyde as a cross-linking agent were investigated. CLEA aggregates formed under the optimal conditions showed higher catalytic efficiency and stabilities (thermal, pH, and storage, against denaturation) as well as high reusability compared to free laccase for both fungal strains. The best concentration of glutaraldehyde seemed to be 50 mM and higher efficiency of cross-linking was observed at a low temperature 4 °C. An insignificant increase in optimum pH for CLEA laccases with respect to free laccases for both fungi was observed. The results show that the optimum temperature for both free laccase and CLEA laccase was 35 °C for  and 30 °C for . The CLEAs retained 80% of their initial activity for  and 74% for  after 70 days of cultivation. Prepared cross-linked enzyme aggregates were also investigated for their decolourisation activity on malachite green, bromothymol blue, and methyl red dyes. Immobilised CLEA laccase from  showed 95% decolourisation potential and CLEA from  demonstrated 90% decolourisation efficiency within 10 h for all dyes used. These results suggest that these CLEAs have promising potential in dye decolourisation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid27869681,

title = {Induction of Laccase, Lignin Peroxidase and Manganese Peroxidase Activities in White-Rot Fungi Using Copper Complexes},

author = {Martina Vrsanska and Stanislava Voberkova and Vratislav Langer and Dagmar Palovcikova and Amitava Moulick and Vojtech Adam and Pavel Kopel},

doi = {10.3390/molecules21111553},

issn = {1420-3049},

year  = {2016},

date = {2016-11-01},

journal = {Molecules},

volume = {21},

number = {11},

abstract = {Ligninolytic enzymes, such as laccase, lignin peroxidase and manganese peroxidase, are biotechnologically-important enzymes. The ability of five white-rot fungal strains , , ,  and  to produce these enzymes has been studied. Three different copper(II) complexes have been prepared ((Him)[Cu(im)₄(H₂O)₂](btc)·3H₂O, where im = imidazole, H₃btc = 1,3,5-benzenetricarboxylic acid, [Cu₃(pmdien)₃(btc)](ClO₄)₃·6H₂O) and [Cu₃(mdpta)₃(btc)](ClO₄)₃·4H₂O, where pmdien = ,,','',''-pentamethyl-diethylenetriamine and mdpta = ,-bis-(3-aminopropyl)methyl- amine), and their potential application for laccase and peroxidases induction have been tested. The enzyme-inducing activities of the complexes were compared with that of copper sulfate, and it has been found that all of the complexes are suitable for the induction of laccase and peroxidase activities in white-rot fungi; however, the newly-synthesized complex M1 showed the greatest potential for the induction. With respect to the different copper inducers, this parameter seems to be important for enzyme activity, which depends also on the fungal strains.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid26139336,

title = {Biofilm formation and extracellular polymeric substances (EPS) production by Bacillus subtilis depending on nutritional conditions in the presence of polyester film},

author = {Stanislava Voběrková and Soňa Hermanová and Kamila Hrubanová and Vladislav Krzyžánek},

doi = {10.1007/s12223-015-0406-y},

issn = {1874-9356},

year  = {2016},

date = {2016-03-01},

journal = {Folia Microbiol (Praha)},

volume = {61},

number = {2},

pages = {91--100},

abstract = {The influence of biofilm formation as the mode of microorganism growth on degradation of synthetic polymers represents an important research topic. This study focuses on the effect of biofilm developed by Bacillus subtilis (BS) cultivated submerged under various nutrition conditions on biodeterioration of poly(ε-caprolactone) film. Polymer in the film form (thickness 0.7 mm) was incubated for 21 days either continuously or by regularly renewed system. The scission of polyester chain bonds took place in all biotic media and was enhanced by biofilm formation in nutrient-rich media.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}