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Qiang Fu, Alexander Sutherland, Emil Gustafsson, Md Monsur Ali, Leyla Soleymani, Robert H Pelton
The structure and electrochemical properties of adsorbed complexes based on mixtures of polyvinylamine-g-TEMPO (PVAm-T) and laccase were related to the ability of the adsorbed complexes to oxidize cellulose. PVAm-T10 with 10% of the amines bearing TEMPO moieties (i.e. DS= 10%), adsorbed onto gold-sulfonate EQCM-D sensor surfaces giving a hydrogel film, 7 nm thick, 89% water and encasing laccase (200 mM) and TEMPO moieties (33 mM). For DS values >10% all of the TEMPOs in the hydrogel film were redox-active, in that they could be oxidized by the electrode...
July 21, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Daniel M Lewis, Michael R Blatchley, Kyung Min Park, Sharon Gerecht
Oxygen (O2) acts as a potent upstream regulator of cell function. In both physiological and pathophysiological microenvironments, the O2 concentration is not uniformly distributed but instead follows a gradient that depends on distance from oxygen-carrying blood vessels. Such gradients have a particularly important role in development, tissue regeneration, and tumor growth. In this protocol, we describe how to use our previously reported gelatin-based O2-controllable hydrogels that can provide hypoxic microenvironments in vitro...
August 2017: Nature Protocols
Thais Dal Picolli, Kaliane Regalin Aver, Roselei Claudete Fontana, Marli Camassola
Biological pre-treatment seems to be promising being an eco-friendly process, with no inhibitor generated during the process. The potential for elephant grass pre-treatment with white degradation fungi Pleurotus ostreatus, Agaricus blazei, Lentinula edodes, Pleurotus citrinopileatus and Pleurotus djamor, in isolated or mixed cultures of these strains, was evaluated. The highest activities of enzymes involved in the degradation of lignocellulosic biomass (laccases, endoglucanases, xylanases and β-glucosidases) were observed for A...
July 20, 2017: Biotechnology Progress
H Schalchli, E Hormazábal, O Rubilar, G Briceño, A Mutis, G J Zocolo, C Diez
AIMS: The aim of this study was to evaluate the synthesis of ligninolytic enzymes and some diffusible antifungal compounds by white-rot fungi using peels or discarded potato as the sole nutrient source. METHODS AND RESULTS: The strain Trametes hirsuta Ru-513 has been highlighted for its laccase activity (595 ± 33 U l(-1) ), which is able to decolourise 87% of an anthraquinone dye using potato peels as the sole nutritional support. A native polyacrylamide gel of laccase proteins showed the presence of two isoenzymes, corresponding to proteins of 56 and 67 kDa, which were detected by SDS-PAGE...
July 18, 2017: Journal of Applied Microbiology
Thomas Gillgren, Mattias Hedenström, Leif J Jönsson
Lignin, an underutilized by-product from chemical pulping of wood, can be modified enzymatically through oxidation by laccase. However, little is known about the molecular details surrounding the cross-linking which is a result of the oxidation. To reduce this lack of knowledge, we used oxygen consumption rate data, phenolic content data and molecular weight data together with data from NMR and FTIR spectroscopy to characterize laccase-catalyzed cross-linking of the industrial lignin preparations organosolv lignin and lignosulfonate...
July 12, 2017: International Journal of Biological Macromolecules
Nasrin Jafari, Shahla Rezaei, Rezvan Rezaie, Haleh Dilmaghani, Mohammad Reza Khoshayand, Mohammad Ali Faramarzi
Extremozymes have gained importance for their ability to efficiently develop the processes in rigorous industrial conditions with incidence in the recycling of especially robust natural wastes. The production of an extracellular laccase from the halophilic bacterium Chromohalobacter salexigens aided for the bio-delignification of almond shell was optimized using response surface methodology followed by one-factor-at-a-time, resulting in an 80-fold increase in the enzyme yield. Out of 10 different medium components, CuSO4, ZnSO4, glucose, and urea were shown to have the greatest effects on the laccase production...
July 11, 2017: International Journal of Biological Macromolecules
Wen Zhou, Zheng-Bing Guan, Yu Chen, Feng Zhang, Yu-Jie Cai, Cheng-Wen Xu, Xu-Sheng Chen, Xiang-Ru Liao
Given that spore laccase from the Bacillus genus is heat- and alkali-resistant, it is more suitable for industrial applications than fungal laccase. To determine the optimal culture conditions for spore laccase production, the effects of Cu(2+) concentration, oxygen content, and culture time on spore laccase production from Bacillus pumilus W3 were investigated. The optimal production parameters were 0.2 mM of Cu(2+), 200 rpm shaking speed, 100 mL liquid loading, and 5 days of cultivation. Spore laccase was efficiently immobilized on amino-functionalized celite...
July 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Julien Le Roy, Anne-Sophie Blervacq, Anne Créach, Brigitte Huss, Simon Hawkins, Godfrey Neutelings
BACKGROUND: Bast fibres are characterized by very thick secondary cell walls containing high amounts of cellulose and low lignin contents in contrast to the heavily lignified cell walls typically found in the xylem tissues. To improve the quality of the fiber-based products in the future, a thorough understanding of the main cell wall polymer biosynthetic pathways is required. In this study we have carried out a characterization of the genes involved in lignin biosynthesis in flax along with some of their regulation mechanisms...
July 14, 2017: BMC Plant Biology
D Ratautas, L Tetianec, L Marcinkevičienė, R Meškys, J Kulys
In this paper we designed and investigated bioanode with alcohol dehydrogenase (ADH) catalysing oxidation of glycerol and glyceraldehyde. The most effective bioanode was fabricated when ADH was immobilized on gold nanoparticles (AuNPs) modified with 4-aminothiophenol. This electrode catalysed the oxidation of both glycerol and glyceraldehyde thus demonstrating a consecutive two-step process. The bioanode generated the current density of 510µAcm(-2) at pH 7.0 and 0V vs. SCE. It was demonstrated that the electrode acted effectively due to the direct electron exchange between heme of ADH and modified AuNPs...
June 27, 2017: Biosensors & Bioelectronics
Ruowen Wang, Jing Yang, Guoqing Zhang, Yapeng Chao, Zhimin Li, Qin Ye, Shijun Qian
Trichoderma reesei strain Rut-C30 was modified with enhanced beta-glycosidase (BGL) activity to balance the cellulase system and generated laccase (LAC) protein for lignin degradation. Initially, the binary plasmid p1300-w1 was constructed to express T. reesei bgl2 under the control of promoter P pki and T-nos terminator. Random insertion was performed via Agrobacterium tumefaciens-mediated transformation. A total of 353 mutants were obtained, and 34PTrb2 was exceptionally stable with increased FPA and BGL activity after screening for extracellular enzyme activity...
August 2017: Molecular Biotechnology
A Luna-Acosta, Marine Breitwieser, T Renault, H Thomas-Guyon
The production of melanin is a complex process involving biochemical cascades, such as the pro-phenoloxidase (proPO) system, and enzymes, such as phenoloxidases (POs). Different studies have shown a strong correlation between the decrease in PO activities and the occurrence of diseases in bivalve invertebrates, leading to mortalities in the host. Results of these studies suggest that POs could play a fundamental role in defense mechanisms in bivalves. This article reviews the fundamental knowledge on the proPO system in bivalves and the methods used to assess PO activities...
June 30, 2017: Marine Pollution Bulletin
Daniela Baldantoni, Raffaella Morelli, Alessandro Bellino, Maria Vittoria Prati, Anna Alfani, Flavia De Nicola
In order to validate the use of compost in soil PAH bioremediation, the degradation of anthracene and benzo(a)pyrene was monitored in soils artificially contaminated and incubated in mesocosms under controlled conditions. The dynamics observed in compost amended soil were compared to those observed in soil added with a fungal consortium and untreated soil. At the same time, three microbial enzyme activities usually involved in PAH degradation (laccase, o-diphenol oxidase and peroxidase activities) were monitored...
June 21, 2017: Journal of Hazardous Materials
Chaolin Guo, Liting Zhao, Feng Wang, Jian Lu, Zhongyang Ding, Guiyang Shi
Laccase is widely used in several industrial applications and co-culture is a common method for enhancing laccase production in submerged fermentation. In this study, the co-culture of four yeasts with Pleurotus eryngii var. ferulae was found to enhance laccase production. An analysis of sterilization temperatures and extraction conditions revealed that the stimulatory compound in yeasts was temperature-sensitive, and that it was fat-soluble. An LC-MS analysis revealed that the possible stimulatory compound for laccase production in the four yeast extracts was β-carotene...
2017: Frontiers in Microbiology
M Taheran, M Naghdi, S K Brar, E J Knystautas, M Verma, R Y Surampalli
The continuous release of antibiotic compounds through wastewater effluent into environment has raised concerns about their potential problems for different organisms. Enzymatic degradation with laccase is a green option for removal of pharmaceutical compounds from aqueous media. In this study, laccase was immobilized onto homemade Polyacrylonitrile-biochar composite nanofibrous membrane and the obtained biocatalyst was employed for removal of chlortetracycline, a widely used antibiotic, from aqueous media in continuous mode...
June 29, 2017: Science of the Total Environment
Aarjoo Sharma, Vijaya Gupta, Mussarat Khan, Sanjeev Balda, Naveen Gupta, Neena Capalash, Prince Sharma
Laccases have potential applications in industrial, biotechnological, and environmental set ups. Development of cost effective and efficient production technologies has gained significant attention in recent years. To enhance the laccase production from Rheinheimera sp. (Gram negative) using submerged fermentation (SmF) and from Lysinibacillus sp. (Gram positive) using solid-state fermentation (SSF), the inducing effect of various flavonoid-rich agro-industrial residues was investigated. Peels of citrus fruits, soybean meal, tofu dreg, lignin monomers, and lingo-cellulosic waste, used tea leaves and peels of onion and kiwi, paper, and dying industry effluents were tested as inducers...
July 2017: 3 Biotech
Francesca Martani, Fabrizio Beltrametti, Danilo Porro, Paola Branduardi, Marina Lotti
White-rot fungi are the main natural producers of lignin modifying enzymes, i.e. laccases and peroxidases, whose secretion and activity allows the depolymerization of lignin and the release of polysaccharides contained in lignocellulose. These enzymes are able to oxidize, in addition to lignin, a wide spectrum of natural and synthetic substrates, making their industrial and biotechnological application appealing. However, the complex regulation of the synthesis of lignin modifying enzymes, as well as the heterogeneous physiology of fungi in response to nutrients, make the use of white-rot fungi as production platforms challenging...
June 26, 2017: FEMS Microbiology Letters
Laura Palli, Francesc Castellet-Rovira, Miriam Pérez-Trujillo, Donatella Caniani, Montserrat Sarrà-Adroguer, Riccardo Gori
The fungus Pleurotus ostreatus was investigated to assess its ability to remove diclofenac, ketoprofen and atenolol spiked at 10 mg/L each one in hospital wastewater. The degradation test was carried out in a fluidized bed bioreactor testing both the batch and the continuous mode (hydraulic retention time in the range 1.63-3 d). In batch mode, diclofenac disappeared in less than 24 h, ketoprofen was degraded up to almost 50% in 5 d while atenolol was not removed. In continuous mode, diclofenac and ketoprofen removals were about 100% and 70% respectively; atenolol degradation was negligible during the first 20 d but it increased up to 60% after a peak of laccase production and notable biomass growth...
June 27, 2017: Biotechnology Progress
Christoph J Behrens, Diana Linke, Aldrige B Allister, Katerina Zelena, Ralf G Berger
A laccase of the basidiomycete Pleurotus pulmonarius (PpuLcc) possessed strong decolorizing abilities towards artificial and natural dyes. The PpuLcc was purified from the culture supernatant via FPLC, and the corresponding gene cloned and expressed in Pichia pastoris GS115. To examine the impact of the C-terminal tail region and the signal peptide on the recombinant expression of PpuLcc, a non-modified version or different truncations (-2, -5, -13 AA) of the target protein were combined with different secretion signals...
June 23, 2017: Protein Expression and Purification
Muhammad B Asif, Faisal I Hai, Jingwei Hou, William E Price, Long D Nghiem
White-rot fungi (WRF) and their ligninolytic enzymes have been investigated for the removal of a broad spectrum of trace organic contaminants (TrOCs) mostly from synthetic wastewater in lab-scale experiments. Only a few studies have reported the efficiency of such systems for the removal of TrOCs from real wastewater. Wastewater derived organic and inorganic compounds can inhibit: (i) WRF growth and their enzyme production capacity; (ii) enzymatic activity of ligninolytic enzymes; and (iii) catalytic efficiency of both WRF and enzymes...
June 23, 2017: Journal of Environmental Management
Mostafa Zahmatkesh, Henri Spanjers, Jules B van Lier
In this study we tested a new approach to facilitate the application of white rot fungi (WRF) under non-sterile conditions, by introducing grain sorghum as carrier and sole carbon and nutrient source for WRF. To this end, Trametes versicolor was immobilized on sorghum, and its ability to remove humic acid (HA) from synthetic and real industrial wastewater was studied. HA removal was measured as colour reduction and also analysed via size exclusion chromatography (SEC). Under sterile conditions, 80% colour removal was achieved for both synthetic and real wastewater using immobilized WRF on sorghum, without adding any additional carbon or nutrient sources...
June 26, 2017: Environmental Technology
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