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Xudong Wang, Sai Yin, Zhihao Yang, Bing Zhou
Multicopper oxidases (MCOs) are a specific group of enzymes that contain multiple copper centers through which different substrates are oxidized. Main members of MCO family include ferroxidases, ascorbate oxidases, and laccases. MCO type of ferroxidases is key to iron transport across the plasma membrane. In Drosophila, there are four potential multiple oxidases, MCO1-4. No convincing evidence has been presented so far to indicate any of these, or even any insect multicopper oxidase, to be a ferroxidase. Here we show Drosophila MCO3 (dMCO3) is highly likely a bona fide ferroxidase...
April 20, 2018: Biochimica et Biophysica Acta
Natalia Pozdnyakova, Ekaterina Dubrovskaya, Marina Chernyshova, Oleg Makarov, Sergey Golubev, Svetlana Balandina, Olga Turkovskaya
The degradation of two isomeric three-ringed polycyclic aromatic hydrocarbons by the white rot fungus Pleurotus ostreatus D1 and the litter-decomposing fungus Agaricus bisporus F-8 was studied. Despite some differences, the degradation of phenanthrene and anthracene followed the same scheme, forming quinone metabolites at the first stage. The further fate of these metabolites was determined by the composition of the ligninolytic enzyme complexes of the fungi. The quinone metabolites of phenanthrene and anthracene produced in the presence of only laccase were observed to accumulate, whereas those formed in presence of laccase and versatile peroxidase were metabolized further to form products that were further included in basal metabolism (e...
May 2018: Fungal Biology
Konstantin V Moiseenko, Daria V Vasina, Katerina T Farukshina, Olga S Savinova, Olga A Glazunova, Tatiana V Fedorova, Tatiana V Tyazhelova
Laccase (benzenediol:oxygen oxidoreductase, EC is an enzyme that has been studied for over 100 y and is present in virtually all fungi. As increasing numbers of fungal genomes have been sequenced, it has become apparent that the laccase genes in white-rot fungi commonly form multigene families consisting of many nonallelic genes. Although a number of reports focussing on laccase gene expression in different fungal species were published over the decades, the fundamental questions of why fungi need such a redundant array of genes and how they manage this array to perform biological function(s) remain far from answered...
May 2018: Fungal Biology
Hui Chen, Haibo Hai, Hong Wang, Qian Wang, Mingjie Chen, Zhiyong Feng, Ming Ye, Jinjing Zhang
Hypsizygus marmoreus is an important industrialized mushroom, yet the lack of basic research on this fungus has hindered further development of its economic value. In this study, mycelia injured by scratching were treated with hydrogen-rich water (HRW) to investigate the involvement of the redox system in fruiting body development. Compared to the control group, damaged mycelia treated with HRW regenerated earlier and showed significantly enhanced fruiting body production. Antioxidant capacity increased significantly in damaged mycelia after HRW treatment, as indicated by higher antioxidant enzyme activities and antioxidant contents; the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) were also reduced at the mycelial regeneration stage after treatment with HRW...
May 2018: Fungal Biology
Pedro H Mainardi, Valker A Feitosa, Livia B Brenelli de Paiva, Rafaella C Bonugli-Santos, Fabio M Squina, Adalberto Pessoa, Lara D Sette
Laccase production in saline conditions is still poorly studied. The aim of the present study was to investigate the production of laccase in two different types of bioreactors by the marine-derived basidiomycete Peniophora sp. CBMAI 1063. The highest laccase activity and productivity were obtained in the Stirred Tank (ST) bioreactor, while the highest biomass concentration in Air-lift (AL) bioreactor. The main laccase produced was purified by ion exchange and size exclusion chromatography and appeared to be monomeric with molecular weight of approximately 55 kDa...
May 2018: Fungal Biology
Reiko Nihei, Mizuki Usami, Taro Taguchi, Seigo Amachi
Previously, we hypothesized that microbial laccase oxidizes iodide (I- ) in soils to molecular iodine (I2 ) or hypoiodous acid (HIO), both of which are easily incorporated into natural soil organic matter, and thus plays a role in iodine sorption on soils. In this study, soil iodide oxidase activity was determined by a colorimetric assay to evaluate if laccase is responsible for iodide oxidation in soils. Three types of Japanese soil showed significant iodide oxidase activities (0.751-2.87 mU g soil-1 ) at pH 4...
April 14, 2018: Journal of Environmental Radioactivity
Madan Kumar, Arti Mishra, Shashi Shekhar Singh, Shaili Srivastava, Indu Shekhar Thakur
In the present study, a non-blue laccase gene from previously reported lignin degrading bacterium, Pandoraea sp. ISTKB, was isolated, cloned and expressed in E. coli. Bioinformatics analysis of sequence discovered twin-arginine translocation signal sequence, copper binding motifs and presence of more random coil compare to helices and sheets in structure. The enzyme was found to be active on wide pH range and the pH optima was observed at pH 4 and 8 on substrate 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and 2,6-Dimethoxyphenol respectively...
April 14, 2018: International Journal of Biological Macromolecules
Flávia Thiebaut, Cristian A Rojas, Clícia Grativol, Edmundo P da R Calixto, Mariana R Motta, Helkin G F Ballesteros, Barbara Peixoto, Berenice N S de Lima, Lucas M Vieira, Maria Emilia Walter, Elvismary M de Armas, Júlio O P Entenza, Sergio Lifschitz, Laurent Farinelli, Adriana S Hemerly, Paulo C G Ferreira
Studies have highlighted the importance of non-coding RNA regulation in plant-microbe interaction. However, the roles of sugarcane microRNAs (miRNAs) in the regulation of disease responses have not been investigated. Firstly, we screened the sRNA transcriptome of sugarcane infected with Acidovorax avenae . Conserved and novel miRNAs were identified. Additionally, small interfering RNAs (siRNAs) were aligned to differentially expressed sequences from the sugarcane transcriptome. Interestingly, many siRNAs aligned to a transcript encoding a copper-transporter gene whose expression was induced in the presence of A...
December 20, 2017: Non-Coding RNA
Raj Kumar Pandey, Salil Tewari, Lakshmi Tewari
A mycoremedial study was undertaken for decolourization of synthetic dyes using wood rot fungal culture Lenzites elegans WDP2. The culture was isolated from decaying wood as fruiting body, and identified on the basis of 5.8S ITS rRNA gene sequence analysis. Qualitative plate screening of culture showed extracellular laccase and lignin peroxidase production, while only laccase enzyme was produced in higher amount (156.793 Uml-1 ) in minimal salt broth medium containing glucose and veratryl alcohol. Laccase activity was increased up to 189...
April 12, 2018: Ecotoxicology and Environmental Safety
Ze-Hua Wang, Rong-Min Hu, Xi-Qian Ye, Jian-Hua Huang, Xue-Xin Chen, Min Shi
Laccase (EC is a phenoloxidase found in many insect species. The Laccase 1 gene from Plutella xylostella (PxLac1) was cloned, and its expression patterns and functions were determined using qPCR and RNAi methods. The results showed that the expression levels of PxLac1 were consistently high in all larval stages, and the most abundant was in the midgut during the 4th instar stage. Moreover, the expression of PxLac1 was up-regulated in response to bacterial infection, and decreased 24 h after being parasitized by Cotesia vestalis...
April 4, 2018: Journal of Insect Physiology
Veera Hämäläinen, Toni Grönroos, Anu Suonpää, Matti Wilhem Heikkilä, Bastiaan Romein, Petri Ihalainen, Sara Malandra, Klara R Birikh
Main hurdles of lignin valorization are its diverse chemical composition, recalcitrance, and poor solubility due to high-molecular weight and branched structure. Controlled fragmentation of lignin could lead to its use in higher value products such as binders, coatings, fillers, etc. Oxidative enzymes (i.e., laccases and peroxidases) have long been proposed as a potentially promising tool in lignin depolymerization. However, their application was limited to ambient pH, where lignin is poorly soluble in water...
2018: Frontiers in Bioengineering and Biotechnology
Nur Fatin Athirah Ahmad Rizal, Mohamad Faizal Ibrahim, Mohd Rafein Zakaria, Ezyana Kamal Bahrin, Suraini Abd-Aziz, Mohd Ali Hassan
The combination of superheated steam (SHS) with ligninolytic enzyme laccase pretreatment together with size reduction was conducted in order to enhance the enzymatic hydrolysis of oil palm biomass into glucose. The oil palm empty fruit bunch (OPEFB) and oil palm mesocarp fiber (OPMF) were pretreated with SHS and ground using a hammer mill to sizes of 2, 1, 0.5 and 0.25 mm before pretreatment using laccase to remove lignin. This study showed that reduction of size from raw to 0.25 mm plays important role in lignin degradation by laccase that removed 38...
April 2, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Keke Zhang, Mei Huang, Jiangshan Ma, Zeyi Liu, Jiarui Zeng, Xuanming Liu, Ting Xu, Xiang Wang, Ying Liu, Zhigang Bu, Yonghua Zhu
OBJECTIVE: To identify and characterize a novel bacterial pyranose 2-oxidase (P2Ox) and investigate its potential use in lignin degradation applications. RESULTS: A new bacterial P2Ox (PaP2Ox) enzyme was identified in the lignocellulolytic bacterium Pantoea ananatis Sd-1. The PaP2Ox open reading frame was cloned, and the encoded protein was heterologously expressed in an Escherichia coli expression system. Unlike another reported bacterial P2Ox enzyme, the purified PaP2Ox exhibits a homotetrameric spatial conformation that is similar to fungal P2Oxs, with each subunit having a molecular mass of 65 kDa...
March 31, 2018: Biotechnology Letters
Yingjie Su, Xiaoxiao Yu, Yang Sun, Gang Wang, Huan Chen, Guang Chen
The biological pretreatment of lignocellulosic biomass is a low-cost and eco-friendly method for facilitating enzymatic hydrolysis. In this study, strains with lignin depletion capability were screened using a high-throughput screening method. Sixty-three strains were screened out and Myrothecium verrucaria secreted three lignin-degrading enzymes simultaneously during the bio-pretreatment process. The activity levels of laccase, lignin peroxidase and manganese peroxidase were 6.61, 0.78 and 1.31 U g-1 dry biomass...
March 29, 2018: Scientific Reports
Erik Breslmayr, Marija Hanžek, Aoife Hanrahan, Christian Leitner, Roman Kittl, Božidar Šantek, Chris Oostenbrink, Roland Ludwig
Background: Lytic polysaccharide monooxygenases (LPMO) release a spectrum of cleavage products from their polymeric substrates cellulose, hemicellulose, or chitin. The correct identification and quantitation of these released products is the basis of MS/HPLC-based detection methods for LPMO activity. The duration, effort, and intricate analysis allow only specialized laboratories to measure LPMO activity in day-to-day work. A spectrophotometric assay will simplify the screening for LPMO in culture supernatants, help monitor recombinant LPMO expression and purification, and support enzyme characterization...
2018: Biotechnology for Biofuels
Eduardo C Moraes, Thabata M Alvarez, Gabriela F Persinoti, Geizecler Tomazetto, Livia B Brenelli, Douglas A A Paixão, Gabriela C Ematsu, Juliana A Aricetti, Camila Caldana, Neil Dixon, Timothy D H Bugg, Fabio M Squina
Background: Lignin is a heterogeneous polymer representing a renewable source of aromatic and phenolic bio-derived products for the chemical industry. However, the inherent structural complexity and recalcitrance of lignin makes its conversion into valuable chemicals a challenge. Natural microbial communities produce biocatalysts derived from a large number of microorganisms, including those considered unculturable, which operate synergistically to perform a variety of bioconversion processes...
2018: Biotechnology for Biofuels
Sarah J Phillips, Julie A Stenken
An in situ chemical surface modification method to attach heparin to the inner lumen of a single hollow fiber poly(ether sulfone) (PES) membrane incorporated into a commercial microdialysis sampling device is described. The immobilization process uses gentle, room-temperature conditions with the enzyme laccase (E.C. and 4-hydroxybenzoic acid (4HBA). The resulting functionalized inner membrane surface with a carboxylic acid functional groups allowed for (1-ethyl-3-(3-(dimethylamino)propyl) carbodimide)/ N-hydroxysuccinimide) EDC/NHS chemistry to attach heparin to the membrane surface...
April 3, 2018: Analytical Chemistry
Monika Osińska-Jaroszuk, Magdalena Jaszek, Magdalena Starosielec, Justyna Sulej, Anna Matuszewska, Monika Janczarek, Renata Bancerz, Jerzy Wydrych, Adrian Wiater, Anna Jarosz-Wilkołazka
Four bacterial EPSs extracted from Rhizobium leguminosarum bv. trifolii Rt24.2, Sinorhizobium meliloti Rm1021, Bradyrhizobium japonicum USDA110, and Bradyrhizobium elkanii USDA76 were determined towards their metal ion adsorption properties and possible modification of Cerrena unicolor laccase properties. The highest magnesium and iron ion-sorption capacity (~ 42 and ~ 14.5%, respectively) was observed for EPS isolated from B. japonicum USDA110. An evident influence of EPSs on the stability of laccase compared to the control values (without EPSs) was shown after 30-day incubation at 25 °C...
March 26, 2018: Bioprocess and Biosystems Engineering
Jie Jiang, Wenbo Ye, Juan Yu, Yimin Fan, Yuko Ono, Tsuguyuki Saito, Akira Isogai
Laccase mediator oxidation was applied to chitin at pH 6.8 and 30 °C to prepare chitin nanocrystals with a catalytic amount of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO). When 40 mM TEMPO and a total of 500 U laccase were added to 1 g chitin, the yield of water-insoluble oxidized chitin was more than 95%, and the carboxylate content was 0.43 mmol/g. Adsorption of laccase molecules on chitin particles occurred in a buffer at pH 6.8, which may have been caused by electrostatic interactions between positively charged C2-ammonium groups of chitin and anionically charged groups of laccase...
June 1, 2018: Carbohydrate Polymers
M Loi, L Quintieri, F Fanelli, L Caputo, G Mulè
Milk protein crosslink through the action of enzymes represents a feasible strategy to impart new functionalities to cheese. In this work we reported the effects of a laccase mediator system (LMS) on protein crosslink and antioxidant property of curd. The crosslinking activity of a purified recombinant laccase Ery4 and a commercial enzyme preparation (cLC), with three mediators was firstly evaluated in milk and then applied before curd manufacture. Only Ery4-LMS significantly increased curd weight compared to that of the control sample...
April 2018: Food Research International
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