Laccases for enzymatic colouration of unbleached cotton

The concept presented in this paper is the utilisation of the natural flavonoids present in cotton as anchors to attach other phenolic compounds to the fiber surface. Laccase can catalyze the oxidation of flavonoids in solution producing quinones that can be further polymerised and grafted onto surface of the cotton providing yellow to brown colouration, depending on the external flavonoids used and on the reaction conditions. Factors such as temperature, time of reaction, pretreatment of cotton, mechanical agitation and the role of an organic solvent were studied in order to improve this laccase colouration reaction. After dyeing, colour measurements and fastness tests (washing, friction and weathering fastness) were performed. A strong mechanical agitation, an increased reaction temperature (from 30 to 50 °C), and the addition of an organic solvent improved dyeing. The natural flavonoids present on cotton were found to play an important role on the grafting reaction, improving dyeing and colour fastness. Since the traditional bleaching pretreatment of cotton removes these natural flavonoids from cotton, the proposed laccase colouration reaction could be carried out without a previous bleaching treatment resulting in a more environmentally friendly process

Enzymatic Functionalization of Wood as an Antifouling Strategy against the Marine Bacterium Cobetia marina

The protection of wood in marine environments is a major challenge due to the high sensitivity of wood to both water and marine microorganisms. Besides, the environmental regulations are pushing the industry to develop novel effective and environmentally friendly treatments to protect wood in marine environments. The present study focused on the development of a new green methodology based on the laccase-assisted grafting of lauryl gallate (LG) onto wood to improve its marine antifouling properties. Initially, the enzymatic treatment conditions (laccase dose, time of reaction, LG concentration) and the effect of the wood specie (beech, pine, and eucalyptus) were assessed by water contact angle (WCA) measurements. The surface properties of the enzymatically modified wood veneers were assessed by X-ray photoelectron spectroscopy (XPS), Fourier transform-infrared spectroscopy (FTIR). Antifouling properties of the functionalized wood veneers against marine bacterium Cobetia marina were studied by scanning electron microscopy (SEM) and protein measurements. XPS and FTIR analysis suggested the stable grafting of LG onto the surface of wood veneers after laccase-assisted treatment. WCA measurements showed that the hydrophobicity of the wood veneers significantly increased after the enzymatic treatment. Protein measurements and SEM pictures showed that enzymatically-hydrophobized wood veneers modified the pattern of bacterial attachment and remarkably reduced the bacterium colonization. Thus, the results observed in the present study confirmed the potential efficiency of laccase-assisted treatments to improve the marine antifouling properties of wood.This research was funded by ERDF and Xunta de Galicia (Grant Numbers 09TMT012E, EM2014/041 and Eq3-GRC2017-I751)

Pengaruh Varietas dan Pupuk Petroganik Terhadap Pertumbuhan, Produksi dan Viabilitas Benih Jagung (Zea mays L.)

The Effect of Varieties and Petroganik Fertilizer to Growth, Production, and SeedViability of Corn (Zea mays L) ABSTRACT The purpose of this study was to determine the effect of varieties and Petroganik fertilizer on the growth , production, and seed viability of corn as well as the interaction that occurbetween the two treatments . This study was conducted in the Experimental Laboratory of theFaculty of Agriculture and Laboratory of Seed Science and Technology, Syiah Kuala University from March to August 2013. The design used both in the field and the laboratory wasRandomized Block Design (RBD ) factorial with 2 treatment. The first treatment was doses ofPetroganik fertilizer with 4 levels , namely 0 kg / ha ( P0 ) , 500 kg / ha ( P1 ) , 750 kg / ha ( P2 )and 1000 kg / ha ( P3 ) and the second was varieties with 3 different varieties namely Srikandi(V1) , Lamuru ( V2 ) and Bisma ( V3 ), and repeated three times. The parameters observed in the field include plant height ( cm ) , stem diameter ( mm ) , number of leaves ( strands ) , leaf length( cm ), width of leaf ( cm ) , number of cobs per plant , cob weight with cornhusk (g) , cob weight without cornhusk ( g ) , cob length without cornhusk ( cm ) , cob without cornhusk diameter ( mm ) , dried shelled weight ( g ) and the potential yield / ha ( kg ) . For observations in the laboratory include growth potential, germination, growth speed , growth simultaneity and dry weight of normal seedling ( g ). The results showed that the use of Petroganik fertilizers witha dose of 1000 kg / ha showed the best results in almost every parameter of observation , whereas for varieties , use of Srikandi varieties showed the best results in almost all parameters of the observations in terms of growth , yield and seed viability in laboratory level. Keyword : Varities, Petroganik Fertilizer, Corn PENGARUH VARIETAS DAN PUPUK PETROGANIK TERHADAP PERTUMBUHAN,PRODUKSI DAN VIABILITAS BENIH JAGUNG (Zea mays L.). ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh varietas dan pemberian pupuk Petroganik terhadap pertumbuhan, produksi, dan viabilitas benih jagung serta interaksi yang terjadi diantara perlakuan pupuk Petroganik dan perlakuan varietas. Penelitian inidilaksanakan di Kebun Percobaan Fakultas Pertanian dan Laboratorium Ilmu dan TeknologiBenih Universitas Syiah Kuala. Penelitian dilaksanakan dari bulan Maret sampai dengan Agustus2013, Rancangan yang digunakan baik di lapangan maupun di laboratorium adalah RancanganAcak Kelompok (RAK) pola faktorial dengan 2 perlakuan yaitu dosis pupuk Petroganik dengan4 taraf, yaitu 0 kg/ha (P0), 500 kg/ha (P1), 750 kg/ha (P2) dan 1000 kg/ha (P)dan perlakuankedua yaitu varietas dengan 3 varietas yang berbeda yaitu Srikandi (V1),Lamuru (V2) dan Bisma(V3) dengan tiga ulangan. Parameter yang diamati di lapangan meliputi tinggi tanaman (cm),diameter pangkal batang (mm), jumlah daun (helai), panjang daun (cm) lebar daun (cm), jumlah tongkol per tanaman, bobot tongkol berkelobot (g), bobot tongkol tanpa kelobot (g), panjang tongkol tanpa kelobot (cm), diameter tongkol tanpa kelobot (mm), berat pipilan kering (g) danpotensi hasil/ha (kg). Untuk pengamatan di laboratorium antara lain potensi tumbuh, daya berkecambah, kecepatan tumbuh, keserempakan tumbuh dan berat kering kecambah normal (g). Hasil penelitian menunjukkan bahwa penggunaan pupuk Petroganik dengan dosis 1000 kg/hamenunjukkan hasil terbaik hampir pada setiap parameter pengamatan, sedangkan untuk varietas, penggunaan varietas Srikandi menunjukkan hasil terbaik hampir di seluruh parameter pengamatan baik dari segi pertumbuhan, hasil dan tingkat viabilitas benih di laboratorium.Banda Ace

Enhanced stability of laccase by xylitol

Laccase is a multicopper oxidase able to perform one-electron oxidation of several aromatic substrates. The application of laccase on wood delignification, drug analysis, biosensor, wine clarification, bioremediation, etc., was proposed [1]. As every enzymatic system, laccase has some limitations due to the reaction conditions, mainly temperature and pH. Deactivation of laccase at pH values over 6 and lower 3 are undesirable properties that must be improved. The addition of some compounds is an easy and conventional way to get the stabilization of laccase [2]. In this work laccase from Trametes hirsuta was studied in order to get its stabilization towards different pH values by addition of xylitol, a polyol used in food industry with optimal characteristics with respect to its prize and non-toxical properties

Antimicrobial performance of lignin embedded in bacterial nanocellulose membranes

The development of bio-based antimicrobial polymeric composites has never been so urgent. Novel antimi- crobial fibrous-based biocomposites will certainly allow the development of important solutions to fight the present and future Pandemics, while reducing the dependence of petrochemical based polymers and fibers. Lignin has a pivotal function in preventing the invasion of phytopathogens, thus, this work explores the anti- microbial potential of lignin when embedded in a biosynthesized fibrous nanomatrix with superior mechanical properties: bacterial nanocellulose (BNC). Lignin was subjected to alkali treatment to promote the inclusion of lignin within BNC which comprises pores ranging from 20 to 300 nm. Both alkali treatment efficiency, bac- tericidal and antiviral activities were investigatedThe authors would like to acknowledge the project PLASMAMED - PTDC/CTM-TEX/28295/2017 fnanced by FCT, FEDER and POCI in the frame of the Portugal 2020 program, the project UID/CTM/00264/2019 of 2C2T under the COMPETE and FCT/MCTES (PIDDAC) co-fnanced by FEDER through the PT2020 program. Liliana Melro acknowledges her Doctoral grant awarded by FCT (2020.04919.BD)

Procedural-Mind Generación de entornos 3D a través de la interacción natural con el usuario

Uno de los problemas a los que tiene que enfrentarse la industria del videojuego y del entretenimiento hoy en día es a los altos costes del desarrollo de escenarios en 3D derivado del gran tiempo que tienen que dedicar los desarrolladores a esta tarea. Este trabajo busca agilizar esta tarea generando escenarios de forma procedural que, además, son a la medida de cada persona. El sistema utiliza una basta base de conocimiento de objetos que podrá ser usada tanto por los desarrolladores como por personas menos puestas en la materia (artistas, directivos, clientes, etc.) para generar y recolectar a través de la voz lo que el usuario desee crear. Además, la voz no es la única fuente de datos del sistema, puesto que este también hace uso del reconocimiento de imágenes (para extraer características de los objetos que la componen) o de la geolocalización del usuario. El programa tiene la capacidad de definir un entorno espaciotemporal para los objetos que se generan a partir de un objeto base. De esta manera en función de la geolocalización (por defecto la ubicación del usuario) y la época elegida, los objetos que se generen serán distintos, a pesar incluso de que sean las mismas peticiones. Por ejemplo, si se pide un coche y se marca como época el sigo XVIII, lo que se regenerará será un vehículo a vapor. Finalmente, el sistema implementa algoritmos de generación de ríos, terrenos, caminos y objetos, que se adaptan a los escenarios previamente creados

Laccase for biobleaching of eucalypt kraft pulp by means of a modified industrial bleaching sequence

Biobleaching of kraft pulp is a possible application of laccase, but it has not been described in detail for complete industrial bleaching sequences yet. Therefore, in this work, the biobleaching of Eucalyptus globulus kraft pulp was performed using a modified industrial totally chlorine-free sequence. The modification consisted in the substitution of an enzymatic delignification stage, based on the application of laccase from Trametes villosa, for the first alkaline extraction one. The enzymatic stage was performed with several synthetic and natural mediators, namely 1-hydroxybenzotriazole (HBT), violuric acid (VA), methyl syringate, and syringaldehyde. Several pulp properties were analyzed after each stage of the bleaching process—kappa number, ISO brightness, viscosity, and optical properties of CIEL*a*b* system. The new biobleaching sequence improved the pulp properties, in comparison to the conventional bleaching sequence, if HBT or VA was used as mediators. VA was selected as the best mediator of those tested and the effect of its concentration in the enzymatic stage was subsequently studied. Reducing the initial concentration by 30%, the same pulp quality was obtained, but if the reduction attained 60%, an important decrease in pulp integrity was detected. The modified bleaching sequence could improve the bleached pulp properties (kappa number 10%, ISO brightness 1%, and viscosity 5%) in comparison to the mill sequenc

Laccase-Oriented Immobilization Using Concanavalin A as an Approach for Efficient Glycoproteins Immobilization and Its Application to the Removal of Aqueous Phenolics

An expanding number of human activities are contributing to the rising levels of aromatic compounds, which pose a major threat to the ecosystem. However, readily available microbial enzymes might be used to remediate contaminated wastewater in an economical and environmentally benign manner. In this study, an efficient method of laccase-oriented immobilization on modified Immobead 150P was proposed. The oriented immobilization technique using aminated laccase exceeds in both protein loading onto the carrier (4.26 mg/g) and immobilization yield (93.57%) due to the availability of more active sites. The oriented aminated laccase preserves 100% and 95% of its original activity after six and ten cycles of operation, respectively. The thermal stability performance of the oriented enzyme was the best among both free and random immobilized forms, since it was able to conserve 79% and 44% of its initial activity after 6 h at 50 °C and 60 °C, respectively. The ideal pH of oriented immobilized laccase was altered from 3.0 to 4.0, and it was more stable than both free and random immobilized laccases at pH 7.0. Finally, the integration of the adsorption capacity of Immobead 150P and the biodegradation ability of laccase promises the efficient removal of aqueous phenolics. Oriented immobilized laccase may provide a significant new approach for wastewater treatment, according to these findings