APYME en tiempos de flexiblización laboral

En este escrito nos proponemos analizar las posturas de una organización de pequeños empresarios, la Asamblea de Pequeños y Medianos Empresarios (APYME) acerca de las políticas laborales del gobierno menemista y del gobierno de la Alianza tendientes a la flexibilización del mercado de trabajo, específicamente las leyes 24.467 de 1995, 25.013 de 1998 y la 25.250 de 2000. Nos detendremos en las principales disposiciones de estas normativas y cómo éstas han sido evaluadas por la organización objeto de estudio, ya que parte de los argumentos legitimadores de las modificaciones sobre el trabajo apuntaban a la necesidad de modernizar las relaciones laborales y generar competitividad en las pequeñas y medianas empresasThis paper addresses the position taken by the SMEs organization Asamblea de Pequeños y Medianos Empresarios (APYME) on employment policies tending towardslabor market flexibilization during Menem´s and De la Rua´s Governments in Argentina. We will focus on the main provisions of public laws 24.467 of 1995, 25.013 of 1998, and 25.250 of 2000 and how APYME has assessed them taking into account that some of the legitimizing arguments government put forward to introduce changes into labor laws was the need to modernize labor relations and promote SMEs’ competitivenessFil: Martinez Fernandez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Investigaciones Socio-historicas Regionales. Centro de Estudios Sociales Regionales - Nodo Cesor - Ishir; Argentin

Microwave-assisted embedding of bis-vanillin and bis-eugenol into SBA-15: Synthesis of chemosensors precursors for the detection of metal cations

In this work we evaluate the necessary experimental conditions to carry out the embedding of bis-vanillin and bis-eugenol, two potential precursors of chemosensors, in the porous structure of the mesoporous silica SBA-15 through a microwave assisted process. The physicochemical characterization of the developed bis-vanillin-SBA-15 and bis-eugenol-SBA-15 materials confirmed the successful immobilization of these molecules in the mesoporous composite. The most important characteristic of these systems is the possibility of activating the release of the organic molecules embedding into SBA-15, depending on the liquid medium in which these composites are suspended.Fil: Guntero, Vanina Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Espinoza Martinez, Dailenys. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Ferretti, Cristián Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

Modificações e características das superfícies que favorecem a osseointegração em implantes dentários. Uma revisão sistemática integrativa

Introdução: Os princípios básicos da osseointegração passaram por mudanças significativas que estão a modificar as modalidades terapêuticas enfrentadas pela profissão. A compatibilidade de materiais é a questão mais importante a ser considerada para um implante dentário de bom sucesso e está intimamente relacionada com o comportamento das células, particularmente com a adesão que tem sobre uma superfície. Uma modificação da topografia da superfície do implante tem sido considerada um parâmetro essencial para a osseointegração. Existem diversos tratamentos de superfícies utilizados atualmente na confeção de implantes dentários mais também uma lacuna sobre a influência da nanoestructura modificada. Objetivo: A presente investigação procura comparar ou descrever se os tipos de modificações na superfície implantar ou características físico-químicas têm favorecido a osseointegração nos implantes dentários. Material e métodos: Realizou-se uma pesquisa bibliográfica na base de dados eletrónicos Medline/PubMed com as seguintes palavras-chaves determinadas pelo MeSH (Medical Subject Headings): “dental implants”; “surface treatment”, “osseointegration”; “bone to implant contact” and “titanium”. Artigos publicados nos últimos 10 anos, com full-text disponível e texto em inglês foram alguns dos critérios de inclusão selecionados. Resultados: Um total de 13 artigos de estudos comparativos foram analisados em relação ao contacto osso-implante. Após a análise dos estudos notou-se que a topografia da superfície de implantes dentários influencia o comportamento celular nos períodos iniciais. Superfícies com rugosidade micrométrica ou nanométricas são superiores às superfícies lisas/mecanizadas favorecendo a osseointegração em relação aos níveis de contato ósseo-implante. Conclusão: A modificação da topografia superficial aumenta favoravelmente adesão de células resultando em maiores valores de BIC. Novos estudos são necessários para avaliação da resposta celular nestas superfícies em períodos mais longos.Introduction: The basic principles of osseointegration have gone through significant changes that are modifying the therapeutic modalities faced by the profession. Material compatibility is the most important issue to be considered for a successful dental implant and is closely related to the cell behaviors, particularly the adhesion they have on a surface. A modification of the implant surface topography has been considered an essential parameter for osseointegration. There are several surface treatments currently used in the manufacture of dental implants, but also a gap on the influence of modified nanostructure. Objective: The present investigation seeks to compare or describe whether the types of modifications on the implant surface or physicochemical characteristics have favored osseointegration in dental implants. Materials and methods: A bibliographic search was carried out in the Medline/PubMed electronic database with the following keywords determined by MeSH (Medical Subject Headings): “dental implants”; “surface treatment”, “osseointegration”; “bone to implant contact” and “titanium”. Articles published in the last 10 years, with full-text available and english text were some of the inclusion criteria selected. Results: A total of 13 articles from comparative studies were analyzed in relation to bone-implant contact. After analyzing the studies, it was noticed that the surface topography of dental implants influences the cellular behavior in the initial periods. Surfaces with micrometric or nanometric roughness are superior to smooth/mechanized surfaces, favoring osseointegration in relation to bone-implant contact levels. Conclusion: Modification of the surface topography favorably increases cell adhesion resulting in higher BIC values. New studies are needed to evaluate the cellular response on these surfaces over longer periods

Evaluation of the influence of carbon sources on cellulases and xylanases production by microbacterium sp.

The lignocellulose is one of the main constituents of vegetable biomass. Besides being a renewable and abundant source of energy, it has a high potencial for bioconversion to value-added bioproducts. Among its components, the hemicellulose portions (mainly xylans) represent around 25% to 40% of their composition after cellulose that constitute the main component which represents between 50% and 70% of the total. In adition to the lignin, both the cellulose and hemicellulose, make its structure to be resistant to the enzymatic degradation. Thus, it is necessary the cooperative and synergistic effect of various enzymes, including cellulases and xylanases, to reach higher yields for its degadacion. In the present study Microbacterium sp. AR462-2, a cellulolytic and xylanolytic actinobacteria isolated from intestines of wood beetle larvae, was characterized. The effect of various carbon sources was evaluated on cellulases and xylanases production into Omeliansky mineral culture medium. The substrates assayed as sole carbon source were xylan, lactose, glucose, sucrose, fructose, maltose, carboxymethylcellulose (CMC) and filter paper. This strain was taxonomically identified as a member of Microbacterium spp. according to the sequence analysis of the 16S ribosomal gene. Microscopic observation of AR462-2 strain showed small yellow rods (RAL 1014). Physiological studies showed that this strain did not produce melanic nor soluble pigment. Growth was observed between 5.0 and 8.0 pH units and showed halotolerance and lysozyme resistance. It was able to grow in presence of various carbon sources. M. sp. AR462-2 secreted cellulases when glucose 1% (w/v) was used as a sole carbon source which activity measured was 0.1 U/ml. Also, this strain showed evidence of mild degradation of filter paper in liquid mineral medium. Xylanolytic activities were detected in all culture medias, but the highest xylanase production was recorded when lactose 1% (w/v) was added individually in Omeliansky´s medium. The highest xylanase activity measured was 1.03 U/ml within 7 days using lactose, while in presence of CMC was 1.14 U/ml but after 14 days of culture. Further assays were performed in order to improve both growth and production, by adding casein peptone. Production rates were similar although growth was significatively shortened to 3 days. These results suggest that lactose could be used for enzyme production by Microbacterium sp. AR462-2 as an inexpensive carbon source, since lactic whey is an abundant industrial by-product.Fil: Di Marco, Enzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Perotti, Nora Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Martinez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXI Congreso Argentino de Microbiología GeneralCórdobaArgentinaSociedad Argentina de Microbiología Genera

Stability assessment and improvement of enzymatic activity of the endoglucanases from bacillus sp. Ar03

The lignocellulosic biomass is well known like a promising source to biorefinery due to its abundant and its renewable feature. Cellulose, the major compound of this material, needs the cooperative action of at least three types of enzymes to be degraded: exoglucanases, endoglucanases and β-glucosidases. Microorganisms and their enzymes are biotechnical tools that nature has designed to utilize biomass that is present in the habitat around them. In this sense, Bacteria are extensively considered as a source of novel cellulases because of their diversity and due to their higher growth rate and their extensive repertoire of glycoside hydrolases. The aim of the present work was to produce and to characterize endoglucanases from Bacillus sp. AR03, isolated from sugarcane bagasse liquor, to further generate lignocellulosic hydrolysates. The isolate AR03 was grown in a peptone broth amended with carboxymethyl cellulose 1% (w/v) and sucrose 1%(w/v) at 30 °C and 200 rpm. After 48 h, the culture supernatant was recovered by centrifugation and the endoglucanase activity was estimated by measuring reducing sugar released from CMC by the dinitrosalicylic acid (DNS) method. Zymograms of the culture supernatant were carried out by native PAGE. The effects of temperature, pH, cations and others additives such as EDTA, PEG, SDS and Tween 80 were assayed to assess their influence on the activity and stability of the endoglucanases produced. The enzyme production reached 3 IU/mL in the crude extract (culture supernatant) and the optimal endoglucanase activity was registered at 60 °C and pH 6.0. The evaluated enzymatic extracts showed that the enzyme activity was completely retained after pretreatments at temperatures £ to 40 °C, although it did not show thermal stability after preheating at 60 °C for one hour. Endoglucanases from AR03 isolate maintained approximately 80% of the total activity within a wide range of pH (3.0 to 10.0). The native PAGE revealed at least three bands with endoglucanase activity, having apparent molecular masses of 286, 208 and 157 kDa. Even when most of the effectors assayed did not affect significantly the enzymatic activity, the addition of Mn2+ and Co2+ (5 mM) to the enzymatic reaction mixture produced a noteworthy improvement of the endoglucanase activity from the crude extracts. The endoglucanase activity was upgraded as much as 150% and 80% when salts containing Mn2+ and Co2+ were added, respectively. Those increments were confirmed by means of HPLC measurements since it has been reported interference between some divalent cations and the DNS reagent. The results regarding the broad range of pH stability and the strong improvement of enzymatic activity by the presence of manganese are the most relevant features of the endoglucanases from Bacillus sp. AR03 to be considered as promising for further studies and for biotechnological applications.Fil: Pisa, José Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Manfredi, Adriana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Perotti, Nora Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Martinez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXI Congreso de Microbiología GeneralCórdobaArgentinaAsociación Civil de Microbiología Genera

Essential oils from Argentinean native species reduce in vitro methane production

The aim of this study was to evaluate the effect of Argentinean essential oils (EO) on methane production during in vitro fermentation compared to EO with proven effects as rumen fermentation modifiers. A complete randomized block design was used and the treatments included EO from Aloysia gratissima (50, 100, 150 and 300 mg/L), Eucalyptus globulus (5, 50, 150 and 300 mg/L), Lippia turbinata (30, 60, 120 and 240 mg/L), Mentha x piperita var. vulgaris (50, 100, 200 and 400 mg/L), Origanum vulgare ssp. hirtum cv. Compacto (0.5, 5, 50 and 250 mg/L) and cv. Mendocino (50, 150, 250 and 350 mg/L), Rosmarinus officinalis (100, 300, 500 and 700 mg/L), Schinus molle (75, 150, 300 and 600 mg/L), Tagetes minuta (5, 50, 125 and 250 mg/L), and Thymus vulgaris (5, 50, 150 and 300 mg/L). Two controls were included: control (not containing EO) and monensin (1.87 mg/L). Variables measured were: digestibility of neutral detergent fiber, gas and methane production. Compared to the control, monensin reduced methane production by 44%, but with a 15% reduction in fiber digestibility. Except for E. globulus and L. turbinata, each variable measured was significantly reduced with the higher level of inclusion compared to the control, representing that overall microbial activity was affected. L. turbinata (60.8% limonene) reduced methane by half compared to control, and by 35 to 85% when compared to monensin, without affecting digestibility of the fiber. Some essential oils from native Argentinean plants exhibited great potential to reduce enteric methane production without affecting digestibility, of which L. turbinata was the most promising alternative.El objetivo de este estudio fue evaluar el efecto de aceites esenciales (AE) de plantas nativas de Argentina en la producción de metano durante la fermentación in vitro, en comparación con AE con efectos comprobados como modificadores de la fermentación ruminal. Se realizó un diseño en bloque completos al azar y los AE y dosis evaluados fueron: Aloysia gratissima (0,5, 5, 50 y 250 mg/L) , Eucalyptus globulus (5, 50, 150 y 300 mg/L), Lippia turbinata (30, 60, 120 y 240 mg/L), Mentha x piperita var. vulgaris (50, 100, 200 y 400 mg/L), Origanum vulgare ssp. hirtum cv. Compacto (0,5, 5, 50 y 250 mg/L) y cv. Mendocino (50, 150, 250 y 350 mg/L), Rosmarinus officinalis (100, 300, 500 y 700 mg/L), Schinus molle (75, 150, 300 y 600 mg/L), Tagetes minuta (5, 50, 125 y 250 mg/L), y Thymus vulgaris (5, 50, 150 y 300 mg/L). Se incluyeron dos controles: control (sin AE) y monensina (1,87 mg/L). Las variables evaluadas fueron: digestibilidad in vitro de la fibra en detergente neutro, producción de gas y metano. En comparación al control, la monensina redujo la producción de metano en un 44%, pero con una reducción de un 15% en la digestibilidad de la fibra. Con excepción a E. globulus y L. turbinata, todas las variables fueron reducidas significativamente con el mayor nivel de inclusión comparado con el control, lo cual representa que la actividad microbiana se vio afectada. L. turbinata (60,8% limoneno) redujo la producción de metano a la mitad comparado al control, y entre un 35 y 85% en comparación a la monensina, sin que la digestibilidad de la fibra se vea afectada. Algunos aceites esenciales de plantas nativas de Argentina demostraron gran potencial para reducir la producción de metano entérico sin afectar la digestibilidad, de los cuales L. turbinata fue la alternativa más promisoria.EEA ManfrediFil: García, F. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Brunetti, Maria Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Lucini, Enrique I. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias,; ArgentinaFil: Scorcione Turcato, M.C. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moreno, Maria Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Frossasco, Georgina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomia; Argentina.Fil: Martinez, Maria Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Martinez Ferrer, Jorge. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; Argentin

Amaranth (Amaranthus hypochondriacus) Vicilin Subunit Structure

The 7S-globulin fraction is a minor component of the amaranth storage proteins. The present work provides new information about this protein. The amaranth 7S-globulin or vicilin presented a sedimentation coefficient of 8.6 ± 0.6 S and was composed of main subunits of 66, 52, 38, and 16 kDa. On the basis of mass spectrometry (MS) analysis of tryptic fragments, the 52, 38, and 16 kDa subunits presented sequence homology with sesame vicilin, whereas the 66 kDa subunit showed sequence similarity with a putative vicilin. Several characteristics of the 66 kDa subunit were similar to members of the convicilin family. Results support the hypothesis that the 7S-globulin molecules are composed of subunits coming from at least two gene families with primary products of 66 and 52 kDa, respectively. According to the present information, amaranth vicilin may be classified into the vicilin group that includes pea, broad bean, and sesame vicilins, among others.Fil: Quiroga, Alejandra Viviana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Martinez, Estela Nora. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Rogniaux, Hélène. Instituto National de Recherches Agronomiques. Biopolymères Interactions Assemblages; FranciaFil: Geairon, Audrey. Instituto National de Recherches Agronomiques. Biopolymères Interactions Assemblages; FranciaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

State of the art in compliance with the compensation measures imposed in the issuance of environmental licenses in Colombia

Hoy en día, el Derecho al medio ambiente está amparado constitucionalmente y quien tiene su guarda fundamental es el estado, quién a través de sus entidades debe velar por el cumplimiento de sus fines esenciales para proteger y salvaguardar el ecosistema y a las comunidades afectadas, pero, dentro de estos fines también surge la necesidad de un desarrollo económico a nivel nacional, que genera la necesidad de iniciar procesos de explotación y exploración como mecanismos para impulsar la economía y sacar provecho de los hidrocarburos, que generan gran crecimiento económico al país, pero que tanto se debe sacrificar el medio ambiente y la naturaleza en donde se pone en riesgo, el agua, los páramos, la flora y la fauna, y la salud de las comunidades, en procesos que son irreversibles y que destruyen el medio ambiente. Observaremos de qué forma el Estado intenta mitigar ese daño ambiental con la imposición de medidas de compensación, cuál es su cumplimiento y cuál es su efectividad, además de la operancia de los procesos sancionatorios a infractores con datos estadísticos y de consulta que pretenden dejar al descubierto la verdadera situación del proceso ambiental en Colombia. Palabras clave: Licencias Ambientales, Compensación ambientalEspecialización de Derecho Administrativo de la Universidad Libre, Facultad de DerechoToday, the Right to the environment is constitutionally protected and who has its fundamental guardian is the state, which through its entities must ensure the fulfillment of its essential purposes to protect and safeguard the ecosystem and the affected communities, but, Within these purposes, the need for economic development at the national level also arises, which generates the need to initiate exploitation and exploration processes as mechanisms to boost the economy and take advantage of hydrocarbons, which generate great economic growth for the country, but which both the environment and nature must be sacrificed where it is put at risk, water, moors, flora and fauna, and the health of communities, in processes that are irreversible and destroy the environment. We will observe how the State tries to mitigate this environmental damage with the imposition of compensation measures, what is its compliance and what is its effectiveness, in addition to the operation of the sanctioning processes against offenders with statistical and consultation data that they intend to expose. the true situation of the environmental processes in Colombia

Synergistic effect of xylanases produced in co-culture of bacillus sp. Ar03 and paenibacillus sp. Ar247

In nature, the plant biomass is degraded by a process that requires the cooperative action of multiple microorganisms capable of producing a variety of enzymes to attack the complex structure of lignocelluloses. This work assessed the production and the enzymatic activity over the main hemicellulolytic fraction of plant biomass, xylan, in monoculture and co-culture systems of bacteria isolated from regional niches associated with sugar cane bagasse. The enzyme activity was estimated by measuring reducing sugars released using the dinitrosalicylic acid method. All cultivation assays were performed at 200 rpm and 30 °C in a diluted peptone broth supplemented with 1% CMC (w/v). The viability and the growth of both isolates were estimated by the number of colony forming units, fact that was possible since both isolates exhibited different colony morphology. The specific xylanolytic activity of the co-culture of Bacillus sp. AR03 and Paenibacillus sp. AR247 was of 7.03 ± 0.46 IU/mg and 8.36 ± 0.49 IU/mg at 48 h and 96 h of cultivation, respectively. In contrast, each isolate assayed simultaneously under identical conditions, produced significantly lower xylanase activities, even when both isolates grew similarly in both, individual and co-cultures, reaching approximately 1011 CFU/ml in all cases. These values were of 4.18 ± 0.24 IU/mg and 4.55 ± 0.29 IU/mg of xylanolytic activity at 48 h and 96 h, respectively, for Bacillus sp. AR03, while Paenibacillus sp. AR247 reached values of 0.59 ± 0.09 IU/mg and 0.40 ± 0.03 IU/mg at the same periods of cultivation. When mixtures (1:1) of the cell-free supernatant of individual cultures were assayed, it was observed that the enzymatic activity reached a maximum of 4.16 ± 0.39 IU/mg after 48 h of cultivation. This value was close to that obtained by the sum of the enzymatic activity of individual cultures, which was 4.77 IU/mg, for the same cultivation time. The obtained results were consistent with the observation of a synergistic effect on the degradation of xylan in the co-culture evaluated, with an estimated degree of synergism of 1.69 at 96 h. This synergy, which has been described for enzyme mixtures on industrial substrates, was observed here during the co-cultivation of Bacillus sp. AR03 and Paenibacillus sp. AR247. This system displayed a higher xylanolytic activity with respect to the individual cultivation of each isolate and a different zymographic pattern along the cultivation period. The obtained results of the xylanolytic activity for individual strains and the co-culture might indicate that the observed effect could not depend on an only addition of enzyme activities so that we may suggest the existence of a synergistic cooperation during the growth in the co-cultivation of the microorganism evaluated.Fil: Hero, Johan Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pisa, José Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Perotti, Nora Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Romero, Cintia Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Martinez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXI Congreso Argentino de Microbiología GeneralCórdobaArgentinaAsociación Civil de Microbiología Genera