Tailoring fungal morphology of Aspergillus niger MYA 135 by altering the hyphal morphology and the conidia adhesion capacity: biotechnological applications

Current problems of filamentous fungi fermentations and their further successful developments as microbial cell factories are dependent on control fungal morphology. In this connection, this work explored new experimental procedures in order to quantitatively check the potential of some culture conditions to induce a determined fungal morphology by altering both hyphal morphology and conidia adhesion capacity. The capacity of environmental conditions to modify hyphal morphology was evaluated by examining the influence of some culture conditions on the cell wall lytic potential of Aspergillus niger MYA 135. The relative value of the cell wall lytic potential was determined by measuring a cell wall lytic enzyme activity such as the mycelium-bound β-N-acetyl-Dglucosaminidase (Mb-NAGase). On the other hand, the quantitative value of conidia adhesion was considered as an index of its aggregation capacity. Concerning microscopic morphology, a highly negative correlation between the hyphal growth unit length (lHGU) and the specific Mb-NAGase activity was found (r = −0.915, P < 0.001). In fact, the environment was able to induce highly branched mycelia only under those culture conditions compatible with specific Mb-NAGase values equal to or higher than 190 U gdry.wt -1. Concerning macroscopic morphology, a low conidia adhesion capacity was followed by a dispersed mycelial growth. In fact, this study showed that conidia adhesion units per ml equal to or higher than 0.50 were necessary to afford pellets formation. In addition, it was also observed that once the pellet was formed the lHGU had an important influence on its final diameter. Finally, the biotechnological significance of such results was discussed as well.Fil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET- Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina;Fil: Baigori, Mario Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET- Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina; Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina;Fil: Pera, Licia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET- Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina

Influence of culture conditions on a mycelium-bound lipase production from Aspergillus niger MYA 135

Introduction: Lipases (EC 3.1.1.3) are enzymes that hydrolyse the ester bonds of water insoluble substrates at the interface between the substrate and the water. This reaction is reversible. Lipases may also catalyze ester synthesis and transesterification in reaction mixtures with low water contents. Objective: The aim of this work was to study the influence of culture conditions on a mycelium-bound lipase production from Aspergillus niger MYA 135. Materials and methods: The fermentation medium comprised (in g/l): sucrose 10; NH4NO3 2; KH2PO4 1; MgSO4.7H2O 0.2; CuSO4.5H2O 0.06. The effect of modification in the environmental condition on lipase production was tested by changing the initial pH of the medium as well as by the addition of CaCl2, FeCl3 or Tween (20, 40, 60, and 80). Lipase activity was determined using 0.01 g of wet mycelium and p-nitrophenyl palmitate as substrate. Results and conclusions: The assayed culture conditions scientifically influences the lipase production. The highest specific activity (36.6 mU/g of DW) was obtained with either initial pH 8 or in presence of 0.5% Tween 60. This work was supported by grants PIP 6062 and PICTO 761.Fil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Baigori, Mario Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pera, Licia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXXIII Jornadas Científicas de la Asociación de Biología de TucumánTafí del ValleArgentinaAsociación de Biología de Tucumá

Bioemulsifier-producing Aspergillus niger MYA 135: effect of culture conditions

Bioemulsifiers are surface-active molecules synthetized by microorganisms, which play an important physiological role in hydrocarbon degradation. Few reports have shown the bioemulsifier production by filamentous fungi being the amount, quality and nature dependent not only on the microorganism but also on the culture conditions. Bioemulsifiers have the advantages of biodegradability, low toxicity, effectiveness and these properties enable their wide application on bioremediation, food, cosmetic and pharmaceutical industries, etc. The aim of this work was to study the bioemulsifier production by Aspergillus niger MYA 135 under different culture conditions. Methods: The bioemulsifier production was conducted in mineral medium during 96 hours, at different initial pH and with the addition of CaCl2 or FeCl3. The emulsification index was determinated after 24 h (E-24) in supernatants using kerosene as immiscible liquid. E-24 was estimated as the height of the emulsion layer divided by the total height and multiplied by 100. Results and conclusions: Bioemulsifier production reached maximum levels at 2 days of cultivation suggesting that its accumulation was growth-associated. Although all the emulsions were stable, the maximum values of E-24 were obtained at initial pH 2 (60.0 ± 0.71 %) and with the addition of FeCl3 (50.5 ± 0.70 %).This work was supported by grants PIP 6062 & PICTO 761Fil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Baigori, Mario Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pera, Licia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología MolecularVilla Carlos PazArgentinaSociedad Argentina de Investigaciones Bioquímicas y Moleculare

Integral use of sugarcane vinasse for biomass production of actinobacteria: Potential application in soil remediation

The use of living actinobacteria biomass to clean up contaminated soils is an attractive biotechnology approach. However, biomass generation from cheap feedstock is the first step to ensure process sustainability. The present work reports the ability of four actinobacteria, Streptomyces sp. M7, MC1, A5, and Amycolatopsis tucumanensis, to generate biomass from sugarcane vinasse. Optimal vinasse concentration to obtain the required biomass (more than 0.4 g L−1) was 20% for all strains, either grown individually or as mixed cultures. However, the biomass fraction recovered from first vinasse was discarded as it retained trace metals present in the effluent. Fractions recovered from three consecutive cycles of vinasse re-use obtained by mixing equal amounts of biomass from single cultures or produced as a mixed culture were evaluated to clean up contaminated soil with lindane and chromium. In all cases, the decrease in pesticide was about 50% after 14 d of incubation. However, chromium removal was statistically different depending on the preparation methodology of the inoculum. While the combined actinobacteria biomass recovered from their respective single cultures removed about 85% of the chromium, the mixed culture biomass removed more than 95%. At the end of the reused vinasse cycle, the mixed culture removed more than 70% of the biological oxygen demand suggesting a proportional reduction in the effluent toxicity. These results represent the first integral approach to address a problematic of multiple contaminations, concerning pesticides, heavy metals and a regionally important effluent like vinasse.Fil: Aparicio, Juan Daniel. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina. Universidad Santo Tomás de Aquino; ArgentinaFil: Almeida, César Américo. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Polti, Marta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentin

Production of extracellular emulsifying agent by Streptomyces SP. MC1

Emulsifier of microbial origin have significant implications in the biological treatment of pollutants from environmental. They are employed in mechanisms for hydrocarbon and inorganic pollutants bioremediation, including heavy metals. Streptomyces sp. MC1 isolated from sugar cane, showed significant capacity to reduction of Cr(VI) to Cr(III) in minimal medium supplemented with sulphate or phosphate ions. The aim of this work is to evaluate now the effect of these ions, either in presence and absence of Cr(VI) on emulsifier production from this strain. Cells of Streptomyces sp. MC1 were grown in liquid minimal medium either with or without 20 mg/L of Cr(VI) added as K2Cr2O7 , and different concentrations of Na2SO4 (5 to 20 mM). Cultures were incubated at 30ºC in orbital shaker at 170 rpm. Emulsifiers production was monitored using kerosene as water-immiscible substrate. After 48 h of cultivation, only in presence of phosphate ions it was detected the emulsifier production in supernatant of this strain, with a highly-stable emulsion. However, supplementation of Cr(VI) to the minimal medium inhibited the emulsifier production. Results presented here may have important implications in bioremediation of hydrocarbon and inorganic pollutants. Therefore, optimization studies of produced emulsifier could be required for future applications.Fil: Pereira, Claudia Elizabeth. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Villegas, Liliana Beatriz. Universidad del Norte Santo Tomás de Aquino. Facultad de Ciencias de la Salud; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Abate, Carlos Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaXLVII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología MolecularSan LuisArgentinaSociedad Argentina de Investigación en Bioquímica y Biología Molecula

Soil washing contaminated with heavy metals by using bacterial bioemulsifier at laboratory scale

Heavy metal cannot be degradable into innocuous products and they tend to be strongly absorbed on the matrix of soils and sediments. These characteristics limit their solubilization and subsequent removal. An effective method to increase the metal-desorption of soil and sediments involves washing technologies assisted with surface active compounds as such bioemulsifiers. However, there is little information found in the literature regarding bacterial bioemulsfiers used for this purpose. In previous studies, it have being demonstrated the ability to produce bioemulsifier by an actinobacterium, Amycolatopsis tucumanensis DSM 45259, using different carbon and nitrogen sources. Also it was showed that both production and hence functional properties of bioemulsifier is associated mainly to carbon sources used for biosynthesis. Following these studies, the objective of the present work was to study the applicability of bioemulsifiers produced by A. tucumanensis DSM 45259 from different carbon a nitrogen sources, as washing agents in environmental remediation technologies, as well as to determine whether Cu(II) or Cr(VI) presence affecting the bioemuslfier production. To achieve this, soil samples were artificially contaminated with Cu(II) or Cr(VI) added as CuSO 4 .5H 2 O and K 2 Cr 2 O 7 , respectively, at final concentration of 200 mg kg −1 of soil. Washing experiments were performed using 2.0 g of contaminated soil in flasks. Soils were washed with 10 ml of aqueous solutions of the partially purified bioemulsifiers, using deionized water as control. Emulsification index of each bioemulsifier solution was previously adjusted to 60%. The washing procedures were performed by shaking at 30 ºC between 12 to 24 h. Soil samples were centrifuged at 10,000g and the concentration of Cu(II) and Cr(VI) in supernatants were analyzed by atomic absorption spectrometry and Cr(VI) concentration was measured using a colorimetric method. Under these assayed conditions, no significant Cu(II) removal could be detected after 12 h of washed either with H 2 Od or bioemulsifier solutions. However, A. tucumanensis bioemulsifiers seemed to be effective for Cr(VI) recovery, whose removal from soil increased 2 fold while compared to H 2 Od. Cr removed in the washing experiments remains in its hexavalent state. The increase of the in the washing time, did not improve the Cu(II) and Cr(VI) removal. Analysing the different effects of carbon and nitrogen sources and metal type, the last one was the most relevant variable that influence on the washing efficiency. In relation to the production of bioemulsifier by A. tucumanensis DSM 45259 in the presence of metals, the results showed that the assayed concentrations of Cu(II) and Cr(VI) (10, 20 and 30 ppm) in the culture media did not affect the bioemulsifier production. These are the first advances conducted in our research group focused on the direct application of microbial products in heavy metal remediation strategies.Fil: Castro, María Fernanda. Universidad Nacional de Tucumán; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Villegas, Liliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaIX Congreso de Microbiologia GeneralRosarioArgentinaSociedad Argentina de Microbiología Genera

Applied of actinobacteria consortia-based bioremediation to restore co-contaminated systems

Global industrialization and natural resources extraction have left cocktails of environmental pollutants. Thus, this work focuses on developing a defined actinobacteria consortium able to restore systems co-contaminated with pollutants occurring in Argentinian environments. In this context, five actinobacteria were tested in solid medium to evaluate antagonistic interactions and tolerance against lindane (LIN), Reactive Black B–V (RBV), phenanthrene (Ph) and Cr(VI). The strains showed absence of antagonism, and most of them tolerated the presence of individual pollutants and their mixtures, except Micromonospora sp. A10. Thus, a quadruple consortium constituted by Streptomyces sp. A5, M7, MC1, and Amycolatopsis tucumanensis DSM 45259T, was tested in liquid systems with individual contaminants. The best microbial growth was observed in the presence of RBV and the lowest on Cr(VI). Removals detected were 83.3%, 65.0% and 52.4% for Ph, RBV and LIN, respectively, with absence of Cr(VI) dissipation. Consequently, the consortium performance was tested against the organic mixture, and a microbial growth similar to the biotic control and a LIN removal increase (61.2%) were observed. Moreover, the four actinobacteria of the consortium survived the mixture bioremediation process. These results demonstrate the potential of the defined actinobacteria consortium as a tool to restore environments co-contaminated with organic pollutants.Fil: Antezana, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Bourguignon, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

Influence of calcium chloride on cellular polarity of Aspergillus Niger MYA 135

Introducción: La hifa, unidad estructural y funcional de los hongos filamentosos es una célula tubular cuya forma se conserva gracias a la existencia de una pared celular, sitio de diversas actividades enzimáticas. Dentro de las enzimas líticas de pared, la b-N-acetil-D-glucosaminidasa (NAGasa) puede ser empleada como un marcador relativo de la morfología de las hifas ya que, resultados previos muestran una interrelación entre su actividad y el grado de ramificación y/o presencia de células bulbosas en el micelio de Aspergillus niger. Considerando que la pared es esencial para mantener el balance osmótico y la forma celular y que la actividad de sus enzimas puede ser modulada, entre otras cosas, por factores ambientales; el efecto estimulante del Ca+2 sobre la actividad NAGasa se vio reflejado en un incremento del grado de ramificación del micelio y presencia de abundantes células bulbosas. Así, dentro de este marco teórico, la pérdida de polaridad celular que se observa en las células bulbosas o globosas podría ser el resultado de una pared fuertemente debilitada. Objetivo: Determinar si la polaridad celular es restaurada con el suplemento de un estabilizador osmótico al medio de cultivo. Materiales y Métodos: El microorganismo empleado en el presente trabajo es Aspergillus niger ATCC MYA 135, una cepa aislada y caracterizada en nuestro laboratorio. El micelio que desarrolla en medio salino a 30°C se considera estándar. Los cambios morfológicos se estudiaron en micelios obtenidos en presencia de 0,5 g/l de CaCl2 con y sin el suplemento de NaCl 1,5 M como de estabilizador osmótico. El análisis microscópico de la morfología (100 X) se realiza luego de 72 horas de cultivo. Resultados: En el micelio desarrollado en presencia NaCl prácticamente no se observaron células bulbosas mientras que, en ausencia del mismo, estas células fueron prominentes y abundantes. Conclusiones: La morfología celular fue restaurada en un medio de alta osmolaridad, lo que sugiere la presencia de una pared celular debilitada.Fil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Baigori, Mario Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pera, Licia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXXV Jornadas Científicas de la Asociación de Biología de TucumánTafi del ValleArgentinaAsociación de Biología de Tucumá

Evaluación de la toxicidad de la vinaza resultante del crecimento de Aspergillus sp. V1 empleando Artemia salina como organismo indicador

La vinaza es un efluente industrial líquido muy voluminoso con bajo pH y elevados valores de DQO (Demanda Química de Oxígeno), que resulta de la producción de alcohol etílico. De no ser tratada adecuadamente, la vinaza puede generar problemas de contaminación ambiental, sobre todo en los cuerpos de agua que son los principales receptores de este efluente. La bioeconomía ha ganado importancia debido a la necesidad de transitar hacia formas de producción que minimicen o eliminen la generación de desechos. En este sentido, nuestro grupo de trabajo logró la bioconversión de vinaza sucro-alcoholera en biomasa fúngica con 41% de proteína, la cual podría emplearse como ingrediente económico para piensos acuícolas. El hongo empleado para este propósito, Aspergillus sp. V1, produjo un incremento en el pH de la vinaza cercano a la neutralidad, y una reducción del 30% en la DQO del efluente. El objetivo de este estudio fue emplear al crustáceo Artemia Salina para estimar la ecotoxicidad de la vinaza, antes (V0) y después de la producción de biomasa fúngica (VB). Para esto, nauplios de Artemia Salina se incubaron con 100 µl de diferentes diluciones de V0 y VB, durante 24 h a temperatura ambiente. Transcurrido el periodo de incubación, se calculó la concentración letal 50 (CL50), es decir, la concentración de V0 y VB que mata al 50% de los organismos de prueba. En nuestras condiciones de ensayo, la CL50 fue de 1,9% para V0 y 25,0% para VB. Estos resultados demuestran la efectiva reducción en la toxicidad de la vinaza asociada al crecimiento del hongo (VB) respecto a V0, ya que la concentración requerida para matar el 50% de los nauplios de Artemia salina fue aproximadamente 13 veces mayor.Fil: del Gobbo, Luciana Melisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Polti, Marta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXXIX Jornadas de Jóvenes InvestigadoresSucreBoliviaUniversidad Mayor, Real y Pontificia de San Francisco Xavier de ChuquisacaAsociación de Universidades Grupo Montevide