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Anthropogenic activities are often related to the occurrence of simultaneous contaminations with heavy metals and toxic organic compounds. In addition, the increasing demand for food, clothing, and technology has increased the worldwide contamination level. Although it is not fully demonstrated, the high level of contamination in association with the indiscriminate use of antibiotics, led to the appearance of multi-resistant pathogenic microorganisms. Grey and red biotechnologies try to counteract the negative effects of pollution and antimicrobial resistance respectively. Streptomyces is well known in the field of biotechnology. In this review, we discussed the potential of these bacteria to deal with organic and inorganic pollutants and produce nanostructures with antimicrobial activity. To our knowledge, this is the first work in which a biotechnological bacterial genus such as Streptomyces is revised in two different fields of global concern, contamination, and multi-drugs resistant microorganisms.

Old Yellow Enzymes play key roles in several cellular processes and have become an important family of enzymes withbiotechnological potential. One of the major challenges of biotechnology consists of the bioremediation of co-polluted soilswith organic and inorganic compounds. In co-contaminated areas, chromium normally exists in its more toxic and carcinogenicform Cr(VI). Microorganisms can reduce this metal to the insoluble and less toxic Cr(III).Streptomycessp. M7 is a strain able toefficiently bioremediate polluted soils withγ-hexachlorocyclohexane and Cr(VI). The complete degradation pathway for γ-hexachlorocyclohexane was recently elucidated in this strain. In the present work, we confirmed the ability ofStreptomycessp.M7 to eliminate a high percentage of Cr(VI) from a synthetic culture medium. After a transcriptional study in the presence ofCr(VI), we also report the molecular cloning of a gene coding for an Old Yellow Enzyme with chromate reductase activity. Ourresults suggest that the elimination of Cr(VI) byStreptomycessp. M7 is directly related to the activity of this Old Yellow Enzyme.The importance of our work is in identifying for the first time an Old Yellow Enzyme with chromate reductase activity inStreptomycesand Actinobacteria. Finding this enzyme helps understand chromium homeostasis inStreptomycessp. M7, inaddition to opening a new research window related to Old Yellow Enzymes from Actinobacteria. Fil: Sineli, Pedro Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Guerrero, Daiana. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina Fil: Alvarez, Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina

The genus Streptomyces is widely recognized for its biotechnological potential. Due to a need to improve crops,clean up the environment and produce novel antimicrobial molecules exploiting Streptomyces has become apriority. To further explore the biotechnological potential of these organisms we analyzed the genome of thestrain Streptomyces sp. Z38 isolated from contaminated roots tissues. Our analysis not only confirmed the abilityof the strain to produce plant growth promoting traits but also a range of mechanisms to cope with the toxiceffect of heavy metals through genes involved in metal homeostasis and oxidative stress response. The production of silver nanoparticles indicated that Streptomyces sp. Z38 may find utility in Green, Grey and Redbiotechnology Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Hoskisson, Paul Alan. University of Strathclyde; Reino Unido Fil: Paterlini, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Romero, Cintia Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Alvarez, Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina

Highly γ-hexachlorocyclohexane (lindane) contaminated areaswere reported worldwide. Low aqueous solubility and high hydrophobicitymake lindane particularly resistant to microbial degradation.Physiological and genetic Streptomyces features make this genus moreappropriate for bioremediation compared with others. Complete degradationof lindane was only proposed in the genus Sphingobium although themetabolic context of the degradation was not considered. Streptomyces sp.M7 has demonstrated ability to remove lindane from culture media andsoils. In this study, we used MS-based label-free quantitative proteomic,RT-qPCR and exhaustive bioinformatic analysis to understand lindanedegradation and its metabolic context in Streptomyces sp. M7. Weidentified the proteins involved in the up-stream degradation pathway. Inaddition, results demonstrated that mineralization of lindane is feasiblesince proteins from an unusual down-stream degradation pathway were alsoidentified. Degradative steps were supported by an active catabolism thatsupplied energy and reducing equivalents in the form of NADPH. To ourknowledge, this is the first study in which degradation steps of anorganochlorine compound and metabolic context are elucidate in abiotechnological genus as Streptomyces. These results serve as basementto study other degradative actinobacteria and to improve the degradationprocesses of Streptomyces sp. M7. Fil: Sineli, Pedro Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Herrera, Héctor Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Cuozzo, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina

Actinobacteria are well-known degraders of toxic materials that have the ability to tolerate and remove organochloride pesticides; thus, they are used for bioremediation. The biodegradation of organochlorines by actinobacteria has been demonstrated in pure and mixed cultures with the concomitant production of metabolic intermediates including γ-pentachlorocyclohexene (γ-PCCH); 1,3,4,6-tetrachloro-1,4-cyclohexadiene (1,4-TCDN); 1,2-dichlorobenzene (1,2-DCB), 1,3-dichlorobenzene (1,3-DCB), or 1,4-dichlorobenzene (1,4-DCB); 1,2,3-trichlorobenzene (1,2,3-TCB), 1,2,4-trichlorobenzene (1,2,4-TCB), or 1,3,5-trichlorobenzene (1,3,5-TCB); 1,3-DCB; and 1,2-DCB. Chromatography coupled to mass spectrometric detection, especially GC–MS, is typically used to determine HCH-isomer metabolites. The important enzymes involved in HCH isomer degradation metabolic pathways include hexachlorocyclohexane dehydrochlorinase (LinA), haloalkane dehalogenase (LinB), and alcohol dehydrogenase (LinC). The metabolic versatility of these enzymes is known. Advances have been made in the identification of actinobacterial haloalkane dehydrogenase, which is encoded by linB. This knowledge will permit future improvements in biodegradation processes using Actinobacteria. The enzymatic and genetic characterizations of the molecular mechanisms involved in these processes have not been fully elucidated, necessitating further studies. New advances in this area suggest promising results. The scope of this paper encompasses the following: (i) the aerobic degradation pathways of hexachlorocyclohexane (HCH) isomers; (ii) the important genes and enzymes involved in the metabolic pathways of HCH isomer degradation; and (iii) the identification and quantification of intermediate metabolites through gas chromatography coupled to mass spectrometry (GC–MS). Fil: Cuozzo, Sergio Antonio. 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 Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: Sineli, Pedro Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Tortella, G.. Universidad de La Frontera. Núcleo Científico y Tecnológico en Recursos Naturales; Chile

The resistance of common or resurgent pathogens to standard antibiotic therapies is a significant health problem, so the need for new antimicrobial sources is imperative. It is widely known that the most promising source of new drugs remains natural products, mainly those of microbial origin. Such is the case of microbial nanoparticles (NPs) which have unusual physical, chemical, and biological properties like as powerful antibacterial activities. While NPs synthesized by chemical methods involve hazardous and expensive processes, nano-biosynthesis is a green technology by which NPs are obtained through biological processes such as the reduction of a metal salt by the action of biomolecules.

Highly toxic compounds have been released into the environment by direct or indirect inputs over a long time. Pesticides are among the most widely used and released chemicals in the world. The disposal of obsolete pesticide stocks has resulted in many long-term contaminated sites in Latin America, many of which are currently illegal. The general scenario is to find a mixture of pollutants of both organic and inorganic nature, which are typical in industrial, urban and agricultural areas. With the scope of reducing the concentration and toxicity of these chemicals, eco-friendly techniques have emerged for cleaning up polluted sites using plants and/or microbial species. Among the organisms used in the bioremediation of polluted sites, actinobacteria are one of the most popular biological vectors for in situ bioremediation. These bacteria play an important role in recycling substances in natural world because they metabolize complex organic molecules and polymers. The ecological role performed by actinobacteria is demonstrated by their capability to breakdown and transform pesticides and metals, among other chemicals. This chapter focuses on how different techniques using actinobacteria can contribute to improve the bioremediation of pesticide- and metal-polluted environments.

Microbial mineralization offers an efficient alternative to obtain metallic nanoparticles. The aim of this work was to synthesize green silver nanoparticles (AgNPs) using the metal resistant strain Streptomyces sp. M7. In addition, molecular modeling and docking studies were performed in order to understand how stabilizing proteins interact with the nanoparticle’s surface. The production of AgNPs was influenced by the incubation time. AgNPs showed a moderate polydispersity of size and spherical shape. The hydrodynamic diameter was determined by Dynamic Light Scattering (DLS). Fourier Transform Infrared Spectroscopy (FTIR) and Raman analysis showed that organic molecules such as oxide-reduction enzymes coated the AgNPs surface. Molecular modeling and docking studies indicated that actually different enzymes may be simultaneously bound to the nanoparticle surface forming a layer capping-protein with different affinities. Thermogravimetric analysis (TGA) showed high thermal resistance of AgNPs, probably by the presence of organic residues on the surface. The green synthesized AgNPs showed antimicrobial activity against several multidrug-resistant bacteria, particularly Serratia marcescens SmCR371. This strain belongs to a cluster with epidemic behavior, harboring an extended spectrum of β -lactamases and carbapenemase. AgNPs produced by Streptomyces sp. M7 could be considered as a new line of defense against microbial resistance or as a complement of traditional antibiotics.

Actinobacteria exhibit cosmopolitan distribution since their members are widely distributed in aquatic and terrestrial ecosystems. In the environment they play relevant ecological roles including recycling of substances, degradation of complex polymers, and production of bioactive molecules. Biotechnological potential of actinobacteria in the environment was demonstrated by their ability to remove organic and inorganic pollutants. This ability is the reason why actinobacteria have received special attention as candidates for bioremediation, which has gained importance because of the widespread release of contaminants into the environment. Among organic contaminants, pesticides are widely used for pest control, although the negative impact of these chemicals in the environmental balance is increasingly becoming apparent. Similarly, the extensive application of heavy metals in industrial processes lead to highly contaminated areas worldwide. Several studies focused in the use of actinobacteria for cleaning up the environment were performed in the last 15 years. Strategies such as bioaugmentation, biostimulation, cell immobilization, production of biosurfactants, design of defined mixed cultures and the use of plant-microbe systems were developed to enhance the capabilities of actinobacteria in bioremediation. In this review, we compiled and discussed works focused in the study of different bioremediation strategies using actinobacteria and how they contributed to the improvement of the already existing strategies. In addition, we discuss the importance of omic studies to elucidate mechanisms and regulations that bacteria use to cope with pollutant toxicity, since they are still little known in actinobacteria. A brief account of sources and harmful effects of pesticides and heavy metals is also given. Fil: Alvarez, Analia. 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 Ciencias Naturales e Instituto Miguel Lillo; Argentina Fil: Sáez, Juliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Cuozzo, Sergio Antonio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Polti, Marta Alejandra. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina

The aims of this study were (1) to isolate new multi-resistant actinobacteria from soil, rhizosphere and plant samples collected from an ancient illegal pesticide storage and (2) to elucidate the effects of these microorganisms developed with maize root exudates on lindane and Cr(VI) removal. Fifty-seven phenotypically different actinobacteria were isolated and four of them, belonging to the genus Streptomyces exhibit tolerance to a mixture of lindane and Cr(VI). Two rhizospheric strains named as Streptomyces sp. Z38 and Streptomyces sp. Z2 were selected to be grown with root exudates because they showed the highest Cr(VI) and lindane removal in co-contaminated medium. When root exudates were the only carbon source, metal dissipation increased significantly either as single or mixed contaminant, compared to metal dissipation with glucose. No significant differences were found on lindane removal with root exudates or glucose, so a higher lindane concentration was evaluated. Despite of this, lindane removal remained stable while metal dissipation was notoriously lower when lindane concentration was enhanced. In addition to a good performance growing with mixed contaminants, Streptomyces strains showed plant growth promoting traits that could improve plant establishment. The results presented in this study show the importance of the screening programs addressed to find new actinobacteria able to grow in co-contaminated systems. It was also evidenced that root exudates of maize improve the growth of Streptomyces strains when they were used as carbon source, being the dissipation of Cr(VI) considerably improved in presence of lower lindane concentration. Fil: Simón Solá, María Zoleica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Lovaisa, Nadia Carolina. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Benimeli, Claudia Susana. Universidad Nacional de Catamarca; Argentina Fil: Polti, Marta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Alvarez, Analia. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina

The bacterium Rhodococcus jostii RHA1 synthesizes large amounts of triacylglycerols (TAG) under conditions of nitrogen starvation. To better understand the molecular mechanisms behind this process, we performed proteomic studies in this oleaginous bacterium. Upon nitrogen starvation, we observed a re-routing of the carbon flux towards the formation of TAG. Under these conditions, the cellular lipid content made up more than half of the cell?s dry weight. On the proteome level, this coincided with a shift towards non-glycolytic carbohydrate-metabolizing pathways. These pathways (Entner-Doudoroff and pentose-phosphate shunt) contribute NADPH and precursors of glycerol-3-phosphate and acetyl-CoA to lipogenesis. The expression of proteins involved in the degradation of branched-chain-amino acids and the methyl malonyl-CoA pathway probably provided propionyl-CoA for the biosynthesis of odd-numbered fatty acids, which make up almost 30% of RHA1 fatty acid composition. Additionally, lipolytic and glycerol-degrading enzymes increased in abundance, suggesting a dynamic cycling of cellular lipids. Conversely, abundance of proteins involved in consuming intermediates of lipogenesis decreased. Furthermore, we identified another level of lipogenesis regulation through redox-mediated thiol modification in R. jostii. Enzymes affected included acetyl-CoA carboxylase and a β-ketoacyl-[ACP] synthase II (FabF). An integrative metabolic model for the oleaginous RHA1 strain is proposed based on our results. Fil: Dávila Costa, José Sebastián. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina Fil: Herrero, O. Marisa. Universidad Nacional de la Patagonia "san Juan Bosco". Facultad de Ciencias Naturales - Sede Comodoro; Argentina Fil: Alvarez, Hector Manuel. Universidad Nacional de la Patagonia "san Juan Bosco". Facultad de Ciencias Naturales - Sede Comodoro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Leichert, Lars. Ruhr-Universitat Bochum; Alemania

Rhodococcus jostii RHA1 is able to degrade toxic compounds and accumulate high amounts of triacylglycerols (TAG) upon nitrogen starvation. These NADPH-dependent processes are essential for the adaptation of rhodococci to fluctuating environmental conditions. In this study, we used an MS-based, label-free and quantitative proteomic approach to better understand the integral response of R. jostii RHA1 to the presence of methyl viologen (MV) in relation to the synthesis and accumulation of TAG. The addition of MV promoted a decrease of TAG accumulation in comparison to cells cultivated under nitrogen-limiting conditions in the absence of this pro-oxidant. Proteomic analyses revealed that the abundance of key proteins of fatty acid biosynthesis, the Kennedy pathway, glyceroneogenesis and methylmalonyl-CoA pathway, among others, decreased in the presence of MV. In contrast, some proteins involved in lipolysis and β-oxidation of fatty acids were upregulated. Some metabolic pathways linked to the synthesis of NADPH remained activated during oxidative stress as well as under nitrogen starvation conditions. Additionally, exposure to MV resulted in the activation of complete antioxidant machinery comprising superoxide dismutases, catalases, mycothiol biosynthesis, mycothione reductase and alkyl hydroperoxide reductases, among others. Our study suggests that oxidative stress response affects TAG accumulation under nitrogen-limiting conditions through programmed molecular mechanisms when both stresses occur simultaneously. Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentina Fil: Silva, Roxana Alejandra. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentina Fil: Leichert, Lars. Ruhr Universität Bochum; Alemania Fil: Alvarez, Hector Manuel. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentina

Rhodococcus spp. are oleaginous bacteria that accumulate glycogen during exponential growth. Despite the importance of these microorganisms in biotechnology, little is known about the regulation of carbon and energy storage, mainly the relationship between glycogen and triacylglycerols metabolisms. Herein, we report the molecular cloning and heterologous expression of the gene coding for ADP-glucose pyrophosphorylase (EC 2.7.7.27) of Rhodococcus jostii, strain RHA1. The recombinant enzyme was purified to electrophoretic homogeneity to accurately characterize its oligomeric, kinetic, and regulatory properties. The R. jostii ADP-glucose pyrophosphorylase is a homotetramer of 190 kDa exhibiting low basal activity to catalyze synthesis of ADP-glucose, which is markedly influenced by different allosteric effectors. Glucose-6P, mannose-6P, fructose-6P, ribose-5P, and phosphoenolpyruvate were major activators; whereas, NADPH and 6P-gluconate behaved as main inhibitors of the enzyme. The combination of glucose-6P and other effectors (activators or inhibitors) showed a cross-talk effect suggesting that the different metabolites could orchestrate a fine regulation of ADP-glucose pyrophosphorylase in R. jostii. The enzyme exhibited some degree of affinity toward ATP, GTP, CTP, and other sugar-1P substrates. Remarkably, the use of glucosamine-1P was sensitive to allosteric activation. The relevance of the fine regulation of R. jostii ADP-glucose pyrophosphorylase is further analyzed in the framework of proteomic studies already determined for the bacterium. Results support a critical role for glycogen as a temporal reserve that provides a pool of carbon able of be re-routed to produce long-term storage of lipids under certain conditions. Fil: Cereijo, Antonela Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Asención Diez, Matías Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Dávila Costa, José Sebastián. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia ; Argentina Fil: Alvarez, Hector Manuel. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia ; Argentina Fil: Iglesias, Alberto Alvaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina

Copper is a redox-active metal which acts as a catalyst in the formation of Reactive Oxygen Species (ROS) encouraging oxidative stress. Protection against oxidants is intrinsic to every living cell, however in stress conditions, cells are forced to increase and expand their antioxidative network. In this work, the novel copper-resistant strain Amycolatopsis tucumanensis and the copper-sensitive Amycolatopsis eurytherma were grown under copper increasing concentrations in order to elucidate the dissimilar effects of the metal on the strains viability, mainly on morphology and antioxidant capacity. Although biosorbed copper encouraged ROS production in a dose-dependent manner in both strains, the increase in ROS production from the basal level to the stress conditions in A. tucumanensis is lesser than in the copper-sensitive strain; likewise, in presence of copper A. eurytherma suffered inexorable morphological alteration while A. tucumanensis was not affected. The levels of antioxidant enzymes and metallothioneins (MT) were all greater in A. tucumanensis than in A. eurytherma; in addition MT levels as well as superoxide dismutase and thioredoxin reductase activities in A. tucumanensis, were higher as higher the concentration of copper in the culture medium. This work has given evidence that an efficient antioxidant defence system might aid microorganisms to survive in copper-stress conditions; besides it constitutes the first report of oxidative stress study in the genus Amycolatopsis and contributes to enlarge the knowledge on the copper-resistance mechanisms of A. tucumanensis. Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina Fil: Albarracín, Virginia Helena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Tucumán; Argentina Fil: Abate, Carlos Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Tucumán; Argentina

Amycolatopsis tucumanensis, a recently recognized novel species showed remarkable copper resistance as well as efficient Specific Cupric Reductase Activity (SRACu) in both, copper adapted and non-adapted cells, under different temperatures of incubation. Its copper resistance strength was highlighted against other metal-resistant actinobacteria (Streptomyces sp. AB5A) and sensitive strains (Amycolatopsis eurytherma and Streptomyces coelicolor). Pre-adapted cells of A. tucumanensis displayed values of SRACu, on average, 65% higher than those obtained from non-adapted cells. In addition, preadaptation of A. tucumanensis improved the rate of Cu(II) reduction which was approximately, two-, seven- and ninefold higher than pre-adapted cells from Streptomyces sp. AB5A, A. eurytherma and S. coelicolor, respectively. A. tucumanensis showed the highest levels of SRACu at all temperatures and also the highest copper resistance profile, suggesting that these two abilities may be in close relationship. This ostensible versatility, related to the temperature, of adapted cells from A. tucumanensis might support the application of this strain under different bioremediation conditions. To our knowledge this is the first time that cupric reductase activity was demonstrated within the genus Amycolatopsis.

The organochlorine insecticide γ-hexachlorocyclohexane (γ-HCH, lindane) and its non-insecticidal α- and β-isomers continue to pose serious environmental and health concerns, although their use has been restricted or completely banned for decades. In this study we report the first evidence of the growth ability of a Streptomyces strain in a mineral salt medium containing high doses of α- and β-HCH (16.6 mg l−1) as a carbon source. Degradation of HCH isomers by Streptomyces sp. M7 was investigated after 1, 4, and 7 days of incubation, determining chloride ion release, and residues in the supernatants by GC with µECD detection. The results show that both the α- and β-HCH isomers were effectively metabolized by Streptomyces sp. M7, with 80 and 78 % degradation respectively, after 7 days of incubation. Moreover, pentachlorocyclohexenes and tetrachlorocyclohexenes were detected as metabolites. In addition, the formation of possible persistent compounds such as chlorobenzenes and chlorophenols were studied by GC–MS, while no phenolic compounds were detected. In conclusion, we have demonstrated for the first time that Streptomyces sp. M7 can degrade α- and β-isomers individually or combined with γ-HCH and could be considered as a potential agent for bioremediation of environments contaminated by organochlorine isomers. Fil: Sineli, Pedro Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Tortella, G.R. Universidad de La Frontera; Chile Fil: Dávila Costa, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina Fil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina. Universidad del Norte Santo Tomás de Aquino; Argentina Fil: Cuozzo, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina

Heavy metal pollution is widespread causing serious ecological problems in many parts of the world; especially in developing countries where a budget for remediation technology is not affordable. Therefore, screening for microbes with high accumulation capacities and studying their stable resistance characteristics is advisable to define cost-effective any remediation strategies. Herein, the copper-resistome of the novel copper-resistant strain Amycolatopsis tucumanensis was studied using several approaches. Two dimensional gel electrophoresis revealed that proteins of the central metabolism, energy production, transcriptional regulators, two-component system, antioxidants and protective metabolites increased their abundance upon copper-stress conditions. Transcriptome analysis revealed that in presence of copper, superoxide dismutase, alkyl hydroperoxide reductase and mycothiol reductase genes were markedly induced in expression. The oxidative damage of protein and lipid from A. tucumanensis was negligible compared with that observed in the copper-sensitive strain Amycolatopsis eurytherma. Thus, we provide evidence that A. tucumamensis shows a high adaptation towards copper, the sum of which is proposed as the copper-resistome. This adaptation allows the strain to accumulate copper and survive this stress; besides, it constitutes the first report in which the copper-resistome of a strain of the genus Amycolatopsis with bioremediation potential has been evaluated.