Streptomyces griseus: a new biocatalyst with N-oxygenase activity

Aromatic nitro compounds are key building blocks for many industrial syntheses and are also components of explosives, drugs and pesticides. Due to the environmentally unfriendly experimental conditions involved in their chemical syntheses, industrial processes would benefit from the use of biocatalysts. Among potentially useful enzymes, N-oxygenases, whose role is to oxygenate primary amines, are becoming relevant. These enzymes are involved in different secondary metabolic pathways in Streptomyces and in few other bacteria, forming part of the enzyme pools implicated in antibiotic synthesis. In this work, a group of Streptomyces strains, whose biomass was obtained from simple and novel culture media, were identified as new sources of N-oxygenase activity. Furthermore, the use of unspecific metabolic stimulation strategies allowed substantial improvements in the activity of whole cells as biocatalysts. It is remarkable the 6 to 50-fold increase in nitro compound yields compared to the biotransformation under standard conditions when Streptomyces griseus was the biocatalyst. In addition, biocatalyst substrate acceptance was studied in order to determine the biocatalytic potential of this enzyme.Fil: Nóbile, Matías Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Stricker, Abigail M.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Iribarren, Adolfo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Lewkowicz, Elizabeth Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin

N-oxygenation of amino compounds: early stages in its application to the biocatalyzed preparation of bioactive compounds

Among the compounds that contain unusual functional groups, nitro is perhaps one of the most interesting due to the valuable properties it confers on pharmaceuticals and explosives. Traditional chemistry has for many years used environmentally unfriendly strategies; in contrast, the biocatalyzed production of this type of products offers a promising alternative. The small family of enzymes formed by N-oxygenases allows the conversion of an amino group to a nitro through the sequential addition of oxygen. These enzymes also make it possible to obtain other less oxidized N-O functions, such as hydroxylamine or nitroso, present in intermediate or final products. The current substrates on which these enzymes are reported to work encompass a few aromatic molecules and sugars. The unique characteristics of N-oxygenases and the great economic value of the products that they could generate, place them in a position of very high scientific and industrial interest. The most important and best studied N-oxygenases will be presented here.Fil: Nóbile, Matías Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; ArgentinaFil: Stricker, Abigail M.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Marchesano, Lucas. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Iribarren, Adolfo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; ArgentinaFil: Lewkowicz, Elizabeth Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; Argentin

An Alternative Proposal for the Teaching of Chemistry in High School: A Technical Visit to a Soft Drink Factory

The current teaching progress in schools is very distant from the needs required for the student’s formation as a citizen. In order to get the student’s interest in exploring and comprehending of everyday facts, a visit to a soft drink factory was carried out. This proposal allows not only a good learning process but also the integration of theoretical concepts and living experiences

Proposta Alternativa para Ensino de Química no Ensino Médio: Visita à Fábrica de Refrigerantes

O atual ensino nas escolas está muito distante das necessidades requeridas para a formação do aluno como cidadão. A visita à fábrica de refrigerantes tem como objetivo despertar o interesse dos alunos pela exploração e compreensão de situações do cotidiano. Essa proposta permite não só propiciar uma boa aprendizagem bem como promover uma integração dos conteúdos teóricos com a vivência prática

Neuroimmunology of rabies: New insights into an ancient disease

International audienceRabies is an ancient neuroinvasive viral (genus Lyssavirus, family Rhabdoviridae) disease affecting approximately 59,000 people worldwide. The central nervous system (CNS) is targeted, and rabies has a case fatality rate of almost 100% in humans and animals. Rabies is entirely preventable through proper vaccination, and thus, the highest incidence is typically observed in developing countries, mainly in Africa and Asia. However, there are still cases in European countries and the United States. Recently, demographic, increasing income levels, and the coronavirus disease 2019 (COVID‐19) pandemic have caused a massive raising in the animal population, enhancing the need for preventive measures (e.g., vaccination, surveillance, and animal control programs), postexposure prophylaxis, and a better understanding of rabies pathophysiology to identify therapeutic targets, since there is no effective treatment after the onset of clinical manifestations. Here, we review the neuroimmune biology and mechanisms of rabies. Its pathogenesis involves a complex and poorly understood modulation of immune and brain functions associated with metabolic, synaptic, and neuronal impairments, resulting in fatal outcomes without significant histopathological lesions in the CNS. In this context, the neuroimmunological and neurochemical aspects of excitatory/inhibitory signaling (e.g., GABA/glutamate crosstalk) are likely related to the clinical manifestations of rabies infection. Uncovering new links between immunopathological mechanisms and neurochemical imbalance will be essential to identify novel potential therapeutic targets to reduce rabies morbidity and mortality