Characterization of dioxygenases and biosurfactants produced by crude oil degrading soil bacteria

ABSTRACT Role of microbes in bioremediation of oil spills has become inevitable owing to their eco friendly nature. This study focused on the isolation and characterization of bacterial strains with superior oil degrading potential from crude-oil contaminated soil. Three such bacterial strains were selected and subsequently identified by 16S rRNA gene sequence analysis as Corynebacterium aurimucosum, Acinetobacter baumannii and Microbacterium hydrocarbonoxydans respectively. The specific activity of catechol 1,2 dioxygenase (C12O) and catechol 2,3 dioxygenase (C23O) was determined in these three strains wherein the activity of C12O was more than that of C23O. Among the three strains, Microbacterium hydrocarbonoxydans exhibited superior crude oil degrading ability as evidenced by its superior growth rate in crude oil enriched medium and enhanced activity of dioxygenases. Also degradation of total petroleum hydrocarbon (TPH) in crude oil was higher with Microbacterium hydrocarbonoxydans. The three strains also produced biosurfactants of glycolipid nature as indicated d by biochemical, FTIR and GCMS analysis. These findings emphasize that such bacterial strains with superior oil degrading capacity may find their potential application in bioremediation of oil spills and conservation of marine and soil ecosystem.

Aspectos clínico-epidemiológicos e microbiológicos de processos infecciosos causados por Corynebacterium spp em pacientes de centro de referência oncológico – Rio de Janeiro, Brasil / Clinical-epidemiological and microbiological aspects of infectious processes caused by Corynebacterium spp in pacients at the National Cancer Institute in Rio de Janeiro, Brazil

Os resultados permitiram a redação de quatro artigos. Aspectos microbiológicos e clínicos de corinebacterioses em pacientes com câncer observados durante cinco anos foram descritos no Artigo 1. No Artigo 2 foram apresentados casos de bacteremia causados por corinebactérias invasivas não toxigênicas em dois períodos com intervalo de sete anos. As infecções em pacientes com câncer por C. diphtheriae, causando casos clínicos atípicos foram descritas no Artigo 3, além do estudo dos principais fatores de virulência de uma cepa de C. diphtheriae isolada de infecção associada ao cateter de nefrostomia foi descrita no Artigo 4. Resumidamente no Artigo 1, além dos aspectos clínico-epidemiológicos foram avaliados os perfis de resistência aos antimicrobianos e o potencial de virulência dos micro-organismos. Em cinco anos, 932 amostras de corinebactérias, com perfis de resistência aos antimicrobianos testados, foram isoladas de pacientes com câncer. As espécies predominantes foram Corynebacterium amycolatum (44,7%), Corynebacterium minutissimum (18,3%) e Corynebacterium pseudodiphtheriticum (8,5%). O uso de catéteres de longa permanência e a neutropenia, foram às condições importantes para infecção por corinebactérias. As doenças de base mais comuns foram os tumores sólidos. Pacientes hospitalizados apresentaram risco seis vezes maior de morrer, quando relacionadas às taxas de mortalidade com 30 dias (RC= 5,5; IC 95%= 1,15-26,30; p= 0,033). As bacteremias (Artigo 2) causadas por corinebactérias foram observadas em dois períodos: 2003-2004 (n=38) e de 2012-2013 (n=24). As espécies multirresistentes C. amycolatum e Corynebacterium jeikeium foram os principais responsáveis pelos quadros de bacteremia. Havia 34 pacientes com tumores sólidos e 28 pacientes com doenças linfoproliferativas, sendo que 21 deles apresentavam neutropenia e 54 utilizavam cateter venoso central. Em 41 pacientes havia infecção relacionada ou associada aos dispositivos intravasculares...

A retrospective study at the InstitutoNacional doCâncer-INCA (National Cancer Institute) in Rio de Janeiro, Brazil examined infections of Corynebacterium sp. in cancer patients. The results were presented in four papers. Article 1 describes microbiological and clinical aspects of corynebacteriosis in cancer patients observed over five years. Article 2 presents cases of bacteremia caused by invasive non-toxigenic corynebacteria observed in 2003-2004 and seven years later in 2012-2013. Article 3 presents atypical clinical cases of cancer patients infected by Corynebacterium diphtheriae, while Article 4 is a study of the major bacterial virulence factors of an isolated strain of C. diphtheriae in infections associated with nephrostomy catheters.In addition to clinical and epidemiological aspects, Article 1 evaluates the antimicrobial resistance profiles and potential virulence factor of microorganisms. Over a period of five years, 932 samples of corynebacteria with antimicrobial resistance profiles were isolated from patients with cancer. The predominant species were Corynebacterium amycolatum (44.7%), Corynebacterium minutissimum (18.3%) and Corynebacterium pseudodiphtheriticum (8.5%).Long-term catheter use and neutropenia were the major conditions for infection by corynebacteria. Solid tumors were the most common underlying illness. The 30-day mortality rate for patients with corynebacteria infections was six times greater in hospitalized patients than for non-hospitalized patients (OR = 5.5, 95% CI = 1.15 to 26.30, p = 0.033).In Article 2, bacteremia caused by corynebacteria were observed in two time frames: 2003 to 2004 (n=38) and 2012 to 2103 (n=24). The multidrug-resistant species C. amycolatum and Corynebacterium jeikeium were responsible for invasive diseases.There were 34 patients with solid tumors and 28 patients with lymphoproliferative diseases, of which 21 had neutropenia and 54 used central venous catheter...

Produccion de l-lisina por celulas en no crecimiento de Corynebacterium glutamicum / L-lysine production by corynebacterium glutamicum non growing cells

Los efectos estrógenos y la progesterona en el control endocrino de las funciones sexuales son bien conocidos. Sin embargo, su papel en el control de áreas extrahipotalámicas ha sido poco estudiado. Trabajos previos realizados en nuestro laboratorio demuestran que el 17 Beta-Estradiol tiene un efecto inhibitorio en la transmisión cortico-caudado. En el presente trabajo se exploraron los efectos de la inyección intravenosa de 17 alpha-Hidroxi-Progesterona sobre esta misma conexión. Ratas hembras intactas, hembras ovariectomizadas y machos intactos, de la variedad Sprague Dawley, de 250 a 300 g de peso, fueron anestesiadas con Hidrato de Cloral (40 mg/100 g; i.p.). La hormona se administró a través de um catéter colocado en la vena yugular derecha (10 mul; 2,5 mg/ml). Se usaron métodos electrofisiológicos convencionales, utilizando electrodos de vidrio para el registro de las respuestas en el Caudado y electrodos metálicos para la estimulacióncortical, aislados excepto en la punta. Las respuestas excitatorias fueron analizadas por una computadora, integrando barridos sucessivos para construir histogramas post-estímulos. La administración de la 17 alpha-Hidroxi-Progesterona produjo un aumento significativo de las respustas en la mayoría de las células (95 por ciento). En algunas células (35 por ciento), este aumento fue acompañado de una disminución también significativa. En una sola neurona la respuesta excitatoria disminuyó. Los cambios descritos se observaron a partir de los primeros 5-10 minutos después de la administración hormonal, y se prolongan por una hora o más, luego de lo cual se observa recuperación de la respuesta inicial. Los resultados demuestran que la 17 alpha-Hidroxi-Progesterona estimula la transmisión cortico-caudado en la rata. La corta latencia de estos efectos hace suponer que pueden estar mediados por mecanismos no genómicos.