8 research outputs found
Efficient degradation of various emerging pollutants by wild type and evolved fungal DyP4 peroxidases
The accumulation of emerging pollutants in the environment remains a major concern as evidenced by the increasing number of reports citing their potential risk on environment and health. Hence, removal strategies of such pollutants remain an active area of investigation. One way through which emerging pollutants can be eliminated from the environment is by enzyme-mediated bioremediation. Enzyme-based degradation can be further enhanced via advanced protein engineering approaches. In the present study a sensitive and robust bioanalytical liquid chromatography-tandem mass spectrometry (LCMSMS)-based approach was used to investigate the ability of a fungal dye decolorizing peroxidase 4 (DyP4) and two of its evolved variants—that were previously shown to be H2O2 tolerant—to degrade a panel of 15 different emerging pollutants. Additionally, the role of a redox mediator was examined in these enzymatic degradation reactions. Our results show that three emerging pollutants (2-mercaptobenzothiazole (MBT), paracetamol, and furosemide) were efficiently degraded by DyP4. Addition of the redox mediator had a synergistic effect as it enabled complete degradation of three more emerging pollutants (methyl paraben, sulfamethoxazole and salicylic acid) and dramatically reduced the time needed for the complete degradation of MBT, paracetamol, and furosemide. Further investigation was carried out using pure MBT to study its degradation by DyP4. Five potential transformation products were generated during the enzymatic degradation of MBT, which were previously reported to be produced during different bioremediation approaches. The current study provides the first instance of the application of fungal DyP4 peroxidases in bioremediation of emerging pollutants
Molecular and Immunological Evaluation of Some Bacteria Causing Calf Diarrhea
One issue that intensive farming has to deal with is neonatal calf diarrhea, and probiotics are seen to be a viable solution to improve the health of calves. The aim of this study was to assess the effects of short-term administration of an antibiotic or probiotic to diarrheal calves on total leukocytic count, serum bactericidal activity, and phagocytosis, as well as to identify potential bacteria that may cause calf diarrhea in early life stages. 55 diarrheal calves, ranging in age from 1 to 20 days, were sampled for feces at a private dairy farm in the Sharkia governorate. E. coli, Salmonella spp., and Clostridium species were among the isolated bacteria, with prevalence rates of 58.2%, 8%, and 12%, respectively. The O26, O111, O119, O128 and O125 serogroups of E. coli isolates were the identified serotypes. While S. Typhimurium and S. Enteritidis were the recovered Salmonella serotypes. The results of the polymerase chain reaction (PCR) showed that the invA gene was amplified in the four salmonella isolates but the phoA gene was amplified in all E. coli isolates. Since only the alpha toxin gene was present in each isolate of C. perfringens, they were all type A. Antibiogram test results showed that most isolated species were multi-drug resistant to the ten commonly used antibiotics. On the other hand, isolates of E. coli, salmonella, and clostridium that demonstrated sensitivity for amoxicillin with percentages of 93.3%, 100%, and 66.7%, respectively, represented the medicine that was most successful. Regardless of infection, probiotic or antibiotic treatment, the total leukocytic count values in all diarrheal calves were considerably greater than those in the control group. Serum bactericidal activity in probiotic-treated calves was significantly higher than in the control and antibiotic-treated groups, while it was significantly lower in the antibiotic-treated group. Calf polymorphonuclear leukocytes treated with antibiotics or probiotics had considerably increased phagocytic activity than the control group. In conclusion, probiotics supplementation is an effective strategy for the prevention and control of calf diarrhea
ANÁLISE COMPARATIVA DOS RESULTADOS OBTIDOS PELOS MÉTODOS DE CALIBRAÇÃO DE CAMPO TRIDIMENSIONAL E BIDIMENSIONAL
Os recursos de automação têm facilitado a utilização da Fotogrametria Digital em várias aplicações. Um processo complexo e crítico em Fotogrametria, a calibração de câmaras, pode ser realizado automaticamente, existindo programas comerciais com essa capacidade. Dentre os métodos de calibração, destaca-se o método de calibração de campo, usando conjunto de pontos bidimensionais ou tridimensionais. Alguns programas comerciais utilizam um modelo de campo bidimensional (Placa 2D) que possibilita o reconhecimento automático de alvos, como por exemplo, o PhotoModeler. Entretanto, o campo de calibração tridimensional pode ser mais adequado para algumas aplicações, como por exemplo, para a modelagem tridimensional de objetos. No intuito de avaliar a influência nos parâmetros de orientação interior decorrente do uso de campos 2D ou 3D, foram realizadas 3 calibrações, utilizando 2 campos 2D e 1 campo 3D, as quais foram processadas em programas comercial e científico (PhotoModeler e Calibração com Múltiplas Câmaras). A forma de análise dos resultados consistiu em uma análise comparativa entre as calibrações, pelo estudo de influência dos Parâmetros de Orientação Interior (POI) na reconstrução de coordenadas de alvos sinalizados em um tripleto de imagens. Foram simuladas duas situações distintas (orientação exterior direta e indireta) e por fim, verificou-se o impacto dos POI nas coordenadas no plano e fora deste plano. A calibração com campo 3D, se comparada à calibração com o campo 2D, permitiu redução de correlação entre a distância focal e a coordenada Z do centro perspectivo (Z0). Verificou-se esse resultado na orientação direta e indireta. Observou-se, também, que o método de calibração 3D leva a melhores resultados no cálculo das coordenadas do tripleto de imagens para os alvos fora do plano