Preparation and process optimization of microbial organic copper as a feed additive / Preparação e otimização do processo de cobre orgânico microbiano como aditivo alimentar

As an essential trace element for animals, copper significantly contributes to the growth and health of animals. Compared to inorganic trace elements, organic trace elements are better supplements; notably, they are acquired through microbial transformation. Therefore, we screened for copper-enriched microorganisms from high copper content soil to obtain organic copper. Sodium diethyldithio carbamate trihydrate was applied as a chromogenic agent for determining micro amounts of intracellular copper through spectrophotometry. In total, 50 fungi were isolated after the successful application of the screening platform for copper-rich microbes. Following morphological and molecular biology analyses, the N-2 strain, identified as Aspergillus niger sp. demonstrated showed better copper enrichment potential than others. Notably, the strain tolerance to copper was nearly thrice that of Saccharomyces cerevisiae, up to 1600mg/L. The content of the organic bound copper was 22.84mg Cu/g dry cell. Using the Central Composite Design (CCD) response surface method, we optimized the fermentation condition (inoculation amount, 13%; temperature, 28(C; pH, 5.0). Compared to the original strain results under the single factor fermentation condition, we reported an increase by 24.18% under the optimized conditions. Collectively, these findings provide a reference for uncovering new and low-cost organic copper additives.(AU)

Como elemento traço essencial para os animais, o cobre contribui significativamente para o crescimento e saúde dos animais. Comparado aos oligoelementos inorgânicos, os oligoelementos orgânicos são melhores suplementos; notavelmente, eles são adquiridos através de transformação microbiana. Portanto, nós selecionamos microorganismos enriquecidos com cobre de solos com alto teor de cobre para obter cobre orgânico. O carbamato de sódio diethyldithio trihidratado foi aplicado como agente cromogênico para a determinação de micro quantidades de cobre intracelular através da espectrofotometria. No total, 50 fungos foram isolados após a aplicação bem sucedida da plataforma de triagem para micróbios ricos em cobre. Após análises morfológicas e de biologia molecular, a cepa N-2, identificada como Aspergillus niger sp. demonstrou um melhor potencial de enriquecimento de cobre do que outras. Notavelmente, a tolerância da estirpe ao cobre foi quase três vezes maior que a da Saccharomyces cerevisiae, até 1600mg/L. O conteúdo de cobre ligado orgânico era de 22,84mg Cu/g de célula seca. Usando o método de superfície de resposta Central Composite Design (CCD), nós otimizamos a condição de fermentação (quantidade de inoculação, 13%; temperatura, 28C; pH, 5,0). Em comparação com os resultados da deformação original sob a condição de fermentação de fator único, relatamos um aumento de 24,18% sob as condições otimizadas. Coletivamente, estas descobertas fornecem uma referência para descobrir novos aditivos de cobre orgânico de baixo custo.(AU)

Molecular biology and clinical implication of hepatitis C virus

Hepatitis C virus (HCV) was first described in 1989 as the putative viral agent of non-A non-B hepatitis. It is a member of the Flaviviridae family and has been recognized as the major causative agent of chronic liver disease, including chronic active hepatitis, cirrhosis and hepatocellular carcinoma. HCV is a positive RNA virus with a genome containing approximately 9500 nucleotides. It has an open reading frame that encodes a large polyprotein of about 3000 amino acids and is characterized by extensive genetic diversity. HCV has been classified into at least 6 major genotypes with many subtypes and circulates within an infected individual as a number of closely related but distinct variants known as quasispecies. This article reviews aspects of the molecular biology of HCV and their clinical implication.