The operational conditions for an aqueous two‐phase system (ATPS) for β‐galactosidase purification were optimized and applied to the design of a purification strategy as an alternative to the primary purification steps. The ATPS proved to be suitable for the recovery and primary enzyme purification. The purification process design developed by ATPS, diafiltration, ion exchange, and diafiltration/ultrafiltration was successful, yielding a more than tenfold purification. The purification strategy design resulted in a powerful integrated purification and recovery process, an evidence of the potential for a scale‐up of the β‐galactosidase purification process.
A purification technique to obtain keratinolytic proteases produced by Bacillus sp. P45 in a medium containing chicken feather meal as substrate is presented. e experiments were carried out in a dead-end ultrafiltration unit, and the influence of the membrane cutoff, pH of enzymatic extract, and operating pressure on the purification of keratinase were studied. e one-step ultrafiltration process with the membrane molecular mass cutoff of 10 kDa at pH 8.0 and operating pressure of 0.147 MPa showed an enzyme recovery of 87.8% and a 4.1-fold purification factor. It is showed that ultrafiltration could be potentially used in the purification of keratinases.
Este trabalho teve como objetivo identificar os microorganismos presentes nas mãos e fossas nasais de manipuladores de alimentos da cozinha de um hospital universitário. Foram realizadas coletas de amostras de 24 manipuladores de alimentos, usando swab embebido em solução salina. As amostras foram semeadas em meio de cultivo específico para isolamento e identificação dos microorganismos presentes. Dos 24 manipuladores analisados, todos albergavam Staphylococcus aureus , sendo que 41,67% albergavam esta bactéria nas fossas nasais, 41,67% apenas na palma das mãos, e 16,67% albergavam tanto nas mãos quanto nas fossas nasais.Escherichia coli esteve presente em 29,17% dos manipuladores, sendo 28,57% nas fossas nasais e 71,43% nas mãos dos manipuladores. Em 12,5% dos manipuladores foram encontradas ambas as bactérias, S. aureus e E. coli , nas mãos. Ademonstração de S. aureus e E. coli nas amostras isoladas dos manipuladores de alimento apontam para a possibilidade da contaminação de alimentos, a partir da colonização das mãos e fossas nasais de manipuladores. A prevenção desta contaminação pode ser feita pelo meio de medidas educativas e disponibilização de produtos que facilitem a higienização adequada das mãos no ambiente de trabalho.
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