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| Marques,Daniela A. Viana; Cunha,Márcia N. Carneiro; Araújo,Janete M.; Lima-Filho,José L.; Converti,Attilio; Pessoa-Jr,Adalberto; Porto,Ana L. Figueiredo. |
| Clavulanic acid is a β-lactam antibiotic which has a potent β-lactamase inhibiting activity. In order to optimize its production by the new isolate Streptomyces DAUFPE 3060, the influence of two independent variables, temperature and soybean flour concentration, on clavulanic acid and biomass concentrations was investigated in 250 mL-Erlenmeyers according to a 2² central composite design. To this purpose, temperature and soybean flour (SF) concentration were varied in the ranges 26-34°C and 10-50 g/L, respectively, and the results evaluated utilizing the Response Surface Methodology. The experimental maximum production of clavulanic acid (629 mg/L) was obtained at 32°C and 40 g/L SF after 48 h, while the maximum biomass concentration (3.9 g/L) at 30°C and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clavulanic acid; Response surface methodology; Production; Optimization; Streptomyces sp. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000200030 |
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| Ribeiro,Marcela Zanella; Silva,Daniel Pereira; Vitolo,Michele; Roberto,Inês Conceição; Pessoa-Jr,Adalberto. |
| Glucose-6-phosphate dehydrogenase (G6PDH) is an important enzyme used in biochemical and medical studies and in several analytical methods that have industrial and commercial application. This work evaluated the extraction of G6PDH in aqueous two-phase system (ATPS) of poly(ethyleneglycol) (PEG)/phosphate buffer, using as enzyme source a medium prepared through commercial baker's yeast disruption. Firstly, the effects of PEG molar mass on the enzyme partition and of homogenization and rest on the system equilibrium were investigated. Afterwards, several ATPS were prepared using statistical analysis (2² factorial design). The results, including kinetic and thermodynamic parameters for the G6PDH activity, showed partial purification of this enzyme in ATPS... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aqueous two-phase systems; Glucose-6-phosphate dehydrogenase; Liquid-liquid extraction; Saccharomyces cerevisiae. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822007000100016 |
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