RESUMO
The combined effects of significant physical and chemical factors affect hyperthermostable ß amylase production under submerged fermentation by Bacillus subtilis DJ5. The above was studied using the experimental design and response surface methodology. A 23 full-factorial central composite design was chosen to analyze interactions among three factors i.e. substrate concentration, medium pH and incubation temperature. The experimental data were fitted into a polynomial model for the yield of enzyme and an optimum level was arrived at with optimized conditions. Solving the coded values using Excel equation function indicated that maximum enzyme production is possible at a substrate concentration of 7.07 mg mL-1, pH 6.622 and temperature of 35.435°C. Such prediction was validated with practical experiments in which, at the prescribed condition maximum yield of 15.62 U mg-1, nearly 1.5 fold higher than non-optimized condition was observed.
Os efeitos combinados de fatores físicos e químicos significativos influenciam a produção hipertermoestável de amilase ß sob fermentação submersa por Bacillus subtilis DJ5. O esquema experimental e metodologia de superfície de resposta foram usados, com 23 planejamento fatorial composto, para analisar as interações entre os três fatores, ou seja, concentração de substrato, pH médio e temperatura de incubação. Os dados experimentais foram ajustados a um modelo polinomial para a produção de enzima e chegou-se a um nível ótimo através de condições otimizadas. A solução dos valores codificados por equação de Excel indicou que a produção máxima da enzima é possível a uma concentração de substrato de 7,07 mg mL-1, pH 6,622 e temperatura de 35,435°C. Tal previsão foi validada com experimentos práticos, onde na condição prescrita de rendimento máximo de 15,62 U mg-1, foram observados cerca de 1,5 vezes maior do que o estado não otimizado.
Assuntos
Bacillus subtilisRESUMO
PURPOSE: To assess the methods for the clinical evaluation of the longitudinal bone changes after implantation of tooth ash-plaster mixture into the defect area of human jaws. MATERIALS AND METHODS: Tooth ash-plaster mixtures were implanted into the defects of 8 human jaws. 48 intraoral radiograms taken with copper step wedge as reference at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture were used. X-ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner were digitized and analyzed by NIH image program. Cu-equivalent values were measured at the implanted sites from the periodic digital images. Analysis was performed by the bidirectional subtraction with color enhancement and the surface plot of resliced contiguous image. The obtained results by the two methods were compared with Cu-equivalent value changes. RESULTS: The average determination coefficient of Cu-equivalent equations was 0.9988 and the coefficient of variation of measured Cu values ranged from 0.08 ~ 0.10. The coefficient of variation of Cu-equivalent values measured at the areas of the mixture and the bone by the conversion equation ranged from 0.06 ~0.09. The analyzed results by the bidirectional subtraction with color enhancement were coincident with the changes of Cu-equivalent values. The surface plot of the resliced contiguous image showed the three dimensional view of the longitudinal bone changes on one image and also coincident with Cu-equivalent value changes after implantation. CONCLUSION: The bidirectional subtraction with color enhancement and the surface plot of the resliced contiguous image was very effective and reasonable to analyze clinically and qualitatively the longitudinal bone change. These methods are expected to be applicable to the non-destructive test in other fields.