International Journal of Pharmaceutics, Jun 1, 2007
Large volume parenteral solutions (LVPS) that are widely used in the healthcare system must be pr... more Large volume parenteral solutions (LVPS) that are widely used in the healthcare system must be processed by moist-heat treatment to an assured sterility level in which the efficacy is measured by a bioindicator (BI) that provides fast, accurate and reliable results. This study evaluated the thermal stability of green fluorescent protein (GFP) into glucose-based LVPS (1.5-50%) solutions to determine its utility as a BI for thermal processes. GFP, expressed by Escherichia coli, isolated/purified by TPP/HIC, was diluted in buffered (each 10mM: Tris-EDTA, pH 8; phosphate, pH 6 and 7; acetate, pH 5) and in water for injection (WFI; pH 6.70+/-0.40) glucose solutions (1.5-50%) and exposed to constant temperatures from 80 degrees C to 95 degrees C. The thermal stability was expressed in decimal reduction time (D-value, time required to reduce 90% of the GFP fluorescence intensity). At 95 degrees C, the D-values for GFP in 1.5-50% glucose were: (i) 1.63+/-0.23 min (pH 5); (ii) 2.64+/-0.26 min (WFI); (iii) 2.50+/-0.18 min (pH 6); (iv) 3.24+/-0.28 min (pH 7); (v) 2.89+/-0.44 min (pH 8). By the convenient measure of fluorescence intensity and its thermal stability, GFP has the potential as a BI to assay the efficacy of moist-heat processing of LVPS at temperatures < or =100 degrees C.
Spores of Bacillus stearothermophilus ATCC 7953 were developed at 62 degrees C on 32 media compos... more Spores of Bacillus stearothermophilus ATCC 7953 were developed at 62 degrees C on 32 media composed of various amounts of 11 components: D-glucose, L-glutamic acid, yeast extract, peptone, sodium chloride, magnesium sulfate, ammonium phosphate, potassium phosphate, calcium chloride, ferrous sulfate and manganese sulfate. Statistical models were used and demonstrated a strong interaction of yeast/peptone/ammonium phosphate, contributing positively to the best sporulation yield (6-7 log10 spores). The most influential medium components on the thermal resistance (at 121 degrees C) of spores in suspension (calcium acetate, pH 9.7) were yeast extract (positively) and potassium phosphate (negatively), both creating the positive interaction, for spores from a 6-day incubation period. However, the strong negative effect of sodium chloride decreased the D-value from 1.81 min to 0.57 min upon increasing the incubation period (62 degrees C) from 3 days to 6 days. The D-glucose and peptone exhibited greater effects than the yeast extract and potassium phosphate interaction on D-values for 3-day spores on strip, just as the highly joint-positive peptone/sodium chloride effect maintained the thermal resistance of 6-day spores on strips. The spores on strip system showed less stability than the spores in suspension. The most stable spore system confirmed D-values at 121 degrees C at a range between 1.5 min and 1.9 min, which were obtained by keeping sodium chloride and potassium phosphate at minimum concentrations and yeast extract and peptone at maximum concentrations, regardless of the 3- to 6-day sporulation.
A equipe de manutenção da Faculdade de Ciências Farmacêuticas pela atenção, amizade e prontidão d... more A equipe de manutenção da Faculdade de Ciências Farmacêuticas pela atenção, amizade e prontidão de atendimento às minhas solicitações.
Large-volume parenteral solutions were submitted to heat treatments after being inoculated with B... more Large-volume parenteral solutions were submitted to heat treatments after being inoculated with Bacillus stearothermophilus ATCC 7953 (Tr = 121 degrees C) and Bacillus subtilis ATCC 9372 (Tr = 104.5 degrees C) spores. The average decimal reduction time for B. stearothermophilus ranged from a D121 degrees C value of 1.31 to 3.14 min, in glucophysiologic and Ringer's solutions respectively. For B. subtilis, D104.5 degrees C value increased from 0.69 to 1.37 min, in Ringer's (pH=5.91) and 50% glucose (pH 3.05) solutions respectively. The z value ranged from 7.95 degrees C (20% mannitol solution) to 13.14 degrees C (50% glucose solution), corresponding to an activation energy (Ea) of 81.48 and 49.30 kcal/mol, respectively.
The recombinant green fluorescent protein (gfpuv) was expressed by Escherichia coli DH5-a cells t... more The recombinant green fluorescent protein (gfpuv) was expressed by Escherichia coli DH5-a cells transformed with the plasmid pGFPuv. The gfpuv was selectively permeabilized from the cells in buffer solution (25 mM Tris-HCI, pH 8.0), after freezing (-70°C for 15 h), by four freeze (-20°C)/thaw cycles interlaid by sonication. The average content of released gfpuv (experiment 2) was 7.76, 34.58, 39.38,12.90, and 5.38%, for the initialfreezing (-70°C) and the first, second, third and fourth freeze / thaw cycles, respectively. Superfusion on freezing was observed between-11 °C and-14°C, after which it reached-20°C at 0.83°C/min. Index Entries: gfp uti Escherichia coli; physical permeabilization; superfusion phenomenon; freeze/thaw/sonication procedures. endogenous cytoplasmic material (6-9). The aim of the present study was the expression of the recombinant gfpuv in the cytoplasm of E. coli DH5-a cells, to apply freeze/thaw cycles interlaid by sonication to the cell pellets for the purpose of permeating the
Bacterial cellulose (BC) was synthesized by Acetobacter xylinum using a carbon source of coconut ... more Bacterial cellulose (BC) was synthesized by Acetobacter xylinum using a carbon source of coconut shell hydrolysate, which was treated with an ultra-low concentration of sulfuric acid. The coconut shell was found to contain 57.13% holocellulose and 27.42% lignin. The effect of sulfuric acid concentration, reaction temperature, and reaction time on hydrolysis of coconut shell were evaluated by response surface methodology. The reducing sugar concentration was 8.39 g/L under the predicted optimum treatment at 200 °C for 32 min with a solution of 0.07% sulfuric acid. The holocellulose conversion rate was 56.1% at this condition. In a detoxification process using calcium hydroxide and activated carbon, furfural and hydroxymethylfurfural in the hydrolysate were almost completely removed, whereas formic acid and acetic acid levels decreased by 30%. After cultivation for 7 days at the reducing sugar status of 5 g/L, the BC production in medium with the detoxified hydrolysate could reach 1.66 g/L. After fermentation for 21 days, BC yield in medium using composited carbon source (20 g/L) of glucose and hydrolysate was 5.30 g/L. Structural analysis showed that BC obtained from medium of control and detoxified hydrolysate exhibited similar properties. This work provided a potential method for BC production.
The applications of microalgae biomass have been widely studied worldwide. The classical processe... more The applications of microalgae biomass have been widely studied worldwide. The classical processes used in outdoor cultivations of microalgae, in closed or open photobioreactors, occur in the presence of bacteria. Understanding how communication between cells occurs through quorum sensing and evaluating co-cultures allows the production of microalgae and cyanobacteria to be positively impacted by bacteria, in order to guarantee safety and profitability in the production process. In addition, the definition of the effects that occur during an interaction, promotes insights to improve the production of biomolecules, and to develop innovative products. This review presents the interactions between microalgae and bacteria, including compounds exchanges and communication, and addresses the development of new pharmaceutical, cosmetic and food bioproducts from microalgae based on these evaluations, such as prebiotics, vegan skincare products, antimicrobial compounds, and culture media with...
concentrations in seawater-based f/2 medium, by semi-continuous process applying different medium... more concentrations in seawater-based f/2 medium, by semi-continuous process applying different medium feeding percentage (F = 20% and 80%). Semi-continuous process allowed the achievement of higher cell productivity (Px up to 6.7 × 10 4 cells mL -1 day -1 ; culture medium 1N:1P and F = 20%) in comparison with batch process. Maximum cell density (Xm) was not dependent on F, but the best results were obtained when using 1.5N:1.5P medium (Xm up to 5.6 × 10 5 cells mL -1 , with F = 80%). On the other hand, β-carotene content was higher in cells grown in 1N:1P medium (up to 53.4 mg g -1 and 57.5 mg g -1 , with F of 20% and 80%, respectively). The closed tubular photobioreactor employment for this microalga cultivation, under 12 h light/12 h dark cycle, contributed to successful cell growth without contamination by protozoa.
International Journal of Pharmaceutics, Jun 1, 2007
Large volume parenteral solutions (LVPS) that are widely used in the healthcare system must be pr... more Large volume parenteral solutions (LVPS) that are widely used in the healthcare system must be processed by moist-heat treatment to an assured sterility level in which the efficacy is measured by a bioindicator (BI) that provides fast, accurate and reliable results. This study evaluated the thermal stability of green fluorescent protein (GFP) into glucose-based LVPS (1.5-50%) solutions to determine its utility as a BI for thermal processes. GFP, expressed by Escherichia coli, isolated/purified by TPP/HIC, was diluted in buffered (each 10mM: Tris-EDTA, pH 8; phosphate, pH 6 and 7; acetate, pH 5) and in water for injection (WFI; pH 6.70+/-0.40) glucose solutions (1.5-50%) and exposed to constant temperatures from 80 degrees C to 95 degrees C. The thermal stability was expressed in decimal reduction time (D-value, time required to reduce 90% of the GFP fluorescence intensity). At 95 degrees C, the D-values for GFP in 1.5-50% glucose were: (i) 1.63+/-0.23 min (pH 5); (ii) 2.64+/-0.26 min (WFI); (iii) 2.50+/-0.18 min (pH 6); (iv) 3.24+/-0.28 min (pH 7); (v) 2.89+/-0.44 min (pH 8). By the convenient measure of fluorescence intensity and its thermal stability, GFP has the potential as a BI to assay the efficacy of moist-heat processing of LVPS at temperatures < or =100 degrees C.
Spores of Bacillus stearothermophilus ATCC 7953 were developed at 62 degrees C on 32 media compos... more Spores of Bacillus stearothermophilus ATCC 7953 were developed at 62 degrees C on 32 media composed of various amounts of 11 components: D-glucose, L-glutamic acid, yeast extract, peptone, sodium chloride, magnesium sulfate, ammonium phosphate, potassium phosphate, calcium chloride, ferrous sulfate and manganese sulfate. Statistical models were used and demonstrated a strong interaction of yeast/peptone/ammonium phosphate, contributing positively to the best sporulation yield (6-7 log10 spores). The most influential medium components on the thermal resistance (at 121 degrees C) of spores in suspension (calcium acetate, pH 9.7) were yeast extract (positively) and potassium phosphate (negatively), both creating the positive interaction, for spores from a 6-day incubation period. However, the strong negative effect of sodium chloride decreased the D-value from 1.81 min to 0.57 min upon increasing the incubation period (62 degrees C) from 3 days to 6 days. The D-glucose and peptone exhibited greater effects than the yeast extract and potassium phosphate interaction on D-values for 3-day spores on strip, just as the highly joint-positive peptone/sodium chloride effect maintained the thermal resistance of 6-day spores on strips. The spores on strip system showed less stability than the spores in suspension. The most stable spore system confirmed D-values at 121 degrees C at a range between 1.5 min and 1.9 min, which were obtained by keeping sodium chloride and potassium phosphate at minimum concentrations and yeast extract and peptone at maximum concentrations, regardless of the 3- to 6-day sporulation.
A equipe de manutenção da Faculdade de Ciências Farmacêuticas pela atenção, amizade e prontidão d... more A equipe de manutenção da Faculdade de Ciências Farmacêuticas pela atenção, amizade e prontidão de atendimento às minhas solicitações.
Large-volume parenteral solutions were submitted to heat treatments after being inoculated with B... more Large-volume parenteral solutions were submitted to heat treatments after being inoculated with Bacillus stearothermophilus ATCC 7953 (Tr = 121 degrees C) and Bacillus subtilis ATCC 9372 (Tr = 104.5 degrees C) spores. The average decimal reduction time for B. stearothermophilus ranged from a D121 degrees C value of 1.31 to 3.14 min, in glucophysiologic and Ringer's solutions respectively. For B. subtilis, D104.5 degrees C value increased from 0.69 to 1.37 min, in Ringer's (pH=5.91) and 50% glucose (pH 3.05) solutions respectively. The z value ranged from 7.95 degrees C (20% mannitol solution) to 13.14 degrees C (50% glucose solution), corresponding to an activation energy (Ea) of 81.48 and 49.30 kcal/mol, respectively.
The recombinant green fluorescent protein (gfpuv) was expressed by Escherichia coli DH5-a cells t... more The recombinant green fluorescent protein (gfpuv) was expressed by Escherichia coli DH5-a cells transformed with the plasmid pGFPuv. The gfpuv was selectively permeabilized from the cells in buffer solution (25 mM Tris-HCI, pH 8.0), after freezing (-70°C for 15 h), by four freeze (-20°C)/thaw cycles interlaid by sonication. The average content of released gfpuv (experiment 2) was 7.76, 34.58, 39.38,12.90, and 5.38%, for the initialfreezing (-70°C) and the first, second, third and fourth freeze / thaw cycles, respectively. Superfusion on freezing was observed between-11 °C and-14°C, after which it reached-20°C at 0.83°C/min. Index Entries: gfp uti Escherichia coli; physical permeabilization; superfusion phenomenon; freeze/thaw/sonication procedures. endogenous cytoplasmic material (6-9). The aim of the present study was the expression of the recombinant gfpuv in the cytoplasm of E. coli DH5-a cells, to apply freeze/thaw cycles interlaid by sonication to the cell pellets for the purpose of permeating the
Bacterial cellulose (BC) was synthesized by Acetobacter xylinum using a carbon source of coconut ... more Bacterial cellulose (BC) was synthesized by Acetobacter xylinum using a carbon source of coconut shell hydrolysate, which was treated with an ultra-low concentration of sulfuric acid. The coconut shell was found to contain 57.13% holocellulose and 27.42% lignin. The effect of sulfuric acid concentration, reaction temperature, and reaction time on hydrolysis of coconut shell were evaluated by response surface methodology. The reducing sugar concentration was 8.39 g/L under the predicted optimum treatment at 200 °C for 32 min with a solution of 0.07% sulfuric acid. The holocellulose conversion rate was 56.1% at this condition. In a detoxification process using calcium hydroxide and activated carbon, furfural and hydroxymethylfurfural in the hydrolysate were almost completely removed, whereas formic acid and acetic acid levels decreased by 30%. After cultivation for 7 days at the reducing sugar status of 5 g/L, the BC production in medium with the detoxified hydrolysate could reach 1.66 g/L. After fermentation for 21 days, BC yield in medium using composited carbon source (20 g/L) of glucose and hydrolysate was 5.30 g/L. Structural analysis showed that BC obtained from medium of control and detoxified hydrolysate exhibited similar properties. This work provided a potential method for BC production.
The applications of microalgae biomass have been widely studied worldwide. The classical processe... more The applications of microalgae biomass have been widely studied worldwide. The classical processes used in outdoor cultivations of microalgae, in closed or open photobioreactors, occur in the presence of bacteria. Understanding how communication between cells occurs through quorum sensing and evaluating co-cultures allows the production of microalgae and cyanobacteria to be positively impacted by bacteria, in order to guarantee safety and profitability in the production process. In addition, the definition of the effects that occur during an interaction, promotes insights to improve the production of biomolecules, and to develop innovative products. This review presents the interactions between microalgae and bacteria, including compounds exchanges and communication, and addresses the development of new pharmaceutical, cosmetic and food bioproducts from microalgae based on these evaluations, such as prebiotics, vegan skincare products, antimicrobial compounds, and culture media with...
concentrations in seawater-based f/2 medium, by semi-continuous process applying different medium... more concentrations in seawater-based f/2 medium, by semi-continuous process applying different medium feeding percentage (F = 20% and 80%). Semi-continuous process allowed the achievement of higher cell productivity (Px up to 6.7 × 10 4 cells mL -1 day -1 ; culture medium 1N:1P and F = 20%) in comparison with batch process. Maximum cell density (Xm) was not dependent on F, but the best results were obtained when using 1.5N:1.5P medium (Xm up to 5.6 × 10 5 cells mL -1 , with F = 80%). On the other hand, β-carotene content was higher in cells grown in 1N:1P medium (up to 53.4 mg g -1 and 57.5 mg g -1 , with F of 20% and 80%, respectively). The closed tubular photobioreactor employment for this microalga cultivation, under 12 h light/12 h dark cycle, contributed to successful cell growth without contamination by protozoa.
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