Production and characterization of a biosurfactant produced by Streptomyces sp. DPUA 1559 isolated from lichens of the Amazon region

Surfactants are amphipathic compounds containing both hydrophilic and hydrophobic groups, capable to lower the surface or interfacial tension. Considering the advantages of the use of biosurfactants produced by microorganisms, the aim of this paper was to develop and characterize a biosurfactant produced by Streptomyces sp. DPUA1559 isolated from lichens of the Amazon region. The microorganism was cultured in a mineral medium containing 1% residual frying soybean oil as the carbon source. The kinetics of biosurfactant production was accompanied by reducing the surface tension of the culture medium from 60 to values around 27.14 mN/m, and by the emulsification index, which showed the efficiency of the biosurfactant as an emulsifier of hydrophobic compounds. The yield of the isolated biosurfactant was 1.74 g/L, in addition to the excellent capability of reducing the surface tension (25.34 mN/m), as observed from the central composite rotational design when the biosurfactant was produced at pH 8.5 at 28°C. The critical micelle concentration of the biosurfactant was determined as 0.01 g/mL. The biosurfactant showed thermal and pH stability regarding the surface tension reduction, and tolerance under high salt concentrations. The isolated biosurfactant showed no toxicity to the micro-crustacean Artemia salina, and to the seeds of lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.). The biochemistry characterization of the biosurfactant showed a single protein band, an acid character and a molecular weight around 14.3 kDa, suggesting its glycoproteic nature. The results are promising for the industrial application of this new biosurfactant.

Production and characterization of a biosurfactant produced by Streptomyces sp. DPUA 1559 isolated from lichens of the Amazon region.

Surfactants are amphipathic compounds containing both hydrophilic and hydrophobic groups, capable to lower the surface or interfacial tension. Considering the advantages of the use of biosurfactants produced by microorganisms, the aim of this paper was to develop and characterize a biosurfactant produced by Streptomyces sp. DPUA1559 isolated from lichens of the Amazon region. The microorganism was cultured in a mineral medium containing 1% residual frying soybean oil as the carbon source. The kinetics of biosurfactant production was accompanied by reducing the surface tension of the culture medium from 60 to values around 27.14 mN/m, and by the emulsification index, which showed the efficiency of the biosurfactant as an emulsifier of hydrophobic compounds. The yield of the isolated biosurfactant was 1.74 g/L, in addition to the excellent capability of reducing the surface tension (25.34 mN/m), as observed from the central composite rotational design when the biosurfactant was produced at pH 8.5 at 28°C. The critical micelle concentration of the biosurfactant was determined as 0.01 g/mL. The biosurfactant showed thermal and pH stability regarding the surface tension reduction, and tolerance under high salt concentrations. The isolated biosurfactant showed no toxicity to the micro-crustacean Artemia salina, and to the seeds of lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.). The biochemistry characterization of the biosurfactant showed a single protein band, an acid character and a molecular weight around 14.3 kDa, suggesting its glycoproteic nature. The results are promising for the industrial application of this new biosurfactant.

Spirometry reference values in the Brazilian population.

The aim of the present study was to provide new spirometry reference equations in a sample of the Brazilian population for the following parameters: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, peak of expiratory flow (PEF), forced expiratory flow at 50% (FEF50%), 75% average vital capacity (FEF25-75%), and average forced expiratory flow time (FEFT). This was a prospective study using results from chest radiographs, electrocardiograms, and questionnaires to investigate the participants' respiratory symptoms, sedentarism, and comorbidities (Charlson comorbidity index). From December 2010 to July 2014, individuals were randomly selected from various locations in the state of Rio de Janeiro. All individuals were examined by a single technician in the morning at the laboratory, and performed the spirometry with the same spirometer. Spirometry values were tabulated for the creation of three equation models: linear regression, logarithmic regression, and logarithms through a method that incorporates the lambda, median, and coefficient of variation (LMS method). Initially, 7003 individuals from both genders were contacted, and 454 were recruited. The data from the new equations were compared with one Brazilian and eight international equations, resulting in a high correlation (r>0.9). The values derived from the LMS method and linear regression were very similar (P>0.5), and both could be used to acquire the reference values for Brazilian spirometry. Data derived from the equations of this study were different from the current Brazilian equation, which could be justified by the different method used.

Ventilation distribution and small airway function in patients with systemic sclerosis.

BACKGROUND: Despite the importance of traditional pulmonary function tests (PFTs) in managing systemic sclerosis (SSc), many patients with pulmonary disease diagnosed by computed tomography (CT) present with normal PFTs. OBJECTIVE: To evaluate the efficacy of the nitrogen single-breath washout (N2SBW) test in diagnosing SSc and to correlate N2SBW parameters with the PFT indexes used in the follow-up of these patients, clinical data, and CT findings. METHODS: Cross-sectional study in which 52 consecutive SSc patients were subjected to spirometry, body plethysmography, analysis of the diffusing capacity for carbon monoxide (DLCO), analysis of respiratory muscle strength, N2SBW testing, and CT analysis. RESULTS: Twenty-eight patients had a forced vital capacity (FVC) that was <70% of the predicted value. In the N2SBW test, 44 patients had a phase III slope (Phase III slopeN2SBW) that was >120% of the predicted value, while 15 patients had a closing volume/vital capacity (CV/VC) that was >120% of the predicted value. A significant difference in Phase III slopeN2SBW was observed when the patients with predominant traction bronchiectasis and honeycombing were compared to the patients with other CT patterns (p<0.0001). The Phase III slopeN2SBW was correlated with FVC (rs=-0.845, p<0.0001) and DLCO (rs=-0.600, p<0.0001), and the CV/VC was correlated with FVC (rs=-0.460, p=0.0006) and residual volume/total lung capacity (rs=0.328, p=0.017). CONCLUSION: Ventilation heterogeneity is a frequent finding in SSc patients that is associated with restrictive damage, changes in pulmonary diffusion, and CT patterns. In addition, approximately one-third of the patients presented with findings that were compatible with small airway disease.

Can we use the 6-minute step test instead of the 6-minute walking test? An observational study.

OBJECTIVE: To verify whether or not heart rate is maintained below the calculated submaximal level in healthy, sedentary subjects when they perform the 6-minute step test (6MST) and the 6-minute walking test (6MWT), and to compare the maximal heart rate achieved by the subjects at the end of each test. DESIGN: Observational, cross-sectional study. SETTING: One tertiary centre. PARTICIPANTS: Two hundred and fifty-three participants from a pool of 330 healthy and sedentary subjects between 20 and 80 years of age. INTERVENTIONS: Both the 6MWT and the 6MST were performed in accordance with the American Thoracic Society's statement. Dyspnoea, blood pressure, oxygen saturation and heart rate were measured before and after each test. RESULTS: Mean heart rate immediately after the 6MST was significantly higher than mean heart rate immediately after the 6MWT {125 [standard deviation (SD) 19] vs 111 (SD 17) beats/minute; mean difference 13 (95% confidence interval of the difference 10 to 16); P<0.001}. Moreover, mean heart rate during (3minutes after commencement) the 6MST [118 (SD 18) beats/minute] was statistically higher than mean heart rate at the end of the 6MWT [111 (SD 18) beats/minute; P<0.001]. None of the subjects achieved the calculated submaximal heart rate. CONCLUSIONS: The 6MST and 6MWT are safe and produce submaximal effort in healthy participants. However, they are not interchangeable, and the 6MST requires more energy than the 6MWT.

Spirometry reference values in the Brazilian population

The aim of the present study was to provide new spirometry reference equations in a sample of the Brazilian population for the following parameters: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, peak of expiratory flow (PEF), forced expiratory flow at 50% (FEF50%), 75% average vital capacity (FEF25-75%), and average forced expiratory flow time (FEFT). This was a prospective study using results from chest radiographs, electrocardiograms, and questionnaires to investigate the participants' respiratory symptoms, sedentarism, and comorbidities (Charlson comorbidity index). From December 2010 to July 2014, individuals were randomly selected from various locations in the state of Rio de Janeiro. All individuals were examined by a single technician in the morning at the laboratory, and performed the spirometry with the same spirometer. Spirometry values were tabulated for the creation of three equation models: linear regression, logarithmic regression, and logarithms through a method that incorporates the lambda, median, and coefficient of variation (LMS method). Initially, 7003 individuals from both genders were contacted, and 454 were recruited. The data from the new equations were compared with one Brazilian and eight international equations, resulting in a high correlation (r>0.9). The values derived from the LMS method and linear regression were very similar (P>0.5), and both could be used to acquire the reference values for Brazilian spirometry. Data derived from the equations of this study were different from the current Brazilian equation, which could be justified by the different method used.

Public green areas and urban environmental quality of the city of São Carlos, São Paulo, Brazil / Áreas verdes públicas e a qualidade ambiental urbana do Município de São Carlos, Estado de São Paulo, Brasil

Abstract Assess the state of public green areas, their importance and influence on environmental quality and living in urban centers is an arduous task considering the conceptual and scientific regarding quantification and data analysis methods divergence. In this study, we aimed to determine two indicators of public green areas relative to the percentage of public green areas (PPGA) and the public green areas index (PGAI) in the urban area of São Carlos, SP. The study area was organized into administrative regions (ARs), using satellite images, topographical maps of 1:10,000 Geographic and Cartographic Institute (1990) and data provided by the Municipality of São Carlos. The results show that public green areas comprise 6.55% of the municipality, with a public green areas index (PGAI) of 18.85 m2/inhabitant, indicating good urban environmental quality when compared to rates of 15 m2/capita for public green areas for recreation, suggested by the Brazilian Society of Urban Forestry. The differences between the administrative regions are concern with situations from 4.16 to 36.30 m2/inhabitant. In this context, it is recommend specific public policies and popular participation in the process of continuous improvement for increasing public green areas in the less favored regions. The Genebrino method applied to indicators of public green areas (GPGA – amount of public green areas divided by population density), showed a commendable goal above 40% for urban environmental quality.

Resumo Diagnosticar a situação das áreas verdes públicas, sua importância e influência na qualidade ambiental e de vida nos centros urbanos é uma tarefa árdua, considerando a divergência conceitual e de métodos científicos no que tange a quantificação e a análise dos dados. Neste estudo, objetivou-se determinar dois indicadores de áreas verdes públicas, referentes ao percentual de áreas verdes públicas (PAVP) e ao índice de áreas verdes públicas (IAVP) no perímetro urbano do Município de São Carlos, SP. A área de estudo foi organizada em regiões administrativas (RAs), utilizando imagens de satélite, cartas topográficas 1:10.000 do Instituto Geográfico e Cartográfico (1990) e dados fornecidos pela Prefeitura Municipal de São Carlos. Os resultados demonstram que as áreas verdes públicas compreendem 6,55% do território do município, com um índice de áreas verdes públicas (IAVP) de 18,85 m2/habitante, indicando uma boa qualidade ambiental urbana quando comparado aos índices de 15 m2/habitante para áreas verdes públicas destinadas à recreação, sugerido pela Sociedade Brasileira de Arborização Urbana. As diferenças entre as regiões administrativas são preocupantes, com situações de 4,16 a 36,30 m2/habitantes. Neste contexto, recomendam-se políticas públicas específicas e a participação popular no processo de melhoria contínua para o incremento das áreas verdes públicas nas regiões menos favorecidas. O método genebrino, aplicado aos indicadores de áreas verdes públicas (IAVP – somatório das áreas verdes públicas dividido pela densidade populacional), apontou uma meta recomendável acima de 40% para a qualidade ambiental urbana.

Public green areas and urban environmental quality of the city of São Carlos, São Paulo, Brazil.

Assess the state of public green areas, their importance and influence on environmental quality and living in urban centers is an arduous task considering the conceptual and scientific regarding quantification and data analysis methods divergence. In this study, we aimed to determine two indicators of public green areas relative to the percentage of public green areas (PPGA) and the public green areas index (PGAI) in the urban area of São Carlos, SP. The study area was organized into administrative regions (ARs), using satellite images, topographical maps of 1:10,000 Geographic and Cartographic Institute (1990) and data provided by the Municipality of São Carlos. The results show that public green areas comprise 6.55% of the municipality, with a public green areas index (PGAI) of 18.85 m2/inhabitant, indicating good urban environmental quality when compared to rates of 15 m2/capita for public green areas for recreation, suggested by the Brazilian Society of Urban Forestry. The differences between the administrative regions are concern with situations from 4.16 to 36.30 m2/inhabitant. In this context, it is recommend specific public policies and popular participation in the process of continuous improvement for increasing public green areas in the less favored regions. The Genebrino method applied to indicators of public green areas (GPGA - amount of public green areas divided by population density), showed a commendable goal above 40% for urban environmental quality.

Antimicrobial and anti-adhesive potential of a biosurfactant Rufisan produced by Candida lipolytica UCP 0988.

In the last years, researches developed with biosurfactants for application in the medical area have been revealing the promising biological activities of these biomolecules. In this work the antimicrobial and anti-adhesive properties of a biosurfactant Rufisan isolated from the yeast Candida lipolytica UCP 0988, growth in a medium supplemented with ground nut refinery residue was determined against several microorganisms. The biosurfactant was able to reduce the water surface tension from 70 to 25.3 mN/m and showed a critical micelle concentration (CMC) of 0.03%. The biosurfactant was isolated after 72 h of fermentation and was tested in concentrations varying from 0.75 to 12 mg/l. The highest antimicrobial activities were observed against Streptococcus agalactiae, Streptococcus mutans, Streptococcus mutans NS, Streptococcus mutans HG, Streptococcus sanguis 12, Streptococcus oralis J22 at a concentration superior to the biosurfactant critical micelle concentration. Moreover, the biosurfactant showed anti-adhesive activity against most of the microorganisms tested. As far as we know, this is the first compilation of data on antimicrobial and anti-adhesive activities of a biosurfactant obtained from a Candida strain against such a broad group of microorganisms. The results obtained in this work showed that the biosurfactant from C. lipolytica is a potential antimicrobial and/or anti-adhesive agent for several biomedical applications.

Glycerol as substrate for the production of biosurfactant by Pseudomonas aeruginosa UCP0992.

In this work the influence of the carbon source concentration, of the type and concentration of the nitrogen source and of the cultivation conditions (temperature, aeration and agitation speed) in mineral medium formulated with glycerol was studied for biosurfactant production by Pseudomonas aeruginosa UCP0992. The kinetics of microorganism growth and biosurfactant production have been described for the medium supplemented with 3% glycerol and 0.6% NaNO(3), at 28 degrees C during 120 h under 200 rpm, showing a growth-associated production. The isolated biosurfactant corresponded to a concentration of 8.0 g/l after 96 h. The medium surface tension was reduced to 27.4 mN/m and the emulsification index of hexadecane reached 75-80% after 72 h. A CMC of 700 mg/l and an interfacial tension against hexadecane of 2 mN/m were obtained. The biosurfactant showed stability when submitted at 90 degrees C during 2 h, and thermal (4-120 degrees C) and pH (4-12) stability regarding the surface tension reduction and the emulsification capacity of vegetable oils and hydrocarbons, and tolerance under high salt concentrations (2-10%). The biosurfactant was characterized as a group of rhamnolipids with anionic nature. The crude biosurfactant did not show toxicity against the microcrustacean Artemia salina and the cabbage (Brassica oleracea), while the isolated biosurfactant showed toxicity against the microcrustacean at the CMC. The application of the biosurfactant in diesel recovery from sand was demonstrated by removal percentiles above 85%. The results obtained in this work are noteworthy for possible biosurfactant production from glycerol with potential of application in the environment.