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.

Estabelecimento in vitro e aclimatização de Lippia alba (Mill. ) N. E. Brown / In vitro establishment and acclimatization of Lippia alba (Mill. ) N. E. Brown

O presente trabalho teve por objetivo estabelecer in vitro a espécie Lippia alba (Mill.) N. E. Brown e promover a aclimatização de mudas dessa espécie. Para isso, foi testada a influência de diferentes concentrações e tempos de imersão em hipoclorito de sódio na assepsia dos explantes. Segmentos nodais foram imersos em hipoclorito de sódio nas concentrações 0,4; 0,6; 0,8 e 1,0 % e nos tempos 8, 12 e 16 minutos. Após 30 dias avaliou-se a contaminação bacteriana (%), número de brotos, número de folhas, e a taxa de sobrevivência (%). A concentração de 1% de hipoclorito de sódio foi a mais eficiente no controle da contaminação. Ápices caulinares de L. alba foram estabelecidos in vitro em meio MS suplementado com diferentes doses de BAP (0; 0,5; 1,0; 1,5 mg L-1). Após 140 dias avaliou-se a contaminação (%), a taxa de sobrevivência (%), a oxidação (%) e o número de brotos. Os melhores resultados foram obtidos para a dose 1,5 mg L-1 deste regulador. Para a aclimatização foram testados quatro tipos de substratos: pó de coco + calcário (1 g L-1), Plantmax® + calcário (1 g L-1), vermiculita + calcário (1 g L-1) e pó de coco + Plantmax® + vermiculita (1:1:1) + calcário (1 g L-1). Avaliou-se a taxa de sobrevivência (%), comprimento da parte aérea (cm), comprimento da raiz (cm), massa fresca da parte aérea e da raiz (g), e a massa seca da parte aérea e da raiz (g). Os melhores resultados foram obtidos quando com o substrato comercial Plantmax®.

The present study aimed to establish the species Lippia alba (Mill.) N. E. Brown in vitro and promote the acclimatization of the seedlings of this species. Therefore, we tested the effect of different concentrations and immersiog times in sodium hypochloritetfor the disinfection of explants. Nodal segments were immersed in sodium hypochlorite at the different concentrations of ,.4; ,.6; ,.8 and ,.0% during the different times of 8, 12 and 16 minutes. After 30 days, bacterial contamination (%), number of shoots, number of leaves and survival rate (%) were evaluated. The 1% concentration of sodium hypochlorite was more effective in controlling contamination. Shoot apices of L. alba were established in vitro on MS medium supplemented with different concentrations of BAP (;, ,.5; ,.0; ,.5 mg L-1). After 140 days, we evaluated the contamination (%), survival rate (%), oxidation (%) and number of shoots. The best results were obtained when we used the dose of ,.5 mg L-1 of this regulator. For acclimatization, we tested four types of substrates: coconut powder + lime (1 g L-1), Plantmax® + lime (1 g L-1), vermiculite + lime (1 g L-1) and coconut powder + Plantmax® + vermiculite (1:1:1) + lime (1 g L-1). We evaluated the survival rate (%), shoot length (cm), root length (cm), fresh weight of shoot and root (g) and dry weight of shoot and root (g). The best results were obtained when using the substrate Plantmax®.

Hematoma de bainha dos retos / Hematoma of the rectus abdominis sheaths

Os autores relatam sua experiência com 4 casos de hematoma de bainha dos retos, analisando o diagóstico e a conduta terapêutica

Tumores de nariz y senos paranasales.Serie del Hospital Infantil de Mexico 1958-1979. / Tumors of the nose and paranasal sinuses. Series of the Hospital Infantil de Mexico 1958-19779

Se presenta una serie de neoplasias de nariz y senos paranasales en ninos y adolescentes, estudiados y tratados en el Hospital Infantil de Mexico (1958-1979), correspondiente a 70 pacientes del sexo masculino y 30 del sexo femenino. Se consideraron las neoplasias como benignas, intermedias y malignas, de acuerdo a una clasificacion clinohistologica. El estudio comprendio los sintomas y signos importantes, las areas de localizacion, los metodos de diagnostico y los tratamientos utilizados en ese lapso de tiempo. Los resultados del tratamiento en conjunto fueron seguidos en lo posible, hasta observar un 42% de curaciones, 13% de recidivas, 8% de fallecimientos por la enfermedad y 37% desconocidos o com tiempo insuficiente para concluir. El objetivo del trabajo se refiere a senalar la importancia del diagnostico temprano, del manejo adecuado en intituciones apropiadas, de comparar las actuales tecnicas de tratamiento y la experiencia de la institucion al revisar series de otros autores