Violacein is a versatile pigment from a bacterium Chromobacterium violaceum that exhibits several biological activities and, at present, has gained increasing importance in industrial markets, such as in medicine, cosmetics, and textiles. In this mini-review, we aimed to describe violacein production and to explore its various biological properties in a pharmacological context, including its antioxidant, immunomodulatory, antitumoral, and antiparasitic activities. In addition, its use in the fields of cosmetics, textiles, food, toys, and insecticides has emerged as unusual potential areas of application to be discussed here.

The main characteristic of biosurfactants is their property of reducing the superficial and interfacial tension between two immiscible liquids of different polarities. The main obstacle to the application of biosurfactants is the high production costs, the use of alternative substrates being indicated to solve this problem. This work report the production of biosurfactant by Bacillus subtilis LB5a on a pilot scale using cassava wastewater as the substrate, and the study of the parameters related to its production. The cassava wastewater was heated, centrifuged and poured into a 40-liter batch pilot bioreactor adapted for simultaneous foam collection during the fermentative process. The temperature was maintained at 35 degrees C, agitation at 150 rpm and aeration 0.38 vvm during the first 12 h, and 0.63 vvm for the rest of the process. Samples of liquid fermentate were collected at regular intervals for the analysis of total carbohydrates, reducing sugars, pH, CFU/mL count and superficial tension. The foam was centrifuged and the biosurfactant purified. The kinetic data of the process showed that both the microbial population, which reached a maximum after about 24 h, and the foam production of 10.6 L, peaked between 24 and 36 h, coinciding with the greatest production of biosurfactant. The yield of semi-purified surfactant in the foam was 2.4 g/L. The superficial tension of the medium was reduced from 51 to 27 mN/m and the critical micellar concentration was 11 mg/L, which, in principle, characterizes it as a good tensoactive agent. As a function of its composition and productivity, cassava wastewater was identified as a good substrate for the production of the biosurfactant.

Alkaline xylanases produced by four different strains of Bacillus pumilus were characterized. The optimal pH and temperature were pH 9.0 and 60ºC for strain 13 a , and pH 8.0 and 55ºC for strains 5 2 , 5 14 , and 4 a. Under these conditions the following activities were found after 10 min in the presence of 1% xylan (birchwood): 328 U.ml-1 , 131 U.ml-1 , 90 U.ml-1 , and 167 U.ml-1 , respectively, for the four strains. The enzymes were stable at 40ºC, with 40% of the xylanase activity remaining after 2 hours for the enzymes of strain 5 2 and 60% for the other three strains. Stability at 50ºC was improved by addition of glycerol. Taking into account the conditions under which kraft pulps are bleached during the manufacture of paper, xylanases from B. pumilus exhibit favorable potential for application to bleaching in the paper making process.

The extract of sugar-cane yeast (Saccharomyces cerevisiae) was enzymatically hydrolysed by Alcalase, Protex or Viscozyme. Hydrolysates were fractionated using a membrane ultrafiltration system and peptides smaller than 5kDa were evaluated for iron chelating ability through measurements of iron solubility, binding capacity and dialyzability. Iron-chelating peptides were isolated using immobilized metal affinity chromatography (IMAC). They showed higher content of His, Lys, and Arg than the original hydrolysates. In spite of poor iron solubility, hydrolysates of Viscozyme provided higher iron dialyzability than those of other enzymes. This means that more chelates of iron or complexes were formed and these kept the iron stable during simulated gastro-intestinal digestion in vitro, improving its dialyzability.

The production of manganese peroxidase (MnP) from Bacillus pumilus and Paenibacillus sp.

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ResumoEste trabalho teve como objetivo fazer um levantamento sucinto da presença de resíduos de medicamentos no ambiente aquático e em estações de tratamento de esgotos, bem como discutir a necessidade iminente de ações que possam auxiliar nesse tipo de contaminação ao reduzir as emissões, orientar o gerenciamento adequado de resíduos de farmácia e de descarte em domicílios. Além disso, foram apresentados resultados de ensaios ecotoxicológicos empregados na avaliação de efeitos da fluoxetina em Vibrio fischeri e em H. azteca, organismos aquáticos frequentemente expostos a contaminantes ambientais. Dos resultados obtidos, observou-se que a partir de 0,3 mg. AbstractThe objective of this paper was to review data on residues of medical products in aquatic environments and at wastewater treatment plants. Secondarily the paper presents a discussion about the need for a good management of drugs residues and effluents generated by this sector. Bringing the evidences of environmental possible damages reported by ecotoxicity data on the effects of fluoxetine to Vibrio fischeri and H. azteca, aquatic organisms daily exposed to environmental contaminants. From the results we observed that 0.3 mg.l-1 of fluoxetine hidrochloride induced lethality to H. azteca and 30 mg.l-1 reduced the luminescence of Vibrio fischeri. This assay evidenced higher toxicity when we used the "generic" product.