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streptomycesPor Juliana Pacheco da Rosa, Elisa Korenblum, Marcella Novaes Franco-Cirigliano, Fernanda Abreu, Ulysses Lins, Rosângela M. A. Soares, Andrew Macrae, Lucy Seldin, and Rosalie R. R. Coelho

Um actinomiceto, o Streptomyces lunalinharesii Strain 235 isolado de solo brasileiro demonstrou atividade antimicrobiana contra uma bactéria envolvida em processo de biocorrosão, a Desulfovibrio alaskensis NCIMB 1349.

Esta pesquisa descreve pela primeira vez uma substância isolada de um actinomiceto com ação contra uma bactéria causadora de biocorrosão e abre um caminho para  a descoberta de novas  substancias biocidas  com aplicação industrial principalmente na indústria petroleira. 

Streptomyces lunalinharesii Strain 235 Shows the Potential to Inhibit Bacteria Involved in Biocorrosion Processes

Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biolm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria.  e antimicrobial activity was seen over a wide range of pH, and aer treatment with several chemicals and heat but not with proteinase K and trypsin.  

 The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the frst report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these  fndings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.

BioMed Research International

Volume 2013, Article ID 309769

http://www.hindawi.com/journals/bmri/2013/309769/

osmundaria obtusilobaPor Lauro M. de Souza , Guilherme L. Sassaki , Maria Teresa Villela Romanos and Eliana Barreto-Bergter

Um sulfolipídio foi isolado e caracterizado da alga vermelha Osmundaria Obtusiloba, coletada no Brasil, especificamente na praia rasa em Búzios. Esta macroalga tem sido alvo de diversos estudos e substâncias bioativas de importância medicinal têm sido isoladas.

Este sulfulipídio éum glicolipídio e mostrou atividade contra os vírus do Herpes simples que são responsáveis por infecções humanas com o HSV-1 (Herpes oral ou labial) e HSV-2 (Herpes genital). Apesar de o aciclovir ser a droga de escolha, para estas infecções virais, a existência  de cepas resistentes  faz com que a pesquisa de novas substâncias com atividade contra este grupo de vírus seja de grande importância. O sulfolipidio além de demonstrar excelente ação antiviral  apresenta baixa toxidade em culturas de células.

Structural Characterization and Anti-HSV-1 and HSV-2  Activity of Glycolipids from the Marine Algae Osmundari  obtusiloba Isolated from Southeastern Brazilian Coast

Glycolipids were extracted from the red alga Osmundaria   obtusiloba from  Southeastern  Brazilian coast.  The acetone insoluble  material  was extracted with chloroform/methanol and the lipids, enriched in glycolipids, were fractionated on a silica gel column eluted with chloroform, acetone and then methanol. Three major orcinol-positive bands were found in  the acetone and methanol  fractions, being  detected  by  thin  layer chromatography.  The  structures  of  the corresponding  glycolipids  were  elucidated  by ESI-MS and  1 H/ 13 C NMR analysis, on the basis of their tandem-MS behavior and HSQC, TOCSY fingerprints. For the first time, the structure of sulfoquinovosyldiacylglycerol from the  red  alga  Osmundaria  obtusiloba  was  characterized. This molecule exhibited  potent antiviral activity against HSV-1 and HSV-2 with EC 50  values of 42 µg/mL to HSV-1 and 12 µg/mL to HSV-2, respectively. Two other glycolipids, mono- and digalactosyldiacylglycerol, were also found in the alga, being characterized by ESI-MS/MS. The structural elucidation of algae glycolipids is a first step for a better understanding of the relation between these structures and their biological activities.

Trabalho publicado  no  periódico: Marine Drugs

oleo essecialPor Danielle Cristina Machado Costa, Alane Beatriz Vermelho, Catia Amancio Almeida, Edilma Paraguai de Souza Dias, Sabrina Martins Lage Cedrola, Maria de Fatima Arrigoni-Blank, Arie Fitzgerald Blank, Celuta Sales Alviano e Daniela Sales Alviano

Os fungos dermatófitos são caracterizados por sua capacidade de penetração nos tecidos epidérmicos. Um dos mecanismos de patogenicidade conhecido é a liberação de enzimas extracelulares como as peptidases, incluindo neste grupo as queratinases.

Neste trabalho realizado por pesquisadores do Instituto de Microbiologia, UFRJ e da Universidade Federal do Sergipe, uma fração rica no óleo essencial linalol foi obtida da planta Lippia Alba, conhecida como erva cidreira. Este óleo demonstrou efeito inibidor nas peptidases e queratinases de três fungos dermatófitos: Trichophyton rubrum, Epidermophyton floccosum e  Microsporum gypseum,

Estes resultados sugerem que as queratinases e outras peptidases podem ser um potencial alvo quimioterápico para o controle destas infecções fúngicas.

Inhibitory effect of linalool-rich essential oil from Lippia alba on the peptidase and keratinase activities of dermatophytes 

Lippia alba (Miller) N.E. Brown is an aromatic plant known locally as ‘‘Erva-cidreira-do-campo’’ that has great importance in Brazilian folk medicine. The aim of our study was to evaluate the antidermatophytic potential of linalool-rich essential oil (EO) from L. alba and analyze the ability of this EO to inhibit peptidase and keratinase activities, which are important virulence factors in dermatophytes. The minimum inhibitory concentrations (MICs) of L. alba EO were 39, 156 and 312 mg/mL against Trichophyton rubrum, Epidermophyton floccosum and Microsporum gypseum, respectively.  To evaluate  the  influence  of  L.  alba  EO  on  the  proteolytic  and  keratinolytic activities  of  these  dermatophytes,  specific  inhibitory  assays  were  performed.  The  results

indicated that linalool-rich EO from L. alba inhibited the activity of proteases and keratinases secreted from dermatophytes, and this inhibition could be a possible mechanism of action against dermatophytes. Due to the effective antidermatophytic activity of L. alba EO, further experiments  should  be  performed  to  explore  the  potential  of  this  linalool-rich  EO  as  an alternative antifungal therapy

EO  (essential oil)

Publicado em : .J Enzyme Inhib Med Chem, Early Online: 1–6  013

Informa UK Ltd. DOI: 10.3109/14756366.2012.743537

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