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AbstractThis work investigated chloroform extracts from culture supernatants of two human probiotic bacteria, Lactobacillus casei CRL 431 and Lactobacillus acidophilus CRL 730 for the production of virulence factors and quorum sensing (QS) interference against three Pseudomonas aeruginosa strains. Both extracts inhibited biofilm biomass (up to 50%), biofilm metabolic activity (up to 39%), the production of the enzyme elastase (up to 63%) and pyocyanin (up to 77%), and decreased QS, without presenting any antibacterial acgivity. In addition, the chloroform extracts of both strains disrupted preformed biofilms of the three strains of P. aeruginosa analyzed (up to 40%). GC-MS analysis revealed that the major compounds detected in the bioactive extracts were four diketopiperazines. This study suggests that the metabolites of L. casei and L. acidophilus could be a promising alternative to combat the pathogenicity of P. aeruginosa. 相似文献
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Daniela Calzia Simona Candiani Greta Garbarino Federico Caicci Silvia Ravera Maurizio Bruschi Lucia Manni Alessandro Morelli Carlo Enrico Traverso Giovanni Candiano Carlo Tacchetti Isabella Panfoli 《Cellular and molecular neurobiology》2013,33(5):637-649
Vertebrate retinal rod outer segments (OS) consist of a stack of disks surrounded by the plasma membrane, where phototransduction takes place. Energetic metabolism in rod OS remains obscure. Literature described a so-called Mg2+-dependent ATPase activity, while our previous results demonstrated the presence of oxidative phosphorylation (OXPHOS) in OS, sustained by an ATP synthetic activity. Here we propose that the OS ATPase and ATP synthase are the expression of the same protein, i.e., of F1Fo-ATP synthase. Imaging on bovine retinal sections showed that some OXPHOS proteins are expressed in the OS. Biochemical data on bovine purified rod OS, characterized for purity, show an ATP synthase activity, inhibited by classical F1Fo-ATP synthase inhibitors. Moreover, OS possess a pH-dependent ATP hydrolysis, inhibited by pH values below 7, suggestive of the functioning of the inhibitor of F1 (IF1) protein. WB confirmed the presence of IF1 in OS, substantiating the expression of F1Fo ATP synthase in OS. Data suggest that the OS F1Fo ATP synthase is able to hydrolyze or synthesize ATP, depending on in vitro or in vivo conditions and that the role of IF1 would be pivotal in the prevention of the reversal of ATP synthase in OS, for example during hypoxia, granting photoreceptor survival. 相似文献
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Paolo Barghini Deborah Moscatelli Anna Maria Vittoria Garzillo Silvia Crognale Massimiliano Fenice 《Enzyme and microbial technology》2013
The Antarctic fungus Lecanicillium muscarium CCFEE-5003 was preliminary cultivated in shaken flasks to check its chitinase production on rough shrimp and crab wastes. Production on shrimp shells was much higher than that on crab shells (104.6 ± 9.3 and 48.6 ± 3.1 U/L, respectively). For possible industrial applications, bioprocess optimization was studied on shrimp shells in bioreactor using RSM to state best conditions of pH and substrate concentration. Optimization improved the production by 137% (243.6 ± 17.3). Two chitinolytic enzymes (CHI1 and CHI2) were purified and characterized. CHI1 (MW ca. 61 kDa) showed optima at pH 5.5 and 45 °C while CHI2 (MW ca. 25 kDa) optima were at pH 4.5 and 40 °C. Both enzymes maintained high activity levels at 5 °C and were inhibited by Fe++, Hg++ and Cu++. CHI2 was strongly allosamidin-sensitive. Both proteins were N-acetyl-hexosaminidases (E.C. 3.2.1.52) but showed different roles in chitin hydrolysis: CHI1 could be defined as “chitobiase” while CHI2 revealed a main “eso-chitinase” activity. 相似文献
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