RESUMO
Four cyanobacterial biofilms, raised from cyanobacterial mats and dominated by Phormidium and Oscillatoria spp., were successfully grown attached to polyester mesh discs, and were tested for their probable application in [Formula: see text] -P removal from domestic sewage and other nutrient enriched wastewaters. Biofilm # 2, dominated by Phormidium fragile, best removed [Formula: see text] -P; nevertheless, some of it also grew outside the substrate making harvesting difficult. Other biofilms also efficiently removed [Formula: see text] -P from the medium in the following order: Biofilm # 1 > Biofilm # 3 > Biofilm # 4. Their growths were restricted to discs and are therefore better candidates as they can be efficiently harvested after [Formula: see text] -P removal. [Formula: see text] -P removal was primarily due to its uptake during growth of the biofilm rather than because of precipitation as pH of the medium remained <8.5. [Formula: see text] -N concentration in the medium determined [Formula: see text] -P removal efficiency of the test biofilms and therefore optimum N:P ratio is necessary for optimizing [Formula: see text] -P removal. The test biofilms could also efficiently remove [Formula: see text] -N from the medium.
Assuntos
Biofilmes , Cianobactérias/fisiologia , Microbiologia Industrial/métodos , Fosfatos/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Biomassa , Meios de Cultura , Cianobactérias/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Microbiologia Industrial/instrumentação , Nitratos/metabolismo , Nitrogênio/metabolismo , Fosfatos/metabolismo , Fósforo/metabolismo , Poliésteres , Esgotos , Águas Residuárias/químicaRESUMO
Plasminogen activator inhibitor-1 (PAI-1/Serpin E1) is classically known for its antifibrinolytic activity via inhibiting uPA and tPA of the fibrinolytic pathway. PAI-1 has a paradoxical role in tumor progression, and its molecular functions are poorly understood. PAI-1 is a widely accepted secretory protease inhibitor, however, a study suggested the localization of PAI-1 in the cytoplasm and the nucleus. Besides the plethora of its biological functions as a secretory protein, intracellular localization, and functions of PAI-1 remain unexplored at the molecular level. In this study, using various in silico approaches, we showed that PAI-1 possesses a nuclear export signal. Using the CRM1-specific inhibitor leptomycin B, we demonstrated that PAI-1 has a functional CRM1-dependent NES, indicating the possibility of its nuclear localization. Further, we confirm that PAI-1 is localized in the nucleus of endothelial cells using fluorescence microscopy and immunoprecipitation. Notably, we identified an unconventional distribution of PAI-1 in the PML bodies of the nucleus of normal endothelial cells, while the protein was restricted in the cytoplasm of slow-growing cells. The data showed that the localization of PAI-1 in PML bodies is highly correlated with the growth potential of endothelial cells. This conditional nucleocytoplasmic shuttling of PAI-1 during the aging of cells could impart a strong link to its age-related functions and tumor progression. Together, this study identifies the novel behavior of PAI-1 that might be linked with cell aging and may be able to unveil the elusive role of PAI-1 in tumor progression.
RESUMO
Prompted by the fact that interaction of metals with cyanobacterial mats has been little studied, the present study evaluates the response of a cyanobacterial mat, dominated by Phormidium bigranulatum, to elevated concentrations of Cd²âº in the medium. The mat failed to grow at 7 µM of Cd²âº when the metal as also the mat inoculum were simultaneously added to the medium right in the beginning of the experiment due to marked sensitivity of P. bigranulatum, the main constituent of the mat, to high concentrations of Cd²âº. However, the mat previously grown in Cd²âº-free medium for a time period of 1-4 weeks grew successfully when exposed to media containing very high concentrations of Cd²âº. Four-week-old mat could grow at 250 µM of Cd²âº, which has been found toxic to many cyanobacteria and algae by previous researchers. Greater tolerance of older mats to Cd²âº may be due to greater proportion of exopolysaccharides, which are well known to sequester metal ions extracellularly, in them. Whereas the relative proportion of P. bigranulatum declined at high concentrations of the test metal that of green algae increased due most likely to their tolerance to Cd²âº. Air bubbles were seen entrapped in the mat due obviously to photosynthetic activity. Elevated concentrations of Cd²âº reduced the number of air bubbles in the mat. Decline in number of air bubbles at high concentrations of metal ions was more prominent in the case of younger mat than in the older one. The present study also evaluated changes in species composition of mats of different age that were subsequently grown in Cd²âº enriched culture medium. Younger mats showed change in species composition at very low concentrations of Cd²âº, but older mats showed little changes even at very high concentrations of the test metal. Hence older mats more strongly resisted to changes in its species composition than the younger ones upon exposure to high concentrations of Cd²âº. The growing mat successfully removed Cd²âº from the medium, which was greater at lower concentrations of Cd²âº in the external environment.