Colón-González Maritrini, Méndez-Ortiz M Marcela, Membrillo-Hernández Jorge
Laboratorio de Microbiología y Genética Molecular, Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, P.O. Box 70-228, Coyoacán, 04510 Mexico City, Mexico.
Res Microbiol. 2004 Sep;155(7):514-21. doi: 10.1016/j.resmic.2004.03.004.
Association with a surface in a structure known as biofilm is the prevailing microbial lifestyle. Here we show the kinetics of biofilm formation of Escherichia coli W3110 in static cultures growing under aerobic or anaerobic conditions. Aerobically growing cells in LB medium started to produce detectable amounts of biofilm after 4 to 8 h, displaying maximal accumulation of formed biofilm at 24 h, corresponding to the onset of stationary phase. Then an abrupt reduction in the biomass of the biofilm was observed. This decrease was not prevented by external addition of fresh nutrients and coincided with the depletion of oxygen as measured by the enzymatic activity of the AdhE protein. No biofilm formation was detected in cultures grown anaerobically in LB or LB supplemented with nitrate, nitrite, DMSO or fumarate, even after 72 h of incubation, well inside the stationary phase, suggesting that under anaerobic growth conditions E. coli cannot form biofilms.
与生物膜这种结构中的表面相结合是微生物普遍的生存方式。在此，我们展示了在有氧或无氧条件下生长的静态培养物中大肠杆菌W3110生物膜形成的动力学。在LB培养基中需氧生长的细胞在4至8小时后开始产生可检测量的生物膜，在24小时时形成的生物膜积累达到最大值，这与稳定期的开始相对应。然后观察到生物膜生物量的突然减少。外部添加新鲜营养物质并不能阻止这种减少，并且这与通过AdhE蛋白的酶活性测量的氧气消耗相吻合。在LB或补充了硝酸盐、亚硝酸盐、二甲基亚砜或富马酸盐的LB中厌氧培养的培养物中，即使在培养72小时后，即在稳定期内，也未检测到生物膜形成，这表明在厌氧生长条件下大肠杆菌无法形成生物膜。
