EFFECTS OF CARBON AND OXYGEN LIMITATIONS AND CALCIUM CONCENTRATIONS ON BIOFILM REMOVAL PROCESSES
EFFECTS OF CARBON AND OXYGEN LIMITATIONS AND CALCIUM CONCENTRATIONS ON BIOFILM REMOVAL PROCESSES
复制标题
DOI：
10.1002/bit.260370105
复制
发表时间：
1991-01-05
影响因子：
3.8
通讯作者：
BRYERS, JD
中科院分区：
文献类型：
--
作者：
APPLEGATE, DH;BRYERS, JD
在湍流系统中研究了由于剪切和灾难性坍塌引起的细菌生物膜去除过程，在碳氧基质限制和水相钙浓度变化的条件下进行了研究。测定了兼性好氧菌恶臭假单胞菌ATCC 11172的纯培养生物膜的细胞膜和胞外聚合物碳、总生物膜碳和总生物膜质量以及生物膜钙浓度。结果表明，限氧生物膜比限碳生物膜具有更高的稳态有机碳水平。氧气限制生物膜还表现出(1)在整个生物膜发育过程中具有较高的胞外聚合物-碳：细胞-碳的比例，(2)生物膜钙含量高于碳限制生物膜。在这两种情况下，增加水相钙浓度都会增加生物膜中的钙量；在研究的整个范围内，氧限制生物膜中的钙积累速率随着液体钙浓度的增加而增加，而碳限制生物膜中的钙积累速度似乎与高于11.0 mg/L的水相钙浓度无关。然而，正是氧气受限的生物膜经历了灾难性的坍塌事件。这里研究的碳限制生物膜从来不会脱落，即使故意长期剥夺所有营养物质也是如此。氧限制生物膜的剪切去除减少和对脱落的敏感性归因于它们相对较大的胞外聚合物产生所购买的更紧密的结构。
Bacterial biofilm removal processes due to shear and catastrophic sloughing have been investigated in a turbulent flow system under conditions of carbon versus oxygen substrate limitations and varying aqueous phase calcium concentrations. Biofilm cellular and extracellular polymer carbon, total biofilm carbon and mass, and biofilm calcium concentrations are measured for pure culture biofilms of the facultative aerobe, Pseudomonas putida ATCC 11172. Results indicate oxygen-limited biofilms reach a higher steady-state biofilm organic carbon level than carbon-limited biofilms. Oxygen-limited biofilms also exhibit (1) a higher extracellular polymer-carbon: cell-carbon ratio throughout biofilm development and (2) a higher biofilm calcium content than carbon-limited biofilms. Increasing aqueous phase calcium concentrations increase the amount of biofilm calcium in both cases; the rate of calcium accumulation in oxygen-limited biofilms increases with increasing liquid phase calcium concentrations over the entire range studied while the rates of calcium accumulation in carbon-limited biofilms appear independent of aqueous phase calcium concentrations above 11.0 mg/L. Oxygen-limited biofilms with their higher extracellular polymer and calcium content exhibit shear removal rates that are 20-40% of those observed for carbon-limited biofilms. However, it is the oxygen-limited biofilms that experience catastrophic sloughing events. The carbon-limited biofilms studied here never sloughed even if subjected to intentional long-term deprivation of all nutrients. Reduced shear removal and the susceptibility to sloughing of the oxygen-limited biofilms are attributed to their more cohesive structure bought about by their relatively greater extracellular polymer production.