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首页> 外文期刊>Infection and immunity >Phosphorylcholine stimulates capsule formation of phosphate-limited mucoid Pseudomonas aeruginosa.
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Phosphorylcholine stimulates capsule formation of phosphate-limited mucoid Pseudomonas aeruginosa.

机译：磷酸胆碱刺激磷酸盐限制的粘液状铜绿假单胞菌的胶囊形成。

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Production of both alginic acid and lipopolysaccharide by a mucoid strain of Pseudomonas aeruginosa, SRM-3, was studied in a chemostat system during growth under nutrient-limiting conditions chosen to reflect the chronic growth conditions in the lungs of cystic fibrosis patients. Since mucoid strains have been shown to elaborate extracellular proteases and phospholipase C, nitrogen and phosphate limitation were selected for analysis. A modified alginate-promoting medium containing either 1 mM glutamate or 0.05 mM K2HPO4 as limiting nutrient and doubling times of 1.6 to 15.7 h were used. Under nitrogen limitation, strain SRM-3 produced 1.4 mg of uronic acid per mg (dry weight) of cells at all doubling times studied. However, phosphate limitation resulted in the synthesis of only 0.4 mg of uronic acid per mg (dry weight) of cells. The role of phosphate in alginic acid polysaccharide production was further investigated by using phosphorylcholine, a product of phospholipase C activity on phosphatidylcholine, the major lung surfactant. No only were mucoid cells capable of utilizing phosphorylcholine for growth, but a highly specific interaction occurred among phosphorylcholine, alginate, and whole cells, resulting in greatly enhanced culture viscosity. Electron micrographs showed the gradual formation of a capsule during growth on phosphorylcholine, indicating that the mucoid strain has the ability to utilize surfactant not only as a nutrient source but also for constructing a capsule with greatly enhanced adhesive properties.
机译：在化肥系统中，在营养限制条件下生长期间，在化肥系统中研究了铜绿假单胞菌黏液样菌株SRM-3生产藻酸和脂多糖的情况，该条件反映了囊性纤维化患者肺部的慢性生长条件。由于已显示粘液样菌株可精制细胞外蛋白酶和磷脂酶C，因此选择了氮和磷酸盐限制进行分析。使用含有1 mM谷氨酸或0.05 mM K2HPO4作为极限营养素且倍增时间为1.6至15.7 h的改良藻酸盐促进培养基。在氮限制下，菌株SRM-3在所研究的所有加倍时间内每毫克（干重）细胞产生1.4毫克尿酸。但是，磷酸盐的限制导致每毫克（干重）细胞仅合成0.4毫克的尿酸。通过使用磷脂酰胆碱（磷脂酶C对主要的肺表面活性物质磷脂酰胆碱的活性的产物）进一步研究了磷酸盐在藻酸多糖生产中的作用。粘液样细胞不仅能够利用磷酸胆碱生长，而且在磷酸胆碱，藻酸盐和全细胞之间发生了高度特异性的相互作用，从而大大提高了培养液的粘度。电子显微照片显示在磷胆碱上生长期间胶囊的逐渐形成，表明粘液样菌株不仅具有利用表面活性剂作为营养源的能力，而且还具有构建具有大大增强的粘合性能的胶囊的能力。

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