We investigated the effect of temperature on the biofilm formation of Pseudomonas aeruginosa and revealed that the biofilm formation increased rapidly at temperatures lower than 25°C. P. aeruginosa formed the most robust biofilm of a conspicuous mushroom-like structure at 20°C. However, when the temperature increased to 25°C, the biofilm formation rapidly decreased. Above 25°C, as the temperature rose, the biofilm formation increased again little by little despite its less-structured form, indicating that 25°C is the low point of biofilm formation. The intracellular 3′,5′-cyclic diguanylate (c-di-GMP) levels also decreased rapidly as the temperature rose from 20 to 25°C. The expression levels of pelA, algD, and pslA encoding Pel, alginate, and Psl, respectively, were also dramatically affected by temperature, with pelA being regulated in a pattern similar to that of the intracellular c-di-GMP levels, and the pattern seen for algD regulation was the most similar to the actual biofilm formation pattern. Total exopolysaccharide production was thermoregulated and followed the regulation pattern of c-di-GMP. Interestingly, the thermoregulation patterns in biofilm formation were different depending on the strain of P. aeruginosa. Unlike PAO1, another strain, PA14, showed a gradual decrease in biofilm formation and c-di-GMP in the range of 20 to 37°C, and P. aeruginosa clinical isolates also showed slightly different patterns in biofilm formation in conjunction with temperature change, suggesting that different strains may sense different temperature ranges for biofilm formation. However, it is obvious that P. aeruginosa forms more biofilms at lower temperatures and that temperature is an important factor in determining the biofilm formation.

中文翻译：

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铜绿假单胞菌中生物膜形成的温度调节。

我们研究了温度对铜绿假单胞菌生物膜形成的影响，并揭示了在低于25°C的温度下生物膜形成迅速增加。铜绿假单胞菌在20°C时形成了最坚固的具有明显蘑菇状结构的生物膜。但是，当温度升至25°C时，生物膜形成迅速减少。高于25°C时，随着温度升高，尽管生物膜的形成结构较少，但生物膜的形成又逐渐增加，这表明25°C是生物膜形成的最低点。随着温度从20°C升高到25°C，细胞内3'，5'-环状双鸟苷酸（c-di-GMP）水平也迅速降低。pelA，algD和pslA的表达水平编码Pel，藻酸盐和Psl的蛋白也分别受到温度的显着影响，pelA的调控模式与细胞内c-di-GMP水平相似，而algD调控的模式与细胞内c-di-GMP水平最为相似。实际的生物膜形成模式。胞外多糖总产量受温度调节，并遵循c-di-GMP的调节模式。有趣的是，取决于铜绿假单胞菌的菌株，生物膜形成中的温度调节模式是不同的。与PAO1不同，另一株PA14在20至37°C的温度范围内表现出生物膜形成和c-di-GMP的逐渐降低，以及铜绿假单胞菌临床分离株还显示出随着温度变化生物膜形成的模式略有不同，这表明不同的菌株可能会感觉到不同的温度范围以形成生物膜。然而，很明显铜绿假单胞菌在较低温度下会形成更多的生物膜，而温度是决定生物膜形成的重要因素。