Abstract The hydraulic characteristics along agricultural irrigation pipelines directly affect the local near-wall hydraulic shear stress and biofilm accumulation. However, the variations in the microbial community during the process remain unknown. Based on the Couette-Taylor reactor, a device was developed to accurately control the hydraulic shear stress. The results indicated that the near-wall hydraulic shear stresses showed quadratic correlations with microbial contents (represented by phospholipid fatty acids r > 0.77, p < 0.05), and the maximum values were obtained under the shear stresses of 0.20-0.35 Pa. For two types of treated wastewater, the mutual operational taxonomic units among different shear stress treatments showed good consistency (>185). Their corresponding response in the microbial community was represented by the quantitative correlations between the near-wall hydraulic shear stresses and the polymorphism indices (r > 0.82, p < 0.05). Among the microorganisms, Firmicutes at the phylum level were significantly affected by the shear stress and significantly influenced the biofilm accumulation process.

中文翻译：

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农业灌溉系统不同近壁水剪应力下生物膜微生物群落的变化

摘要 农业灌溉管道沿线的水力特性直接影响局部近壁水力剪应力和生物膜积累。然而，在这个过程中微生物群落的变化仍然未知。基于Couette-Taylor反应器，开发了一种精确控制液压剪切应力的装置。结果表明，近壁水剪应力与微生物含量呈二次相关（以磷脂脂肪酸r>0.77，p<0.05为代表），在0.20-0.35Pa的剪应力下获得最大值。对于两个处理废水的类型，不同剪应力处理之间的相互操作分类单元表现出良好的一致性（> 185）。它们在微生物群落中的相应响应由近壁水剪应力和多态性指数之间的定量相关性表示 (r > 0.82, p < 0.05)。在微生物中，厚壁菌门受剪应力显着影响，对生物膜积累过程有显着影响。