Role of shear stress on biofilm formation of Candida krusei in a rotating disk system
Role of shear stress on biofilm formation of Candida krusei in a rotating disk system
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DOI：
10.1016/j.jfoodeng.2010.08.029
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发表时间：
2011-02
影响因子：
5.5
通讯作者：
L. Brugnoni;M. A. Cubitto;J. E. Lozano
中科院分区：
文献类型：
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作者：
L. Brugnoni;M. A. Cubitto;J. E. Lozano
在工业条件下，在管道、接头和热交换器上形成的生物膜暴露于由流体流动引起的变化的剪切应力条件。在这项研究中，我们研究了剪切的效果，所产生的切向液体流在旋转盘系统（RDS）的粘附和生物膜形成的克鲁斯念珠菌。C.在不锈钢（AISI 304 2B食品级）上形成Krusei生物膜，同时暴露于由两种转速（350和800 rpm）产生的不同剪切应力（从0到91 Nm-2）。每隔24小时用荧光素二乙酸酯（FDA）检查一次，共4天。生物膜的形态和C. Krusei细胞在层流和移行流中有显著差异。过渡流中生物膜的形态特征揭示了水动力阻力的影响。生物膜发展的早期阶段几乎不受剪切应力的影响。然而，在成熟的生物膜中，剪切应力决定了生物膜细胞在表面上的分布。在所有测试的剪切应力下，小菌落大约在48小时开始出现，并且生物膜形成在整个实验期间持续。此外，生物膜的形状可能是由连续施加的剪切应力。最后，在较高的剪切应力下形成的生物膜显着不同，在他们的安排，相比，在较低的剪切条件下形成的。
In industrial conditions, biofilms formed on pipes, joints and heat exchangers are exposed to varying shear stress conditions caused by fluid flow. In this study we examined the effect of shear, created by the tangential liquid flow in a rotating disk system (RDS) on adhesion and biofilm formation of Candida krusei. C. krusei biofilms were formed on stainless steel (AISI 304 2B food grade) while being exposed to different shear stresses (from 0 to 91Nm−2) generated by two rotational speeds (350 and 800rpm). The coupons were examined by fluorescein diacetate (FDA) at 24-h interval for 4days. The morphology of the biofilms and the disposition of C. krusei cells in laminar and transitional flow were markedly different. The morphology of biofilm features in the transitional flow revealed the influence of hydrodynamic drag. The early stage of biofilm development resulted practically unaffected by shear stress. However, in a mature biofilm, shear stress determined the disposition of biofilm cells onto the surface. Microcolonies began to appear approximately at 48h, at all tested shear stresses, and biofilm formation continued throughout the entire experimental period. Moreover, shape of biofilms was probably governed by the continuous applied shear stress. Finally, biofilms formed under higher shear stress differs significantly in their arrangement, as compared with those formed under lower shear conditions.