School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, China.
Biotechnol Bioeng. 2020 May;117(5):1270-1280. doi: 10.1002/bit.27289. Epub 2020 Feb 11.
Interspecies interactions and phylogenetic distances were studied to reveal the underlying evolutionary adaptations of biofilms sourced from wastewater treatment processes. Based on 380 pairwise cocultures of 40 strains from two microbial aggregates (surface-attached and mobile aggregates [flocs]) at two substrate concentrations (LB broth and 0.1× LB broth), interspecies interactions were explored using biofilm classification schemes. There was a strong source-dependence of biofilm development formed by the monocultures, that is, a higher biofilm formation potential for strains from attached aggregates than for those from sludge flocs at both substrate concentrations. Interestingly, the results showed that total biofilm reduction was dominant in the dual-species biofilm sourced from flocs in both LB broth (67.37%) and 0.1× LB broth (64.21%), indicating high interspecific competition in mobile aggregates and the independence of substrate concentrations. However, biofilm reduction was higher (33.68%) than induction (19.37%) for the biofilms formed by surface-attached aggregates in LB broth, while the opposite trend was apparent in 0.1× LB broth, suggesting the occurrence of indeterministic processes for biofilm formation and important roles of substrate concentrations. In addition, the more closely related phylogenetic relationships of cocultures from mobile aggregates were consistent with higher competition compared with those from surface-attached aggregates. Overall, the underlying evolutionary patterns of biofilms formed from mobile aggregates consistently followed the essence of the "Red Queen Hypothesis," while biofilms developed from surface-attached aggregates were not deterministic. This study advanced our understanding of biofilm-related treatment processes using the principles of microbial ecology.
本研究通过研究种间相互作用和系统发育距离，揭示了来源于废水处理工艺的生物膜的潜在进化适应机制。基于两种微生物聚集体（附着聚集体和可移动聚集体[絮体]）中的 40 株菌的 380 个两两共培养物，在两种基质浓度（LB 肉汤和 0.1×LB 肉汤）下，使用生物膜分类方案探索了种间相互作用。结果表明，在单一培养物中，生物膜的形成具有很强的来源依赖性，即在两种基质浓度下，附着聚集体的菌株比絮体的菌株具有更高的生物膜形成潜力。有趣的是，结果表明，在来自絮体的双物种生物膜中，总生物膜减少是主要的（在 LB 肉汤中为 67.37%，在 0.1×LB 肉汤中为 64.21%），这表明在可移动聚集体中存在强烈的种间竞争，且基质浓度不依赖于这种竞争。然而，在 LB 肉汤中，附着聚集体形成的生物膜的减少（33.68%）高于诱导（19.37%），而在 0.1×LB 肉汤中则相反，这表明生物膜形成的不定过程和基质浓度的重要作用。此外，来自可移动聚集体的共培养物的系统发育关系越密切，与来自附着聚集体的共培养物相比，竞争越激烈。总的来说，来源于可移动聚集体的生物膜的潜在进化模式始终遵循“红皇后假说”的本质，而来源于附着聚集体的生物膜则不是确定的。这项研究利用微生物生态学原理，推进了我们对生物膜相关处理过程的理解。
