School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin 300072, China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin 300072, China.
Sci Total Environ. 2024 Jun 1;927:172376. doi: 10.1016/j.scitotenv.2024.172376. Epub 2024 Apr 9.
Biofilms are widely used and play important roles in biological processes. Low temperature of wastewater inhibits the development of biofilms derived from wastewater activated sludge. However, the specific mechanism of temperature on biofilm development is still unclear. This study explored the mechanism of temperature on biofilm development and found a feasible method to enhance biofilm development at low temperature. The amount of biofilm development decreased by approximately 66 % and 55 % at 4 °C and 15 °C, respectively, as compared to 28 °C. The cyclic dimeric guanosine monophosphate (c-di-GMP) concentration also decreased at low temperature and was positively correlated with extracellular polymeric substance (EPS) content, formation, and adhesion strength. Microbial community results showed that low temperature inhibited the normal survival of most microorganisms, but promoted the growth of some psychrophile bacteria like Sporosarcina, Caldilineaceae, Gemmataceae, Anaerolineaceae and Acidobacteriota. Further analysis of functional genes demonstrated that the abundance of functional genes related to the synthesis of c-di-GMP (K18968, K18967 and K13590) decreased at low temperature. Subsequently, the addition of exogenous spermidine increased the level of intracellular c-di-GMP and alleviated the inhibition effect of low temperature on biofilm development. Therefore, the possible mechanism of low temperature on biofilm development could be the inhibition of the microorganism activity and reduction of the communication level between cells, which is the closely related to the EPS content, formation, and adhesion strength. The enhancement of c-di-GMP level through the exogenous addition of spermidine provides an alternative strategy to enhance biofilm development at low temperatures. The results of this study enhance the understanding of the influence of temperature on biofilm development and provide possible strategies for enhancing biofilm development at low temperatures.
生物膜被广泛应用，并在生物过程中发挥着重要作用。低温会抑制废水活性污泥衍生生物膜的发展。然而，温度对生物膜发展的确切机制仍不清楚。本研究探讨了温度对生物膜发展的影响，并找到了一种在低温下增强生物膜发展的可行方法。与 28°C 相比，在 4°C 和 15°C 时，生物膜发展量分别减少了约 66%和 55%。环二鸟苷单磷酸（c-di-GMP）浓度也随温度降低而降低，并与细胞外聚合物（EPS）含量、形成和粘附强度呈正相关。微生物群落结果表明，低温抑制了大多数微生物的正常生存，但促进了某些嗜冷菌的生长，如芽胞杆菌、Caldilineaceae、Gemmataceae、Anaerolineaceae 和 Acidobacteriota。对功能基因的进一步分析表明，与 c-di-GMP 合成相关的功能基因（K18968、K18967 和 K13590）的丰度在低温下降低。随后，添加外源性亚精胺增加了细胞内 c-di-GMP 的水平，并缓解了低温对生物膜发展的抑制作用。因此，低温对生物膜发展的可能机制可能是抑制微生物活性和减少细胞间的通讯水平，这与 EPS 含量、形成和粘附强度密切相关。通过外源添加亚精胺来提高 c-di-GMP 水平为在低温下增强生物膜发展提供了一种替代策略。本研究的结果增强了对温度对生物膜发展影响的理解，并为在低温下增强生物膜发展提供了可能的策略。
