| Title |
Influence of Repetitive Freeze-Thaw Perturbation on Anammox Microbial Communities in Low-Temperature Environment |
| Authors |
김수빈(Subin Kim) ; 김상균(Sangkyun Kim) ; 박면호(Myeonho Park) ; 김성아(Seunga Kim) ; 이민주(Minjoo Lee) ; 박준홍(Joonhong Park) |
| DOI |
https://doi.org/10.15681/KSWE.2025.41.3.178 |
| Keywords |
Anammox bacteria; Freeze-thaw cycle; Low-temperature reactivation; Microbial community; Specific anammox activity; Water quality |
| Abstract |
In our previous study, freeze-thaw cycle (FTC) pre-treatment in the absence of ammonia and nitrite was found to selectively enrich anammox bacteria adapted to low-temperature environments. However, whether FTC-treated anammox bacteria can be reactivated under low-temperature conditions with substrate addition remains unclear. In this study, survival, activity recovery, and bacterial population dynamics were explored in low-temperature reactivation experiments in anammox microbial communities with repetitive FTC pre-treatment. The results showed that specific anammox activity (SAA) increased with the number of FTC cycles compared to the mesophilic condition (30°C) and no FTC treatment at 15°C. SAA activation was primarily driven by nitrite removal efficiency, whereas ammonia removal efficiency remained low. Additionally, 16S rDNA-based microbiome analysis using next-generation sequencing showed a shift in microbial community structure and population dynamics, with a decreased relative abundance of anammox bacteria and an increased relative abundance of non-anammox microorganisms, especially Pseudomonas, which is known for its ability to maintain high activity under low-temperature conditions. This suggests that the increased Pseudomonas population outcompeted anammox bacteria for nitrite (NO2-), playing a critical role in nitrogen removal efficiency. The study findings suggest that further studies are needed to determine the optimal conditions for reactivating FTC pre-treated anammox consortia under cold conditions. |