Dynamics of coastal bacterial community average ribosomal RNA operon copy number reflect its response and sensitivity to ammonium and phosphate. (May 2020)

• Record Type: Journal Article
• Authors: Dai, Tianjiao; Zhao, Yanan; Ning, Daliang; Huang, Bei; Mu, Qinglin; Yang, Yunfeng; Wen, Donghui
• Is Part Of: Environmental pollution. Volume 260(2020)
• Publication Date: 2020-05
• Subjects: Bacterial community -- Sensitivity -- Nutrients loading -- rRNA operon copy number -- Wastewater disposal; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.113971
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The nutrient-rich effluent from wastewater treatment plants (WWTPs) constitutes a significant disturbance to coastal microbial communities, which in turn affect ecosystem functioning. However, little is known about how such disturbance could affect the community's stability, an important knowledge gap for predicting community response to future disturbances. Here, we examined dynamics of coastal sediment microbial communities with and without a history of WWTP's disturbances (named H1 and H0 hereafter) after simulated nutrient input loading at the low level (5 mg L −1 NH4 + -N and 0.5 mg L −1 PO4 3- -P) or high level (50 mg L −1 NH4 + -N and 5.0 mg L −1 PO4 3- -P) for 28 days. H0 community was highly sensitive to both low and high nutrient loading, showing a faster community turnover than H1 community. In contrast, H1 community was more efficient in nutrient removal. To explain it, we found that H1 community constituted more abundant and diversified r-strategists, known to be copiotrophic and fast in growth and reproduction, than H0 community. As nutrient was gradually consumed, both communities showed a succession of decreasing r-strategists. Accordingly, there was a decrease in community average ribosomal RNA operon (rrn) copy number, a recently established functional trait of r-strategists. Remarkably, the average rrn copy number of H0 communities was strongly correlated with NH4 + -N (R 2 = 0.515, P = 0.009 for low nutrient loading; R 2 = 0.749, P = 0.001 for high nutrient loading) and PO4 3- -P (R 2 = 0.378, P = 0.034 for low nutrient loading; R 2 = 0.772, P = 0.001 for high nutrient loading) concentrations, while that of H1 communities was only correlated with NH4 + -N at high nutrient loading (R 2 = 0.864, P = 0.001). Our results reveal the potential of using rrn copy number to evaluate the community sensitivity to nutrient disturbances, but community's historical contingency need to be taken in account. Graphical abstract: Image 1 Highlights: Bacteria community's stability was influenced by wastewater discharge history. Nutrient loading induced r-K life strategy selection for bacterial community. Average rRNA operon copy number reflected community succession and sensitivity.