Characterizing dissolved organic matter and bacterial community interactions in a river network under anthropogenic landcover

Shengqiang Tu; Qingqian Li; Zhangmu Jing; Hongjie Gao; Dongping Liu; Meiqi Shao; Huibin Yu

doi:10.1016/j.envres.2023.117129

Characterizing dissolved organic matter and bacterial community interactions in a river network under anthropogenic landcover

Environ Res. 2023 Dec 1;238(Pt 1):117129. doi: 10.1016/j.envres.2023.117129. Epub 2023 Sep 12.

Authors

Shengqiang Tu¹, Qingqian Li¹, Zhangmu Jing², Hongjie Gao³, Dongping Liu⁴, Meiqi Shao⁵, Huibin Yu⁶

Affiliations

¹ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
² State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; College of Water Sciences, Beijing Normal University, Beijing, 100875, PR China.
³ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; College of Water Sciences, Beijing Normal University, Beijing, 100875, PR China. Electronic address: gaohj@craes.org.cn.
⁴ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
⁵ Xiamen Lawlink Development Co., Ltd, Xiamen, 361008, PR China.
⁶ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. Electronic address: yhbybx@163.com.

PMID: 37709243
DOI: 10.1016/j.envres.2023.117129

Abstract

Anthropogenic landcover could rise nutrient concentrations and impact the characteristics and bioavailability of dissolved organic matter (DOM) in a river network. Exploring the interactions between DOM and microbials might be conducive to revealing biogeochemistry behaviors of organic matter. In this study, synchronous fluorescence spectra (SFS) with Gaussian band fitting and two-dimensional correlation spectroscopy (2D-COS) were employed to identify DOM fractions and reveal their interactions with bacterial communities. DOM was extracted from a river network under eco-agricultural rural (RUR), eco-residential urban (URB), eco-economical town (TOW), and eco-industrial park (IND) regions in Jiashan Plain of eastern China. The overlapping peaks observed in the SFS were successfully separated into four fractions using Gaussian band fitting, i.e., tyrosine-like fluorescence (TYLF), tryptophan-like fluorescence (TRLF), microbial humic-like fluorescence (MHLF), and fulvic-like fluorescence (FLF) materials. Across all four regions, TRLF (44.79% ± 7.74%) and TYLF (48.09% ± 8.85%) were the dominant components. Based on 2D-COS, variations of TYLF and TRLF were extremely larger than those of FLF in RUR-TOW. However, in URB-IND, the former exhibited lower variations compared to the latter. These suggested that FLF be likely derived continuously from lignin and other residue of terrestrial plant origin along the river network, and TYLF and TRLF be originated discontinuously from domestic wastewater in RUR-TOW. By high-throughput sequenced OTUs, the number of organisms in RUR-TOW could be higher than those in URB-IND, while genes associated with carbohydrate metabolism were lower in former than those in the latter. According to co-occurrence networks, microbes could promote the production of TYLF and TRLF in RUR-TOW. In contrast, microbial communities in URB-IND might contribute to decompose FLF. The obtained results could not only reveal interactions between DOM fractions and bacterial communities in the river network, but this methodology may be applied to other water bodies from different landscapes.

Keywords: Bacterial communities; Co-occurrence network; Dissolved organic matter; Gaussian band fitting; Synchronous fluorescence spectroscopy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria
Dissolved Organic Matter*
Humic Substances / analysis
Rivers* / chemistry
Spectrometry, Fluorescence / methods
Wastewater

Substances

Dissolved Organic Matter
Wastewater
Humic Substances