Composition and Dynamics of Bacterial Communities in a Full-Scale Mineral Water Treatment Plant

Lei Wei; Qingping Wu; Jumei Zhang; Weipeng Guo; Qihui Gu; Huiqing Wu; Juan Wang; Tao Lei; Moutong Chen; Musheng Wu; Aimei Li

doi:10.3389/fmicb.2019.01542

Composition and Dynamics of Bacterial Communities in a Full-Scale Mineral Water Treatment Plant

Front Microbiol. 2019 Jul 24:10:1542. doi: 10.3389/fmicb.2019.01542. eCollection 2019.

Authors

Lei Wei^{1

2}, Qingping Wu², Jumei Zhang², Weipeng Guo², Qihui Gu², Huiqing Wu², Juan Wang³, Tao Lei², Moutong Chen², Musheng Wu⁴, Aimei Li⁴

Affiliations

¹ School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
² State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Science, Guangzhou, China.
³ College of Food Science, South China Agricultural University, Guangzhou, China.
⁴ Guangdong Dinghu Mountain Spring Company Limited, Zhaoqing, China.

Abstract

The aim of this study was to gain insight into the bacterial composition and dynamics in a mineral water treatment system (MWTS). The bacterial community of a full-scale mineral water treatment plant in the Maofeng Mountain, South China, was studied using high-throughput sequencing combined with cultivation-based techniques in both the dry and wet season. Overall, adenosine tri-phosphate (ATP) concentration (6.47 × 10^-11 - 3.32 × 10^-8 M) and heterotrophic plate counts (HPC) (3 - 1.29 × 10³ CFU/mL) of water samples in the wet season were lower than those (ATP concentration 5.10 × 10^-11 - 6.96 × 10^-8 M, HPC 2 - 1.97 × 10³ CFU/mL) in the dry season throughout the whole MWTS. The microbial activity and biomass of water samples obviously changed along with treatment process. All 300 isolates obtained using cultivation-based techniques were distributed in 5 phyla, 7 classes, and 19 genera. Proteobacteria accounted for 55.7% (167) of the total isolates, among which predominant genus was Pseudomonas (19.3%). Illumina sequencing analysis of 16s rRNA genes revealed 15 bacterial phyla (relative abundance >0.1%) as being identified in all water samples. Among these, Proteobacteria constituted the dominant bacteria microbiota in all water samples. A large shift in the proportion of Bacteroidetes, Actinobacteria, and Firmicutes was obtained during the treatment process, with the proportion of Bacteroidetes, Actinobacteria decreasing sharply, whereas that of Firmicutes increased and predominated in the final water product. The core microbiome, which was still present in whole MWTS comprised several genera including Pseudomonas, Acinetobacter, Clostridium, and Mycobacterium, that contain species that are opportunistic pathogens, suggesting a potential threat for mineral water microbiology safety. This study is the first to investigate the bacterial community of a full-scale mineral water treatment plant in China. The results provided data regarding the bacteria composition and dynamics in an MWTS, which will contribute to the beneficial manipulation of the mineral water microbiome.

Keywords: bacterial community; core microbiome; high-throughput sequencing; mineral water treatment system; opportunistic pathogens.