## 3 Results  
### Bacterial Community Analyses  
The diversity of the bacterial community was assessed using high-throughput sequencing on an Illumina HiSeq 2500 PE250 platform (Novogene Bioinformatics Technology Co., Ltd. Beijing, China) for the four stored water samples. Two of the samples were collected in June, and another two were collected in December 2017. The ten most-abundant genera are presented in Figure 1. The bacterial communities in the four water samples mostly consisted of _Xanthobacter_, _Rhizobium_, _Acinetobacter_, _Variovorax_, _Flavobacterium_, _Pseudomonas_, _Neorhizobium_, _Fusibacter_, _Sphingobacterium_, _Brevundimonas_, _Geothrix_, _Novoshingobium_, _Sphingobium_, _Cupiravidus_, _Haliscomenobacter_, _Microbacterium_, _Ralstonia_, _Unidentified_Mitochondria_, and others. Others were predominant in all four water samples, and the genera _Flavobacterium_ and _Pseudomonas_ were detected in all four samples. The most abundant identified genus of the two water samples collected in June was _Xanthobacter_, which accounted for 21.73% of the detected signatures with an average of 10.87% in the two samples. _Rhizobium_ and _Acinetobacter_ took the second and third place, accounting for 14.86% and 11.20% with an average of 7.43% and 5.60%, respectively. Meanwhile, _Xanthobacter_ represented the greatest bacterial proportion of sample No. 9, accounting for 18.46%, and _Acinetobacter_ was the primary genus in sample No. 10, accounting for 3.74%. Other major genera, including _Variovorax_ and _Flavobacterium_, comprised bacterial signatures in the two water samples of 7.44% and 5.49%, respectively. _Flavobacterium_ was present in the greatest bacterial proportion of the identified genera in the two water samples collected in December, accounting for 16.60% with an average of 8.30%. _Pseudomonas_ and _Novoshingobium_ followed in proportion, accounting for 7.21% and 6.87% with an average of 3.61% and 3.44%, respectively. The dominant genera of the two water samples were _Flavobacterium_ (No. NHWS03) and _Novoshingobium_ (No. NHWS04), accounting for 12.81% and 5.24%, respectively. In addition, _Brevundimonas_, _Geothrix_, _Microbacterium_, and _Haliscomenobacter_ were other major members of the bacterial communities in the two samples, and they represented 6.00%, 5.35%, 5.31%, and 4.70%, respectively.  
The distribution of the bacterial communities in the two collections was different; however, the two samples collected at the same time had similar bacterial communities. _Xanthobacter_, _Rhizobium_, and _Acinetobacter_ were the three most-abundant genera in the collection sampled in June, but these were not present in the top ten genera of the samples collected in December. In the same way, the genus _Novoshingobium_, the third largest member of the bacteria represented in the samples collected in December, was present as one of the ten most-abundant genera in June. The composition of other major bacterial communities was also quite different.  
Figure 1: Relative abundance of the ten most-abundant microbial genera among the four samples. The relative abundance for each sample is shown as a percentage. Bacterial genera are colored according to the legend on the right. (**A**) Shows water samples No. 9 and No. 10 collected in June 2017, and (**B**) shows water samples No. NHWS03 and No. NHWS04 collected in December 2017.