(1) The 16S rRNA sequence analysis

Total DNA was extracted using the soil strong DNA extraction kit (DNeasy PowerSoil Kit, QIAGEN, Hilden, Germany). The DNA was diluted to 10 ng/µL for PCR amplification. According to Tamaki [54], the V4-V5 hypervariable region of the 16S rRNA gene of the experimental sample was amplified by primers 515F(50 -GTGYCAGCMGCCGCGGTA-3 0 ) and 909R (50 -CCCCGYCAATTCMTTTRAGT-30 ). Reaction system: every 25 µL PCR reaction solution contains 1× PCR buffer, 1.5 mM MgCl2, 0.2 mM dNTP (Transgen, Beijing, China), 1.0 µM primers, 0.25U Ex Taq (TaKaRa, Beijing, China), and 10 ng DNA template. The PCR reaction procedure was pre-denatured at 94 ◦C for 3 min, then extended for 10 min at 72 ◦C after 30 cycles of conventional amplification (denatured at 94 ◦C for 40 s, annealing at 56 ◦C for 60 s, extension at 72 ◦C for 60 s). The same sample was amplified twice, and the two PCR products obtained from the same sample were mixed. After 1.2% agarose gel electrophoresis, the gel was cut and purified by sanPrep DNA gel recovery kit (Raw engineering, China). After all the purified DNA was mixed in the same amount, PE250 sequencing was carried out using the Illumina Miseq platform [55].

The original sequencing data were spliced using the FLASH1.2.8 software and screened using the QIIME1.9.0 software after splicing [29,56,57], using the Uchime program [58] to detect and remove chimera sequences, then using the QIIME1.9.0 software to divide OTUs (Operational Taxonomic Units) according to 97% similarity of sequences, and using the RDP classifier [46] to annotate each species.

## (2) The 18S rRNA sequence analysis

The 18S rRNA was extracted as 16s rRNA. According to Lejzerowicz et al. [59], the V4 hypervariable region of 18s rRNA gene of the experimental sample was amplified by primer TAReuk454WD1 (50 -CCAGCASCYGCGGTAATTCC-30 ) and primer TAReukREV3 (50 -ACTTTCGTTCTTGATYRA-30 ). PCR reaction system: every 25 µL PCR reaction solution contains 1× PCR buffer, 1.5 mM MgCl2, 0.2 mM dNTP (Transgen, China), 1.0 µM primers, 0.25 U TransFast Taq DNA polymerase (Transgen, China), and 10 ng DNA template. The PCR reaction procedure was the same as that of 16S rRNA. After the completion of the PCR reaction, two PCR products amplified from the same sample were mixed, and the gel was cut using 1.2% agarose gel electrophoresis and purified by the AxyPrep DNA gel recovery kit (Axygen, Hangzhou, China). After all the purified DNA was mixed in the same amount, PE250 sequencing was carried out using the Illumina Miseq platform [29].

The original sequencing data were analyzed as 16S rRNA.

## *3.4. Data Processing*

Microsoft Excel 2019 was used for data processing and analysis, and Origin 2018 was used for drawing.

## **4. Conclusions**


#### **5. Patents**

Chinese patent: A MPBR reactor suitable for sewage purification, CN212833060U. Applicant: Zhongkai University of Agriculture and Engineering. Inventor: Yiyong Li, Yongcong Yang, Kangchun Peng, Baoe Wang, Xueqin Tao, Chong Lin, Zexiang Lei, Jianjun Du.

**Author Contributions:** Conceptualization, Y.L. and B.W.; methodology, Y.L. and Y.Y.; software, W.L. (Wanyi Luo); validation, W.L. (Wen Liu), Z.L., X.T. and B.W.; formal analysis, W.L. (Wanyi Luo); data curation, B.W.; writing—original draft preparation, W.L. (Wanyi Luo); writing—review and editing, Y.L.; supervision, B.W.; funding acquisition, Y.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Science and Technology Planning Project of Guangzhou, China, grant numbers 201803030039, 201704020187, and B318221315.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to confidentiality issues.

**Acknowledgments:** The authors would like to thank the Medicinal Fungi Research Group, Institute of Microbiology, Guangdong Academy of Sciences for the donation of *Cordyceps* sp. C058 strain. The authors would also like to thank Guangdong Meilikang Biotechnology Co., Ltd. for the sequencing process and all the staff who contributed to this experiment.

**Conflicts of Interest:** The authors declare no conflict of interest.
