title: M2-H
design: The extracted DNA samples were sequenced on the DNBseq PE150 platform (BGI company, Shenzhen, China), which generated approximately 20 Gb sequencing data for each sample. The low-quality reads from each raw sample were filtered using Trimmomatic with a minimum length of 150 bp. Megahit was used to co-assemble the paired-end reads from four sludge samples.