How to creat sam.bz2 with already run metaphlan with the output of profile.txt and bowtie2 file

Hi, thanks for your efforts to share such convenient pipeline.

  1. Recently, I am learning the strainphlan. I have one question as below:

How to creat sam.bz2 with already run metaphlan3 with the output of profile.txt and bowtie2 file?

ps, i have run the run metaphlan3 with the output of profile.txt and bowtie2 file, but not sam file before for a large batch of samples. When I want to run strainphlan, do I have to rerun the metphlan again at the first step, or is there any possibility that I can create sam.bz2 based on already run metaphlan with the output of profile.txt and bowtie2 file?

  1. I have try to use the bowtie2 as input file and rerun the metaphlan3, as below:

“metaphlan ./007-MT3_S102_L002.bowtie2.bz2 --input_type bowtie2out --read_min_len 70 --bowtie2db ./Ref_db/MetaPhlAn --index mpa_v30_CHOCOPhlAn_201901 --bt2_ps very-sensitive --min_cu_len 2000 --tax_lev a --avoid_disqm --stat_q 0.2 --stat tavg_g -t rel_ab_w_read_stats --unknown_estimation --add_viruses -o ./007-MT3_S102_L002.txt -s ./007-MT3_S102_L002.sam.bz2 --sample_id 007-MT3_S102_L002 --nproc 32”

Also, I have try to use bowtie2 with fastq as input file to ouput sam, as below:

“bowtie2 -p 6 -3 5 --local -x ./Ref_db/MetaPhlAn/mpa_v30_CHOCOPhlAn_201901 -1 ./MT3/007-MT3_S102_L002_R1_001_kneaddata_paired_1.fastq -2 ./MT3/007-MT3_S102_L002_R1_001_kneaddata_paired_2.fastq -S 007-MT3.sam.bz2”

But I found that both the output sam file is bigger than the file produced by the metaphlan (input: fastq, output with profile, sam, and bowtie2).

Any suggestion or comments. Many thanks!

Celine

Hi @celine77, thanks for getting in touch.
Unfortunately, it is not possible to create the SAM file from the bowtie2out or the profile file, you will have to execute MetaPhlAn again on the reads and save the sam file with the -s option.
Best,
Aitor

Hi, Aitor.

Noted with many thanks!