Read filtering: rm rRNA reads: replace sortmerna

sortmerna's version 2.1 creates "corrupted" output files (see here). The newest version 4.2.0 has issues with the running time (e.g. see here).

Maybe it is better to look for alternatives. E.g. BBDuk.

Test data: /work/projects/ecosystem_biology/local_tools/IMP3devel/test/