the 37-month study period for the MP operation, whereas the relative
abundance of archaea was below 0.5% of the total reads during
the first 8 months and, at the end of study, started to increase,
reaching 23.08% (Fig. 7). For the domain level, more than 99% of the
total reads were classified; however, for lower taxonomic levels,
the classification rate dropped (see Fig. S1).