Microbial community structure
During the intial granulation process 16S rRNA showed that the mixed
microbial community was dominated by Clostridium pasteurianum .
When the SRT was prolonged to 50 d the microbial community shifted to a
community dominated (>50% operational taxonomic unit (OTU)
based) by Bifidobacterium scardovii . Additionally,Propionibacterium thoenii and Megasphaera
cerevisiae were detected and contributed for 20-30% in total to the
community structure based upon 16S rRNA. This community structure
remained similar at an SRT of 10-20 d. While decreasing the SRT to 1-2 d
a more diverse community structure consisting of 4 species, next to the
aforementioned species the 4th observed species wasSaccharibacteria . Once the enrichment matured, again B.
scardovii was the dominant microorganism (>65% OTU
based).
Discussion