Before revision: <ref> Cite journal |last1=He |first1=Shaomei |last2=McMahon |first2=Katherine D. |date=2011-02-21 |title=Microbiology of Candidatus accumulibacter in activated sludge URL |journal=Microbial Biotechnology |volume=4 |issue=5 |pages=603–619 |doi=10.1111/j.1751-7915.2011.00248.x |pmid=21338476 |pmc=3819010 |issn=1751-7915 </ref> Formerly considered the most important PAO in waste treatment, the bacteria is highly abundant in wastewater treatment plants globally.
After revision:  Formerly considered the most important PAO in waste treatment, the bacteria is highly abundant in wastewater treatment plants globally.