The bioreactor contains methanotrophic microorganisms which convert {HEAD ~ the organic contaminants} into {TAIL ~ mainly carbon dioxide} 
into
The bioreactor contains methanotrophic microorganisms which convert { HEAD ~ the organic contaminants } into { TAIL ~ mainly carbon dioxide }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL