In {TAIL ~ a microbial fuel cell}, {HEAD ~ the transgenic microbes} have access to a feedstock 
In
In { TAIL ~ a microbial fuel cell } , { HEAD ~ the transgenic microbes } have access to a feedstock
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH