Microbes may obtain energy from {TAIL ~ a feedstock} or {HEAD ~ material} through a metabolic process 
Microbes may obtain energy from { TAIL ~ a feedstock } or { HEAD ~ material } through a metabolic process
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH