{TAIL ~ The presence} of various different microorganisms in {HEAD ~ a single culture} is generally referred to as a mixed culture 
{ TAIL ~ The presence } of various different microorganisms in { HEAD ~ a single culture } is generally referred to as a mixed culture
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH