Reviews and compares the major types of bioreactors, defines their pros and cons, and identifies research needs and figures of merit that have yet to be addressedDescribes common modes of operation in bioreactorsCovers the three common bioreactor types, including stirred-tank bioreactors, bubble column bioreactors, and airlift bioreactorsDetails less common bioreactors types, including fixed bed bioreactors and novel bioreactor designsDiscusses advantages and disadvantages of each bioreactor and provides a procedure for optimal bioreactor selection based on current process needsReviews the problems of bioreactor selection globally while considering all bioreactor options rather than concentrating on one specific bioreactor type