Complexed cellulase systems allow greater coordination between the different cellulose hydrolyzing enzymes. In aerobic systems, where active aeration and agitation is required, loss of the secreted enzymes and their degradation intermediates might prove detrimental to overall process efficiency. This apparent contradiction might be offset when the energetics of aerobic and anaerobic microorganisms is compared. In general, aerobic microorganisms gain far more energy from glucose than anaerobic microorganisms (38 mole ATP vs. 2-4 mole ATP per mole of glucose). Therefore, the apparently aggressive cellulose hydrolyzing strategy utilized by aerobes might be beneficial given the potential enormous gain in metabolic energy.