Agarases are classified as either α-agarases or β-agarases based upon whether they degrade α or β linkages in agarose, breaking them into oligosaccharides.
When secreted, α-agarases yield oligosaccharides with 3.6 anhydro-L-galactose at the reducing end whereas β-agarases result in D-galactose residues.
From species within genus Vibrio[4] to Alteromonas,[5] the presence of agarase allows agar-degrading bacteria an abundant food source in the ocean.
Research also demonstrates that glucose can inhibit extracellular agarase secretion (but not transcription), causing it to degrade within the cell and thus limit growth of the bacteria.
[6] This further highlights the niche which this class of bacteria usually occupies, as the concentration of glucose or phosphate in the ocean is very low while magnesium concentration is generally much higher, suiting the agar-degrading bacteria’s agarase production; there is simply no need to use glucose in the ocean, so many organisms don't.