[3] This species was first described in the genus Saccharomyces as S. marxianus by the Danish mycologist, Emil Christian Hansen from beer wort.

Separation of these clades based on the presence of the WGD event explains why, even though the two species are closely related, fundamental differences exist between them.

[10][11] When grown on Wickerham's Yeast-Mold (YM) agar, the yeast cells appear globose, ellipsoidal or cylindrical, 2–6 x 3–11 μm in size.

[10] In a glucose-yeast extract broth, K. marxianus grows to produce a ring composed of sediment.

In a Dalmau plate culture containing cornmeal agar and Polysorbate 80, K. marxianus forms a rudimentary to branched pseudomycelium with few blastospores.

[13] Kluyveromyces marxianus is an aerobic yeast capable of respiro-fermentative metabolism that consists of simultaneously generating energy from both respiration via the TCA cycle and ethanol fermentation.

[3] K. marxianus is also able to use multiple carbon substrata at the same time making it highly suited to industrial use.

Kluyveromyces marxianus has been isolated in dairy products, sisal leaves, and sewage from sugar manufacturing factories.

[15] Industrial use of K. marxianus is chiefly in the conversion of lactose to ethanol as a precursor for the production of biofuel.

[9] Certain strains of the fungus can also be used to convert whey to ethyl acetate, an alternative fuel source.

In addition, fermentations at higher temperatures occur more rapidly, making production much more efficient.