[2][3][4] In 1926, Kluyver and Hendrick Jean Louis Donker published the now classic paper, "Die Einheit in der Biochemie" ("Unity in Biochemistry").

Kluyver famously expressed the idea with the aphorism: "From elephant to butyric acid bacterium – it is all the same".

Kluyver's best known student, C. B. van Niel, commented on his mentor's scientific influence and noted that by the middle of the 20th century, his work on biochemical unity was no longer cited.

[8] His career was profoundly influenced[clarification needed] by World War II and the Nazi occupation of the Netherlands.

In 1956, botanist Johannes P. Van der Walt published Kluyveromyces, which is a genus of ascomycetous yeasts in the family Saccharomycetaceae and named in Kluyver's honour.