Marie Antoine Alexandre Guilliermond (19 August 1876 – 1 April 1945)[1] was a French botanist and mycologist who specialized in cytological studies of the yeasts, fungi, and algae.
He lost his father at a young age and after his mother remarried he grew up as a shy and reticent youth.
He became a lecturer at the University of Paris in 1913 and became a chair of botany at Sorbonne in 1935 where he succeeded Pierre Augustin Dangeard.
[3] Guilliermond identified isogamous copulation in the yeast Zygosaccharomyces chevalieri and the formation of an ascus in Schizosaccharomyces octosporus.
[5] He suggested a taxonomy of yeasts in 1928 with 22 genera which was based on morphology, presence or absence of ascospores and their ability to fermentation specific substrates.