KLUYVER S CONTRIBUTIONS TO MICROBIOLOGY AND BIOCHEMISTRY 



[Kluyver and Becking, 1955] groups, and of the nitrate-reducing 

 sporeforming bacteria [Verhoeven, 1950, 1952Tb] contain valuable 

 information relating bacterial taxonomy to ecology; to this category 

 may be added Elazari-Volcani's [1939] investigation of Ps. indigo/era. 



Kluyver s contributions to classification are not restricted to the bac- 

 terial kingdom, however. Through his early studies with yeasts he 

 maintained a profound interest in this group of organisms. He had in- 

 herited Beijerinck's culture collection which included many yeasts, 

 and soon after assuming his duties as Professor of Microbiology Kluy- 

 ver arranged with Professor Johanna Westerdijk, Director of the re- 

 nowned 'Central Bureau of Fungus Cultures' * in Baarn, Holland, to 

 have the yeasts represented in the Baarn collection transferred to the 

 Delft institute. Thus was established what is probably the world's 

 most outstanding collection of yeast pure cultures. It has served as the 

 basis for a series of monographs on the yeasts [Stelling-Dekker, 1931 Th ; 

 Lodder, 1934Tb; Diddens and Lodder, 1942; Lodder and Kreger-van 

 Rij, 1952] comprising the best so far published in this field. The prin- 

 ciples guiding the development of an up-to-date system of yeast classifi- 

 cation, adopted in these treatises, can be found in Kluyver's publication 

 of 1 93 1 which has also been included in this volume. 



Before the first of these monographs had appeared, Kluyver's ex- 

 tensive knowledge of microbiological literature and his keen scient- 

 ific insight had permitted him to recognize the curious phenomenon 

 of mirror-image formation by certain pink yeasts when cultivated on 

 solid media in an inverted position as associated with a mechanism of 

 spore discharge that is characteristically encountered among the basi- 

 diomycetes. This suggested that, contrary to the universally held 

 opinion, not all yeasts should be considered as primitive or reduced 

 ascomycetes, but rather that the basidiomycetes also embrace a fully 

 comparable series of progressively more complex fungi whose simplest 

 representatives are the typical yeasts for which the genus Sporobolomyces 

 was created [Kluyver and Van Niel, 1925, 1927]. 



Similarly, Kluyver's wide experience and microbiological acuity 

 were responsible for the recognition that organisms described by 

 certain specialists as new yeast species or even genera, were, in reality, 



* A note on the history of the Central Bureau of Fungus Cultures has been published 

 by K. B. Raper in Mycologia 49, 884 [1957]. 



145 



