63 - Brettanomyces Kufferath & van Laer

Abstract

This chapter focuses on Brettanomyces genus and its member species. Asexual reproduction in this genus occurs either by multilateral budding or, rarely, by bipolar budding in basipetal succession on a narrow base. Its cells are either spheroidal, subglobose to ellipsoidal, frequently ogival, or cylindroidal to elongate. Pseudomycelium is simple or well-developed, and branched, and one-celled, non-septate mycelium may be formed. The cultures grow slowly and are usually short-lived and acetic acid is produced aerobically from glucose. Fermentation is usually stimulated by molecular oxygen and an extraneous vitamin source is required. The member species of this genus include Brettanomyces anomalus, Brettanomyces bruxellensis, Brettanomyces custersianus, Brettanomyces naardenensis, and Brettanomyces nanus. When Brettanomyces custersianus undergoes growth in malt extract for 5 days at 25° C, the cells become ellipsoidal, frequently ogival and cylindroidal to elongate. The cells reproduce by budding, and occur singly, in pairs or in short, occasionally somewhat in branched chains. When Brettanomyces naardenensis undergoes growth in malt extract 5 days at 25° C, the cells become predominantly cylindroidal to elongate, rarely ellipsoidal or ogival, and reproduce by budding.