Systematics and Evolution, Part A The Mycota

12 Tremellomycetes and Related Groups

MICHAELWEISS^1 ,ROBERTBAUER^1 ,JOSE ́PAULOSAMPAIO^2 ,FRANZOBERWINKLER^1

CONTENTS

I. Introduction............................... 331

A. Historical Concepts..................... 332

B. Modern View ........................... 332

II. Morphology and Anatomy................ 332

A. Basidiocarps ............................ 332

B. Micromorphology ...................... 334

C. Ultrastructure........................... 337

III. Life Cycles.................................. 338

A. Dimorphism ............................ 338

B. Deviance from Dimorphism ........... 339

IV. Ecology..................................... 340

A. Mycoparasitism......................... 340

B. Tremellomycetous Yeasts .............. 340

C. Animal and Human Pathogens ........ 344

V. Biotechnological Applications............ 346

VI. Phylogenetic Relationships............... 346

VII. Taxonomy.................................. 347

A. Taxonomy in Flow ..................... 347

B. Taxonomic Synopsis.................... 347

C. Key Groups ............................. 348

1. Cystofilobasidiales ................... 348


2. Filobasidiales......................... 349


3. Holtermanniales. ..................... 349


4. Trichosporonales..................... 349


5. Tremellales ........................... 350
   D. Possibly Related TaxaIncertae Sedis.. 351
   1.Bartheletia............................ 351
   2.Wallemia............................. 351
   VIII. Conclusions................................ 351
   References.................................. 352

I. Introduction

Tremellomycetes is a fungal group full of con-

trasts. It includes jelly fungi with conspicuous

macroscopic basidiomes, such as some species

ofTremella, as well as macroscopically invisible

inhabitants of other fungal fruiting bodies and

a plethora of species known so far only as

asexual yeasts. Tremellomycetes may be benefi-

cial to humans, as exemplified by the produc-

tion of edibleTremellafruiting bodies, which

increased in China alone from 100 MT in 1998

to more than 250,000 MT in 2007 (Chang and

Wasser 2012 ), or extremely harmful, such as the

systemic human pathogenCryptococcus neofor-

mans. The systematics and taxonomy of many

species now contained in Tremellomycetes

have significantly changed during the past

three decades and are about to change again

as a result of changes in the taxonomic treat-

ment of anamorph forms in the International

Code of Nomenclature for algae, fungi, and

plants (McNeill et al. 2012 ). An integrated sys-

tematic view of the Tremellomycetes has been

hampered by the fact that the anamorphic taxa,

i.e., the yeasts, and the basidiome-forming

dimorphic taxa have traditionally been studied

by different scientific communities. Recently,

the group has been discussed in more integra-

tive treatments (e.g., Boekhout et al. 2011 ; Mill-

anes et al. 2011 ; Sampaio 2004 ).

Since the last edition ofThe Mycota,key

systematic concepts in the Basidiomycota have

changed conspicuously. While the tremello-

mycetous groups were then treated in a sepa-

rateHeterobasidiomyceteschapter (Wells and

Bandoni 2001 ), “Heterobasidiomycetes” is no

Dedicated to the memory of Robert Joseph Bandoni
(1926–2009)

(^1) Fachbereich Biologie, Eberhard-Karls-Universita ̈tTu ̈bingen,
Auf der Morgenstelle 1, 72076 Tu ̈bingen, Germany; e-mail:
[email protected];;
(^2) Centro de Recursos Microbiolo ́gicos, Departamento de Cieˆn-
cias da Vida, Universidade Nova de Lisboa, 2829-516 Caparica,
Portugal
Systematics and Evolution, 2ndEdition
The Mycota VII Part A
D.J. McLaughlin and J.W. Spatafora (Eds.)
©Springer-Verlag Berlin Heidelberg 2014