Relationship between growth behaviour, micro and macroscopic morphologies and freezing sensitivity of the ripening starter Geotrichum candidum is strain specific and mostly related to the morphotypes: the arthrospores/hyphae parameter.
Microscopic conformation, growth behaviour and freezing sensitivity of seven strains of Geotrichum candidum, a ripening starter, were studied and compared according to their macroscopic morphotypes. It has been shown that the thallus forming units (TFU)×ml-1/OD600nm ratio as a function of time is an interesting parameter to follow G. candidum sporulation through the growth behaviour. Microscopic conformation, growth behaviour and freezing sensitivity are clearly strain specific and mostly related to their corresponding morphotypes "yeast", "mould" or "intermediate". The two "mould" strains that sporulate weakly (UCMA103, UCMA499) showed a low survival rate to freezing stress whereas the "yeast" strains expressed a significant resistance owing to the arthrospore abundance. Interestingly, one strain (UCMA96) which appeared on solid medium in accord with the "mould" morphotype respond similarly to freezing stress.
Missous
Ghalia
G
Unité des Microorganismes d'Intérêts Laitier et Alimentaire, IBFA - IFR 146 ICORE, Université de Caen Basse-Normandie, Esplanade de la Paix, 14032 Caen cedex, France.
Thammavongs
Bouachanh
B
Launay
Géraldine
G
Guéguen
Micheline
M
Dieuleveux
Virginie
V
Panoff
Jean-Michel
JM
D000222:Adaptation, Physiological; D005516:Food Microbiology; D005615:Freezing; D005848:Geotrichum / Q000145:classification* / Q000166:cytology* / Q000502:physiology; D025301:Hyphae / Q000502:physiology*; D013172:Spores, Fungal / Q000502:physiology*