Biochemical Mechanisms of Temperature Adaptation in the (+) and (-) Strains of Blakeslea trispora

• Published in: Microbiology (New York) 2005-11, Vol.74 (6), p.650-654
• Main Authors: Feofilova, E. P., Tereshina, V. M., Memorskaya, A. S.
• Format: Article
• Language: English
• Subjects: Blakeslea trispora
• ISSN: 0026-2617; 1608-3237
• DOI: 10.1007/s11021-005-0119-3

Evidence obtained with industrial beta -carotene-superproducing (+)T and (-)T strains, which fail to form zygotes, suggests that the lipids in the mycelium of the (-) strain of Blakeslea trispora lack linolenic acid. This circumstance apparently accounts for the fact that the (+) and (-) strains of B. trispora use different adaptive mechanisms to cope with an increase or decrease in cultivation temperature. In the (+) strain, temperature adaptation is based on changes in the ratio between linoleic and linolenic acyls and, also, involves shortening of acyl chains. In addition, the (+) strain contains a larger amount of protective carbohydrates, such as arabitol and trehalose. This strain is characterized by the presence of glycerol, a cryothermoprotector that protects fungal cells at low temperatures. The (-) strain lacks these biochemical mechanisms, but its neutral lipids contain a comparatively high amount of sterols and their esters. These facts enable us to interpret the enhanced thermotolerance of the (-) strain and its capacity to grow at high temperatures in terms of biochemical adaptation. In the light of the data obtained with wild-type and industrial strains, it is suggested that the lack of linolenic acid in the lipids should be considered an essential sex-specific property of the heterothallic strains of Blakeslea trispora.