[Biochemical mechanisms of temperature adaptation in the (+) and (-) strains of Blakeslea trispora].
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.
Feofilova
E P
EP
Tereshina
V M
VM
Memorskaia
A S
AS
D000222:Adaptation, Physiological; D004952:Esters / Q000378:metabolism; D005658:Fungi / Q000378:metabolism / Q000502:physiology*; D019787:Linoleic Acid / Q000378:metabolism; D025282:Mycelium / Q000378:metabolism; D013261:Sterols / Q000378:metabolism; D013402:Sugar Alcohols / Q000378:metabolism; D013696:Temperature; D014199:Trehalose / Q000378:metabolism; D017962:alpha-Linolenic Acid / Q000378:metabolism
D004952:Esters; D013261:Sterols; D013402:Sugar Alcohols; D017962:alpha-Linolenic Acid; D019787:Linoleic Acid; D014199:Trehalose; C014999:arabitol