Growth, lipid accumulation, and fatty acid composition in obligate psychrophilic, facultative psychrophilic, and mesophilic yeasts.
Obligate psychrophilic, facultative psychrophilic, and mesophilic yeasts were cultured in a carbon-rich medium at different temperatures to investigate whether growth parameters, lipid accumulation, and fatty acid (FA) composition were adaptive and/or acclimatory responses. Acclimation of facultative psychrophiles and mesophiles to a lower temperature decreased their specific growth rate, but did not affect their biomass yield (Y(X/S)). Obligate and facultative psychrophiles exhibited the highest Y(X/S). Acclimation to lower temperature decreased the lipid yield (Y(L/X)) in mesophilic yeasts, but did not affect Y(L/X) in facultative psychrophilic ones. Similar Y(L/X) were found in both groups of psychrophiles, suggesting that lipid accumulation is not a distinctive characteristic of adaptation to permanently cold environments. The unsaturation of FAs was one major adaptive feature of the yeasts colonizing permanently cold ecosystems. Remarkable amounts of alpha-linolenic acid were found in obligate psychrophiles at the expense of linoleic acid, whereas it was scarce or absent in all the other strains. Increased unsaturation of FAs was also a general acclimatory response of facultative psychrophiles to a lower temperature. These results improve the knowledge of the responses enabling psychrophilic yeasts to cope with the cold and may be of support for potential biotechnological exploitation of these strains.
Rossi
Maddalena
M
Department of Chemistry, University of Modena and Reggio Emilia, 41100 Modena, Italy, rossi.maddalena@unimore.it
Buzzini
Pietro
P
Cordisco
Lisa
L
Amaretti
Alberto
A
Sala
Maurizio
M
Raimondi
Stefano
S
Ponzoni
Chiara
C
Pagnoni
Ugo Maria
UM
Matteuzzi
Diego
D
D000064:Acclimatization; D003080:Cold Temperature; D005227:Fatty Acids / Q000096:biosynthesis*; D050356:Lipid Metabolism; D015003:Yeasts / Q000254:growth & development* / Q000378:metabolism*; D017962:alpha-Linolenic Acid / Q000096:biosynthesis
D005227:Fatty Acids; D017962:alpha-Linolenic Acid