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Effect of temperature on sulphate reduction, growth rate and growth yield in five psychrophilic sulphate‐reducing bacteria from Arctic sediments
Author(s) -
Knoblauch Christian,
Jørgensen Bo Barker
Publication year - 1999
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1046/j.1462-2920.1999.00061.x
Subject(s) - psychrophile , biology , bacteria , growth rate , yield (engineering) , arctic , bacterial growth , ecology , physics , thermodynamics , genetics , geometry , mathematics
Five psychrophilic sulphate‐reducing bacteria (strains ASv26, LSv21, PSv29, LSv54 and LSv514) isolated from Arctic sediments were examined for their adaptation to permanently low temperatures. All strains grew at −1.8°C, the freezing point of sea water, but their optimum temperature for growth ( T opt ) were 7°C (PSv29), 10°C (ASv26, LSv54) and 18°C (LSv21, LSv514). Although T opt was considerably above the in situ temperatures of their habitats (−1.7°C and 2.6°C), relative growth rates were still high at 0°C, accounting for 25–41% of those at T opt . Short‐term incubations of exponentially growing cultures showed that the highest sulphate reduction rates occurred 2–9°C above T opt . In contrast to growth and sulphate reduction rates, growth yields of strains ASv26, LSv54 and PSv29 were almost constant between −1.8°C and T opt . For strains LSv21 and LSv514, however, growth yields were highest at the lowest temperatures, around 0°C. The results indicate that psychrophilic sulphate‐reducing bacteria are specially adapted to permanently low temperatures by high relative growth rates and high growth yields at in situ conditions.