Effect of temperature on sulphate reduction, growth rate and growth yield in five psychrophilic sulphate‐reducing bacteria from Arctic sediments

• Published in: Environmental Microbiology
• Main Authors: Knoblauch, Christian, Jørgensen, Bo Barker
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1999
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.1046/j.1462-2920.1999.00061.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1462-2920.1999.00061.x; http://onlinelibrary.wiley.com/wol1/doi/10.1046/j.1462-2920.1999.00061.x/fullpdf

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.