Carbon isotopic fractionations associated with thermophilic bacteria Thermotoga maritima and Persephonella marina.
Stable carbon isotopes can provide insight into carbon cycling pathways in natural environments. We examined carbon isotope fractionations associated with a hyperthermophilic fermentative bacterium, Thermotoga maritima, and a thermophilic chemolithoautotrophic bacterium Persephonella marina. In T. maritima, phospholipid fatty acids (PLFA) are slightly enriched in 13C relative to biomass (epsilon = 0.1-0.8 per thousand). However, PLFA and biomass are depleted in 13C relative to the substrate glucose by approximately 8 per thousand. In P. marina, PLFA are 1.8-14.5 per thousand enriched in 13C relative to biomass, which suggests that the reversed tricarboxylic acid (TCA) cycle or the 3-hydroxypropionate pathway may be used for CO2 fixation. This is supported by small fractionation between biomass and CO2 (epsilon = -3.8 per thousand to -5.0 per thousand), which is similar to fractionations reported for other organisms using similar CO2 fixation pathways. Identification of the exact pathway will require biochemical assay for specific enzymes associated with the reversed TCA cycle or the 3-hydroxypropionate pathway.
Zhang
Chuanlun L
CL
Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA. zhangcl@missouri.edu
Ye
Qi
Q
Reysenbach
Anna-Louise
AL
Götz
Dorothee
D
Peacock
Aaron
A
White
David C
DC
Horita
Juske
J
Cole
David R
DR
Fong
Jon
J
Pratt
Lisa
L
Fang
Jiasong
J
Huang
Yongsong
Y
D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis*; D005227:Fatty Acids / Q000032:analysis; D013696:Temperature; D020124:Thermotoga maritima / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
D002247:Carbon Isotopes; D005227:Fatty Acids; D002245:Carbon Dioxide