TY - JOUR
T1 - Heterotrophic carbon metabolism and energy acquisition in Candidatus Thioglobus singularis strain PS1, a member of the SUP05 clade of marine Gammaproteobacteria
AU - Spietz, Rachel L.
AU - Lundeen, Rachel A.
AU - Zhao, Xiaowei
AU - Nicastro, Daniela
AU - Ingalls, Anitra E.
AU - Morris, Robert M.
N1 - Funding Information:
The authors would like to thank members of the Center for Environmental Genomics at the University of Washington for assistance and support during data collection, synthesis and writing of the manuscript, particularly Dr. Gabrielle Rocap for insightful conversations and constructive feedback. This research was funded in part by three grants from the National Science Foundation awarded to R. Morris (OCE-1232840), to R. Morris and A. Ingalls (OCE-1558483), and a Graduate Research Fellowship Program award to R. Spietz. This work was supported by a grant from the Simons Foundation (SF Award 385428, A.E.I.). The cryo-electron tomography data were collected in the UT South-western Cryo-Electron Microscopy Facility, which is funded in part by the CPRIT Core Facility Support Award RP170644.
Funding Information:
The authors would like to thank members of the Center for Environmental Genomics at the University of Washington for assistance and support during data collection, synthesis and writing of the manuscript, particularly Dr. Gabrielle Rocap for insightful conversations and constructive feedback. This research was funded in part by three grants from the National Science Foundation awarded to R. Morris (OCE-1232840), to R. Morris and A. Ingalls (OCE-1558483), and a Graduate Research Fellowship Program award to R. Spietz. This work was supported by a grant from the Simons Foundation (SF Award 385428, A.E.I.). The cryo-electron tomography data were collected in the UT Southwestern Cryo-Electron Microscopy Facility, which is funded in part by the CPRIT Core Facility Support Award RP170644.
Publisher Copyright:
© 2019 Society for Applied Microbiology and John Wiley & Sons Ltd.
PY - 2019/7
Y1 - 2019/7
N2 - A hallmark of the SUP05 clade of marine Gammaproteobacteria is the ability to use energy obtained from reduced inorganic sulfur to fuel autotrophic fixation of carbon using RuBisCo. However, some SUP05 also have the genetic potential for heterotrophic growth, raising questions about the roles of SUP05 in the marine carbon cycle. We used genomic reconstructions, physiological growth experiments and proteomics to characterize central carbon and energy metabolism in Candidatus Thioglobus singularis strain PS1, a representative from the SUP05 clade that has the genetic potential for autotrophy and heterotrophy. Here, we show that the addition of individual organic compounds and 0.2 μm filtered diatom lysate significantly enhanced the growth of this bacterium. This positive growth response to organic substrates, combined with expression of a complete TCA cycle, heterotrophic pathways for carbon assimilation, and methylotrophic pathways for energy conversion demonstrate strain PS1's capacity for heterotrophic growth. Further, our inability to verify the expression of RuBisCO suggests that carbon fixation was not critical for growth. These results highlight the metabolic diversity of the SUP05 clade that harbours both primary producers and consumers of organic carbon in the oceans and expand our understanding of specific pathways of organic matter oxidation by the heterotrophic SUP05.
AB - A hallmark of the SUP05 clade of marine Gammaproteobacteria is the ability to use energy obtained from reduced inorganic sulfur to fuel autotrophic fixation of carbon using RuBisCo. However, some SUP05 also have the genetic potential for heterotrophic growth, raising questions about the roles of SUP05 in the marine carbon cycle. We used genomic reconstructions, physiological growth experiments and proteomics to characterize central carbon and energy metabolism in Candidatus Thioglobus singularis strain PS1, a representative from the SUP05 clade that has the genetic potential for autotrophy and heterotrophy. Here, we show that the addition of individual organic compounds and 0.2 μm filtered diatom lysate significantly enhanced the growth of this bacterium. This positive growth response to organic substrates, combined with expression of a complete TCA cycle, heterotrophic pathways for carbon assimilation, and methylotrophic pathways for energy conversion demonstrate strain PS1's capacity for heterotrophic growth. Further, our inability to verify the expression of RuBisCO suggests that carbon fixation was not critical for growth. These results highlight the metabolic diversity of the SUP05 clade that harbours both primary producers and consumers of organic carbon in the oceans and expand our understanding of specific pathways of organic matter oxidation by the heterotrophic SUP05.
UR - http://www.scopus.com/inward/record.url?scp=85065094878&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85065094878&partnerID=8YFLogxK
U2 - 10.1111/1462-2920.14623
DO - 10.1111/1462-2920.14623
M3 - Article
C2 - 30951247
AN - SCOPUS:85065094878
SN - 1462-2912
VL - 21
SP - 2391
EP - 2401
JO - Environmental Microbiology
JF - Environmental Microbiology
IS - 7
ER -