Corrinoids are essential cofactors of reductive dehalogenases in Dehalococcoides mccartyi, an important bacterium in bioremediation, yet sequenced D. mccartyi strains do not possess the complete pathway for de novo corrinoid biosynthesis. Pelosinus sp. and Desulfovibrio sp. have been detected in dechlorinating communities enriched from contaminated groundwater without exogenous cobalamin corrinoid. To investigate the corrinoid-related interactions among key members of these communities, we constructed consortia by growing D. mccartyi strain 195 (Dhc195) in cobalamin-free, trichloroethene (TCE)- and lactate-amended medium in cocultures with Desulfovibrio vulgaris Hildenborough (DvH) or Pelosinus fermentans R7 (PfR7) and with both in tricultures. Only the triculture exhibited sustainable dechlorination and cell growth when a physiological level of 5,6-dimethylbenzimidazole (DMB), the lower ligand of cobalamin, was provided. In the triculture, DvH provided hydrogen while PfR7 provided corrinoids to Dhc195, and the initiation of dechlorination and Dhc195 cell growth was highly dependent on the growth of PfR7. Corrinoid analysis indicated that Dhc195 imported and remodeled the phenolic corrinoids produced by PfR7 into cobalamin in the presence of DMB. Transcriptomic analyses of Dhc195 showed the induction of the CbiZ-dependent corrinoid-remodeling pathway and BtuFCD corrinoid ABC transporter genes during corrinoid salvaging and remodeling. In contrast, another operon annotated to encode a putative iron/cobalamin ABC transporter (DET1174-DET1176) was induced when cobalamin was exogenously provided. Interestingly, a global upregulation of phage-related genes was observed when PfR7 was present. These findings provide insights into both the gene regulation of corrinoid salvaging and remodeling in Dhc195 when it is grown without exogenous cobalamin and microbe-to-microbe interactions in dechlorinating microbial communities.
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http://dx.doi.org/10.1128/AEM.03477-13 | DOI Listing |
J Bacteriol
November 2024
Department of Microbiology, University of Georgia, Athens, Georgia, USA.
Cobamides (Cbas) are cobalt-containing cyclic tetrapyrroles used by cells from all domains of life as co-catalyst of diverse reactions. There are several structural features that distinguish Cbas from one another. The most relevant of those features discussed in this review is the lower ligand, which is the nucleobase of a ribotide located in the lower face of the cyclic tetrapyrrole ring.
View Article and Find Full Text PDFNature
May 2024
Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany.
Cobalamin (vitamin B, herein referred to as B) is an essential cofactor for most marine prokaryotes and eukaryotes. Synthesized by a limited number of prokaryotes, its scarcity affects microbial interactions and community dynamics. Here we show that two bacterial B auxotrophs can salvage different B building blocks and cooperate to synthesize B.
View Article and Find Full Text PDFEnviron Microbiol Rep
April 2024
Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan.
Transplant Cell Ther
February 2023
Blood and Marrow Transplant Program, Rogel Cancer Center, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-5932. Electronic address:
mSystems
August 2022
Department of Plant & Microbial Biology, University of California, Berkeleygrid.47840.3f, Berkeley, California, USA.
All organisms rely on complex metabolites such as amino acids, nucleotides, and cofactors for essential metabolic processes. Some microbes synthesize these fundamental ingredients of life , while others rely on uptake to fulfill their metabolic needs. Although certain metabolic processes are inherently "leaky," the mechanisms enabling stable metabolite provisioning among microbes in the absence of a host remain largely unclear.
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