Dataset Information

The physiological opportunism of Desulfitobacterium hafniense strain TCE1 towards organohalide respiration with tetrachloroethene.

ABSTRACT: Desulfitobacterium hafniense strain TCE1 is capable of metabolically reducing tetra- and trichloroethenes by organohalide respiration. A previous study revealed that the pce gene cluster responsible for this process is located on an active composite transposon, Tn-Dha1. In the present work, we investigated the effects on the stability of the transposon during successive subcultivations of strain TCE1 in a medium depleted of tetrachloroethene. At the physiological level, an increased fitness of the population was observed after 9 successive transfers and was correlated with a decrease in the level of production of the PceA enzyme. The latter observation was a result of the gradual loss of the pce genes in the population of strain TCE1 and not of a regulation mechanism, as was postulated previously for a similar phenomenon described for Sulfurospirillum multivorans. A detailed molecular analysis of genetic rearrangements occurring around Tn-Dha1 showed two independent but concomitant events, namely, the transposition of the first insertion sequence, ISDha1-a, and homologous recombination across identical copies of ISDha1 flanking the transposon. A new model is proposed for the genetic heterogeneity around Tn-Dha1 in D. hafniense strain TCE1, along with some considerations for the cleavage mechanism mediated by the transposase TnpA1 encoded by ISDha1.

SUBMITTER: Duret A

PROVIDER: S-EPMC3416639 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The physiological opportunism of Desulfitobacterium hafniense strain TCE1 towards organohalide respiration with tetrachloroethene.

Duret Aurélie A Holliger Christof C Maillard Julien J

Applied and environmental microbiology 20120622 17

Desulfitobacterium hafniense strain TCE1 is capable of metabolically reducing tetra- and trichloroethenes by organohalide respiration. A previous study revealed that the pce gene cluster responsible for this process is located on an active composite transposon, Tn-Dha1. In the present work, we investigated the effects on the stability of the transposon during successive subcultivations of strain TCE1 in a medium depleted of tetrachloroethene. At the physiological level, an increased fitness of t ...[more]

PMID: 22729540

Similar Datasets

Project description:IntroductionDesulfitobacterium hafniense was isolated for its ability to use organohalogens as terminal electron acceptors via organohalide respiration (OHR). In contrast to obligate OHR bacteria, Desulfitobacterium spp. show a highly versatile energy metabolism with the capacity to use different electron donors and acceptors and to grow fermentatively. Desulfitobacterium genomes display numerous and apparently redundant members of redox enzyme families which confirm their metabolic potential. Nonetheless, the enzymes responsible for many metabolic traits are not yet identified.MethodsIn the present work, we conducted an extended proteomic study by comparing the proteomes of Desulfitobacterium hafniense strain DCB-2 cultivated in combinations of electron donors and acceptors, triggering five alternative respiratory metabolisms that include OHR, as well as fermentation. Tandem Mass Tag labelling proteomics allowed us to identify and quantify almost 60% of the predicted proteome of strain DCB-2 (2,796 proteins) in all six growth conditions. Raw data are available via ProteomeXchange with identifier PXD030393.Results and discussionThis dataset was analyzed in order to highlight the proteins that were significantly up-regulated in one or a subset of growth conditions and to identify possible key players in the different energy metabolisms. The addition of sodium sulfide as reducing agent in the medium - a very widespread practice in the cultivation of strictly anaerobic bacteria - triggered the expression of the dissimilatory sulfite reduction pathway in relatively less favorable conditions such as fermentative growth on pyruvate, respiration with H2 as electron donor and OHR conditions. The presence of H2, CO2 and acetate in the medium induced several metabolic pathways involved in carbon metabolism including the Wood-Ljungdahl pathway and two pathways related to the fermentation of butyrate that rely on electron-bifurcating enzymes. While the predicted fumarate reductase appears to be constitutively expressed, a new lactate dehydrogenase and lactate transporters were identified. Finally, the OHR metabolism with 3-chloro-4-hydroxyphenylacetate as electron acceptor strongly induced proteins encoded in several reductive dehalogenase gene clusters, as well as four new proteins related to corrinoid metabolism. We believe that this extended proteomic database represents a new landmark in understanding the metabolic versatility of Desulfitobacterium spp. and provides a solid basis for addressing future research questions.

Project description:Desulfitobacterium hafniense was originally isolated for its ability to use organohalogens as terminal electron acceptors in the process of organohalide respiration (OHR). However, in contrast to obligate OHR bacteria, Desulfitobacterium spp. show a highly versatile energy metabolism with the capacity to use many possible electron donors and acceptors and to grow fermentatively also. The sequencing of several Desulfitobacterium genomes displaying numerous and apparently redundant members of redox enzyme families has confirmed their large metabolic potential. Nonetheless, the enzymes responsible for many metabolic traits are not yet identified. In the present work, we conducted an extended proteomic study by comparing the proteomes of D. hafniense strain DCB-2 cultivated in different combinations of electron donors and acceptors, triggering five alternative respiratory metabolisms that include OHR, as well as fermentation. The Tandem Mass Tag labelling proteomic approach allowed us to identify almost 60% of the predicted proteome of strain DCB-2 in all six growth conditions and to quantify the relative abundance of 2796 proteins. This dataset was analysed in order to highlight the proteins that were up-regulated in one or a subset of growth conditions to identify possible key players in the different energy metabolisms. The addition of sodium sulfide as reducing agent in the medium – a very widespread practice in the cultivation of strictly anaerobic bacteria – triggered the expression of the dissimilatory sulfite reduction pathway in relatively less favourable conditions such as fermentative growth on pyruvate, respiration with H2 as electron donor and OHR conditions. The presence of H2, CO2 and acetate in the medium induced several metabolic pathways involved in carbon metabolism including the Wood-Ljungdahl pathway and two pathways related to the fermentation of butyrate that rely on electron-bifurcating enzymes. While the predicted fumarate reductase appears to be constitutively expressed, a new lactate dehydrogenase and lactate transporters were identified. Finally, the OHR metabolism with 3-chloro-4-hydroxyphenylacetate as electron acceptor strongly induced proteins encoded in several reductive dehalogenase gene clusters including four new proteins, the function of which is discussed. Overall, we believe that this extended proteomic database represents a new landmark in understanding the metabolic versatility of Desulfitobacterium spp. and provides a solid basis for addressing present and future research questions.

Dataset Information

The physiological opportunism of Desulfitobacterium hafniense strain TCE1 towards organohalide respiration with tetrachloroethene.

Publications

The physiological opportunism of Desulfitobacterium hafniense strain TCE1 towards organohalide respiration with tetrachloroethene.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets