scholarly journals Organohalide-respiringDesulfolunaspecies isolated from marine environments

2019 ◽  
Author(s):  
Peng Peng ◽  
Tobias Goris ◽  
Yue Lu ◽  
Bart Nijsse ◽  
Anna Burrichter ◽  
...  

AbstractThe genusDesulfolunacomprises two anaerobic sulfate-reducing strains,D. spongiiphilaAA1⊤andD. butyratoxydansMSL71⊤of which only the former was shown to perform organohalide respiration (OHR). Here we isolated a third member of this genus from marine intertidal sediment, designedD. spongiiphilastrain DBB. All threeDesulfolunastrains harbour three reductive dehalogenase gene clusters (rdhABC) and corrinoid biosynthesis genes in their genomes. Brominated but not chlorinated aromatic compounds were dehalogenated by all three strains. TheDesulfolunastrains maintained OHR in the presence of 20 mM sulfate or 20 mM sulfide, which often negatively affect OHR. Strain DBB sustained OHR with 2% oxygen in the gas phase, in line with its genetic potential for reactive oxygen species detoxification. Reverse transcription-quantitative PCR (RT-qPCR) revealed differential induction ofrdhAgenes in strain DBB in response to 1,4-dibromobenzene or 2,6-dibromophenol. Proteomic analysis confirmed differential expression ofrdhA1with 1,4-dibromobenzene, and revealed a possible electron transport chain from lactate dehydrogenases and pyruvate oxidoreductase to RdhA1 via menaquinones and either RdhC, or Fix complex (electron transfer flavoproteins), or Qrc complex (Type-1 cytochrome c3:menaquinone oxidoreductase).

2020 ◽  
Vol 14 (3) ◽  
pp. 815-827 ◽  
Author(s):  
Peng Peng ◽  
Tobias Goris ◽  
Yue Lu ◽  
Bart Nijsse ◽  
Anna Burrichter ◽  
...  

AbstractThe genus Desulfoluna comprises two anaerobic sulfate-reducing strains, D. spongiiphila AA1T and D. butyratoxydans MSL71T, of which only the former was shown to perform organohalide respiration (OHR). Here we isolated a third strain, designated D. spongiiphila strain DBB, from marine intertidal sediment using 1,4-dibromobenzene and sulfate as the electron acceptors and lactate as the electron donor. Each strain harbors three reductive dehalogenase gene clusters (rdhABC) and corrinoid biosynthesis genes in their genomes, and dehalogenated brominated but not chlorinated organohalogens. The Desulfoluna strains maintained OHR in the presence of 20 mM sulfate or 20 mM sulfide, which often negatively affect other organohalide-respiring bacteria. Strain DBB sustained OHR with 2% oxygen in the gas phase, in line with its genetic potential for reactive oxygen species detoxification. Reverse transcription-quantitative PCR revealed differential induction of rdhA genes in strain DBB in response to 1,4-dibromobenzene or 2,6-dibromophenol. Proteomic analysis confirmed expression of rdhA1 with 1,4-dibromobenzene, and revealed a partially shared electron transport chain from lactate to 1,4-dibromobenzene and sulfate, which may explain accelerated OHR during concurrent sulfate reduction. Versatility in using electron donors, de novo corrinoid biosynthesis, resistance to sulfate, sulfide and oxygen, and concurrent sulfate reduction and OHR may confer an advantage to marine Desulfoluna strains.


2021 ◽  
Vol 31 (1) ◽  
pp. 36-56
Author(s):  
Vanessa Schnaars ◽  
Lars Wöhlbrand ◽  
Sabine Scheve ◽  
Christina Hinrichs ◽  
Richard Reinhardt ◽  
...  

The genus Desulfonema belongs to the deltaproteobacterial family Desulfobacteraceae and comprises marine, sulfate-reducing bacteria that form filaments and move by gliding. This study reports on the complete, manually annotated genomes of Dn. limicola 5ac10T (6.91 Mbp; 6,207 CDS) and Dn. magnum 4be13T (8.03 Mbp; 9,970 CDS), integrated with substrate-specific proteome profiles (8 vs. 11). The richness in mobile genetic elements is shared with other Desulfobacteraceae members, corroborating horizontal gene transfer as major driver in shaping the genomes of this family. The catabolic networks of Dn. limicola and Dn. magnum have the following general characteristics: 98 versus 145 genes assigned (having genomic shares of 1.7 vs. 2.2%), 92.5 versus 89.7% proteomic coverage, and scattered gene clusters for substrate degradation and energy metabolism. The Dn. magnum typifying capacity for aromatic compound degradation (e.g., p-cresol, 3-phenylpropionate) requires 48 genes organized in operon-like structures (87.7% proteomic coverage; no homologs in Dn. limicola). The protein complements for aliphatic compound degradation, central pathways, and energy metabolism are highly similar between both genomes and were identified to a large extent (69–96%). The differential protein profiles revealed a high degree of substrate-specificity for peripheral reaction sequences (forming central intermediates), agreeing with the high number of sensory/regulatory proteins predicted for both strains. By contrast, central pathways and modules of the energy metabolism were constitutively formed under the tested substrate conditions. In accord with their natural habitats that are subject to fluctuating changes of physicochemical parameters, both Desulfonema strains are well equipped to cope with various stress conditions. Next to superoxide dismutase and catalase also desulfoferredoxin and rubredoxin oxidoreductase are formed to counter exposure to molecular oxygen. A variety of proteases and chaperones were detected that function in maintaining cellular homeostasis upon heat or cold shock. Furthermore, glycine betaine/proline betaine transport systems can respond to hyperosmotic stress. Gliding movement probably relies on twitching motility via type-IV pili or adventurous motility. Taken together, this proteogenomic study demonstrates the adaptability of Dn. limicola and Dn. magnum to its dynamic habitats by means of flexible catabolism and extensive stress response capacities.


2009 ◽  
Vol 192 (5) ◽  
pp. 1410-1415 ◽  
Author(s):  
Minoru Tanigawa ◽  
Tomomitsu Shinohara ◽  
Katsushi Nishimura ◽  
Kumiko Nagata ◽  
Morio Ishizuka ◽  
...  

ABSTRACT Helicobacter pylori is a microaerophilic bacterium associated with gastric inflammation and peptic ulcers. Knowledge of how pathogenic organisms produce energy is important from a therapeutic point of view. We found d-amino acid dehydrogenase-mediated electron transport from d-proline or d-alanine to oxygen via the respiratory chain in H. pylori. Coupling of the electron transport to ATP synthesis was confirmed by using uncoupler reagents. We reconstituted the electron transport chain to demonstrate the electron flow from the d-amino acids to oxygen using the recombinant cytochrome bc 1 complex, cytochrome c-553, and the terminal oxidase cytochrome cbb 3 complex. Upon addition of the recombinant d-amino acid dehydrogenase and d-proline or d-alanine to the reconstituted electron transport system, reduction of cytochrome cbb 3 and oxygen consumption was revealed spectrophotometrically and polarographically, respectively. Among the constituents of H. pylori's electron transport chain, only the cytochrome bc 1 complex had been remained unpurified. Therefore, we cloned and sequenced the H. pylori NCTC 11637 cytochrome bc 1 gene clusters encoding Rieske Fe-S protein, cytochrome b, and cytochrome c 1, with calculated molecular masses of 18 kDa, 47 kDa, and 32 kDa, respectively, and purified the recombinant monomeric protein complex with a molecular mass of 110 kDa by gel filtration. The absorption spectrum of the recombinant cytochrome bc 1 complex showed an α peak at 561 nm with a shoulder at 552 nm.


1987 ◽  
Vol 33 (11) ◽  
pp. 1006-1010 ◽  
Author(s):  
Gerrit Voordouw ◽  
Helen M. Kent ◽  
John R. Postgate

Cloned genes encoding cytochrome c3 and hydrogenase from Desulfovibrio vulgaris Hildenborough have been used to probe the genomes of 15 other desulfovibrios. The D. vulgaris strains Wandle and Brockhurst Hill cannot be distinguished from the Hildenborough strain by Southern hybridization using either probe, indicating similar genomes. Desulfovibrio vulgaris Groningen is completely different and lacks homologous cytochrome c3 and hydrogenase genes. The genomes of D. vulgaris ssp. oxamicus Monticello and D. desulfuricans strains El Agheila Z, Berre sol, and Canet 41 contain genes encoding a homologous but not identical periplasmic hydrogenase and cytochrome c3. Weak hybridization was observed with the cytochrome c3 gene probe for genomes of seven other sulfate-reducing bacteria, which reflects the known amino acid sequence divergence of cytochrome c3 in Desulfovibrio. The hydrogenase gene probe shows weak hybridization to the DNA from two strains of D. salexigens only, while the gene may be absent from D. vulgaris Groningen, two strains of D. africanus, D. thermophilus, D. gigas, and D. desulfuricans strains Norway and Teddington R. In desulfovibrios carrying cryptic plasmids the cytochrome c3 and hydrogenase genes are apparently chromosomal.


2005 ◽  
Vol 3 (1-2) ◽  
pp. 81-91 ◽  
Author(s):  
Alejandro López-Cortés ◽  
Sergey Bursakov ◽  
Angelo Figueiredo ◽  
Anders E. Thapper ◽  
Smilja Todorovic ◽  
...  

2007 ◽  
Vol 189 (8) ◽  
pp. 3156-3165 ◽  
Author(s):  
Arunima Mishra ◽  
Asis Das ◽  
John O. Cisar ◽  
Hung Ton-That

ABSTRACT Two types of adhesive fimbriae are expressed by Actinomyces; however, the architecture and the mechanism of assembly of these structures remain poorly understood. In this study we characterized two fimbrial gene clusters present in the genome of Actinomyces naeslundii strain MG-1. By using immunoelectron microscopy and biochemical analysis, we showed that the fimQ-fimP-srtC1-fimR gene cluster encodes a fimbrial structure (designated type 1) that contains a major subunit, FimP, forming the shaft and a minor subunit, FimQ, located primarily at the tip. Similarly, the fimB-fimA-srtC2 gene cluster encodes a distinct fimbrial structure (designated type 2) composed of a shaft protein, FimA, and a tip protein, FimB. By using allelic exchange, we constructed an in-frame deletion mutant that lacks the SrtC2 sortase. This mutant produces abundant type 1 fimbriae and expresses the monomeric FimA and FimB proteins, but it does not assemble type 2 fimbriae. Thus, SrtC2 is a fimbria-specific sortase that is essential for assembly of the type 2 fimbriae. Together, our experiments pave the way for several lines of molecular investigation that are necessary to elucidate the fimbrial assembly pathways in Actinomyces and their function in the pathogenesis of different biofilm-related oral diseases.


2007 ◽  
Vol 73 (9) ◽  
pp. 2990-2999 ◽  
Author(s):  
Massimo Marzorati ◽  
Francesca de Ferra ◽  
Hilde Van Raemdonck ◽  
Sara Borin ◽  
Elena Allifranchini ◽  
...  

ABSTRACT A mixed culture dechlorinating 1,2-dichloroethane (1,2-DCA) to ethene was enriched from groundwater that had been subjected to long-term contamination. In the metagenome of the enrichment, a 7-kb reductive dehalogenase (RD) gene cluster sequence was detected by inverse and direct PCR. The RD gene cluster had four open reading frames (ORF) showing 99% nucleotide identity with pceB, pceC, pceT, and orf1 of Dehalobacter restrictus strain DSMZ 9455T, a bacterium able to dechlorinate chlorinated ethenes. However, dcaA, the ORF encoding the catalytic subunit, showed only 94% nucleotide and 90% amino acid identity with pceA of strain DSMZ 9455T. Fifty-three percent of the amino acid differences were localized in two defined regions of the predicted protein. Exposure of the culture to 1,2-DCA and lactate increased the dcaA gene copy number by 2 log units, and under these conditions the dcaA and dcaB genes were actively transcribed. A very similar RD gene cluster with 98% identity in the dcaA gene sequence was identified in Desulfitobacterium dichloroeliminans strain DCA1, the only known isolate that selectively dechlorinates 1,2-DCA but not chlorinated ethenes. The dcaA gene of strain DCA1 possesses the same amino acid motifs as the new dcaA gene. Southern hybridization using total genomic DNA of strain DCA1 with dcaA gene-specific and dcaB- and pceB-targeting probes indicated the presence of two identical or highly similar dehalogenase gene clusters. In conclusion, these data suggest that the newly described RDs are specifically adapted to 1,2-DCA dechlorination.


2021 ◽  
Author(s):  
Juan David Guzman ◽  
Andreas Vilcinskas

Abstract Acetobacteraceae is an economically important family of bacteria that is used for industrial fermentation in the food/feed sector and for the preparation of sorbose and bacterial cellulose. It comprises two major groups: acetous species (acetic acid bacteria) associated with flowers, fruits and insects, and acidophilic species, a phylogenetically basal and physiologically heterogeneous group inhabiting acid or hot springs, sludge, sewage and freshwater environments. Despite the biotechnological importance of the family Acetobacteraceae, the literature does not provide any information about its ability to produce specialized metabolites. We therefore constructed a phylogenomic tree based on concatenated protein sequences from 127 type strains of the family and predicted the presence of small-molecule biosynthetic gene clusters (BGCs) using the antiSMASH tool. This dual approach allowed us to associate certain biosynthetic pathways with particular taxonomic groups. We found that acidophilic and acetous species contain on average ~6 and ~3.4 BGCs per genome, respectively. All the Acetobacteraceae strains encoded proteins associated involved in hopanoid biosynthesis, with many also featuring genes encoding type-1 and type-3 polyketide and non-ribosomal peptide synthases, and enzymes for aryl polyene, lactone and ribosomal peptide biosynthesis. Our in silico analysis indicated that the family Acetobacteraceae is a potential source of many undiscovered bacterial metabolites and deserves more detailed experimental exploration.


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