Terminal oxidases of <i>Azoarcus</i> sp. BH72, a strictly respiratory diazotroph

Reinhold‐Hurek, Barbara; Zhulin, Igor B.

doi:10.1016/s0014-5793(97)00111-7

Cited by 12 publications

(9 citation statements)

References 44 publications

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“…Previous biochemical studies suggested the existence of a cbb 3 ‐type cytochrome c oxidase in Azoarcus sp. BH72 (Reinhold‐Hurek and Zhulin, ), which has been corroborated by genome sequence analysis (Krause et al ., ). Oxygen tensions in its host plants appear to be sufficiently low to allow nitrogenase gene expression inside roots of Kallar grass (Hurek et al ., ) and rice (Egener et al ., ).…”

Section: Introductionmentioning

confidence: 68%

“…Biochemical evidence for a branched respiratory chain with cytochrome c oxidase and quinol oxidase has already been reported for Azoarcus sp. BH72 (Reinhold‐Hurek and Zhulin, ). Accordingly, three gene clusters encoding for cytochrome oxidases and two encoding for quinol oxidases were found to be present in the genome.…”

Section: Resultsmentioning

confidence: 99%

“…BH72 appears to possess a complex branched respiratory chain. Since aerobic growth was not impeded by the mutation and microaerobic growth only by factor 2, other oxidases such as quinol oxidases found in biochemical (Reinhold‐Hurek and Zhulin, ) and genome (Krause et al ., ) analyses must have partially complemented the function of the cbb 3 ‐type oxidase. Strain BH72 has a strictly respiratory type of metabolism (Reinhold‐Hurek et al ., ).…”

Section: Resultsmentioning

confidence: 99%

“…Membranes were isolated after disruption of cells by French press as previously described (Reinhold‐Hurek and Zhulin, ). Difference spectra were recorded as previously reported (Reinhold‐Hurek and Zhulin, ), either oxidized with air or reduced with Na‐dithionite, on a Shimazdu 3000 spectrophotometer at a band width of 1 nm and a scan speed of 50 nm min −1 .…”

Section: Methodsmentioning

confidence: 99%

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Global expression analysis of the response to microaerobiosis reveals an important cue for endophytic establishment of Azoarcus sp. BH72

Sarkar

Marszałkowska

Schäfer

et al. 2016

Environmental Microbiology

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The endophyte Azoarcus sp. BH72, fixing nitrogen microaerobically, encounters low O tensions in flooded roots. Therefore, its transcriptome upon shift to microaerobiosis was analyzed using oligonucleotide microarrays. A total of 8.7% of the protein-coding genes were significantly modulated. Aerobic conditions induced expression of genes involved in oxidative stress protection, while under microaerobiosis, 233 genes were upregulated, encoding hypothetical proteins, transcriptional regulators, and proteins involved in energy metabolism, among them a cbb -type terminal oxidase contributing to but not essential for N fixation. A newly established sensitive transcriptional reporter system using tdTomato allowed to visualize even relatively low bacterial gene expression in association with roots. Beyond metabolic changes, low oxygen concentrations seemed to prime transcription for plant colonization: Several genes known to be required for endophytic rice interaction were induced, and novel bacterial colonization factors were identified, such as azo1653. The cargo of the type V autotransporter Azo1653 had similarities to the attachment factor pertactin. Although for short term swarming-dependent colonization, it conferred a competitive disadvantage, it contributed to endophytic long-term establishment inside roots. Proteins sharing such opposing roles in the colonization process appear to occur more generally, as we demonstrated a very similar phenotype for another attachment protein, Azo1684. This suggests distinct cellular strategies for endophyte establishment.

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Section: Introductionmentioning

confidence: 68%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Global expression analysis of the response to microaerobiosis reveals an important cue for endophytic establishment of Azoarcus sp. BH72

Sarkar

Marszałkowska

Schäfer

et al. 2016

Environmental Microbiology

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“…Heme extraction and HPLC analysis. Non-covalently-bound hemes were extracted from membrane samples as described previously (23,35,38). Aliquots of membrane preparations were dissolved in 0.5 ml of acetone-HCl (19:1 [vol/vol]) and incubated for 20 min on a rotary mixer.…”

Section: Methodsmentioning

confidence: 99%

Loss of Cytochrome c Oxidase Activity and Acquisition of Resistance to Quinone Analogs in a Laccase-Positive Variant of Azospirillum lipoferum

et al. 1999

Self Cite

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Laccase, a p-diphenol oxidase typical of plants and fungi, has been found recently in a proteobacterium, Azospirillum lipoferum. Laccase activity was detected in both a natural isolate and an in vitro-obtained phase variant that originated from the laccase-negative wild type. In this study, the electron transport systems of the laccase-positive variant and its parental laccase-negative forms were compared. During exponential (but not stationary) growth under fully aerobic (but not under microaerobic) conditions, the laccase-positive variant lost a respiratory branch that is terminated in a cytochrome c oxidase of theaa 3 type; this was most likely due to a defect in the biosynthesis of a heme component essential for the oxidase. The laccase-positive variant was significantly less sensitive to the inhibitory action of quinone analogs and fully resistant to inhibitors of the bc 1 complex, apparently due to the rearrangements of its respiratory system. We propose that the loss of the cytochrome c oxidase-containing branch in the variant is an adaptive strategy to the presence of intracellular oxidized quinones, the products of laccase activity.

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Oxygen: Effect on Marine Microbial Communities

Revsbech

Finster

2003

Encyclopedia of Environmental Microbiology

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Historical Record of O 2 in the Sea Oxygen Toxicity The Distribution of Oxygen in Water and Sediment Oxygen and Photosynthesis Effect of Oxygen on the Iron and Manganese Cycles Oxygen and the Sulfur Cycle Analysis of Oxygen at a Scale Relevant to the World of Microorganisms

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Terminal oxidases of Azoarcus sp. BH72, a strictly respiratory diazotroph

Cited by 12 publications

References 44 publications

Global expression analysis of the response to microaerobiosis reveals an important cue for endophytic establishment of Azoarcus sp. BH72

Global expression analysis of the response to microaerobiosis reveals an important cue for endophytic establishment of Azoarcus sp. BH72

Loss of Cytochrome c Oxidase Activity and Acquisition of Resistance to Quinone Analogs in a Laccase-Positive Variant of Azospirillum lipoferum

Oxygen: Effect on Marine Microbial Communities

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