scholarly journals Knockout and Overexpression of Pyrroloquinoline Quinone Biosynthetic Genes in Gluconobacter oxydans 621H

2006 ◽  
Vol 188 (21) ◽  
pp. 7668-7676 ◽  
Author(s):  
Tina Hölscher ◽  
Helmut Görisch
Keyword(s):  
Energy Source ◽  
Wild Type Strain ◽  
Gluconobacter Oxydans ◽  
Analysis Data ◽  
Pyrroloquinoline Quinone ◽  
Vital Role ◽  
Reverse Transcription Pcr ◽  
Membrane Bound ◽  
Pqq Biosynthesis

ABSTRACT In Gluconobacter oxydans, pyrroloquinoline quinone (PQQ) serves as the cofactor for various membrane-bound dehydrogenases that oxidize sugars and alcohols in the periplasm. Proteins for the biosynthesis of PQQ are encoded by the pqqABCDE gene cluster. Our reverse transcription-PCR and promoter analysis data indicated that the pqqA promoter represents the only promoter within the pqqABCDE cluster of G. oxydans 621H. PQQ overproduction in G. oxydans was achieved by transformation with the plasmid-carried pqqA gene or the complete pqqABCDE cluster. A G. oxydans mutant unable to produce PQQ was obtained by site-directed disruption of the pqqA gene. In contrast to the wild-type strain, the pqqA mutant did not grow with d-mannitol, d-glucose, or glycerol as the sole energy source, showing that in G. oxydans 621H, PQQ is essential for growth with these substrates. Growth of the pqqA mutant, however, was found with d-gluconate as the energy source. The growth behavior of the pqqA mutant correlated with the presence or absence of the respective PQQ-dependent membrane-bound dehydrogenase activities, demonstrating the vital role of these enzymes in G. oxydans metabolism. A different PQQ-deficient mutant was generated by Tn5 transposon mutagenesis. This mutant showed a defect in a gene with high homology to the Escherichia coli tldD gene, which encodes a peptidase. Our results indicate that the tldD gene in G. oxydans 621H is involved in PQQ biosynthesis, possibly with a similar function to that of the pqqF genes found in other PQQ-synthesizing bacteria.

scholarly journals Cloning and Nucleotide Sequencing of the Membrane-Bound l-Sorbosone Dehydrogenase Gene of Acetobacter liquefaciens IFO 12258 and Its Expression in Gluconobacter oxydans

1995 ◽  
Vol 61 (5) ◽  
pp. 2069-2069
Author(s):  
M Shinjoh ◽  
N Tomiyama ◽  
A Asakura ◽  
T Hoshino
Keyword(s):  
Alcohol Dehydrogenase ◽  
Glucose Dehydrogenase ◽  
Gluconobacter Oxydans ◽  
Pyrroloquinoline Quinone ◽  
Nucleotide Sequencing ◽  
Common Region ◽  
Quinone Binding ◽  
Dehydrogenase Gene ◽  
Membrane Bound

Volume 61, no. 2, p. 419, column 1, lines 15-19: this sentence should read as follows. "The alcohol dehydrogenase and glucose dehydrogenase have a common region reported to be related to pyrroloquinoline quinone binding (2, 10), but SNDH does not contain such a region, indicating that SNDH is not a quinoprotein." Page 419, column 2, line 12: "(Table 4)" should read "(Table 3)." [This corrects the article on p. 413 in vol. 61.].

scholarly journals Membrane-Bound Pyrroloquinoline Quinone-Dependent Dehydrogenase in Gluconobacter oxydans M5, Responsible for Production of 6-(2-Hydroxyethyl) Amino-6-Deoxy-l-Sorbose

2008 ◽  
Vol 74 (16) ◽  
pp. 5250-5253 ◽  
Author(s):  
Xue-Peng Yang ◽  
Liu-Jing Wei ◽  
Jin-Ping Lin ◽  
Bo Yin ◽  
Dong-Zhi Wei
Keyword(s):  
Gene Disruption ◽  
Gluconobacter Oxydans ◽  
Pyrroloquinoline Quinone ◽  
Sorbitol Dehydrogenase ◽  
Antidiabetic Drug ◽  
Dehydrogenase Gene ◽  
Membrane Bound

ABSTRACT A membrane-bound protein purified from Gluconobacter oxydans M5 was confirmed to be a pyrroloquinoline quinone-dependent d-sorbitol dehydrogenase. Gene disruption and complementation experiments demonstrated that this enzyme is responsible for the oxidation of 1-(2-hydroxyethyl) amino-1-deoxy-d-sorbitol (1NSL) to 6-(2-hydroxyethyl) amino-6-deoxy-l-sorbose (6NSE), which is the precursor of an antidiabetic drug, miglitol.

scholarly journals Generation of a Gluconobacter oxydans knockout collection for improved extraction of rare earth elements

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexa M. Schmitz ◽  
Brooke Pian ◽  
Sean Medin ◽  
Matthew C. Reid ◽  
Mingming Wu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Transport System ◽  
Glucose Dehydrogenase ◽  
Single Gene ◽  
Gluconobacter Oxydans ◽  
Pyrroloquinoline Quinone ◽  
Whole Genome ◽  
Membrane Bound ◽  
Specific Transport System

AbstractBioleaching of rare earth elements (REEs), using microorganisms such as Gluconobacter oxydans, offers a sustainable alternative to environmentally harmful thermochemical extraction, but is currently not very efficient. Here, we generate a whole-genome knockout collection of single-gene transposon disruption mutants for G. oxydans B58, to identify genes affecting the efficacy of REE bioleaching. We find 304 genes whose disruption alters the production of acidic biolixiviant. Disruption of genes underlying synthesis of the cofactor pyrroloquinoline quinone (PQQ) and the PQQ-dependent membrane-bound glucose dehydrogenase nearly eliminates bioleaching. Disruption of phosphate-specific transport system genes enhances bioleaching by up to 18%. Our results provide a comprehensive roadmap for engineering the genome of G. oxydans to further increase its bioleaching efficiency.

90 ENDOGENOUS MODIFICATIONS OF AURORA B AND AURORA C KINASE EXPRESSION IN MOUSE OOCYTES AND EARLY EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 146
Author(s):  
C. A. Lima ◽  
V. Huntress ◽  
E. W. Overström
Keyword(s):  
Protein Localization ◽  
Somatic Cells ◽  
Early Embryo ◽  
Vital Role ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Mouse Oocytes ◽  
Reverse Transcription Pcr ◽  
Early Embryos

The Aurora (Aur) proteins are a family of serine/threonine kinases that play fundamental roles in controlling M-phase progression. Previous reports have shown that AurB is vital for proper completion of karyokinesis and cytokinesis in somatic cells. The role of AurC in somatic cells has been found to be much less significant, whereas it appears to play an important role in spermatogenesis. The role of these Aur proteins is not well characterized in mouse oocytes and early embryos. The objective of this study was to assess changes of AurB and AurC mRNA and protein expression in mouse oocytes and early embryos as development progresses through the activation of the zygotic genome. Oocytes and embryos were collected from the oviducts of hormone-stimulated CF-1 mice. After culturing for varying amounts of time, cumulus-denuded samples were either fixed for immunofluorescence microscopy studies or lysed for analysis of mRNA levels through the use of reverse transcription-PCR (RT-PCR). Samples were processed for immunofluorescence using markers of spindle morphology (tubulin) and AurB. Analysis of relative levels of AurB and AurC mRNA were assessed by RT-PCR methods. Marked differences were observed in the localization of AurB when unfertilized oocytes or prezygotic genome activation (ZGA) embryos were compared with post-ZGA samples. There was no evidence of AurB protein localized to the mitotic spindle or resultant midbody in oocyte and early embryo samples. Embryos fixed post-ZGA demonstrated AurB localization, as is conventionally found in somatic cells. The AurB protein was found co-localized with DNA in metaphase stage blastomeres and associated with the midbody in blastomeres near completion of cytokinesis. Relative levels of AurB mRNA were not found to be significantly different when pre- and post-ZGA samples were compared. A significant decrease in relative levels of AurC mRNA was observed in fertilized pre-ZGA samples when compared with unfertilized oocyte counterparts. These observations demonstrate significant differences in the status of AurB and AurC mRNA levels and protein localization in mouse oocytes and early embryos when compared with somatic cells. Given earlier reports showing the vital role of AurC in spermatogenesis, the elevated levels of AurC mRNA observed in prefertilization oocytes may be indicative of a similar role of AurC during oogenesis. Elucidating temporal and localization details of Aur expression is vital to gaining further understanding of cell-cycle regulation in oogenesis and early embryogenesis.

scholarly journals Utilization of d-Lactate as an Energy Source Supports the Growth of Gluconobacter oxydans

2015 ◽  
Vol 81 (12) ◽  
pp. 4098-4110 ◽  
Author(s):  
Binbin Sheng ◽  
Jing Xu ◽  
Yingxin Zhang ◽  
Tianyi Jiang ◽  
Sisi Deng ◽  
...  
Keyword(s):  
Energy Source ◽  
Carbon Source ◽  
Electron Acceptor ◽  
Gluconobacter Oxydans ◽  
The Novel ◽  
Hydroxy Acids ◽  
Lactate Oxidase ◽  
Content Type ◽  
Membrane Bound ◽  
Lactate Dehydrogenases

ABSTRACTd-Lactate was identified as one of the few available organic acids that supported the growth ofGluconobacter oxydans621H in this study. Interestingly, the strain usedd-lactate as an energy source but not as a carbon source, unlike other lactate-utilizing bacteria. The enzymatic basis for the growth ofG. oxydans621H ond-lactate was therefore investigated. Although two putative NAD-independentd-lactate dehydrogenases, GOX1253 and GOX2071, were capable of oxidizingd-lactate, GOX1253 was the only enzyme able to support thed-lactate-driven growth of the strain. GOX1253 was characterized as a membrane-bound dehydrogenase with high activity towardd-lactate, while GOX2071 was characterized as a soluble oxidase with broad substrate specificity towardd-2-hydroxy acids. The latter used molecular oxygen as a direct electron acceptor, a feature that has not been reported previously ind-lactate-oxidizing enzymes. This study not only clarifies the mechanism for the growth ofG. oxydansond-lactate, but also provides new insights for applications of the important industrial microbe and the noveld-lactate oxidase.

scholarly journals Role of Stress Response Sigma Factor SigG in Mycobacterium tuberculosis

2007 ◽  
Vol 190 (3) ◽  
pp. 1128-1133 ◽  
Author(s):  
Jong-Hee Lee ◽  
Deborah E. Geiman ◽  
William R. Bishai
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Sos Response ◽  
Wild Type ◽  
Recognition Sequence ◽  
Reverse Transcription Pcr ◽  
Promoter Recognition ◽  
Microarray Studies

ABSTRACT The sigG gene of Mycobacterium tuberculosis was disrupted by homologous recombination, and the genes regulated by SigG were examined by real-time reverse-transcription PCR and microarray studies. The SigG consensus promoter recognition sequence was identified as GCGNGT-N15-18-CGANCA. A ΔsigG mutant was found to be more resistant to mitomycin C treatment than the wild-type strain, indicating that it may be involved in the SOS response in M. tuberculosis.

The mannitol cycle in Eimeria

Parasitology ◽  
1997 ◽  
Vol 114 (7) ◽  
pp. 81-89 ◽  
Author(s):  
D. M. SCHMATZ
Keyword(s):  
Energy Source ◽  
Vital Role ◽  
Enzyme Complex ◽  
Inhibitory Protein ◽  
Sporulation Process ◽  
Futile Cycling ◽  
High Concentrations ◽  
Mannitol Cycle ◽  
Inhibited Enzyme

A metabolic pathway known as the mannitol cycle has been identified in Eimerian parasites. The pathway is a shunt off of the glycolytic pathway at fructose-6-phosphate (F6P). Two enzymes convert F6P to mannitol and two other enzymes are responsible for converting mannitol back to F6P when it is utilized. Although the pathway is present in various stages of the parasite the most apparent role of this pathway is in the sexual portion of the life cycle, particularly in the formation of oocysts. Extremely high concentrations of mannitol, approaching 0.3 M, are present in unsporulated oocysts. Mannitol functions as the endogenous energy source for oocysts to sporulate in the environment outside of the host. An inhibitory protein which inactivates the first enzyme of the mannitol cycle has been isolated from an oocyst derived inhibited enzyme complex and is believed to prevent the futile cycling of F6P during the maturation of oocysts. Evidence of the vital role of mannitol in the development and maturation of Eimeria tenella oocysts has been facilitated through the use of the drug Nitrophenide™, a known anticoccidial which has now been found to be an inhibitor of one of the enzymes responsible for the biosynthesis of mannitol in the parasite. This compound prevents the formation of oocysts and at lower doses reduces mannitol levels in shed oocysts. In addition, oocysts with reduced mannitol levels fail to complete the sporulation process lending further evidence for this polyol's role in the parasite.

Asiana Airlines Flight 214

2014 ◽  
Vol 4 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Stephanie Chow ◽  
Stephen Yortsos ◽  
Najmedin Meshkati
Keyword(s):  
Human Factors ◽  
Aviation Safety ◽  
Cultural Factors ◽  
Vital Role ◽  
Cultural Issues ◽  
Flight Crew ◽  
Pilot Performance ◽  
Engineering Designs ◽  
Flight Deck

This article focuses on a major human factors–related issue that includes the undeniable role of cultural factors and cockpit automation and their serious impact on flight crew performance, communication, and aviation safety. The report concentrates on the flight crew performance of the Boeing 777–Asiana Airlines Flight 214 accident, by exploring issues concerning mode confusion and autothrottle systems. It also further reviews the vital role of cultural factors in aviation safety and provides a brief overview of past, related accidents. Automation progressions have been created in an attempt to design an error-free flight deck. However, to do that, the pilot must still thoroughly understand every component of the flight deck – most importantly, the automation. Otherwise, if pilots are not completely competent in terms of their automation, the slightest errors can lead to fatal accidents. As seen in the case of Asiana Flight 214, even though engineering designs and pilot training have greatly evolved over the years, there are many cultural, design, and communication factors that affect pilot performance. It is concluded that aviation systems designers, in cooperation with pilots and regulatory bodies, should lead the strategic effort of systematically addressing the serious issues of cockpit automation, human factors, and cultural issues, including their interactions, which will certainly lead to better solutions for safer flights.

Energy Efficiency Analysis in ERA using NFL-BA Algorithm

2020 ◽  
pp. 340-348
Author(s):  
Palky Mehta ◽  
H. L. Sharma
Keyword(s):  
Cluster Head ◽  
Vital Role ◽  
Wireless Sensor ◽  
Energy Usage ◽  
Cluster Heads ◽  
Comparison Results ◽  
Current Scenario ◽  
Energy Efficiency Analysis ◽  
Selection Of

In the current scenario of Wireless Sensor Network (WSN), power consumption is the major issue associated with nodes in WSN. LEACH technique plays a vital role of clustering in WSN and reduces the energy usage effectively. But LEACH has its own limitation in order to search cluster head nodes which are randomly distributed over the network. In this paper, ERA-NFL- BA algorithm is being proposed for selects the cluster heads in WSN. This algorithm help in selection of cluster heads can freely transform from global search to local search. At the end, a comparison has been done with earlier researcher using protocol ERA-NFL, which clearly shown that proposed Algorithm is best suited and from comparison results that ERA-NFL-BA has given better performance.

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