scholarly journals Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization

2013 ◽  
Vol 79 (24) ◽  
pp. 7807-7817 ◽  
Author(s):  
Andres Abin-Fuentes ◽  
Magdy El-Said Mohamed ◽  
Daniel I. C. Wang ◽  
Kristala L. J. Prather
Keyword(s):  
Dose Response ◽  
Rhodococcus Erythropolis ◽  
Oil Industry ◽  
Current Standard ◽  
Content Type ◽  
Promising Technology ◽  
Resting Cell ◽  
4S Pathway ◽  
Microbial Desulfurization ◽  
Inhibitory Interactions

ABSTRACTMicrobial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity concomitant with the accumulation of the end product, 2-hydroxybiphenyl (HBP), during the process. BDS experiments were performed by incubatingRhodococcus erythropolisIGTS8 resting-cell suspensions with hexadecane at 0.50 (vol/vol) containing 10 mM dibenzothiophene. The resin Dowex Optipore SD-2 was added to the BDS experiments at resin concentrations of 0, 10, or 50 g resin/liter total volume. The HBP concentration within the cytoplasm was estimated to decrease from 1,100 to 260 μM with increasing resin concentration. Despite this finding, productivity did not increase with the resin concentration. This led us to focus on the susceptibility of the desulfurization enzymes toward HBP. Dose-response experiments were performed to identify major inhibitory interactions in the most common BDS pathway, the 4S pathway. HBP was responsible for three of the four major inhibitory interactions identified. The concentrations of HBP that led to a 50% reduction in the enzymes' activities (IC50s) for DszA, DszB, and DszC were measured to be 60 ± 5 μM, 110 ± 10 μM, and 50 ± 5 μM, respectively. The fact that the IC50s for HBP are all significantly lower than the cytoplasmic HBP concentration suggests that the inhibition of the desulfurization enzymes by HBP is responsible for the observed reduction in biocatalyst activity concomitant with HBP generation.

Canada-US ties will see fewer irritants under Biden

2021 ◽  
Keyword(s):  
United States ◽  
Prime Minister ◽  
Oil Industry ◽  
The United States ◽  
Donald Trump ◽  
Federal Election ◽  
Content Type ◽  
Un Peacekeeping ◽  
Keystone Xl ◽  
Keystone Xl Pipeline

Significance Canada’s Liberal Prime Minister Justin Trudeau is preparing to welcome a more predictable and stable partner in Biden than outgoing Republican President Donald Trump. However, Biden is also expected quickly to cancel the Keystone XL pipeline, cutting another lifeline to Canada’s oil industry and creating some strain in Canada-US ties. Impacts Improved Canada-US ties will persist even if Trudeau loses the next federal election to Conservative Erin O’Toole. Canada will re-engage militarily with UN peacekeeping and NATO deployments. Trudeau will encourage Biden to end US prosecution of Meng Wanzhou, allowing Canada to release her; Biden may agree. Canada’s border with the United States will open in stages as COVID-19 recedes. Ottawa will push Biden to end ‘Buy American’ procurement policies, with little success.

Oil will drive record Guyana growth again in 2022

2021 ◽  
Keyword(s):  
Climate Change ◽  
Oil And Gas ◽  
National Development ◽  
Oil Industry ◽  
Medium Term ◽  
Content Type ◽  
Development Plans ◽  
The Government ◽  
Wage Increases ◽  
Oil And Gas Sector

Significance As in 2020 and 2021, this projected growth will be driven by the ongoing expansion of the oil and gas sector, and related investment and state revenues. These rising revenues will support the government’s ambitious national development plans, which include both increased social and infrastructure spending. Impacts The government will prioritise enhancing the oil and gas investment framework. Investment into joint oil and gas infrastructure with Suriname will benefit the growing oil industry in both countries. The expansionary fiscal policy may lead to a rise in inflation, leading to further calls for wage increases. In the medium term, strong growth in the oil and gas sector could lead to increased climate change activism in the country.

scholarly journals High-Dose Rifamycins Enable Shorter Oral Treatment in a Murine Model ofMycobacterium ulceransDisease

2018 ◽  
Vol 63 (2) ◽  
pp. e01478-18 ◽  
Author(s):  
Till F. Omansen ◽  
Deepak Almeida ◽  
Paul J. Converse ◽  
Si-Yang Li ◽  
Jin Lee ◽  
...  
Keyword(s):  
Oral Treatment ◽  
Buruli Ulcer ◽  
Indirect Costs ◽  
Ceiling Effect ◽  
Mycobacterium Ulcerans ◽  
High Dose ◽  
Current Standard ◽  
Standard Regimen ◽  
Content Type ◽  
Dose Dependent

ABSTRACTBuruli ulcer (BU), caused byMycobacterium ulcerans, is a neglected tropical skin and soft tissue infection that is associated with disability and social stigma. The mainstay of BU treatment is an 8-week course of rifampin (RIF) at 10 mg/kg of body weight and 150 mg/kg streptomycin (STR). Recently, the injectable STR has been shown to be replaceable with oral clarithromycin (CLR) for smaller lesions for the last 4 weeks of treatment. A shorter, all-oral, highly efficient regimen for BU is needed, as the long treatment duration and indirect costs currently burden patients and health systems. Increasing the dose of RIF or replacing it with the more potent rifamycin drug rifapentine (RPT) could provide such a regimen. Here, we performed a dose-ranging experiment of RIF and RPT in combination with CLR over 4 weeks of treatment in a mouse model ofM. ulceransdisease. A clear dose-dependent effect of RIF on both clinical and microbiological outcomes was found, with no ceiling effect observed with tested doses up to 40 mg/kg. RPT-containing regimens were more effective onM. ulcerans. All RPT-containing regimens achieved culture negativity after only 4 weeks, while only the regimen with the highest RIF dose (40 mg/kg) did so. We conclude that there is dose-dependent efficacy of both RIF and RPT and that a ceiling effect is not reached with the current standard regimen used in the clinic. A regimen based on higher rifamycin doses than are currently being evaluated against tuberculosis in clinical trials could shorten and improve therapy of Buruli ulcer.

Dose—response tolerance of the visual pathways and cranial nerves of the cavernous sinus to stereotactic radiosurgery

1998 ◽  
Vol 88 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Klaus A. Leber ◽  
Jutta Berglöff ◽  
Gerhard Pendl
Keyword(s):  
Stereotactic Radiosurgery ◽  
Cavernous Sinus ◽  
Dose Response ◽  
Cranial Nerves ◽  
Visual Pathways ◽  
Content Type ◽  
Number Of Patients ◽  
Response Tolerance ◽  
Fine Print

As the number of patients treated with stereotactic radiosurgery increases, it becomes particularly important to define with precision adverse effects on distinct structures of the nervous system. Object. This study was designed to assess the dose—response tolerance of the visual pathways and cranial nerves after exposure of the cavernous sinus to radiation. Methods. A total of 66 sites in the visual system and 210 cranial nerves of the middle cranial fossa were investigated in 50 patients who had undergone gamma knife treatment for benign skull base tumors. The mean follow-up period was 40 months (range 24–60 months). Follow-up examinations consisted of neurological, neuroradiological, and neuroophthalmological evaluations. The actuarial incidence of optic neuropathy was zero for patients who received a radiation dose of less than 10 Gy, 26.7% for patients receiving a dose in the range of 10 to less than 15 Gy, and 77.8% for those who received doses of 15 Gy or more (p < 0.0001). Previously impaired vision improved in 25.8% and was unchanged in 51.5% of patients. No sign of neuropathy was seen in patients whose cranial nerves of the cavernous sinus received radiation doses of between 5 and 30 Gy. Because tumor control appeared to have been achieved in 98% of the patients, the deterioration in visual function cannot be attributed to tumor progression. Conclusions. The structures of the visual pathways (the optic nerve, chiasm, and tract) exhibit a much higher sensitivity to single-fraction radiation than other cranial nerves, and their particular dose—response characteristics can be defined. In contrast, the oculomotor and trigeminal nerves have a much higher dose tolerance.

Rhodococcus spelaei sp. nov., isolated from a cave, and proposals that Rhodococcus biphenylivorans is a later synonym of Rhodococcus pyridinivorans, Rhodococcus qingshengii and Rhodococcus baikonurensis are later synonyms of Rhodococcus erythropolis, and Rhodococcus percolatus and Rhodococcus imtechensis are later synonyms of Rhodococcus opacus

2021 ◽  
Vol 71 (7) ◽  
Author(s):  
Soon Dong Lee ◽  
In Seop Kim
Keyword(s):  
Type Species ◽  
Gene Sequence ◽  
Sequence Similarity ◽  
Rhodococcus Erythropolis ◽  
Rhodococcus Opacus ◽  
Rrna Gene ◽  
The Novel ◽  
Rrna Gene Sequence ◽  
Content Type ◽  
Link Type

Two novel actinobacterial strains, designated C9-5T and C3-43, were isolated from soil samples of a cave in Jeju Island, Republic of Korea, and subjected to taxonomic study by a polyphasic approach. The organisms exhibited a typical rod–coccus developmental cycle during growth and grew at 10–30 °C, pH 5–9 and 0–3 % (w/v) NaCl. In 92 single-copy core gene sequence analysis, strain C9-5T was loosely associated with Rhodococcus tukisamuensis , albeit sharing low 16S rRNA gene sequence similarity (97.4 %). A combination of morphological and chemotaxonomic characteristics supported assignment with the genus Rhodococcus . With respect to 16S rRNA gene sequence similarity, the novel isolates showed the highest identity to the type strain of Rhodococcus subtropicus (98.7 % sequence similarity), followed by Rhodococcus olei (98.5 %) and Rhodococcus pedocola (98.4 %).The average nucleotide identity and digital DNA–DNA hybridization values between strain C9-5T and members of the genus Rhodococcus were ≤81.5 and ≤37.1 %, respectively. A set of physiological and chemotaxonomic properties together with overall genomic relatedness differentiated the novel isolates from members of the genus Rhodococcus , for which the name Rhodococcus spelaei sp. nov. is proposed. The type strain is C9-5T (=KACC 19822T=DSM 107558T). Based on genome analysis performed here, it is also proposed that Rhodococcus biphenylivorans Su et al. 2015 is a later heterotypic synonym of Rhodococcus pyridinivorans Yoon et al. 2000, Rhodococcus qingshengii Xu et al. 2007 and Rhodococcus baikonurensis Li et al. 2004 are later heterotypic synonyms of Rhodococcus erythropolis (Gray and Thornton 1928) Goodfellow and Alderson 1979 (Approved Lists 1980), and Rhodococcus percolatus Briglia et al. 1996 and Rhodococcus imtechensis Ghosh et al. 2006 are later heterotypic synonyms of Rhodococcus opacus Klatte et al. 1995.

Sustainability strategy of Indonesian and Malaysian palm oil industry: a qualitative analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ratna Wardhani ◽  
Yan Rahadian
Keyword(s):  
Palm Oil ◽  
Stakeholder Engagement ◽  
Business Models ◽  
Oil Industry ◽  
Social Strategies ◽  
Content Type ◽  
Oil Companies ◽  
Sustainability Strategies ◽  
Sustainability Strategy ◽  
Study Results

Purpose Global palm oil production is growing rapidly, especially in Southeast Asia, with Indonesia and Malaysia as the biggest producers. Despite significant contributions to these countries’ economies, environmental and social aspects continue to be debated within this industry. The sustainability strategy is very important for the palm oil industry. This study aims to explore the sustainability strategy using six elements, namely, stakeholder engagement, governance and leadership, sustainability view and the economic, environmental and social strategies of Indonesian and Malaysian palm oil companies. Design/methodology/approach This study observes 21 Indonesian palm oil companies and 44 Malaysian palm oil companies from 2014 to 2018 with a total observation of 280 firm years. The methodology used in this study is a qualitative content analysis of six themes based on the sustainability strategy elements, which was further developed into 40 indicators. Content analysis is carried out on information published in annual reports and sustainability reports. Findings The study results indicate that stakeholder engagement, governance and leadership and strategic view of the palm oil companies in Indonesia and Malaysia are still likely to be weak. Palm oil companies have not demonstrated their focus on implementing economic, environmental and social strategies. Although the results indicate that there is a greater emphasis on environmental and social strategies than on economic issues, attention to both issues is still very low. Practical implications Palm oil companies need to integrate sustainability strategies in their business models and communicate them well to stakeholders to increase their competitive advantage in the palm oil industry. The government also needs to issue stricter rules and incentives to encourage companies to implement sustainability strategies. Social implications The study results provide implications for the communities around palm oil plantations to provide better social control so that companies can implement sustainability strategies in their business processes. Originality/value This study highlights the importance of sustainability practices integrated into palm oil companies’ business models, which have not been well implemented in the palm oil industry in the world’s largest producing countries.

Foreign powers jockey for position in Libya

2021 ◽  
Keyword(s):  
Oil Industry ◽  
Status Quo ◽  
Armed Groups ◽  
Content Type

Significance The outcomes of these meetings may indicate the dynamics of external states' future behaviour, which will shape domestic developments until elections are held on December 24. Impacts Turkish investment in Libya will increase, strengthening Ankara’s foothold. Greece and Egypt will be most affected by Turkish dominance in Libya and both will seek to undermine any status quo that supports it. The new government will rely on oil money to secure support from the various armed groups and constituencies. Investment in the oil industry will rise as government provides support to repair and upgrade infrastructure and increase output.

scholarly journals Genome Sequence of Rhodococcus erythropolis Type Strain JCM 3201

2019 ◽  
Vol 8 (14) ◽  
Author(s):  
Keitaro Yoshida ◽  
Wataru Kitagawa ◽  
Koji Ishiya ◽  
Yasuo Mitani ◽  
Nobutaka Nakashima ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Expression ◽  
Genome Sequence ◽  
Recombinant Proteins ◽  
Type Strain ◽  
Rhodococcus Erythropolis ◽  
Content Type

Rhodococcus erythropolis JCM 3201 can express several recombinant proteins that are difficult to express in Escherichia coli. It is used as one of the hosts for protein expression and bioconversion.

scholarly journals In VitroandIn VivoActivities of Zinc Linolenate, a Selective Antibacterial Agent againstHelicobacter pylori

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Yanqiang Huang ◽  
Xudong Hang ◽  
Xueqing Jiang ◽  
Liping Zeng ◽  
Jia Jia ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Therapeutic Potential ◽  
Combined Therapy ◽  
Peptic Ulcers ◽  
Current Standard ◽  
Gastric Diseases ◽  
Content Type ◽  
H Pylori

ABSTRACTHelicobacter pyloriis a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment forH. pyloriinfection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment ofH. pyloriinfection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates ofH. pyloriin vitrowith no development of resistance during continuous serial passaging. The mechanisms of ZnLla action againstH. pyloriinvolved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistantH. pyloriinfection, ZnLla showedin vivokilling efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla forH. pyloriprovides an attractive candidate for novel targeted anti-H. pyloritreatment.

scholarly journals Interference with Pseudomonas aeruginosa Quorum Sensing and Virulence by the Mycobacterial Pseudomonas Quinolone Signal Dioxygenase AqdC in Combination with the N-Acylhomoserine Lactone Lactonase QsdA

2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Franziska S. Birmes ◽  
Ruth Säring ◽  
Miriam C. Hauke ◽  
Niklas H. Ritzmann ◽  
Steffen L. Drees ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Rhodococcus Erythropolis ◽  
Quorum Quenching ◽  
Signal Molecules ◽  
Content Type ◽  
Acylhomoserine Lactone ◽  
Regulatory Effects ◽  
Epithelial Lung Cells

ABSTRACT The nosocomial pathogen Pseudomonas aeruginosa regulates its virulence via a complex quorum sensing network, which, besides N-acylhomoserine lactones, includes the alkylquinolone signal molecules 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal [PQS]) and 2-heptyl-4(1H)-quinolone (HHQ). Mycobacteroides abscessus subsp. abscessus, an emerging pathogen, is capable of degrading the PQS and also HHQ. Here, we show that although M. abscessus subsp. abscessus reduced PQS levels in coculture with P. aeruginosa PAO1, this did not suffice for quenching the production of the virulence factors pyocyanin, pyoverdine, and rhamnolipids. However, the levels of these virulence factors were reduced in cocultures of P. aeruginosa PAO1 with recombinant M. abscessus subsp. massiliense overexpressing the PQS dioxygenase gene aqdC of M. abscessus subsp. abscessus, corroborating the potential of AqdC as a quorum quenching enzyme. When added extracellularly to P. aeruginosa cultures, AqdC quenched alkylquinolone and pyocyanin production but induced an increase in elastase levels. When supplementing P. aeruginosa cultures with QsdA, an enzyme from Rhodococcus erythropolis which inactivates N-acylhomoserine lactone signals, rhamnolipid and elastase levels were quenched, but HHQ and pyocyanin synthesis was promoted. Thus, single quorum quenching enzymes, targeting individual circuits within a complex quorum sensing network, may also elicit undesirable regulatory effects. Supernatants of P. aeruginosa cultures grown in the presence of AqdC, QsdA, or both enzymes were less cytotoxic to human epithelial lung cells than supernatants of untreated cultures. Furthermore, the combination of both aqdC and qsdA in P. aeruginosa resulted in a decline of Caenorhabditis elegans mortality under P. aeruginosa exposure.

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