scholarly journals The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis

2021 ◽  
Vol 22 (11) ◽  
pp. 5628
Author(s):  
Valquíria Campos Alencar ◽  
Juliana de Fátima dos Santos Silva ◽  
Renata Ozelami Vilas Boas ◽  
Vinícius Manganaro Farnézio ◽  
Yara N. L. F. de Maria ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Quorum Sensing ◽  
Ethanol Production ◽  
N2 Fixation ◽  
Energy Demand ◽  
Zymomonas Mobilis ◽  
Biomass Accumulation ◽  
High Energy ◽  
Gram Negative ◽  
Expression Of Genes

Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.

Simultaneous nitrogen fixation and ethanol production by Zymomonas mobilis

2020 ◽  
Vol 314-315 ◽  
pp. 41-52
Author(s):  
Suriya Palamae ◽  
Wanna Choorit ◽  
Tawan Chatsungnoen ◽  
Yusuf Chisti
Keyword(s):  
Nitrogen Fixation ◽  
Ethanol Production ◽  
Zymomonas Mobilis

Acidosis (Measured by Nuclear Magnetic Resonance) and Ethanol Production in Anoxic Goldfish Acclimated to 5 and 20°C

1991 ◽  
Vol 159 (1) ◽  
pp. 387-405
Author(s):  
AREN VAN WAARDE ◽  
INGRID DE GRAAFF ◽  
GUIDO VAN DEN THILLART ◽  
CEES ERKELENS
Keyword(s):  
Creatine Kinase ◽  
Alcohol Dehydrogenase ◽  
Ethanol Production ◽  
Energy Demand ◽  
White Muscle ◽  
High Energy ◽  
Rapid Decline ◽  
Kinetic Properties ◽  
Time Courses ◽  
Sudden Decrease

Goldfish acclimated to 20 and 5°C were subjected to anoxia (3 h at 20°C and 18 h at 5°C). The intracellular pH (pHi) and the levels of high-energy phosphate compounds in the epaxial muscle were continuously monitored by in vivo31P-n. m.r. spectroscopy. Free [ADP] was calculated from n.m.r.-measured reactants of the creatine kinase reaction and the creatine kinase equilibrium constant. A rapid initial drop in pHi was followed by a sudden decrease in the rate of development of acidosis. Similar biphasic time courses were observed for the increases in the levels of free ADP and inorganic phosphate and the decrease in phosphocreatine concentration. In a parallel series of experiments, fish were placed in the flow cell of the n.m.r. probe (outside the magnet) and anesthetized after different anoxic intervals. Metabolites in red muscle, white muscle and blood were then assayed, using classical biochemical techniques. The transition to a less rapid decline in pH appears to be primarily due to a suppression of energy demand and activation of H+ extrusion; ethanol production becomes significant only after longer periods of anoxia. Anoxic exposure has no influence on the kinetic properties of muscle alcohol dehydrogenase, but acclimation of goldfish to low temperature increases alcohol dehydrogenase activity in white muscle. Note: Present address: PET Center, Academic Hospital, Groningen University, PO Box 30.001, 9700RB Groningen, The Netherlands.

Changes in lipid peroxidation during pregnancy and after delivery in rats: effect of pinealectomy

Reproduction ◽  
2000 ◽  
pp. 143-149 ◽  
Author(s):  
RM Sainz ◽  
RJ Reiter ◽  
JC Mayo ◽  
J Cabrera ◽  
DX Tan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Oxidative Damage ◽  
Energy Demand ◽  
Physiological State ◽  
High Energy ◽  
Free Radical Scavengers ◽  
Radical Scavengers ◽  
Oxygen Requirement ◽  
Pregnant Rats

Pregnancy is a physiological state accompanied by a high energy demand of many bodily functions and an increased oxygen requirement. Because of the increased intake and utilization of oxygen, increased levels of oxidative stress would be expected. In the present study, the degree of lipid peroxidation was examined in different tissues from non-pregnant and pregnant rats after the delivery of their young. Melatonin and other indole metabolites are known to be direct free radical scavengers and indirect antioxidants. Thus the effect of pinealectomy at 1 month before pregnancy on the accumulation of lipid damage was investigated in non-pregnant and pregnant rats after the delivery of their young. Malonaldehyde and 4-hydroxyalkenal concentrations were measured in the lung, uterus, liver, brain, kidney, thymus and spleen from intact and pinealectomized pregnant rats soon after birth of their young and at 14 and 21 days after delivery. The same parameters were also evaluated in intact and pinealectomized non-pregnant rats. Shortly after delivery, lipid oxidative damage was increased in lung, uterus, brain, kidney and thymus of the mothers. No differences were detected in liver and spleen. Pinealectomy enhanced this effect in the uterus and lung. It is concluded that during pregnancy high levels of oxidative stress induce an increase in oxidative damage to lipids, which in some cases is inhibited by the antioxidative actions of pineal indoles.

scholarly journals IoT Platform for Energy Sustainability in University Campuses

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 357
Author(s):  
Pedro Moura ◽  
José Ignacio Moreno ◽  
Gregorio López López ◽  
Manuel Alvarez-Campana
Keyword(s):  
Energy Demand ◽  
New Technologies ◽  
Low Cost ◽  
Sustainable Use ◽  
High Energy ◽  
Appropriate Technology ◽  
Monitoring And Control ◽  
Energy Sustainability ◽  
University Campuses ◽  
Iot Platform

University campuses are normally constituted of large buildings responsible for high energy demand, and are also important as demonstration sites for new technologies and systems. This paper presents the results of achieving energy sustainability in a testbed composed of a set of four buildings that constitute the Telecommunications Engineering School of the Universidad Politécnica de Madrid. In the paper, after characterizing the consumption of university buildings for a complete year, different options to achieve more sustainable use of energy are presented, considering the integration of renewable generation sources, namely photovoltaic generation, and monitoring and controlling electricity demand. To ensure the implementation of the desired monitoring and control, an internet of things (IoT) platform based on wireless sensor network (WSN) infrastructure was designed and installed. Such a platform supports a smart system to control the heating, ventilation, and air conditioning (HVAC) and lighting systems in buildings. Furthermore, the paper presents the developed IoT-based platform, as well as the implemented services. As a result, the paper illustrates how providing old existing buildings with the appropriate technology can contribute to the objective of transforming such buildings into nearly zero-energy buildings (nZEB) at a low cost.

scholarly journals Sigma-1 Receptor Promotes Mitochondrial Bioenergetics by Orchestrating ER Ca2+ Leak during Early ER Stress

Metabolites ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 422
Author(s):  
Zhanat Koshenov ◽  
Furkan E. Oflaz ◽  
Martin Hirtl ◽  
Johannes Pilic ◽  
Olaf A. Bachkoenig ◽  
...  
Keyword(s):  
Er Stress ◽  
Energy Demand ◽  
Molecular Mechanisms ◽  
High Energy ◽  
Human Neuroblastoma Cell ◽  
Mitochondrial Bioenergetics ◽  
Dependent Manner ◽  
Human Neuroblastoma ◽  
Sigma 1 Receptor ◽  
Sigma 1

The endoplasmic reticulum (ER) is a complex, multifunctional organelle of eukaryotic cells and responsible for the trafficking and processing of nearly 30% of all human proteins. Any disturbance to these processes can cause ER stress, which initiates an adaptive mechanism called unfolded protein response (UPR) to restore ER functions and homeostasis. Mitochondrial ATP production is necessary to meet the high energy demand of the UPR, while the molecular mechanisms of ER to mitochondria crosstalk under such stress conditions remain mainly enigmatic. Thus, better understanding the regulation of mitochondrial bioenergetics during ER stress is essential to combat many pathologies involving ER stress, the UPR, and mitochondria. This article investigates the role of Sigma-1 Receptor (S1R), an ER chaperone, has in enhancing mitochondrial bioenergetics during early ER stress using human neuroblastoma cell lines. Our results show that inducing ER stress with tunicamycin, a known ER stressor, greatly enhances mitochondrial bioenergetics in a time- and S1R-dependent manner. This is achieved by enhanced ER Ca2+ leak directed towards mitochondria by S1R during the early phase of ER stress. Our data point to the importance of S1R in promoting mitochondrial bioenergetics and maintaining balanced H2O2 metabolism during early ER stress.

scholarly journals Anti-biofilm and Virulence Factor-Reducing Activities of Essential Oils and Oil Components as a Possible Option for Bacterial Infection Control

Planta Medica ◽  
2020 ◽  
Vol 86 (08) ◽  
pp. 520-537 ◽  
Author(s):  
Jürgen Reichling
Keyword(s):  
Quorum Sensing ◽  
Essential Oil ◽  
Essential Oils ◽  
Virulence Factor ◽  
Model Organisms ◽  
Regulation System ◽  
Expression Of Genes ◽  
Reporter Strains ◽  
Violacein Production ◽  
Essential Oil Compounds

AbstractPathogenic biofilm-associated bacteria that adhere to biological or nonbiological surfaces are a big challenge to the healthcare and food industries. Antibiotics or disinfectants often fail in an attempt to eliminate biofilms from those surfaces. Based on selected experimental research, this review deals with the potential biofilm-inhibiting, virulence factor-reducing, and biofilm-eradicating activities of essential oils and single essential oil compounds using Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Chromobacterium violaceum as model organisms. In addition, for the bacteria reviewed in this overview, different essential oils and essential oil compounds were reported to be able to modulate the expression of genes that are involved in the formation of autoinducer molecules, biofilms, and virulence factors. The anti-quorum sensing activity of some essential oils and single essential oil compounds was demonstrated using the gram-negative bacterium C. violaceum. Reporter strains of this bacterium produce the violet-colored compound violacein whose synthesis is regulated by quorum sensing autoinducer molecules called acylhomeserinlactones. Of great interest was the discovery that enantiomeric monoterpenes affected the quorum sensing regulation system in different ways. While the (+)-enantiomers of carvone, limonene, and borneol increased violacein formation, their (−)-analogues inhibited violacein production.For the successful eradication of biofilms and the bacteria living inside them, it is absolutely necessary that the lipophilic volatile substances can penetrate into the aqueous channels of biofilms. As shown in recent work, hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds with antibacterial effects may contribute to overcome this problem.

scholarly journals Ethanol Production from Glucose and Xylose by Immobilized Zymomonas mobilis CP4(pZB5)

2000 ◽  
Vol 84-86 (1-9) ◽  
pp. 525-542 ◽  
Author(s):  
Mahesh S. Krishnan ◽  
Maria Blanco ◽  
Christopher K. Shattuck ◽  
Nhuan P. Nghiem ◽  
Brian H. Davison
Keyword(s):  
Ethanol Production ◽  
Zymomonas Mobilis

Field Conversion of a Low-Firing Frame 7B Gas Turbine Power Plant to Ultra-Low Emission Combustion

2015 ◽  
Author(s):  
Nicolas Demougeot ◽  
Jeffrey A. Benoit
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Energy Demand ◽  
Water Injection ◽  
Cost Benefit ◽  
High Energy ◽  
Nox Emissions ◽  
Environmental Controls ◽  
Low Emission ◽  
Technical Discussion

The search for power plant sustainability options continues as regulating agencies exert more stringent industrial gas turbine emission requirements on operators. Purchasing power for resale, de-commissioning current capabilities altogether and repowering by replacing or converting existing equipment to comply with emissions standards are economic-driven options contemplated by many mature gas turbine operators. NRG’s Gilbert power plant based in Milford, NJ began commercial operation in 1974 and is fitted with four (4) natural gas fired GE’s 7B gas turbine generators with two each exhausting to HRSG’s feeding one (1) steam turbine generator. The gas turbine units, originally configured with diffusion flame combustion systems with water injection, were each emitting 35 ppm NOx with the New Jersey High Energy Demand Day (HEED) regulatory mandate to reduce NOx emissions to sub 10 ppm by May 1st, 2015. Studies were conducted by the operator to evaluate the economic viability & installation of environmental controls to reduce NOx emissions. It was determined that installation of post-combustion environmental controls at the facility was both cost prohibitive and technically challenging, and would require a fundamental reconfiguration of the facility. Based on this economic analysis, the ultra-low emission combustion system conversion package was selected as the best cost-benefit solution. This technical paper will focus on the ultra low emissions technology and key features employed to achieve these low emissions, a description of the design challenges and solution to those, a summary of the customer considerations in down selecting options and an overview of the conversion scope. Finally, a technical discussion of the low emissions operational flexibility will be provided including performance results of the converted units.

scholarly journals Draft Genome Sequence of Pantoea sp. Strain A4, a Rafflesia-Associated Bacterium That ProducesN-Acylhomoserine Lactones as Quorum-Sensing Molecules

2012 ◽  
Vol 194 (23) ◽  
pp. 6610-6610 ◽  
Author(s):  
Kar-Wai Hong ◽  
Han Ming Gan ◽  
Siew-Moon Low ◽  
Patrick Kok Yuen Lee ◽  
Yee-Meng Chong ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Content Type ◽  
First Time

ABSTRACTPantoeasp. strain A4 is a Gram-negative bacterium isolated from theRafflesiaflower. We present here, for the first time, the genome sequence ofRafflesia-associatedPantoeasp. strain A4, which exhibited quorum-sensing activity.

scholarly journals LGK974 suppresses lipopolysaccharide-induced endotoxemia in mice by modulating the crosstalk between the Wnt/β-catenin and NF-κB pathways

2021 ◽  
Vol 53 (3) ◽  
pp. 407-421
Author(s):  
Jaewoong Jang ◽  
Jaewon Song ◽  
Hyunji Lee ◽  
Inae Sim ◽  
Young V. Kwon ◽  
...  
Keyword(s):  
Animal Model ◽  
Survival Rate ◽  
Wnt Pathway ◽  
Cytokine Production ◽  
Cytokine Storm ◽  
Plasma Cytokine ◽  
Gram Negative ◽  
Multiple Organs ◽  
Expression Of Genes ◽  
Cytokine Levels

AbstractEndotoxemia, a type of sepsis caused by gram-negative bacterial endotoxin [i.e., lipopolysaccharide (LPS)], is associated with manifestations such as cytokine storm; failure of multiple organs, including the liver; and a high mortality rate. We investigated the effect and mechanism of action of LGK974, a Wnt signaling inhibitor, in mice with LPS-induced endotoxemia, an animal model of sepsis. LGK974 significantly and dose-dependently increased the survival rate and reduced plasma cytokine levels in mice with LPS-induced endotoxemia. Transcriptome analysis of liver tissues revealed significant changes in the expression of genes associated with the Wnt pathway as well as cytokine and NF-κB signaling during endotoxemia. LGK974 treatment suppressed the activation of NF-κB signaling and cytokine expression as well as the Wnt/β-catenin pathway in the livers of endotoxemic mice. Coimmunoprecipitation of phospho-IκB and β-transducin repeat-containing protein (β-TrCP) was increased in the livers of endotoxemic mice but was reduced by LGK974 treatment. Moreover, LGK974 treatment decreased the coimmunoprecipitation and colocalization of β-catenin and NF-κB, which were elevated in the livers of endotoxemic mice. Our results reveal crosstalk between the Wnt/β-catenin and NF-κB pathways via interactions between β-TrCP and phospho-IκB and between β-catenin and NF-κB during endotoxemia. The results of this study strongly suggest that the crosstalk between the Wnt/β-catenin and NF-κB pathways contributes to the mutual activation of these two pathways during endotoxemia, which results in amplified cytokine production, liver damage and death, and that LGK974 suppresses this vicious amplification cycle by reducing the crosstalk between these two pathways.

Sign in / Sign up

Export Citation Format

Share Document