Bacterial cyanide degradation is under review: Pseudomonas pseudoalcaligenes CECT5344, a case of an alkaliphilic cyanotroph

2011 ◽  
Vol 39 (1) ◽  
pp. 269-274 ◽  
Author(s):  
Victor M. Luque-Almagro ◽  
Rafael Blasco ◽  
Manuel Martínez-Luque ◽  
Conrado Moreno-Vivián ◽  
Francisco Castillo ◽  
...  

There are thousands of areas in the U.S.A. and Europe contaminated with cyanide-containing wastes as a consequence of a large number of industrial activities such as gold mining, steel and aluminium manufacturing, electroplating and nitrile pesticides used in agriculture. Chemical treatments to remove cyanide are expensive and generate other toxic products. By contrast, cyanide biodegradation constitutes an appropriate alternative treatment. In the present review we provide an overview of how cells deal in the presence of the poison cyanide that irreversible binds to metals causing, among other things, iron-deprivation conditions outside the cell and metalloenzymes inhibition inside the cell. In this sense, several systems must be present in a cyanotrophic organism, including a siderophore-based acquisition mechanism, a cyanide-insensitive respiratory system and a cyanide degradation/assimilation pathway. The alkaliphilic autochthonous bacterium Pseudomonas pseudocaligenes CECT5344 presents all these requirements with the production of siderophores, a cyanide-insensitive bd-related cytochrome [Cio (cyanide-insensitive oxidase)] and a cyanide assimilation pathway that generates ammonium, which is further incorporated into organic nitrogen.

2007 ◽  
Vol 9 (6) ◽  
pp. 1541-1549 ◽  
Author(s):  
Victor M. Luque-Almagro ◽  
María J. Huertas ◽  
M. Dolores Roldán ◽  
Comrado Moreno-Vivián ◽  
Manuel Martínez-Luque ◽  
...  

2020 ◽  
Vol 2 (4) ◽  
pp. 136-140
Author(s):  
Clara Rodrigues Pereira ◽  
Lílian Lefol Nani Guarieiro

Studies show that exposure to particulate matter (PM) from vehicular combustion processes can pose severe risks to human health since the impact degree of PM on the respiratory system will depend on its size and composition. Thus, the objective of this study was to perform a systematic review on this topic, searching information that can highlight causes and solutions that may allow a greater understanding of this problem. We concluded that China is a country that stands out in the number of deaths caused by the emission of PM, given a highly polluted urban scenario. Besides, fine particles (PM2.5) are the most recurrent incidence of respiratory disease, as they are emitted mainly by industrial activities and vehicular emissions.


2011 ◽  
Vol 39 (6) ◽  
pp. 1854-1858 ◽  
Author(s):  
Gracia Becerra ◽  
Rafael Blasco ◽  
Alberto Quesada ◽  
Faustino Merchán ◽  
M. Isabel Igeño

Pseudomonas pseudoalcaligenes CECT5344 can be used in cyanide bioremediation processes because it grows at pH 9.5 using 2.0 mM cyanide at the sole nitrogen source. Cyanide strongly binds to metals creating iron-deprivation conditions. The bacterium responds to the presence of cyanide by inducing several processes such as siderophore synthesis for iron capture, cyanide-insensitive respiration system and defence mechanisms against oxidative stress. Since high concentrations of cyanide cause iron deficiency and because iron is an essential nutrient, bacterial growth in the presence of cyanide requires an efficient iron uptake. Fur is a global transcription factor that regulates a diversity of biological processes such as iron homoeostasis, TCA (tricarboxylic acid) cycle metabolism and oxidative stress response. Fur's regulation of iron uptake and storage genes should play a significant role in the lives of these bacteria. In the present review, current knowledge of Fur is summarized.


2018 ◽  
Vol 16 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Sandra Sherif Amer ◽  
Maha Nasr ◽  
Wael Mamdouh ◽  
Omaima Sammour

Among the common myths in the cosmetics industry is the perception that acne only happens to teenagers, and specifically to females. However, acne is neither limited to a specific age, nor to a certain gender, it creates a stressful problem for many people. Many chemical treatments for acne were proven to be successful, but when administered as such, they showed many adverse effects, starting from itching to skin dryness and inflammation. Natural remedies have also been explored for acne treatment, and despite their safety, they suffered many stability problems attributed to their physicochemical properties, creating an obstacle for their topical delivery. Therefore, many nanocarriers were used to deliver those chemical and natural remedies topically to maximize their therapeutic potential in acne treatment. The present review discusses the different nanocarriers which were proven successful in improving the acne lesions, focusing on vesicular, lipidic, and polymeric systems.


2010 ◽  
Vol 179 (1-3) ◽  
pp. 72-78 ◽  
Author(s):  
M.J. Huertas ◽  
L.P. Sáez ◽  
M.D. Roldán ◽  
V.M. Luque-Almagro ◽  
M. Martínez-Luque ◽  
...  

2006 ◽  
Vol 34 (1) ◽  
pp. 152-155 ◽  
Author(s):  
M.-J. Huertas ◽  
V.M. Luque-Almagro ◽  
M. Martínez-Luque ◽  
R. Blasco ◽  
C. Moreno-Vivián ◽  
...  

Cyanide is one of the most potent and toxic chemicals produced by industry. The jewellery industry of Córdoba (Spain) generates a wastewater (residue) that contains free cyanide, as well as large amounts of cyano–metal complexes. Cyanide is highly toxic to living systems because it forms very stable complexes with transition metals that are essential for protein function. In spite of its extreme toxicity, some organisms have acquired mechanisms to avoid cyanide poisoning. The biological assimilation of cyanide needs the concurrence of three separate processes: (i) a cyanide-insensitive respiratory chain, (ii) a system for iron acquisition (siderophores) and (iii) a cyanide assimilation pathway. Siderophores are low-molecular-mass compounds (600–1500 Da) that scavenge iron (Fe3+) ions (usually with extremely high affinity) from the environment under iron-limiting conditions. There are two main classes of siderophores: catechol and hydroxamate types. The catechol-type siderophores chelate ferric ion via a hydroxy group, whereas the hydroxamate-type siderophores bind iron via a carbonyl group with the adjacent nitrogen. In the presence of cyanide, bacterial proliferation requires this specific metal uptake system because siderophores are able to break down cyano–metal complexes. Pseudomonas pseudoalcaligenes CECT5344 is able to use free cyanide or cyano–metal complexes as nitrogen source. A proteomic approach was used for the isolation and identification, in this strain, of a protein that was induced in the presence of cyanide, namely CN0, that is involved in siderophore biosynthesis in response to cyanide. An overview of bacterial cyanide degradation pathways and the involvement of siderophores in this process are presented.


2016 ◽  
Vol 7 ◽  
pp. 27-37
Author(s):  
AVNISH K. UPADHYAY ◽  
KAUSHAL KUMAR

In Ayurveda, Asthma is known as 'Shwas Roga'. Samprapti (Pathogenesis) of the Shwas Roga according to Ayurveda is the vitiated 'Pranvayu' combined with vitiated 'Kapha dosha' in the lungs causing obstruction in the 'Pranavaha srotasa' (Respiratory system). This results in gasping and laboured breathing which is known as 'Shwas Roga'. Asthma is a chronic illness involving the respiratory system in which the airway occasionally constricts, becomes inflamed, and is lined with excessive amounts of mucus, often in response to one or more triggers. These episodes precipitate by exposure to an environmental stimulant (or allergen), cold air, warm air, moist air, exercise or exertion, or emotional stress. Ayurvedic medicines are very safe and cure the problem to a great extent. Researchers of various disciplines are working on this problem to find out the solutions. Various modern means and measures have been discovered in this regard. Even then the effective drug without any side-effects has not been established yet. Ayurveda is the rich source of the therapeutic measures that can control the disease. Out of such therapeutic measures, various herbs, poly-herbal and herbo-mineral compounds were selected in different studies for the benefit of the increasing number of asthma patients and have been found to be effective. The aims of the present review are to establish the importance of Ethno-medicinal and Ayurvedic approach in the management and treatment of Asthma and explore any new interventions needed.


2005 ◽  
Vol 33 (1) ◽  
pp. 168-169 ◽  
Author(s):  
V.M. Luque-Almagro ◽  
R. Blasco ◽  
M.J. Huertas ◽  
M. Martínez-Luque ◽  
C. Moreno-Vivián ◽  
...  

Pseudomonas pseudoalcaligenes CECT5344 uses cyanide, cyanate, β-cyanoalanine, and other cyanoderivatives as nitrogen sources under alkaline conditions, which prevents volatile HCN (pKa 9.2) formation. The cyanide consumed by this strain is stoichiometrically converted into ammonium. In addition, this bacterium grows with the heavy metal, cyanide-containing waste water generated by the jewellery industry, and is also a cyanide-resistant strain which induces an alternative oxidase and a siderophore-based mechanism for iron acquisition in the presence of cyanide. The detection of cyanase and β-cyanoalanine nitrilase activities in cyanide-induced cells suggests their implication in the cyanide degradation pathway.


2019 ◽  
Vol 20 (12) ◽  
pp. 3008 ◽  
Author(s):  
Lara Paloma Sáez ◽  
Purificación Cabello ◽  
María Isabel Ibáñez ◽  
Víctor Manuel Luque-Almagro ◽  
María Dolores Roldán ◽  
...  

The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 can grow with cyanate, cyanide, or cyanide-containing industrial residues as the sole nitrogen source, but the assimilation of cyanide and cyanate takes place through independent pathways. Therefore, cyanide degradation involves a chemical reaction between cyanide and oxaloacetate to form a nitrile that is hydrolyzed to ammonium by the nitrilase NitC, whereas cyanate assimilation requires a cyanase that catalyzes cyanate decomposition to ammonium and carbon dioxide. The P. pseudoalcaligenes CECT5344 cynFABDS gene cluster codes for the putative transcriptional regulator CynF, the ABC-type cyanate transporter CynABD, and the cyanase CynS. In this study, transcriptional analysis revealed that the structural cynABDS genes constitute a single transcriptional unit, which was induced by cyanate and repressed by ammonium. Mutational characterization of the cyn genes indicated that CynF was essential for cynABDS gene expression and that nitrate/nitrite transporters may be involved in cyanate uptake, in addition to the CynABD transport system. Biodegradation of hazardous jewelry wastewater containing high amounts of cyanide and metals was achieved in a batch reactor operating at an alkaline pH after chemical treatment with hydrogen peroxide to oxidize cyanide to cyanate.


Author(s):  
R. Vasantha Jothi ◽  
R. Saratha ◽  
S. V. Priya

<div><p><em>The present review gives a brief application of environmentally – safe corrosion inhibitors for various metals like aluminum, copper, mild steel, and zinc. Due to the enormous increase of industrial activities, a large amount of mineral acids are consumed. Therefore more number of metals gets corroded. These problems can be solved by using corrosion deterence. Although many chemical deterence are available most of them are highly virulent. So there is a need to explore a new class of corrosion inhibitors with good inhibition efficiency and that are environmentally - safe. Consequently, it can be achieved by using plant materials as corrosion inhibitors which are non-toxic, easily available and biodegradable.</em></p></div>


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