scholarly journals Tin-Carbon Cleavage of Organotin Compounds by Pyoverdine from Pseudomonas chlororaphis

2003 ◽  
Vol 69 (2) ◽  
pp. 878-883 ◽  
Author(s):  
Hiroyuki Inoue ◽  
Osamu Takimura ◽  
Ken Kawaguchi ◽  
Teruhiko Nitoda ◽  
Hiroyuki Fuse ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Fluorescent Pseudomonads ◽  
Organotin Compounds ◽  
Pseudomonas Chlororaphis ◽  
Chelating Ligands ◽  
Metal Chelating ◽  
Degrading Bacterium ◽  
Acyl Substituent ◽  
Degradation Activity ◽  
Culture Supernatants

ABSTRACT The triphenyltin (TPT)-degrading bacterium Pseudomonas chlororaphis CNR15 produces extracellular yellow substances to degrade TPT. Three substances (F-I, F-IIa, and F-IIb) were purified, and their structural and catalytic properties were characterized. The primary structure of F-I was established using two-dimensional nuclear magnetic resonance techniques; the structure was identical to that of suc-pyoverdine from P. chlororaphis ATCC 9446, which is a peptide siderophore produced by fluorescent pseudomonads. Spectral and isoelectric-focusing analyses revealed that F-IIa and F-IIb were also pyoverdines, differing only in the acyl substituent attached to the chromophore part of F-I. Furthermore, we found that the fluorescent pseudomonads producing pyoverdines structurally different from F-I showed TPT degradation activity in the solid extracts of their culture supernatants. F-I and F-IIa degraded TPT to monophenyltin via diphenyltin (DPT) and degraded DPT and dibutyltin to monophenyltin and monobutyltin, respectively. The total amount of organotin metabolites produced by TPT degradation was nearly equivalent to that of the F-I added to the reaction mixture, whereas DPT degradation was not influenced by monophenyltin production. The TPT degradation activity of F-I was remarkably inhibited by the addition of metal ions chelated with pyoverdine. On the other hand, the activity of DPT was increased 13- and 8-fold by the addition of Cu2+ and Sn4+, respectively. These results suggest that metal-chelating ligands common to pyoverdines may play important roles in the Sn-C cleavage of organotin compounds in both the metal-free and metal-complexed states.

scholarly journals Degradation of Triphenyltin by a Fluorescent Pseudomonad

2000 ◽  
Vol 66 (8) ◽  
pp. 3492-3498 ◽  
Author(s):  
Hiroyuki Inoue ◽  
Osamu Takimura ◽  
Hiroyuki Fuse ◽  
Katsuji Murakami ◽  
Kazuo Kamimura ◽  
...  
Keyword(s):  
Molecular Mass ◽  
High Performance ◽  
Solid Phase ◽  
Resting Cells ◽  
Fluorescent Pseudomonad ◽  
Pseudomonas Chlororaphis ◽  
Degrading Bacteria ◽  
Degradation Activity ◽  
Culture Supernatants

ABSTRACT Triphenyltin (TPT)-degrading bacteria were screened by a simple technique using a post-column high-performance liquid chromatography using 3,3′,4′,7-tetrahydroxyflavone as a post-column reagent for determination of TPT and its metabolite, diphenyltin (DPT). An isolated strain, strain CNR15, was identified as Pseudomonas chlororaphis on the basis of its morphological and biochemical features. The incubation of strain CNR15 in a medium containing glycerol, succinate, and 130 μM TPT resulted in the rapid degradation of TPT and the accumulation of approximately 40 μM DPT as the only metabolite after 48 h. The culture supernatants of strain CNR15, grown with or without TPT, exhibited a TPT degradation activity, whereas the resting cells were not capable of degrading TPT. TPT was stoichiometrically degraded to DPT by the solid-phase extract of the culture supernatant, and benzene was detected as another degradation product. We found that the TPT degradation was catalyzed by low-molecular-mass substances (approximately 1,000 Da) in the extract, termed the TPT-degrading factor. The other fluorescent pseudomonads,P. chlororaphis ATCC 9446, Pseudomonas fluorescens ATCC 13525, and Pseudomonas aeruginosaATCC 15692, also showed TPT degradation activity similar to strain CNR15 in the solid-phase extracts of their culture supernatants. These results suggest that the extracellular low-molecular-mass substance that is universally produced by the fluorescent pseudomonad could function as a potent catalyst to cometabolite TPT in the environment.

Dense Monolayers of Metal-Chelating Ligands Covalently Attached to Carbon Electrodes Electrochemically and Their Useful Application in Affinity Binding of Histidine-Tagged Proteins

Langmuir ◽  
2005 ◽  
Vol 21 (8) ◽  
pp. 3362-3375 ◽  
Author(s):  
Ronald Blankespoor ◽  
Benoît Limoges ◽  
Bernd Schöllhorn ◽  
Jean-Laurent Syssa-Magalé ◽  
Dounia Yazidi
Keyword(s):  
Carbon Electrodes ◽  
Affinity Binding ◽  
Chelating Ligands ◽  
Metal Chelating

scholarly journals Biodegradable, metal-chelating compounds as alternatives to EDTA for cultivation of marine microalgae

2021 ◽  
Author(s):  
Justine Sauvage ◽  
Gary H. Wikfors ◽  
Koen Sabbe ◽  
Nancy Nevejan ◽  
Steven Goderis ◽  
...  
Keyword(s):  
Marine Microalgae ◽  
Organic Ligands ◽  
Aquatic Environments ◽  
Growth Enhancement ◽  
Chelating Ligands ◽  
Microalgal Cultivation ◽  
Metal Chelating ◽  
Environmental Compatibility ◽  
Cultivation Practices ◽  
Culture Development

AbstractIron (Fe) is an essential nutrient for microalgal metabolism. The low solubility of Fe in oxic aquatic environments can be a growth-limiting factor for phytoplankton. Synthetic chelating agents, such as ethylenediaminetetraacetic acid (EDTA), are used widely to maintain Fe in solution for microalgal cultivation. The non-biodegradable nature of EDTA, combined with sub-optimal bioavailability of Fe-EDTA complexes to microalgae, indicates opportunity to improve microalgal cultivation practices that amplify production efficiency and environmental compatibility. In the present study, the effects of four organic chelating ligands known to form readily bioavailable organic complexes with Fe in natural aquatic environments were investigated in relation to growth and biochemical composition of two marine microalgae grown as live feeds in shellfish hatcheries (Chaetoceros calcitrans and Tisochrysis lutea). Three saccharides, alginic acid (ALG), glucuronic acid (GLU), and dextran (DEX), as well as the siderophore desferrioxamine B (DFB), were compared to EDTA. Organic ligands characterized by weaker binding capacity for cationic metals (i.e., ALG, GLU, DEX) significantly improved microalgal growth and yields in laboratory-scale static batch cultures or bubbled photobioreactors. Maximal microalgal growth enhancement relative to the control (e.g., EDTA) was recorded for GLU, followed by ALG, with 20–35% increase in specific growth rate in the early stages of culture development of C. calcitrans and T. lutea. Substitution of EDTA with GLU resulted in a 27% increase in cellular omega 3-polyunsaturetd fatty acid content of C. calcitrans and doubled final cell yields. Enhanced microalgal culture performance is likely associated with increased intracellular Fe uptake efficiency combined with heterotrophic growth stimulated by the organic ligands. Based upon these results, we propose that replacement of EDTA with one of these organic metal-chelating ligands is an effective and easily implementable strategy to enhance the environmental compatibility of microalgal cultivation practices while also maximizing algal growth and enhancing the nutritional quality of marine microalgal species commonly cultured for live-feed applications in aquaculture.

scholarly journals Complete Genome of the Chitin-Degrading Bacterium, Paenibacillus xylanilyticus W4

2019 ◽  
Vol 11 (11) ◽  
pp. 3252-3255 ◽  
Author(s):  
Weifang Liao ◽  
Pulin Liu ◽  
Weijie Liao ◽  
Lihong Miao
Keyword(s):  
Complete Genome ◽  
Gc Content ◽  
Circular Chromosome ◽  
Chitin Degradation ◽  
Degrading Bacterium ◽  
Degradation Activity ◽  
Genome Information ◽  
Taxonomic Characterization ◽  
Single Circular Chromosome ◽  
Genome Distance

Abstract Chitinases possess an extraordinary ability to directly hydrolyze highly insoluble chitin polymers to low-molecular-weight chito-oligomers, which possess particular biological functions, such as elicitor action and antitumor activity. A novel strain, Paenibacillus xylanilyticus W4, which was isolated from soil, showed strong chitin degradation activity. Here, we first reported the complete genome information of P. xylanilyticus. Paenibacillus xylanilyticus W4 contains a 5,532,141 bp single circular chromosome with 47.33% GC content. The genome contains 5,996 genes, including 39 rRNA- and 109 tRNA-coding genes. Phylogenetic analysis and Genome-to-Genome Distance revealed its taxonomic characterization into a separate family. Six glycoside hydrolase 18 (GH18) and 2 GH23 enzymes involved in chitin degradation. Although many of the chitinases were conserved in Paenibacillus, several GH18 chitinases share high similarity with Bacillus circulans. The genome information provided here could benefit for understanding the chitin-degrading properties of P. xylanilyticus as well as its potential application in biotechnological and pharmaceutical fields.

scholarly journals A Pseudomonas putida Strain Genetically Engineered for 1,2,3-Trichloropropane Bioremediation

2014 ◽  
Vol 80 (17) ◽  
pp. 5467-5476 ◽  
Author(s):  
Ghufrana Samin ◽  
Martina Pavlova ◽  
M. Irfan Arif ◽  
Christiaan P. Postema ◽  
Jiri Damborsky ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Immobilized Cells ◽  
Packed Bed ◽  
Genetically Engineered ◽  
Packed Bed Reactor ◽  
Content Type ◽  
Degrading Bacterium ◽  
Organic Chlorine ◽  
Degradation Activity ◽  
Step Growth

ABSTRACT1,2,3-Trichloropropane (TCP) is a toxic compound that is recalcitrant to biodegradation in the environment. Attempts to isolate TCP-degrading organisms using enrichment cultivation have failed. A potential biodegradation pathway starts with hydrolytic dehalogenation to 2,3-dichloro-1-propanol (DCP), followed by oxidative metabolism. To obtain a practically applicable TCP-degrading organism, we introduced an engineered haloalkane dehalogenase with improved TCP degradation activity into the DCP-degrading bacteriumPseudomonas putidaMC4. For this purpose, the dehalogenase gene (dhaA31) was cloned behind the constitutivedhlApromoter and was introduced into the genome of strain MC4 using a transposon delivery system. The transposon-located antibiotic resistance marker was subsequently removed using a resolvase step. Growth of the resulting engineered bacterium,P. putidaMC4-5222, on TCP was indeed observed, and all organic chlorine was released as chloride. A packed-bed reactor with immobilized cells of strain MC4-5222 degraded >95% of influent TCP (0.33 mM) under continuous-flow conditions, with stoichiometric release of inorganic chloride. The results demonstrate the successful use of a laboratory-evolved dehalogenase and genetic engineering to produce an effective, plasmid-free, and stable whole-cell biocatalyst for the aerobic bioremediation of a recalcitrant chlorinated hydrocarbon.

scholarly journals Characteristics of a Microcystin-Degrading Bacterium under Alkaline Environmental Conditions

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Kunihiro Okano ◽  
Kazuya Shimizu ◽  
Yukio Kawauchi ◽  
Hideaki Maseda ◽  
Motoo Utsumi ◽  
...  
Keyword(s):  
Water Bloom ◽  
Rrna Gene ◽  
Degrading Bacterium ◽  
Degrading Bacteria ◽  
Optimum Ph ◽  
Degradation Activity ◽  
Ph Conditions ◽  
Toxic Blooms ◽  
The 16S Rrna Gene ◽  
Water Blooms

The pH of the water associated with toxic blooms of cyanobacteria is typically in the alkaline range; however, previously only microcystin-degrading bacteria growing in neutral pH conditions have been isolated. Therefore, we sought to isolate and characterize an alkali-tolerant microcystin-degrading bacterium from a water bloom using microcystin-LR. Analysis of the 16S rRNA gene sequence revealed that the isolated bacterium belonged to the genusSphingopyxis, and the strain was named C-1.Sphingopyxissp. C-1 can grow; at pH 11.0; however, the optimum pH for growth was pH 7.0. The microcystin degradation activity of the bacterium was the greatest between pH 6.52 and pH 8.45 but was also detected at pH 10.0. ThemlrAhomolog encoding the microcystin-degrading enzyme in the C-1 strain was conserved. We concluded that alkali-tolerant microcystin-degrading bacterium played a key role in triggering the rapid degradation of microcystin, leading to the disappearance of toxic water blooms in aquatic environments.

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