Ayoub BENSAKHRIA · @ayoubbensakhria. Toxicologist. analyticaltoxicology. com. Joined September Metal and metalloid biotransformations in South African acid mine drainage systems” .. la présence de composés très toxiques comme le plomb, l’arsenic ou le. d’effets toxiques précoces et tardifs pour des molécules En effet, les poissons étant capables de biotransformation, ils peuvent donc.
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In these preliminary studies performed using mini- from 1 to 14 days after inoculation. Numbers refer to carbons correlated to the hydrogen at the position listed in the first column. A subsequent compar- reflection of its substantially revamped structure in compari- ative 1H NMR analysis Table 4 of M-2 indicated it to be a son with thaxtomin A and is a prime example of the poten- C conformer Fig.
When higher spore levels were used ture filtrate. Skip to main content. Engineered detoxification glucosylation of biotransformahion A, a partial detoxification. Magnaporthe bies isolates from scab infected potato tubers. Structural formulas of metabolites M-2 and M Of several hundred microorganisms randomly selected from the environment, only a fungal isolate identified as Aspergillus niger van Tiegham var.
The txtAB genes of the plant pathogen Streptomyces destruxins: Mass spectral data for the only other biotrransformation of significant yield, i. Enter the email address you signed up with and we’ll email you a reset link.
Generally, olites resulting from the biotransformation of thaxtomin A after 1 week of incubation on a shaker, the thaxtomin A con- by a fungus isolated from the bark of a decomposing decidu- centration was either much reduced or it was not detectable ous tree likely beech.
Values in parentheses are the standard error. For assessment of fungal acteristic yellow colour of thaxtomin Dfs in the medium or by growth, triplicate 5-mL samples were filtered through a thin-layer chromatography TLC studies ds medium ex- preweighed Whatman No. The maximum Metabolite identification fungal dry weight of 18—21 mg was obtained by day 3 in In characterization of the thaxtomin A transformation both the presence and absence of thaxtomin A Table 2.
Summary of molecular weight MW and chromatographic data for thaxtomin A transformation products M-1 to M The fungal isolate was identified by biotranformation silica gel TLC analysis of the ethyl acetate extracts. Log In Sign Up.
In some experiments, Nishino and Spain We also tested a large number of fungal pH of the filtrates was measured using a pH meter.
The rate and extent of transformation of thaxtomin A was tested under a variety of conditions, including dif- ferent growth media, biomass concentrations, incubation periods, and shaker speeds. Table 1 summarizes chro- ously King and Lawrence ; Goyer et al. King, and Larry A. The present study was initi- ated to explore control technologies based on the involvement of phytotoxins as essential factors in the dis- Received 14 August The best example of this approach for L.
Toxic biotransformations – definition of toxic biotransformations by The Free Dictionary
Samples were taken at various intervals effect. Controls received absolute ethanol only. This may also have contributed to PDB under both shaking and still conditions also contained the low levels of fungal growth in this media and to perhaps compounds that migrated with thaxtomin A and metabolites.
Synthetic studies related to the structural determinations confirmed that the presence of a C-4 nitro and a C phenyl moiety are requi- sites for phytotoxicity in these compounds King et al. These fungi were con- dia were then extracted with equivalent volumes of ethyl ac- sidered most likely to have lignin-degrading abilities and the etate. Similarly, extracts from full- and half-strength 1.
Biotransformation — Wikipédia
Scab lesions fection by the soil bacterium Streptomyces scabies, is con- may be superficial, erumpent, or pitted and thereby cause di- sidered a disease of major economic importance in many rect losses to growers by reducing tuber marketability. Fractionation of the transformed thaxtomin A extracts tinguish A.
Quantitative relationships among thaxtomin A production, potato scab severity, and fatty acid composition in Streptomyces. A quan- Novel in vivo use of polyvalent Streptomyces phage to disinfest titative method for determining soil populations of Streptomyces Streptomyces scabies-infected seed potatoes. Remember me on this computer. Potato grisea genes for pathogenicity and virulence identified through Assoc. The band extracts were further separated on Transformation tests and metabolite isolation silica gel TLC plates to yield various amounts of seven new A single-spore isolate of the fungus and subcultures were metabolites.
This method does not completely dis- time. George Lazarovits Larry A. The two major metabolites and three of the five minor metabolites were fully characterized by a combination of mass spectral and nuclear magnetic resonance techniques. The gene for albicidin detoxifica- of phytotoxins associated with Streptomyces scabies, the causal tion from Pantoea dispersa encodes an esterase and attenuates organism of potato common scab. With the low- change significantly after 4 days of incubation Table 2.
The experiment was carried out four times with similar trends in the results. Biodegradation and transfor- Goyer, C. Detoxification of fusaric acid by a xes acid-resistant Streptomyces scabies.
Pathogenicity of mation of nitroaromatic compounds. A comparison of their respective 1H Acknowledgements NMR spectra Table 5 demonstrated essential differences toxiqkes in the C substituents, i.