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Microbial Transformation (microbial + transformation)

Distribution by Scientific Domains

Chemistry	73%
Life Sciences	26%

Selected Abstracts

Microbial Transformation of Mestranol by Cunninghamella elegans.

CHEMINFORM, Issue 3 2006
Muhammad Iqbal Choudhary
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Microbial Transformations of S-Naproxen by Aspergillus niger ATCC 9142.

CHEMINFORM, Issue 39 2003
A. He
No abstract is available for this article. [source]

Microbial Transformations of Gelomulide G: A Member of the Rare Class of Diterpene Lactones

CHEMISTRY & BIODIVERSITY, Issue 10 2005
Iqbal Choudhary
Microbial transformation of gelomulide G (3,,6,- diacetoxy-8,,14,- epoxyabiet-13(15)-en-16,12-olide, 1) was carried out. Incubation of 1 with Aspergillus niger afforded two new metabolites, 3,,6,- diacetoxy-8,,14,- dihydroxyabiet-13(15)-en-16,12-olide (2) and 3,,6,- diacetoxy-14,- hydroxyabieta-8(9),13(15)-dien-16,12-olide (3). While Cunninghamella elegans afforded the 14-epimer of 2, i.e., 3,,6,- diacetoxy-8,,14,- dihydroxyabiet-13(15)-en-16,12-olide (4), along with 3, -acetoxy-6,- hydroxy-8,,14,- epoxyabiet-13(15)-en-16,12-olide (5). The structures of the transformed products 2,5 were deduced to be new on the basis of MS and NMR data. [source]

Microbial transformation of pyrethroid insecticides in aqueous and sediment phases

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2004
Sangjin Lee
Abstract Recent studies showed that synthetic pyrethroids(SPs)can move via surface runoff into aquatic systems. Fifty-six of SP-degrading bacteria strains were isolated from contaminated sediments, of which six were evaluated for their ability to transform bifenthrin and permethrin in the aqueous phase and bifenthrin in the sediment phase. In the aqueous phase, bifenthrin was rapidly degraded by strains of Stenotrophomonas acidaminiphila, and the half-life (t1/2) was reduced from >700 h to 30 to 131 h. Permethrin isomers were degraded by Aeromonas sobria, Erwinia carotovora, and Yersinia frederiksenii. Similar to bifenthrin, the t1/2 of cis - and trans -permethrin was reduced by approximately 10-fold after bacteria inoculation. However, bifenthrin degradation by S. acidaminiphila was significantly inhibited in the presence of sediment, and the effect was likely caused by strong adsorption to the solid phase. Bifenthrin t1/2 was 343 to 466 h for a field sediment, and increased to 980 to 1200 h for a creek sediment. Bifenthrin degradation in the inoculated slurry treatments was not greatly enhanced when compared with the noninoculated system. Therefore, although SP-degrading bacteria may be widespread in aquatic systems, adsorption to sediment could render SPs unavailable to the degraders, thus prolonging their persistence. [source]

Microbial transformation of androst-4-ene-3, 17-dione by Bordetella sp.

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2009
B4 CGMCC 222
Abstract BACKGROUND: Microbial transformation of steroids has attracted widespread attention, especially the transformation of those steroids synthesized with difficulty by chemical methods. In this study, microbial transformation of androst-4-ene-3, 17-dione (AD) by Bordetella sp. B4 was investigated, and the effect of temperature on transformation was studied. RESULTS: Three metabolites were purified by preparative TLC and HPLC, and identified as androsta-1,4-diene-3,17-dione (ADD), 9,-hydroxyandrost-4-ene-3, 17-dione (9,-OH-AD), and 3-hydroxy-9, 10-secoandrost-1, 3, 5-triene-9, 17-dione (3-OH-SATD) by nuclear magnetic resonance imaging (NMR), Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy (MS). It was first reported that the genus of Bordetella has the capability of AD degradation. Microbial transformation of AD was performed at 30 °C, 37 °C, 40 °C and 45 °C. The 9,-OH-AD yield reached a maximum within 16 h when the strain was cultivated in media with AD as sole carbon at 37 °C. Surprisingly, ADD was produced by the strain cultivated at 40 °C but not at 37 °C, which was different from previous reports. It was deduced that the alcohol dehydrogenase that catalyzed the transformation of AD to ADD may be temperature sensitive. CONCLUSION: Androst-4-ene-3,17-dione was converted into 9,-hydroxyandrost-4-ene-3, 17-dione and other metabolites rapidly by Bordetella sp. B4. It is anticipated that the strain Bordetella sp. B4 CGMCC 2229 can be used in the steroids industry. Copyright © 2009 Society of Chemical Industry [source]

Comparative analysis on microbial and rat metabolism of ginsenoside Rb1 by high-performance liquid chromatography coupled with tandem mass spectrometry

BIOMEDICAL CHROMATOGRAPHY, Issue 7 2008
Guangtong Chen
Abstract Ginsenoside Rb1 is an active protopanaxadiol saponin from Panax species. In order to compare the similarities and differences of microbial and mammalian metabolisms of ginsenoside Rb1, the microbial transformation by Acremonium strictum and metabolism in rats were comparatively studied. Microbial transformation of ginsenoside Rb1 by Acremonium strictum AS 3.2058 resulted in the formation of eight metabolites. Ten metabolites (M1,M10) were detected from the in vivo study in rats and eight of them were identified as the same compounds as those obtained from microbial metabolism by liquid chromatography,tandem mass spectrometry analysis and comparison with reference standards obtained from microbial metabolism. Their structures were identified as ginsenoside Rd, gypenoside XVII, 20(S)-ginsenoside Rg3, 20(R)-ginsenoside Rg3, ginsenoside F2, compound K, 12, -hydroxydammar-3-one-20(S) -O-, -d- glucopyranoside, and 25-hydroxyl-(E)-20(22)-ene-ginsenoside Rg3, respectively. The structures of the additional two metabolites were tentatively characterized as 20(22),24-diene-ginsenoside Rg3 and 25-hydroxyginsenoside Rd by HPLC-MS/MS analysis. M7,M10 are the first four reported metabolites in vivo. The time course of rat metabolism of ginsenoside Rb1 was also investigated. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Microbial Transformations of Gelomulide G: A Member of the Rare Class of Diterpene Lactones

Fate and stability of 14C-labeled 2,4,6-trinitrotoluene in contaminated soil following microbial bioremediation processes

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2004
Martin Weiß
Abstract Biological treatment of 2,4,6-trinitrotoluene (TNT) in soil rarely results in complete mineralization of the parent compound. More often, the largest proportion of the TNT carbon is incorporated into the soil organic matrix. Therefore, we evaluated the stability of nonextractable residues from various bioremediation processes of 14C-TNT in soils. The extractable amounts of the residual radioactivity varied between 7 and 33% and thus the nonextractable amount between 93 and 67% (3,15% in fulvic acids, 26,46% in humic acids, and 27,44% in the humin fraction). The residue-containing soils were analyzed for the release of radioactivity after treatment by physical (freeze and thaw, grinding of soil, and steam extraction), chemical (acid rain and addition of metal complexing agent), and biological methods (addition of compost, white rot fungi, radical-generating enzymes, and germination of plants). Freeze and thaw treatment and grinding of the soil did not alter the partitioning of the label significantly. Steam extraction and acid rain extraction increased the water extractability to 11 to 29% and to 51.6% in the native TNT-contaminated soil. The addition of ethylenediamine-tetraacetate (EDTA) increased the extractability from 7 to 12%. After biological treatment, only slightly increased extractability (<<10%) was observed. No increase of extractable TNT or known metabolites was observed with any of the treatments. Thus, under the treatment conditions applied in this study, the residues formed during microbial transformation of TNT may be biogenic residues with low mobilization potential and low hazardous impact. [source]

Microbial transformation of androst-4-ene-3, 17-dione by Bordetella sp.

An appraisal of methods for measurement of pesticide transformation in the groundwater zone,

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2001
Minze Leistra
Abstract Laboratory and field studies show that pesticides may be transformed in the groundwater zone. Possible reaction mechanisms are chemical hydrolysis, catalytic reduction and aerobic or anaerobic microbial transformation. Transformation in the groundwater zone can be an important element in the advanced evaluation of the potential risk arising from a pesticide in the public drinking water supply. However, rate and pathway of transformation can show large differences, depending on the bio-geochemical conditions in the groundwater zone. Knowledge of the reaction mechanisms and the effect of aquifer conditions would allow vulnerable and low-vulnerable application areas for a pesticide to be delimited. An outline is given of possible approaches to quantifying these transformation processes and using the results in registration procedures, especially in the EU and its member states. Furthermore, areas where there is need for continued research and better understanding are highlighted. © 2001 Society of Chemical Industry [source]

Comparative analysis on microbial and rat metabolism of ginsenoside Rb1 by high-performance liquid chromatography coupled with tandem mass spectrometry

Liquid chromatography,tandem mass spectrometry for the identification of l -tetrahydropalmatine metabolites in Penicillium janthinellum and rats

BIOMEDICAL CHROMATOGRAPHY, Issue 1 2006
Li Li
Abstract l-Tetrahydropalmatine (l-THP) is an active alkaloid from Stephania ainiaca Diels. In order to compare the similarities and differences of microbial and mammalian metabolisms of l-THP, the microbial transformation by Penicillium janthinellum and metabolism in rats were investigated. Biotransformation of l-THP by Penicillium janthinellum AS 3.510 resulted in the formation of three metabolites. Their structures were identified as l-corydalmine, l-corypalmine and 9- O -desmethyl-l-THP, respectively, by comprehensive nuclear magnetic resonance and mass spectrometry (MS) analysis. Six metabolites (M1,M6) were detected from the in vivo study in rats and three of which (l-corydalmine, l-corypalmine and 9- O -desmethyl-l-THP) were identified as the same compounds as those obtained from microbial metabolism by liquid chromatography,tandem mass spectrometry (LC-MS[sol ]MS) analysis and comparison with reference standards obtained from microbial metabolism. The structures of the additional three metabolites were tentatively deduced as 2- O -desmethyl-l-THP and two di- O -demethylated l-THP by LC-MS[sol ]MS analysis. Time courses of microbial and rat metabolisms of l-THP were also investigated. Copyright © 2005 John Wiley & Sons, Ltd. [source]

In situ extraction of polar product of whole cell microbial transformation with polyethylene glycol-induced cloud point system

BIOTECHNOLOGY PROGRESS, Issue 5 2008
Zhilong Wang
Abstract A novel polyethylene glycol-induced cloud point system (PEG-CPS) was developed for in situ extraction of moderate polar product by setting a microbial transformation of benzaldehyde into L -phenylacetylcarbinol (L -PAC) with Saccharomyces cerevisiae (baker's yeast) as a model reaction. The biocompatibility of the microorganism in PEG-CPS was comparatively studied with a series of water-organic solvent two-phase partitioning systems. The tolerance of microorganism to the toxic substrate benzaldehyde was increased and the moderate polar product L -PAC was extracted into the surfactant-rich phase in the PEG-CPS. The novel PEG-CPS fills the gap of in situ extraction of polar product in microbial transformation left by water-organic solvent two-phase partitioning system. At the same time, the application of PEG-CPS in a microbial transformation also avoids expensive solvent when compared with that of aqueous two-phase system or CPS. [source]