Microbiological Transformation Research Articles

Microbial Transformations of Aryltetralone and Aryltetralin Lignans by Cunninghamella echinulata and Beauveria bassiana

Microbiological transformation of the aryltetralone lignan (-)-8'-epi-aristoligone (1) with Cunninghamella echinulata ATCC 10028B afforded two known natural lignans, (-)-holostyligone (3) and (-)-arisantetralone (4). Incubation of the aryltetralin lignan (-)-isogalbulin (2), obtained by chemical transformation of 1, with C. echinulata ATCC 10028B afforded the known lignan aryltetralol (5) and seven new metabolites, (-)-8-hydroxyisogalbulin (6), (-)-7-methoxyisogalbulin (7), (-)-4'-O-demethyl-8-hydroxyisogalbulin (8), (-)-7-methoxy-8-hydroxyisogalbulin (9), (-)-4'-O-demethyl-7-methoxyisogalbulin (10), (-)-4',5-O-didemethylcyclogalgravin (11), and (-)-4'-O-demethylcyclogalgravin (12). When 2 was subjected to biotransformation with Beauveria bassiana ATCC 7159, (-)-8-hydroxyisogalbulin (6) was the only isolable product. The structures of all new compounds were established by detailed analysis of their spectroscopic data.

Microbiological transformation of diosgenin by resting cells of filamentous fungus, Cunninghamella echinulata CGMCC 3.2716

Abstract Microbial transformation of the steroidal sapogenin diosgenin ( 1 ) by resting cells of the filamentous fungus, Cunninghamella echinulata CGMCC 3.2716 was studied. Four metabolites were isolated and unambiguously characterized as (25 R )-spirost-5-ene-3β,7β-diol-11-one ( 2 ), (25 R )-spirost-5-ene-3β,7β-diol ( 3 ), (25 R )-spirost-5-ene-3β,7β,11α-triol ( 4 ), and (25 R )-spirost-5-ene-3β,7β,12β-triol ( 5 ), by various spectroscopic methods ( 1 H, 13 C NMR, DEPT, 1 H– 1 H COSY, HMBC, HSQC and NOESY). Compound 2 is a new metabolite. The NMR data and full assignment for the known metabolites (25 R )-spirost-5-ene-3β,7β-diol ( 3 ) and (25 R )-spirost-5-ene-3β,7β,11α-triol ( 4 ) are described here for the first time. The biotransformation characteristics observed included were C-7β, C-11α and C-12β hydroxylations. Compounds 1–5 exhibited no significant cytotoxic activity to human glioma cell line U87.

ChemInform Abstract: Microbiological Transformation. Part 22. Microbiologically-Mediated Baeyer-Villiger Reactions: A Unique Route to Several Bicyclic γ- Lactones in High Enantiomeric Purity.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Microbiological Transformation of Piperidine and Pyridine Derivatives.

Optically active 2-(4-hydroxyphenylcarbamoyloxymethyl)-1-methyl-1,2,5,6-tetrahydropyridine is obtained on microbiological transformation of 1-methyl-2-(N-phenyl-carbamoyloxymethyl)-1,2,5,6-tetrahydropyridine with a growing culture of the fungus C. verticillata VKPM F-430. Transformation of 2-(2-phenylethyl)pyridine by a methanoxidating culture of Methylococcus occurs either by hydroxylation of the side chain or conversion of the substrate into N-oxide, depending on the process conditions.

Biotransformation of 7α-hydroxy- and 7-oxo- ent-atis-16-ene derivatives by the fungus Gibberella fujikuroi

The microbiological transformation of 7α,19-dihydroxy- ent-atis-16-ene by the fungus Gibberella fujikuroi gave 19-hydroxy-7-oxo- ent-atis-16-ene, 13( R),19-dihydroxy-7-oxo- ent-atis-16-ene, 7α,11β,19-trihydroxy- ent-atis-16-ene and 7α,16β,19-trihydroxy- ent-atis-16-ene, while the incubation of 19-hydroxy-7-oxo- ent-atis-16-ene afforded 13( R),19-dihydroxy-7-oxo- ent-atis-16-ene and 16β,17-dihydroxy-7-oxo- ent-atisan-19-al. The biotransformation of 7-oxo- ent-atis-16-en-19-oic acid gave 6β-hydroxy-7-oxo- ent-atis-16-en-19-oic acid, 6β,16β,17-trihydroxy-7-oxo-19- nor- ent-atis-4(18)-ene and 3β,7α-dihydroxy-6-oxo- ent-atis-16-en-19-oic acid.

Microbiological transformation of paeoniflorin and albiflorin

To investigate the microbiological transformation of paeoniflorin and albiflorin. The bacteria strains able to transform paeoniflorin and albiflorin were screened from 18 strains of microorganisms. The products were isolated by chromatography method and their structures were elucidated by spectral technology. It was found that Cunninghamella blakesleana (AS 3.970) and Syncephalastrum racemosum (AS 3.264) could convert paeoniflorin and albiflorin efficiently, respectively. C. blakesleana could convert paeoniflorin to produce albiflorin, while S. racemosum could convert albiflorin to produce paeoniflorin. Paeoniflorin and albiflorin could be converted each other in definited condition.

Microbial transformation of two 15α-hydroxy- ent-kaur-16-ene diterpenes by Mucor plumbeus

The microbiological transformation of candidiol (15α,18-dihydroxy- ent-kaur-16-ene) by Mucor plumbeus led to 3β,15α,18-trihydroxy- ent-kaur-16-ene, 6α,15α,18-trihydroxy- ent-kaur-16-ene, 3α,15α,18-trihydroxy- ent-kaur-16-ene, 11β,15α,18-trihydroxy- ent-kaur-16-ene and 15α,17,18-trihydroxy-11β,16β-epoxy- ent-kaurane, whilst the incubation of 15α,19-dihydroxy- ent-kaur-16-ene gave 9β,15α,19-trihydroxy- ent-kaur-16-ene, 3α,15α,19-trihydroxy- ent-kaur-16-ene, 11β,15α,19-trihydroxy- ent-kaur-16-ene, 6α,15α,19-trihydroxy- ent-kaur-16-ene, 15α,17,19-trihydroxy-11β,16β-epoxy- ent-kaurane, 19-(β- d-glucopyranosyl)-15α-hydroxy- ent-kaur-16-ene and 19-(β- d-glucopyranosyl)-15-oxo- ent-kaur-16-ene. An interesting rearrangement in dilute acid medium of 9β,15α,19-trihydroxy- ent-kaur-16-ene into 16-oxo-19-hydroxy- ent-abiet-8(9),15-diene, is also described in this work.

Bioleaching of arsenic in a drinking water treatment process

Arsenic is found to exist within the shallow zones of groundwater in many countries and a large number of drinking water treatment units have been installed to combat this arsenic poisoning. Microbial activity can greatly affect the mobilization of arsenic under anaerobic conditions when coupled with the oxidation of organic matter. In this study, the bioleaching of arsenic in response to organic matter inclusion in a drinking water treatment process has been elucidated. The decomposition of organic matter due to the microbial action has led to an anaerobic condition within the accumulated sludge in the treatment unit and hence caused the bioleaching of arsenic, above 130 μg/L, with the effluent water. Nevertheless, the biofilm structure, related to the oxygen penetration, had significant influence on the bioleaching of arsenic even in the circumferential aerobic condition of the biofilm. For a biofilm thickness around 400 μm, an anaerobic bottom part was noticed and hence a clear step-up concentration of arsenic was observed in the associated bulk liquid. This study suggests that organic matter would have a sufficiently important influence on the microbiological transformation of arsenic to warrant its consideration in designing safe remediation strategies in the context of arsenic removal processes for drinking water.

Metabolism studies of diclofenac and clofibric acid in activated sludge bioreactors using liquid chromatography with quadrupole – time-of-flight mass spectrometry

Summary Two environmentally relevant pharmaceuticals, the non-steroidal antiinflammatory drug, diclofenac and the pharmacologically active metabolite of several serum triglyceride-lowering pharmaceuticals, clofibric acid, were subjected to microbiological transformation in activated sludge bioreactors, and the production of breakdown products was studied. For separation, detection and identification of diclofenac’s metabolites a UPLC-(+)ESI-QqToF-MS was employed, which enabled the detection of seven transformation products of diclofenac, all including the diagnostic fragment ion at m/z 214. The chemical structure of one metabolite was proposed, which was produced by dehydratation and lactame formation. Further investigations revealed additional two metabolites, which were isomeric structures with an elemental composition C13H10NCl2; however, their chemical structures were not completely resolved. In addition, another biodegradation product showed an abundant fragment ion at m/z 295, the elemental composition of which was confirmed with a high degree of certainty as C14H11NO2Cl2. The biodegradation of clofibric acid revealed one metabolite in the (-)ESI-QqToF chromatogram, 4-chlorophenol, which is known to exhibit a higher toxicity than the parent compound. This study confirms that further research is needed on the formation of stable metabolites both during wastewater treatment and in the environment. It also highlights the need for parallel toxicity testing. In addition, this study suggests that more needs to be known about the environmental fate of pharmaceuticals so that we are able to provide a comprehensive risk assessment.

Microbial transformation of epothilone A by Aspergillus niger AS 3.739

The microbiological transformation of epothilone A (1) by Aspergillus niger AS 3.739 afforded four main metabolites. Their structures were elucidated by 1H, 13C NMR and HSQC, COSY, HMBC, and NOESY spectra as trans-12,13-hydroxylated epothilone A (2), cis-12,13-hydroxylated epothilone A (3), trans-12,15-epoxidated epothilone A (4), and cis-12,15-epoxidated epothilone A (5). All four compounds were firstly found based on their stereochemistry. These new compounds displayed cytotoxicity against human breast carcinoma cells MCF-7 with IC50 9.88 μg/ml of 2, 2.52 μg/ml of 3, 9.88 μg/ml of 4, and 5.68 μg/ml of 5.

Biotransformation of Two ent-Pimara-9(11),15-diene Derivatives by Gibberella fujikuroi

The incubation of 19-hydroxy-13-epi-ent-pimara-9(11),15-diene (4) with Gibberella fujikuroi gave 8 alpha,19-dihydroxy-9 alpha,11alpha-epoxy-13-epi-ent-pimara-15-ene (6), 7-oxo-11 alpha,19-dihydroxy-13-epi-ent-pimara-8(9),15-diene (7), 7-oxo-11beta,19-dihydroxy-13-epi-ent-pimara-8(9),15-diene (9), and 8 alpha,19-dihydroxy-9 alpha,11 alpha:15,16-diepoxy-13-epi-ent-pimarane (11), while the feeding of 13-epi-ent-pimara-9(11),15-diene-19-oic acid (5) with this fungus afforded 1-oxo-2 alpha,9 alpha-dihydroxy-13-epi-ent-pimara-11,15-dien-19-oic acid (13), 1-oxo-2 beta,9 alpha-dihydroxy-13-epi-ent-pimara-11,15-dien-19-oic acid (14), 13-epi-ent-pimara-9(11),15-dien-1,19-dioic acid 1,2-lactone (15), and 1-oxo-12 beta-hydroxy-13-epi-ent-pimara-9(11),15-dien-19-oic acid (16). In both biotransformations, the main reaction was the epoxidation of the 9(11)-double bond, followed by rearrangement to afford allylic alcohols. The formation of lactone 15 represents the first time that a Baeyer-Villiger oxidation has been observed in a microbiological transformation with this fungus.

The use of quadrupole-time-of-flight mass spectrometer for the elucidation of diclofenac biotransformation products in wastewater

The work presented herein discusses the potential of liquid chromatography–quadrupole-time-of-flight mass spectrometry (QqToF–MS) for the chemical structure elucidation of pharmaceutical degradation products (DPs). The model compound, the nonsteroidal anti-inflammatory drug diclofenac was subjected to microbiological transformation in a laboratory scale pilot wastewater treatment plant (WWTP) and its transformation products were detected in the outlet samples. Their chemical structures were elucidated using the principal features of the instrument, i.e. high resolution, accurate mass and MS/MS capability. A hydroxy-diclofenac, a benzoquinone imine derivative and a nitro analogue of diclofenac were successfully identified. The final structural elucidation of the fourth transformation product was not successful. Overall, the study emphasises the capabilities and potential of quadrupole-time-of-flight mass spectrometer showing it to be a powerful tool in both structure elucidation and confirming the identity of environmental contaminants.

Microcosm experiments of oil degradation by microbial mats. II. The changes in microbial species

The influence of microbial mats on the degradation of two crude oils (Casablanca and Maya) and the effect of oil pollution on the mat structure were assessed using model ecosystems, prepared under laboratory conditions subject to tidal movements, from pristine Ebro Delta microbial-mat ecosystems. Both selected oils are examples of those currently used for commercial purposes. Casablanca crude oil is aliphatic with a low viscosity; Maya represents a sulphur-rich heavy crude oil that is predominantly aromatic. In the unpolluted microcosms, Microcoleus chthonoplastes-, Phormidium- and Oscillatoria-like were the dominant filamentous cyanobacterial morphotypes, whilst Synechoccocus-, Synechocystis- and Gloeocapsa-like were the most abundant unicellular cyanobacteria. After oil contamination, no significant changes of chlorophyll a and protein concentrations were observed, though cyanobacterial diversity shifts were monitored. Among filamentous cyanobacteria, M. chthonoplastes-like morphotype was the most resistant for both oils, unlike the other cyanobacteria, which tolerated Casablanca but not Maya. Unicellular cyanobacteria seemed to be resistant to pollution with both essayed oils, with the exception of the morphotype resembling Gloeocapsa, which was sensitive to both oils. The crude-oil addition also had a significant effect on certain components of the heterotrophic microbial community. Casablanca oil induced an increase in anaerobic heterotrophic bacteria, whereas the opposite effect was observed in those heterotrophs when polluted with Maya oil. The overall results, microbiological and crude-oil transformation analysis, indicate that the indigenous community has a considerable potential to degrade oil components by means of the metabolic cooperation of phototrophic and heterotrophic populations.

A Chemobiological Synthesis of Eplerenone

This paper will describe an approach to the synthesis of eplerenone, which is being marketed for the treatment of hypertension. The synthesis begins with DHEA available from wild yams and uses a combination of microbiological and chemical transformations to build eplerenone.

The microbiological transformation of 7α-hydroxy- ent-kaur-16-ene derivatives by Gibberella fujikuroi

The biotransformation of 7α-hydroxy- ent-kaur-16-ene ( epi-candol A) by the fungus Gibberella fujikuroi gave 7α,16α,17-trihydroxy- ent-kaur-16-ene and a seco-ring B derivative, fujenoic acid, whilst the incubation of candicandiol (7α,18-dihydroxy- ent-kaur-16-ene) and canditriol (7α,15α,18-trihydroxy- ent-kaur-16-ene) afforded 7α,18,19-trihydroxy- ent-kaur-16-ene and 7α,11β,15α,18-tetrahydroxy- ent-kaur-16-ene, respectively. The presence of a 7α-hydroxyl group in epi-candol A avoids its biotransformation along the biosynthetic pathway of gibberellins, and directs it to the seco-ring B acids route. The 15α-hydroxyl group in canditriol inhibits oxidation at C-19 and direct hydroxylation at C-11(β). The formation of fujenoic acid, from 7α-hydroxy- ent-kaur-16-ene, probably occurs via 7α-hydroxykaurenoic acid and 7-oxokaurenoic acid, with subsequent hydroxylation at the C-6(β) position.

High performance microbiological transformation of L-tyrosine to L-dopa by Yarrowia lipolytica NRRL-143

BackgroundThe 3,4-dihydroxy phenyl L-alanine (L-dopa) is a drug of choice for Parkinson's disease, controlling changes in energy metabolism enzymes of the myocardium following neurogenic injury. Aspergillus oryzae is commonly used for L-dopa production; however, potential improvements in ease of handling, growth rate and environmental impact have led to an interest in exploiting alternative yeasts. The two important elements required for L-dopa production are intracellular tyrosinases (thus pre-grown yeast cells are required for the transformation of L-tyrosine to L-dopa) and L-ascorbate, which acts as a reducing agent.ResultsPre-grown cells of Yarrowia lipolytica NRRL-143 were used for the microbiological transformation of L-tyrosine to L-dopa. Different diatomite concentrations (0.5–3.0 mg/ml) were added to the acidic (pH 3.5) reaction mixture. Maximum L-dopa biosynthesis (2.96 mg/ml L-dopa from 2.68 mg/ml L-tyrosine) was obtained when 2.0 mg/ml diatomite was added 15 min after the start of the reaction. After optimizing reaction time (30 min), and yeast cell concentration (2.5 mg/ml), an overall 12.5 fold higher L-dopa production rate was observed when compared to the control. Significant enhancements in Yp/s, Qs and qs over the control were observed.ConclusionDiatomite (2.0 mg/ml) addition 15 min after reaction commencement improved microbiological transformation of L-tyrosine to L-dopa (3.48 mg/ml; p ≤ 0.05) by Y. lipolytica NRRL-143. A 35% higher substrate conversion rate was achieved when compared to the control.

Natural sesquiterpenoids

This review covers the isolation, structural determination, synthesis and chemical and microbiological transformations of natural sesquiterpenoids. 421 references are cited.

Sulfur organic compounds in bottom sediments of the eastern Gulf of Finland

Background, Aims and Scope Despite the large number of studies on the forms of sulfur in marine deposits, investigations on sulfur organic compounds are still rare. It is known that the processes leading to formation of intermediate and final sulfur compounds (including organic ones) in modern deposits are the results of microbiological transformation of sulfur containing proteins, as well as the microbiological reduction of sulfate ions. The latter are finally reduced by anaerobic sulfate-reducing bacteria to H2S, HS− and S2−; the total sum of these is referred to as ‘hydrogen sulfide’ in chemical oceanography. Further, the formation of reduced sulfur organic derivatives (sulfides and polysulfides) is the result of interaction of the organic substance destruction products with the sulfide ions. In such cases, the main source of organic substances, as well as sulfates for the sulfur reducing processes, is the pore water in the sediments. The choice of the target of our study is based on the fact that the eastern part of the Gulf of Finland water area receives the bulk of the anthropogenic load of the St. Petersburg region. Low vertical intermixing of the water thickness is observed there (thus creating a deficiency of oxygen near the bottom), and the bottom sea current transfers the polluted salty water of the Baltic Sea into the Neva Bay. The whole of the above are the preconditions for the formation of sulfur-bearing organic compounds. A great number of bottom sediment samples for analytical surveys were collected in the Eastern Gulf of Finland during research expeditions in the years of 1997 and 2001. These were screened for structures of sulfur organic microcontaminants, including organic forms of sulfur, using advanced instrumentation and experienced personnel in our two, cooperating laboratories. This work is a part of the research being carried out on organic micro-admixtures present in bottom sediments, and is the summary of our findings on previously unstudied sulfur organic substances there.

Aerobic processing of organic waste into composts

The current achievements in the field of aerobic waste processing into composts are reviewed, with an emphasis on amelioration of the environment and targeted use for intensification of agriculture. The methods for obtaining microbiological transformation products of household, agricultural, and industrial waste and their characteristics are analyzed.

Microbiological transformation of two labdane diterpenes, the main constituents of Madia species, by two fungi

Microbial transformation of 13 R,14 R,15-trihydroxylabd-7-ene ( 5) and 13 R,14 R,15-trihydroxylabd-8(17)-ene ( 6) by the fungus Debaryomyces hansenii gave 1 (13 R,14 R,15-trihydroxy-6-oxolabd-8-ene) and 3 (7α,13 R,14 R,15-tetrahydroxy-labd-8(17)-ene), respectively. While, microbial transformation of 5 by Aspergillus niger afforded 2 (3β,13 R,14 R,15-tetrahydroxy-labd-7-ene), and 13 R,14 R,15-trihydroxylabd-8,17-ene ( 6) gave 3 and 4 (3 R,14 R,15-3-oxotetrahydroxy-labd-7-ene). The structures of the new compounds, 1 and 2, were assigned by 1D and 2D high-field NMR spectroscopic methods. Antimicrobial activity of these compounds were tested and their MIC were determined.