scholarly journals The isolation and identification of 6-hydroxycyclohepta-1,4-dione as a novel intermediate in the bacterial degradation of atropine

1993 ◽  
Vol 293 (1) ◽  
pp. 115-118 ◽  
Author(s):  
B A Bartholomew ◽  
M J Smith ◽  
M T Long ◽  
P J Darcy ◽  
P W Trudgill ◽  
...  
Keyword(s):  
Growth Medium ◽  
Sole Source ◽  
Bacterial Degradation ◽  
Diauxic Growth ◽  
Growth Substrate ◽  
Isolation And Identification ◽  
Carbon And Nitrogen ◽  
Tropic Acid ◽  
Cell Extracts

Growth of Pseudomonas AT3 on the alkaloid atropine as its sole source of carbon and nitrogen is nitrogen-limited and proceeds by degradation of the tropic acid part of the molecule, with the metabolism of the tropine being limited to the point of release of its nitrogen. A nitrogen-free compound accumulated in the growth medium and was isolated and identified as 6-hydroxycyclohepta-1,4-dione. This novel compound is proposed as an intermediate in tropine metabolism. It served as a growth substrate for the organism and was also the substrate for an NAD(+)-linked dehydrogenase present in cell extracts. The enzyme was induced during the tropine phase of diauxic growth on atropine or during growth on tropine alone.

scholarly journals Characterization of S-Triazine Herbicide Metabolism by a Nocardioides sp. Isolated from Agricultural Soils

2000 ◽  
Vol 66 (8) ◽  
pp. 3134-3141 ◽  
Author(s):  
Edward Topp ◽  
Walter M. Mulbry ◽  
Hong Zhu ◽  
Sarah M. Nour ◽  
Diane Cuppels
Keyword(s):  
Agricultural Soils ◽  
Sole Source ◽  
Bacterial Strains ◽  
Corn Production ◽  
Whole Cells ◽  
Carbon And Nitrogen ◽  
Cell Extracts ◽  
Hydrolytic Reaction ◽  
Central Canada

ABSTRACT Atrazine, a herbicide widely used in corn production, is a frequently detected groundwater contaminant. Nine gram-positive bacterial strains able to use this herbicide as a sole source of nitrogen were isolated from four farms in central Canada. The strains were divided into two groups based on repetitive extragenic palindromic (rep)-PCR genomic fingerprinting with ERIC and BOXA1R primers. Based on 16S ribosomal DNA sequence analysis, both groups were identified as Nocardioides sp. strains. None of the isolates mineralized [ring-U-14C]atrazine. There was no hybridization to genomic DNA from these strains usingatzABC cloned from Pseudomonas sp. strain ADP or trzA cloned from Rhodococcus corallinus. S-Triazine degradation was studied in detail inNocardioides sp. strain C190. Oxygen was not required for atrazine degradation by whole cells or cell extracts. Based on high-pressure liquid chromatography and mass spectrometric analyses of products formed from atrazine in incubations of whole cells with H2 18O, sequential hydrolytic reactions converted atrazine to hydroxyatrazine and then to the end productN-ethylammelide. Isopropylamine, the putative product of the second hydrolytic reaction, supported growth as the sole carbon and nitrogen source. The triazine hydrolase from strain C190 was isolated and purified and found to have a Km for atrazine of 25 μM and a V max of 31 μmol/min/mg of protein. The subunit molecular mass of the protein was 52 kDa. Atrazine hydrolysis was not inhibited by 500 μM EDTA but was inhibited by 100 μM Mg, Cu, Co, or Zn. Whole cells and purified triazine hydrolase converted a range of chlorine or methylthio-substituted herbicides to the corresponding hydroxy derivatives. In summary, an atrazine-metabolizingNocardioides sp. widely distributed in agricultural soils degrades a range of s-triazine herbicides by means of a novel s-triazine hydrolase.

scholarly journals Induction of primary alkylsulphatases and metabolism of sodium hexan-1-yl sulphate by Pseudomonas C12B

1974 ◽  
Vol 138 (1) ◽  
pp. 63-69 ◽  
Author(s):  
John W. Fitzgerald ◽  
Kenneth S. Dodgson ◽  
William J. Payne
Keyword(s):  
Sole Source ◽  
Bacterial Degradation ◽  
Alkyl Sulphate ◽  
Cell Extracts ◽  
The Media

Sodium hexan-1-yl sulphate and certain related alkyl sulphate esters have been shown to serve as inducers of the formation of primary alkylsulphatases (designated as P1 and P2) in Pseudomonas C12B. When the organism is grown on sodium hexan-1-yl [35S]sulphate as the sole source of sulphur or as the sole source of carbon and sulphur only the P2 alkylsulphatase is formed and inorganic 35SO42- is liberated into the media. Cell extracts contain this anion as the major 35S-labelled metabolite although two unidentified labelled metabolites as well as choline O-[35S]sulphate occur in trace quantities in some extracts. Dialysed cell extracts are capable of liberating inorganic 35SO42- from sodium hexan-1-yl [35S]sulphate without the need to include cofactors known to be required for the bacterial degradation of n-alkanes. The collective results suggest that sodium hexan-1-yl sulphate can act as an inducer of P1 alkylsulphatase formation without the need for prior metabolic modification of the carbon moiety of the ester.

scholarly journals Aerobic Degradation of Dinitrotoluenes and Pathway for Bacterial Degradation of 2,6-Dinitrotoluene

2000 ◽  
Vol 66 (5) ◽  
pp. 2139-2147 ◽  
Author(s):  
Shirley F. Nishino ◽  
George C. Paoli ◽  
Jim C. Spain
Keyword(s):  
Burkholderia Cepacia ◽  
Dienoic Acid ◽  
Sole Source ◽  
Bacterial Degradation ◽  
Ring Cleavage ◽  
Bacterial Strains ◽  
Carbon And Nitrogen ◽  
Isolation And Characterization ◽  
Oxidative Pathway

ABSTRACT An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkholderia sp. strain DNT has been reported previously. We report here the isolation of additional strains with the ability to mineralize 2,4-DNT by the same pathway and the isolation and characterization of bacterial strains that mineralize 2,6-dinitrotoluene (2,6-DNT) by a different pathway.Burkholderia cepacia strain JS850 andHydrogenophaga palleronii strain JS863 grew on 2,6-DNT as the sole source of carbon and nitrogen. The initial steps in the pathway for degradation of 2,6-DNT were determined by simultaneous induction, enzyme assays, and identification of metabolites through mass spectroscopy and nuclear magnetic resonance. 2,6-DNT was converted to 3-methyl-4-nitrocatechol by a dioxygenation reaction accompanied by the release of nitrite. 3-Methyl-4-nitrocatechol was the substrate for extradiol ring cleavage yielding 2-hydroxy-5-nitro-6-oxohepta-2,4-dienoic acid, which was converted to 2-hydroxy-5-nitropenta-2,4-dienoic acid. 2,4-DNT-degrading strains also converted 2,6-DNT to 3-methyl-4-nitrocatechol but did not metabolize the 3-methyl-4-nitrocatechol. Although 2,6-DNT prevented the degradation of 2,4-DNT by 2,4-DNT-degrading strains, the effect was not the result of inhibition of 2,4-DNT dioxygenase by 2,6-DNT or of 4-methyl-5-nitrocatechol monooxygenase by 3-methyl-4-nitrocatechol.

Cultivation and Harvesting of Selenium-Enriched Ganoderma lingzhi and Spent Medium Using Kudzu Vine as Substrate

2019 ◽  
Vol 18 (2) ◽  
pp. 152-157
Author(s):  
Zeng Xianlu ◽  
Han Fei ◽  
Zhong Yanmei
Keyword(s):  
Growth Medium ◽  
Wheat Bran ◽  
Fruiting Body ◽  
Sodium Selenite ◽  
Human Consumption ◽  
Growth Substrate ◽  
Organic Selenium ◽  
Significant Difference ◽  
Ganoderma Lingzhi ◽  
Run Speed

In order to harvest selenium-enriched fruiting body and spores of Ganoderma lingzhi and spent medium, G. lingzhi was cultivated in kudzu vine as substrate and the bio-transformation of selenite was evaluated. The growth medium consisted of Kudzu vine supplemented with 20% wheat bran or sawdust or none. The growth medium was supplemented with 0, 10, 20, 30, and 50 mg/kg of sodium selenite. We found a significant difference in spawn run speed, fruiting body and spore yields when Kudzu vine was supplemented with wheat bran or sawdust. However, when whole-kudzu vine was used alone as substrate, it resulted in a significantly lower spawn run speed, fruiting body, and spore yields compared with kudzu vine + sawdust substrate and kudzu vine + wheat bran substrate. The selenium content in fruiting body and spores increased with increasing sodium selenite supplementation and approximately equaled half of the selenium in the substrate. No selenite was detected in both the fruiting body and spores. However, in the spent medium when sodium selenite was supplemented at 10, 20, 30, 50 mg/kg, the residual selenite concentration decreased to 0.45, 0.72, 1.29, and 1.95 mg/kg, respectively, suggesting a higher selenite transformation (92.27–93.57%). In conclusion, if Ganoderma fruiting body and spores were to be harvested for human consumption, approximately 50 mg/kg selenite should be added to the growth substrate. On the other hand, if the spent medium was to be used as an organic selenium source, the optimal sodium selenite supplementation level would be 10 mg/kg.

Transformation of Alachlor by Microbial Communities

Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 416-420 ◽  
Author(s):  
Hone L. Sun ◽  
Thomas J. Sheets ◽  
Frederick T. Corbin
Keyword(s):  
Carbon Source ◽  
Growth Medium ◽  
Basal Medium ◽  
Sole Source ◽  
Ring Cleavage ◽  
Side Chain ◽  
Microbial Culture ◽  
Mixed Microbial Culture ◽  
Alternative Carbon Source ◽  
Thin Layer Chromatographic Analysis

A mixed microbial culture able to transform alachlor at a concentration of 50 μg ml-1was obtained from alachlor-treated soil after an enrichment period of 84 days. The microbial community was composed of seven strains of bacteria. No single isolate was able to utilize alachlor as a sole source of carbon. There was no alachlor left in the enriched culture after a 14-day incubation, but only 12% of the14C-ring-labeled alachlor was converted to14CO2through ring cleavage during 14 days in the basal medium amended with alachlor as a sole carbon source. The presence of sucrose as an alternative carbon source decreased the mineralization potential of the enriched culture, but sucrose increased the mineralizing ability of a three-member mixed culture. Thin-layer chromatographic analysis showed that there were four unidentified metabolites of alachlor produced by the enriched culture. Sucrose decreased the amount of two of the four metabolites. The absence of a noticeable decline in radioactivity beyond the initial 12% suggested that the side chain of alachlor was utilized as carbon source by the enriched culture. Little difference in radioactivity between growth medium and cell-free supernatant of the growth medium suggested that the carbon in the ring was not incorporated into the cells of the degrading microorganisms.

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

scholarly journals AzeR, a transcriptional regulator that responds to azelaic acid in Pseudomonas nitroreducens

Microbiology ◽  
2020 ◽  
Vol 166 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Cristina Bez ◽  
Sree Gowrinadh Javvadi ◽  
Iris Bertani ◽  
Giulia Devescovi ◽  
Corrado Guarnaccia ◽  
...  
Keyword(s):  
Azelaic Acid ◽  
Type Species ◽  
Isocitrate Lyase ◽  
Model Organism ◽  
Transcriptional Regulator ◽  
Sole Source ◽  
Bacterial Degradation ◽  
Content Type ◽  
Link Type ◽  
Pseudomonas Nitroreducens

Azelaic acid is a dicarboxylic acid that has recently been shown to play a role in plant-bacteria signalling and also occurs naturally in several cereals. Several bacteria have been reported to be able to utilize azelaic acid as a unique source of carbon and energy, including Pseudomonas nitroreducens . In this study, we utilize P. nitroreducens as a model organism to study bacterial degradation of and response to azelaic acid. We report genetic evidence of azelaic acid degradation and the identification of a transcriptional regulator that responds to azelaic acid in P. nitroreducens DSM 9128. Three mutants possessing transposons in genes of an acyl-CoA ligase, an acyl-CoA dehydrogenase and an isocitrate lyase display a deficient ability in growing in azelaic acid. Studies on transcriptional regulation of these genes resulted in the identification of an IclR family repressor that we designated as AzeR, which specifically responds to azelaic acid. A bioinformatics survey reveals that AzeR is confined to a few proteobacterial genera that are likely to be able to degrade and utilize azelaic acid as the sole source of carbon and energy.

scholarly journals Molecular Mechanism ofN,N-Dimethylformamide Degradation inMethylobacteriumsp. Strain DM1

2019 ◽  
Vol 85 (12) ◽  
Author(s):  
Xinyu Lu ◽  
Weiwei Wang ◽  
Lige Zhang ◽  
Haiyang Hu ◽  
Ping Xu ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Gene Clusters ◽  
Sole Source ◽  
Human Beings ◽  
Sequencing Data ◽  
Carbon And Nitrogen ◽  
Redundant Genes ◽  
Evolutionary Advantage ◽  
Redundant Gene ◽  
Phenotype Identification

ABSTRACTN,N-Dimethylformamide (DMF) is one of the most common xenobiotic chemicals, and it can be easily emitted into the environment, where it causes harm to human beings. Herein, an efficient DMF-degrading strain, DM1, was isolated and identified asMethylobacteriumsp. This strain can use DMF as the sole source of carbon and nitrogen. Whole-genome sequencing of strain DM1 revealed that it has a 5.66-Mbp chromosome and a 200-kbp megaplasmid. The plasmid pLVM1 specifically harbors the genes essential for the initial steps of DMF degradation, and the chromosome carries the genes facilitating subsequent methylotrophic metabolism. Through analysis of the transcriptome sequencing data, the complete mineralization pathway and redundant gene clusters of DMF degradation were elucidated. The dimethylformamidase (DMFase) gene was heterologously expressed, and DMFase was purified and characterized. Plasmid pLVM1 is catabolically crucial for DMF utilization, as evidenced by the phenotype identification of the plasmid-free strain. This study systematically elucidates the molecular mechanisms of DMF degradation byMethylobacterium.IMPORTANCEDMF is a hazardous pollutant that has been used in the chemical industry, pharmaceutical manufacturing, and agriculture. Biodegradation as a method for removing DMF has received increasing attention. Here, we identified an efficient DMF degrader,Methylobacteriumsp. strain DM1, and characterized the complete DMF mineralization pathway and enzymatic properties of DMFase in this strain. This study provides insights into the molecular mechanisms and evolutionary advantage of DMF degradation facilitated by plasmid pLVM1 and redundant genes in strain DM1, suggesting the emergence of new ecotypes ofMethylobacterium.

Biodegradation of cyanide by Rhodococcus UKMP-5M

Biologia ◽  
2013 ◽  
Vol 68 (2) ◽  
Author(s):  
Maegala Nallapan Maniyam ◽  
Fridelina Sjahrir ◽  
Abdul Ibrahim ◽  
Anthony Cass
Keyword(s):  
Contaminated Soils ◽  
Nitrile Hydratase ◽  
Sole Source ◽  
Optimum Conditions ◽  
Carbon And Nitrogen ◽  
Bacterial Enzyme ◽  
End Products ◽  
Treatment Facilities ◽  
Organic Nutrients ◽  
Structural Levels

AbstractA new bacterial strain, Rhodococcus UKMP-5M isolated from petroleum-contaminated soils demonstrated promising potential to biodegrade cyanide to non-toxic end-products. Ammonia and formate were found as final products during growth of the isolate with KCN as the sole nitrogen source. Formamide was not detected as one of the end-products suggesting that the biodegradation of cyanide by Rhodococcus UKMP-5M may have proceeded via a hydrolytic pathway involving the bacterial enzyme cyanidase. No growth of the bacterium was observed when KCN was supplied as the sole source of carbon and nitrogen even though marginal reduction in the concentration of cyanide was recorded, indicating the toxic effect of cyanide even in cyanide-degrading microorganisms. The cyanide biodegradation ability of Rhodococcus UKMP-5M was greatly affected by the presence of organic nutrients in the medium. Medium containing glucose and yeast extract promoted the highest growth rate of the bacterium which simultaneously assisted complete biodegradation of 0.1 mM KCN within 24 hours of incubation. It was found that growth and cyanide biodegradation occurred optimally at 30°C and pH 6.3 with glucose as the preferred carbon source. Acetonitrile was used as an inducer to enhance cyanide biodegradation since the enzymes nitrile hydratase and/or nitrilase have similarity at both the amino acid and structural levels to that of cyanidase. The findings from this study should be of great interest from an environmental and health point of views since the optimum conditions discovered in the present study bear a close resemblance to the actual scenario of cyanide wastewater treatment facilities.

Simultaneous degradation of acetonitrile and biphenyl by Pseudomonas aeruginosa

1991 ◽  
Vol 37 (6) ◽  
pp. 411-418 ◽  
Author(s):  
Mohamed S. Nawaz ◽  
Kirit D. Chapatwala
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acetic Acid ◽  
Benzoic Acid ◽  
Sole Carbon Source ◽  
Nitrile Hydratase ◽  
Sole Source ◽  
Sole Nitrogen Source ◽  
Carbon And Nitrogen ◽  
Simultaneous Degradation ◽  
Key Words Biodegradation

A bacterium capable of utilizing either acetonitrile as the sole source of carbon and nitrogen or biphenyl as the sole source of carbon was isolated from soil and identified as Pseudomonas aeruginosa. The bacterium also utilized other nitriles, amides, and polychlorinated biphenyls (PCBs) as growth substrates. Acetonitrile- or biphenyl-grown cells oxidized these substrates without a lag. In studies with [14C]acetonitrile, nearly 74% of the carbon was recovered as 14CO2 and 8% was associated with the biomass. In studies with [14C]biphenyl, nearly 68% of the carbon was recovered as 14CO2 and nearly 6% was associated with the biomass. Although higher concentrations of acetonitrile as the sole sources of nitrogen inhibited the rates of [14C]biphenyl mineralization, lower concentrations (0.05%, w/v) gave a 77% stimulation in 14CO2 recovery. Pseudomonas aeruginosa metabolized acetonitrile to ammonia and acetic acid and biphenyl to benzoic acid. The bacterium also simultaneously utilized biphenyl as the sole carbon source and acetonitrile as the sole nitrogen source. However, biphenyl utilization increased only after the depletion of acetronitrile. Metabolites of the mixed substrate were ammonia and benzoic acid, which completely disappeared in the later stages of incubation. Nitrile hydratase and amidase were resposible for the transformation of acetonitrile to acetic acid and ammonia. Key words: biodegradation, acetonitrile, biphenyl, Pseudomonas aeruginosa.

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