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E Grund

Publications and source records attributed to E Grund.

At least 19 recordsLinked to original sources
PubMed1998

Utilization of quinate and p-hydroxybenzoate by actinomycetes: key enzymes and taxonomic relevance.

474 strains of the actinomycete genera Streptomyces (including species of the former genera Chainia and Streptoverticillium), Pseudonocardia and Micromonospora were examined for their ability to degrade quinate (Q) and p-hydroxybenzoate (pHB); selected strains were also tested for their capacity to catabolize benzoate (B). Whereas in the case of Q (5-10 g/l of a mineral salts agar medium) the growth response signalizes assimilation, pHB has to be supplied in lower concentration (routinely 0.3 g/l together with small amounts of peptone and yeast extract in liquid broth), and its degradation has to be determined spectrophotometrically. 27% of the streptomycete strains were able to grow with Q, and 57% with pHB. The three strains of "Chainia" that were tested metabolized Q and pHB, but none of the fourty species of "Streptoverticillium" showed this ability. 80% of the 30 strains of Psn. autotrophica grew with Q, and 100% degraded pHB and B. Two of the five Micromonospora strains gave a positive response with pHB, but not with Q.-Toluene treated cells (preincubated with Q, pHB or B, respectively) gave a positive Rothera reaction with protocatechuate or catechol respectively, thus demonstrating that these organisms employed the beta-ketoadipate pathway (orthofission) for the degradation of Q, pHB and B. The assay of five relevant enzymes in cell-free extracts of nine selected organisms showed that in nocardioform actinomycetes (Pseudonocardia, Rhodococcus) all enzymes of the protocatechuate branch of the ketoadipate pathway seem to be induced by beta-ketoadipate as demonstrated here for protocatechuate-3,4-dioxygenase. In contrast, in Streptomyces this enzyme appears to be induced by its substrate, protocatechuate, whereas the regulation of the other enzymes of this pathway remains to be elucidated.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1992

Cloning and sequence analysis of genes for dehalogenation of 4-chlorobenzoate from Arthrobacter sp. strain SU.

Strains of Arthrobacter catalyze a hydrolytic dehalogenation of 4-chlorobenzoate (4-CBA) to p-hydroxybenzoate. The reaction requires ATP and coenzyme A (CoA), indicating activation of the substrate via a thioester, like that reported for Pseudomonas sp. strain CBS3 (J. D. Scholten, K.-H. Chang, P. C. Babbit, H. Charest, M. Sylvestre, and D. Dunaway-Mariano, Science 253:182-185, 1991). The dehalogenase genes of Arthrobacter sp. strain SU were cloned and expressed in Escherichia coli. Analyses of deletions indicate that dehalogenation depends on three open reading frames (ORFs) which are organized in an operon. There is extensive sequence homology to corresponding gene products in Pseudomonas sp. strain CBS3, suggesting that ORF1 and ORF2 encode a 4-CBA-CoA-ligase and a 4-CBA-CoA dehalogenase, respectively. ORF3 possibly represents a thioesterase, although no homology to the enzyme from Pseudomonas sp. strain CBS3 exists.

Amino Acid Sequence↗
PubMed1992

Naphthalene degradation via salicylate and gentisate by Rhodococcus sp. strain B4.

Rhodococcus sp. strain B4, isolated from a soil sample contaminated with polycyclic aromatic hydrocarbons, grows with naphthalene as the sole source of carbon and energy. Salicylate and gentisate were identified as intermediates in the catabolism of naphthalene. In contrast to the well-studied catabolic pathway encoded by the NAH7 plasmid of Pseudomonas putida, salicylate does not induce the genes of the naphthalene-degradative pathway in Rhodococcus sp. strain B4. The key enzymes of naphthalene degradation in Rhodococcus sp. strain B4 have unusual cofactor requirements. The 1,2-dihydroxynaphthalene oxygenase activity depends on NADH and the salicylate 5-hydroxylase requires NADPH, ATP, and coenzyme A.

Biodegradation, Environmental↗
PubMed1991

Construction of a hybrid plasmid capable of replication in Amycolatopsis mediterranei.

A new plasmid, pA387, has been isolated from "Amycolatopsis sp." (DSM 43387). This plasmid could be isolated from liquid culture as well as mycelium from agar plates by a modified procedure. Plasmid pA387 is about 29.6 kb and can be cured at low frequency by protoplasting and ethidium bromide and heat treatment. Hybridization experiments showed that this plasmid is present in free form and does not integrate into the chromosome. A hybrid plasmid was constructed by cloning a 5.1-kb fragment of pA387 into the Escherichia coli vector pDM10. This hybrid plasmid, termed pRL1, could be transformed into Amycolatopsis mediterranei and A. orientalis by electroporation. A transformation frequency of 2.2 x 10(3) transformants per micrograms of DNA at 12.5 kV/cm and a pulse duration of 10.8 ms was obtained in A. mediterranei, whereas 1.1 x 10(5) transformants per microgram of DNA were obtained at a field strength of 7.5 kV/cm and a pulse duration of 7.6 ms in A. orientalis. Plasmid pRL1 is the first hybrid plasmid which could be used successfully for the transformation of A. mediterranei. The plasmid has a rather high copy number, is genetically stable, and can be easily reisolated from A. mediterranei. Plasmid pRL1 will be useful for further construction of a shuttle vector for E. coli and A. mediterranei and becomes the basis for the development of gene cloning techniques in Amycolatopsis spp.

Cloning, Molecular↗
PubMed1990

Catabolism of benzoate and monohydroxylated benzoates by Amycolatopsis and Streptomyces spp.

Eight actinomycetes of the genera Amycolatopsis and Streptomyces were tested for the degradation of aromatic compounds by growth in a liquid medium containing benzoate, monohydroxylated benzoates, or quinate as the principal carbon source. Benzoate was converted to catechol. The key intermediate in the degradation of salicylate was either catechol or gentisate, while m-hydroxybenzoate was metabolized via gentisate or protocatechuate. p-Hydroxybenzoate and quinate were converted to protocatechuate. Catechol, gentisate, and protocatechuate were cleaved by catechol 1,2-dioxygenase, gentisate 1,2-dioxygenase, and protocatechuate 3,4-dioxygenase, respectively. The requirement for glutathione in the gentisate pathway was dependent on the substrate and the particular strain. The conversion of p-hydroxybenzoate to protocatechuate by p-hydroxybenzoate hydroxylase was gratuitously induced by all substrates that were metabolized via protocatechuate as an intermediate, while protocatechuate 3,4-dioxygenase was gratuitously induced by benzoate and salicylate in two Amycolatopsis strains.

Actinomycetales↗
PubMed1989

Preliminary characterization of a group of actinophages of the thermophilic actinomycete genus Saccharomonospora.

The comparison of the Saccharomonospora phages phi SaC1, phi SaG1, phi SaV1, phi SaV2, phi SaV3, and Tm1 demonstrated that they all belong to a single group of closely related actinophages: they were similar with regard to host range, virion mophology (B1 type), genome length (43-45 kb), and GC content of their genomes (63, 3% G + C). Furthermore, DNA-DNA hybridization showed that the phage genomes had a high degree of homology to each other. The phages are, therefore, proposed as representatives of a new bacteriophage species in the sense of the ICTV.

Actinomycetaceae↗
PubMed1986

Structural determination of a new naturally occurring cyclic vitamin K.

The respiratory quinone composition of 5 members of the genus Nocardia was examined. All species contained a hitherto unknown cyclic vitamin K-like molecule as their predominant lipoquinone. On the basis of mass spectrometry, 1H and 13C nuclear magnetic resonance spectrometry, the novel quinone was shown to correspond to (2E, 14E, 18E, 22E)-2-[3,7, 11,15,19,23-hexamethyl-25-(2,6,6-trimethylcyclohex-2- enyl)pentacosa-2, 14,18,22-tetraenyl]-3-methyl-1,4-naphthoquinone. Results indicate this molecule may represent a valuable phylogenetic marker for the prokaryote genus Nocardia.

Chromatography, High Pressure Liquid↗
PubMed1980

Reduced induction of pyruvate kinase after feeding 2-acetylaminofluorene.

After administration of carcinogens to laboratory animals reduced induction of some enzymes has been found which is believed to be associated with the carcinogenic process. It is suggested that this effect may be used for the testing of chemical substances for carcinogenicity. For this purpose the dietary induction of pyruvate kinase in rat liver was investigated after feeding 2-acetylaminofluorene. The induced activity in the animals fed the carcinogen was found to be significantly lower than in the control, however, the extent of this reduction was too low to be used for testing chemical substances for carcinogenicity.

2-Acetylaminofluorene↗
PubMed1979

[The influence of 2-acetylaminofluorene on the dietary induction of pentose phosphate pathway enzymes (author's transl)].

The influence of feeding 2-acetylaminofluorene on the dietary induction of the enzymes glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase by a fasting-refeeding regime was investigated in the liver of hooded rats. After feeding a diet containing 0,03% acetylaminofluorene for two weeks, the induced activity of glucose-6-phosphate dehydrogenase was diminished significantly; after feeding this carcinogen either for 4 weeks or for 4 weeks followed by feeding carcinogen-free diet for 2 weeks, the diminution of the induction was hardly perceptible. In case of 6-phosphogluconate dehydrogenase the diminution of the induction was only slightly expressed, without statistical significance.

2-Acetylaminofluorene↗
PubMed1978

Use of human-liver microsomes from kidney-transplant donors for the induction of chromatid aberrations and sister-chromatid exchanges by means of pre-carcinogens in Chinese hamster cells in vitro.

Samples of two human livers taken during operation of kidney donor patients were processed for microsome fractions and used for metabolization of cyclophosphamide (CP) and dimethylnitrosamine (DMN) in combination with the NADPH-generating system. Rat-liver microsomes were checked for comparison. Induction of chromatid aberrations and sister-chromatid exchanges in a newly isolated clone of Chinese hamster fibroblasts served as indicators of activity. Human S-9 fractions standardized on protein content showed strong variations of CP and DMN activation. Whereas liver microsomes of one patient (who also suffered from Gaucher's disease) were highly active for both pre-carcinogens and metabolized DMN at the same level as the uninduced rat-liver microsomes, the S-9 fraction from the second patient failed to activate CP, but was distinctly positive for DMN. It is suggested that samples of liver and other organs of renal transplant donors might be a practicable source of freshly prepared human microsome fractions usable in biochemical, genetic and carcinogenetic studies. Problems concerning the extrapolation of results are discussed.

Biotransformation↗
PubMed1978

Comparative study of nitroglycerin and molsidomine. Effects on the integrated systemic venous bed and the arterial pressure in dogs.

The effect of nitroglycerin, N-carboxy-3-morpholino-sydnonimine-ethylester (molsidomine, Corvaton), and its metabolite 3-morpholinosydnonimine upon the peripheral circulation was investigated in 38 dogs with cardio-pulmonary bypass. The three compounds increased the integrated systemic venous blood volume and decreased the mean arterial pressure. The time course of the action of nitroglycerin was different from that of molsidomine: The arterial and venous effects of nitroglycerin began immediately after the injection was started, reached a maximum, and had disappeared after 7 min. The effects of molsidomine started later and showed no tendency to decrease during the observation period of 30 min. When referred to the same decrease in arterial blood pressure, molsidomine acted more strongly upon the systemic venous bed than did nitroglycerin. The arterial and venous effects of the molsidomine metabolite could be antagonized by a dopamine infusion. It is concluded that the hypotensive effect of the three compounds observed in the intact circulation is due to the diminuation of peripheral resistance as well as to the dilatation of the systemic venous bed. The dilatation of the veins effects a decrease in the venous return and thereby in the cardiac output and the arterial pressure. It can be concluded that the antianginal effect of the three compounds is not only due to the diminution of the afterload of the heart; the diminution of the heart; the diminution of the preload also represents an important component of action.

Animals↗
PubMed1977

[Enzyme patterns in connective tissue proliferations (author's transl)].

In a series of benign or semimalignant connective tissue proliferations (4 desmoids, 1 recurrence of a dermatofibrosarcoma protuberans, 4 fibromas, 1 neurofibroma, 3 keloids, 3 Dupuytren's contractures) and a normal fascia for comparison the pattern of 18 enzymes from different metabolic pathways was investigated. It should be clarified whether alterations of the enzyme pattern wouldoccur, asthey are found in malignant tumours. The activity of most of the enzymes investigated increased about twofold in the latter of two extirpations (16 months interval) of a recurring desmoid. In the recurrence of a dermatofibrosarcoma protuberans and in a recurrance of a fibroma a remarkably high activity of glucose-6-phosphate dehydrogenase and pyruvate kinase was found. High activities of these enzymes are known to be characteristic of experimental tumours of animals and human malignant neoplasms. Therefore it is assumed that these differences from the normal patternof enzyme activity are related to recidivity and may be regarded as first signs of a deviation from benignity. Based on these results further studies haveto be done with the aim to find a biochemical tool for, evaluation and prognosis of the course of these diseases.

Dupuytren Contracture↗