| quartromicin, a complex of novel antiviral antibiotics. i. production, isolation, physico-chemical properties and antiviral activity. | a strain of amycolatopsis orientalis no. q427-8 (atcc 53884) was found to produce a complex of new antiviral antibiotics, quartromicin which consisted of at least six components a1, a2, a3, d1, d2 and d3. structural studies suggested that they are a novel type of molecules unrelated to any known antibiotics. each component of quartromicin exhibited antiviral activity against herpes simplex virus type 1, influenza virus type a and human immunodeficiency virus. | 1992 | 1313409 |
| purification and characterization of a dual function 3-dehydroquinate dehydratase from amycolatopsis methanolica. | studies on hydroaromatic metabolism in the actinomycete amycolatopsis methanolica revealed that the organism grows rapidly on quinate (but not on shikimate) as sole carbon- and energy source. quinate is initially converted into the shikimate pathway intermediate 3-dehydroquinate by an inducible nad(+)-dependent quinate/shikimate dehydrogenase. 3-dehydroquinate dehydratase subsequently converts 3-dehydroquinate into 3-dehydroshikimate, which is used partly for the biosynthesis of aromatic amino a ... | 1992 | 1479361 |
| dethymicin, a novel immunosuppressant isolated from an amycolatopsis. fermentation, isolation, physico-chemical properties and biological activities. | in the course of screening for immunomodulators inhibiting the mixed lymphocyte culture reaction (mlcr), we found a novel immunosuppressant, dethymicin in mycelium of amycolatopsis mediterranei mi710-51f6. from physico-chemical properties and biological activity it is different from immunosuppressants produced by microorganisms such as cyclosporins, fk506 and rapamycin. it inhibited immune responses in vitro and in vivo, and prolonged skin allograft in rats. | 1992 | 1490872 |
| nad-linked, factor-dependent formaldehyde dehydrogenase or trimeric, zinc-containing, long-chain alcohol dehydrogenase from amycolatopsis methanolica. | nad-linked, factor-dependent formaldehyde dehydrogenase (fd-fa1dh) of the gram-positive methylotrophic bacterium, amycolatopsis methanolica, was purified to homogeneity. it is a trimeric enzyme with identical subunits (molecular mass 40 kda) containing 6 atoms zn/enzyme molecule. the factor is a heat-stable, low-molecular-mass compound, which showed retention on an aminex hpx-87h column. inactivation of the factor occurred during manipulation, but activity could be restored by incubation with di ... | 1992 | 1597190 |
| dye-linked dehydrogenase activities for formate and formate esters in amycolatopsis methanolica. characterization of a molybdoprotein enzyme active with formate esters and aldehydes. | cell-free extracts of methanol-grown amycolatopsis methanolica contain dye-linked dehydrogenase activities for formate and methyl formate. fractionation of the extracts revealed that the (unstable) activity for formate resides in membrane particles, while that for methyl formate belongs to a soluble enzyme that was purified and characterized. the enzyme, indicated as formate-ester dehydrogenase, appeared to be a molybdoprotein (4 fe, 3 or 4 s, 1 mo and 1 fad were found for each enzyme molecule), ... | 1992 | 1597191 |
| phage typing--a useful tool in actinomycete systematics. | a total of 905 strains of several genera of the actinomycetales were tested in respect to their sensitivity to genus- and species-specific actinophages. the results provided clear evidence that phage typing is a useful aid for the identification of actinomycetes. at the genus level, the specificity of actinophages has led to the correct placement of falsely identified strains, as well as to the rearrangement of genera. at the species level, however, phage typing has been less successful: only so ... | 1992 | 1612443 |
| transformation system for amycolatopsis (nocardia) mediterranei: direct transformation of mycelium with plasmid dna. | a new procedure for transformation of amycolatopsis (nocardia) mediterranei lbg a3136 was developed. the method makes use of polyethylene glycol and alkaline cations and enables direct transformation of the a. mediterranei mycelium with high efficiency: more than 10(6) transformants per microgram of dna were obtained. transformation of a. mediterranei is stimulated by the ionophore antibiotic valinomycin and abolished by arsenate and p-chloromercuribenzenesulfonate. pmea123, a vector based on th ... | 1991 | 1655706 |
| [comparative evaluation of various bacterial growth inhibitors as selective agents for isolation of soil actinomyces]. | tobramycin and dioxidine sensitivity of 57 strains belonging to 14 actinomycetes genera was studied. the cultures of streptomyces were much more sensitive to tobramycin than the cultures of rare genera. the majority of the streptomyces cultures showed a high resistance to dioxidine (mic greater than or equal to 50 micrograms/ml). at the same time the majority of the cultures of rare genera were inhibited by low concentrations of dioxidine (no more than 50 micrograms/ml). for isolation of actinom ... | 1991 | 1805699 |
| menaquinone patterns of amycolatopsis species. | the menaquinones of representative strains of the actinomycete genus amycolatopsis were examined by reverse phase thin-layer chromatography and mass spectrometry. representatives of all seven validly described species contained various combinations of di-, tetra- and hexahydrogenated menaquinones with nine isoprene units as predominant isoprenologues. it seems likely that the variation in the predominant menaquinones merely reflects the stages from the growth cycle from which biomass was taken. ... | 1991 | 1863315 |
| [effect of low molecular weight regulators on the biosynthesis of rifamycin b by amycolatopsis mediterranei strains]. | formation of differentiation regulators of the a-factor group in representatives of nocardia and nocardia-like actinomyces: n. asteroides, n. brasiliensis, amycolatopsis mediterranei and "streptomyces listeri" was observed. the effect of the regulators of different nature (barbital, a-factor and b-factor) on biosynthesis of rifamycin b by a. mediterranei strains was studied. it was shown that the a-factor stimulated rifamycin b production in the adifferentiated low active variant isolated from a ... | 1991 | 1877868 |
| mm 55266 and mm 55268, glycopeptide antibiotics produced by a new strain of amycolatopsis. isolation, purification and structure determination. | two novel glycopeptide antibiotics mm 55266 and mm 55268 containing fatty acid acyl functions, and of molecular formula c86h89n8o35cl5 and c87h91n8o35cl5, respectively, have been isolated and identified from a complex produced by amycolatopsis sp. ncib 40089. fermentation conditions for their production, and methods for their isolation are described. structures have been deduced by use of cosy and noe nmr techniques and supported by chemical degradation studies. both glycopeptides possessed good ... | 1991 | 1917694 |
| 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 pa ... | 1991 | 2039229 |
| [isolation of antibiotic-producing actinomycetes from soil samples exposed to uv light]. | the use of nonroutine means in isolation of microorganisms from natural substrates extended the possibilities of detecting new cultures which often appear to be producers of previously unknown antibiotics. a new procedure for isolating actinomyces of definite groups was developed. it implies preliminary exposure of soil suspensions to uv light. with the use of the procedure, 2539 strains of actinomycetes belonging to different genera were isolated. there was a marked decrease after the irradiati ... | 1990 | 2092642 |
| amplification on the amycolatopsis (nocardia) mediterranei plasmid pmea100: sequence similarities to actinomycete att sites. | an amplification of a 2.0-kb fragment was found on the plasmid pmea100 isolated from a subculture of the wild-type strain lbg a3136 of amycolatopsis (nocardia) mediterranei. plasmid preparations contained a mixture of molecules with copy numbers of the amplified unit in the range of 2 to 10. the amplification on pmea100 was stable; propagation of cells for many generations did not change the pattern of the amplified dna. fragments of the plasmids containing the amplifiable unit of dna (aud) and ... | 1990 | 2096399 |
| mm 47761 and mm 49721, glycopeptide antibiotics produced by a new strain of amycolatopsis orientalis. isolation, purification and structure determination. | two glycopeptide antibiotics mm 47761 and mm 47921 have been isolated from amycolatopsis orientalis ncib 12608. fermentation conditions for their production, and methods for their isolation are described. the metabolites have been characterised by physio-chemical and biological properties and the structure determined by a combination of chemical degradation, cosy and noe nmr studies. both metabolites showed good antibacterial activity against gram-positive organisms. | 1990 | 2120168 |
| in vitro activity of ly264826, a new glycopeptide antibiotic, against gram-positive bacteria isolated from patients with cancer. | the in vitro activity of ly264826, a novel glycopeptide antibiotic produced by amycolatopsis orientalis, was compared with those of vancomycin, teicoplanin, and oxacillin against 311 gram-positive clinical isolates from patients with cancer, ly264826 had lower mics for 90% of isolates (mic90) than vancomycin for all species tested. it was active against oxacillin-resistant isolates including staphylococcus aureus (mic90, 0.5 micrograms/ml), staphylococcus haemolyticus (mic90, 2.0 micrograms/ml), ... | 1990 | 2149921 |
| amycolatopsis methanolica sp. nov., a facultatively methylotrophic actinomycete. | the generic position of a gram-positive, facultatively methylotrophic actinomycete known as nocardia sp. strain 239 was determined by comparing reverse transcriptase sequences of 16s rrna. the assignment of the organism to the genus amycolatopsis was strongly supported by chemotaxonomic and morphological data. a comparison with the type strains of validly described amycolatopsis species showed that the organism formed the nucleus of a new species. the name proposed for this new species is amycol ... | 1990 | 2223611 |
| microbial conversion of milbemycins: 30-oxidation of milbemycin a4 and related compounds by amycolata autotrophica and amycolatopsis mediterranei. | microorganisms were screened for their ability to modify milbemycin a4 (1a). many strains, mostly actinomycetes and zygomycetes, were found to convert milbemycin a4 (1a) to one or more new products. among these products, m-1, m-2, and m-3 were obtained using amycolata autotrophica subsp. amethystina atcc 35204, and were identified as 30-hydroxymilbemycin a4 (1b), 26,30-dihydroxymilbemycin a4 (1c), and milbemycin a4 30-oic acid (1d), respectively. other milbemycins and ll-f28249 alpha (7a) also u ... | 1990 | 2258330 |
| phenotypic and genotypic heterogeneity of glycopeptide resistance determinants in gram-positive bacteria. | gram-positive glycopeptide-resistant bacteria isolated in various hospitals in europe and in the united states between 1986 and 1988 were collected. three resistance phenotypes could be distinguished. thirty-one enterococci were highly resistant to vancomycin and teicoplanin. resistance was transferable to other enterococci by conjugation for 16 of the 22 isolates that were tested. homology was detected by hybridization between a probe specific for the vana gene, which encodes an inducible high- ... | 1990 | 2291654 |
| uk-69,753, a novel member of the efrotomycin family of antibiotics. ii. structure determination and biological activity. | a novel antibiotic, uk-69,753, has been isolated from a submerged fermentation of amycolatopsis orientalis strain n731-15. uk-69,753 has been assigned the structure 1 using spectroscopic means, primarily by nmr analysis. uk-69,753 is a glycoside of factumycin (a40a), a previously reported member of a small group of antibiotics related to aurodox and efrotomycin. uk-69,753 was shown to have potent activity both in vitro and in vivo against the swine pathogen treponema hyodysenteriae. | 1989 | 2584145 |
| uk-69,753, a novel member of the efrotomycin family of antibiotics. i. taxonomy of the producing organism, fermentation and isolation. | uk-69,753 is a novel antibiotic structurally related to efrotomycin and factumycin, produced by a new strain of amycolatopsis orientalis (atcc 53550). the antibiotic potency in the fermentation broth was monitored by hplc with diode array detection. a six tube counter current distribution was used to purify uk-69,753. | 1989 | 2808132 |
| novel antifungal antibiotics octacosamicins a and b. i. taxonomy, fermentation and isolation, physico-chemical properties and biological activities. | two antifungal antibiotics octacosamicins a and b were isolated from the culture broth of a strain of actinomycetes, which was identified as a strain of amycolatopsis. these antibiotics were isolated by resin adsorption and purified by column chromatography and preparative hplc. both antibiotics were found to be new substances from their physico-chemical properties. they showed broad antifungal spectra. | 1988 | 3198488 |
| azicemicins a and b, new antimicrobial agents produced by amycolatopsis. ii. structure determination. | a new structural class of antibiotics, azicemicins a (1) and b (2) were isolated from the culture broth of amycolatopsis sp. mj126-nf4. their structures were elucidated from their physico-chemical properties, various nmr experiments and chemical transformations and were shown to be 3-(1-methyl-2-aziridinyl)- and 3-(2-aziridinyl)-3,4-dihydro-3,7,8,10,12b-pentahydroxy-9,12-dimeth oxy-benz [a]anthracene-1,6(2h,5h)-dione, respectively. | 1995 | 7490223 |
| nucleotide sequences of streptomycete 16s ribosomal dna: towards a specific identification system for streptomycetes using pcr. | to facilitate the differential identification of the genus streptomyces, the 16s rrna genes of 17 actinomycetes were sequenced and screened for the existence of streptomycete-specific signatures. the 16s rdna of the streptomyces strains and amycolatopsis orientalis subsp. lurida exhibited 95-100% similarity, while that of the 16s rdna of actinoplanes utahensis showed only 88% similarity to the streptomycete 16s rdnas. potential genus-specific sequences were found in regions located around nucleo ... | 1995 | 7496525 |
| 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 protocatechuat ... | 1990 | 2339895 |
| nitrite reductase gene cloning of amycolatopsis mediterranei u-32. | southern blot analysis showed great homology existed between niad (nr gene) of aspergillus nidulans and a. mediterranei u-32 chromosome dna. a 5.0kb psti fragment from a. mediterranei u-32 complementary to a. nidulans niad gene was cloned in e. coli nm522 using niad as a probe. an identical dna band was observed through back-hybridization of the cloned dna fragment to psti digest of a. mediterranei u-32 chromosome dna. its 2.1 kb smai-ecorv fragment can only hybridize with total rna from nitrate ... | 1994 | 7534488 |
| efficient transformation of amycolatopsis orientalis (nocardia orientalis) protoplasts by streptomyces plasmids. | conditions for efficient transformation of amycolatopsis orientalis (nocardia orientalis) protoplasts by streptomyces plasmid cloning vectors were identified. three streptomycete plasmid origins of replication function in a. orientalis, as do the apramycin resistance gene from escherichia coli, the thiostrepton resistance gene from streptomyces azureus, and the tyrosinase gene from streptomyces antibioticus. a. orientalis appears to express some restriction and modification, because highest tran ... | 1987 | 3571169 |
| rifamycins: strain improvement program. | rifamycins are primarily produced by gram-positive bacterium amycolatopsis mediterranei, which belongs to the order actinomycetales. these antibiotics, apart from their application against pathogens of tuberculosis and leprosy, have also been found to be effective against several other pathogens including mycobacterium avium and pneumococcus. because of the importance of rifamycin, the producer strain a. mediterranei has been genetically manipulated since 1957 in order to develop a strain that c ... | 1995 | 7576149 |
| identification and functional analysis of the transfer region of plasmid pmea300 of the methylotrophic actinomycete amycolatopsis methanolica. | amycolatopsis methanolica contains a 13.3-kb plasmid (pmea300) that is present either as an integrated element or as an autonomously replicating plasmid. conjugational transfer of pmea300 results in pock formation, zones of growth inhibition that become apparent when plasmid-carrying donor cells develop in a confluent lawn of plasmid-lacking recipient cells. a 6.2-kb pmea300 dna region specifying the functions of conjugation and pock formation was sequenced, revealing 10 open reading frames. thi ... | 1995 | 7592426 |
| molecular cloning with a pmea300-derived shuttle vector and characterization of the amycolatopsis methanolica prephenate dehydratase gene. | an efficient restriction barrier for methylated dna in the actinomycete amycolatopsis methanolica could be avoided by using a nonmethylating escherichia coli strain for dna isolations. the a. methanolica prephenate dehydratase gene was cloned from a gene bank in a pmea300-derived shuttle vector in e. coli and characterized. | 1995 | 7592448 |
| azicemicins a and b, a new antimicrobial agent produced by amycolatopsis. i. taxonomy, fermentation, isolation, characterization and biological activities. | a new structural class of the antibiotic, azicemicins a (1) and b (2) were isolated from the culture broth of the strain mj126-nf4, which was closely related to amycolatopsis sulphurea. they were purified by adsorption on diaion hp-20, silica gel column chromatography and preparative tlc. the molecular formulas of 1 and 2 were determined to be c23h25o9n and c22h23o9n by hrfab-ms, respectively. azicemicins a and b have moderate growth inhibiting activity against gram-positive bacteria and mycobac ... | 1995 | 7730155 |
| menaquinone composition in the classification and identification of aerobic actinomycetes. | menaquinones were the only isoprenoid quinones found in 36 strains representing different species of the genera nocardia, mycobacterium, rhodococcus, amycolatopsis, saccharothrix, streptomyces, nocardiopsis and actinomadura. dihydrogenated menaquinones with nine isoprene units [mk-9(h2)] were the main components isolated from mycobacterium. dihydrogenated and tetrahydrogenated menaquinones with eight isoprene units were the predominant compounds identified in typical rhodococcus and nocardia str ... | 1988 | 3376615 |
| purification and properties of thermostable n-acylamino acid racemase from amycolatopsis sp. ts-1-60. | thermostable n-acylamino acid racemase from amycolatopsis sp. ts-1-60, a rare actinomycete strain selected for its ability to grow on agar plates incubated at 40 degrees c, was purified to homogeneity and characterized. the relative molecular mass (m(r)) of the native enzyme and the subunit was estimated to be 300,000 and 40,000 on gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis respectively. the isoelectric point (pi) of the enzyme was 4.2. the optimu ... | 1995 | 7766084 |
| cloning, dna sequencing and heterologous expression of the gene for thermostable n-acylamino acid racemase from amycolatopsis sp. ts-1-60 in escherichia coli. | the gene encoding the novel enzyme n-acylamino acid racemase (aar) was cloned in recombinant phage lambda-4 from the dna library of amycolatopsis sp. ts-1-60, a rare actinomycete, using antiserum against the enzyme. the cloned gene was subcloned and transformed in escherichia coli jm105 using puc118 as a vector. the aar gene consists of an open-reading frame of 1104 nucleotides, which specifies a 368-amino-acid protein with a molecular mass of 39411da. the molecular mass deduced from the aar gen ... | 1995 | 7766089 |
| amino acid sequence analysis of ribosomal protein at-l30 from members of the family pseudonocardiaceae. | the phylogenetic relationships of the genera belonging to the family pseudonocardiaceae were examined by a novel approach, amino acid sequencing of ribosomal at-l30 proteins. the results of partial amino acid sequencing of at-l30 preparations revealed that the members of the family pseudonocardiaceae are divided into four clusters; the first cluster contains the genus actinopolyspora, the second cluster contains the genus saccharopolyspora, the third cluster contains the genus amycolatopsis, and ... | 1995 | 7857791 |
| enzymes of glucose and methanol metabolism in the actinomycete amycolatopsis methanolica. | the actinomycete amycolatopsis methanolica was found to employ the normal bacterial set of glycolytic and pentose phosphate pathway enzymes, except for the presence of a ppi-dependent phosphofructokinase (ppi-pfk) and a 3-phosphoglycerate mutase that is stimulated by 2,3-bisphosphoglycerate. screening of a number of actinomycetes revealed ppi-pfk activity only in members of the family pseudonocardiaceae. the a. methanolica ppi-pfk and 3-phosphoglycerate mutase enzymes were purified to homogeneit ... | 1994 | 7961441 |
| a plasmid from the methylotrophic actinomycete amycolatopsis methanolica capable of site-specific integration. | amycolatopsis methanolica contains a 13.3-kb plasmid (pmea300) which is present both in the free state and integrated at a unique genomic location. a 2.1-kb pmea300 dna fragment was sequenced, revealing the putative attp site and two open reading frames, xis and int, showing similarity to genes encoding excisionases and integrases, respectively. | 1994 | 7961475 |
| chemical and molecular classification of saccharomonospora strains. | the results of our experiments showed that the 5'-terminal sequences of 23s rrnas can be used to distinguish different genera of actinomycetes, including the genera streptomyces, micromonospora, amycolatopsis, and saccharomonospora. there are small differences (< 1%) among the sequences of some strains belonging to the genera streptomyces (two strains) and saccharomonospora (seven strains). on the basis of the results of morphological and biochemical analyses, strain 9022 belongs in the genus sa ... | 1994 | 7981100 |
| prephenate dehydratase of the actinomycete amycolatopsis methanolica: purification and characterization of wild-type and deregulated mutant proteins. | prephenate dehydratase (pdt) is a key regulatory enzyme in l-phenylalanine biosynthesis in the gram-positive bacterium amycolatopsis methanolica. the pdt protein was purified to homogeneity (1957-fold) from wild-type cells with a final yield of 6.5%. it was characterized as a 150 kda homotetrameric protein with a subunit size of 34 kda. the first 35 n-terminal amino acids were identified, revealing highest similarity to the pdt proteins from corynebacterium glutamicum and bacillus subtilis. kine ... | 1995 | 7755580 |
| novel antibiotics, amythiamicins. i. taxonomy, fermentation, isolation, physico-chemical properties, and antimicrobial activity. | novel antibacterial antibiotics, amythiamicins a, b, c and d, have been isolated from the fermentation broth of amycolatopsis sp. mi481-42f4. in this paper, the taxonomy of the producing strain, fermentation, isolation, physico-chemical properties and biological activities of amythiamicins are reported. amythiamicins inhibit the growth of gram-positive bacteria including multi-drug resistant strains. | 1994 | 8040071 |
| recent trends in rifamycin research. | rifamycin is a clinically useful macrolide antibiotic produced by the gram positive bacterium amycolatopsis mediterranei. this antibiotic is primarily used against mycobacterium tuberculosis and mycobacterium leprae, causative agents of tuberculosis and leprosy, respectively. in these bacteria, rifamycin treatment specifically inhibits the initiation of rna synthesis by binding to beta-subunit of rna polymerase. apart from its activity against the bacteria, rifamycin has also been reported to in ... | 1994 | 7513153 |
| molecular characterization of microbial alcohol dehydrogenases. | there is an astonishing array of microbial alcohol oxidoreductases. they display a wide variety of substrate specificities and they fulfill several vital but quite different physiological functions. some of these enzymes are involved in the production of alcoholic beverages and of industrial solvents, others are important in the production of vinegar, and still others participate in the degradation of naturally occurring and xenobiotic aromatic compounds as well as in the growth of bacteria and ... | 1994 | 8185833 |
| a phylogenetic analysis of the family pseudonocardiaceae and the genera actinokineospora and saccharothrix with 16s rrna sequences and a proposal to combine the genera amycolata and pseudonocardia in an emended genus pseudonocardia. | the 16s rrnas of 15 species of actinomycetes belonging to the genera actinokineospora and saccharothrix and the family pseudonocardiaceae, including amycolatopsis, amycolata, pseudonocardia, saccharomonospora, and saccharopolyspora species, were sequenced by using reverse transcriptase. the sequences were analyzed along with the sequences of reference actinomycetes by using distance matrix and parsimony methods. the wall chemotype iv genus actinokineospora was found to be closely related to spec ... | 1994 | 8186093 |
| amycolatopsis alba sp. nov., isolated from soil. | a new amycolatopsis species isolated from soil produces a new glycopeptide antibiotic related to vancomycin. traditional taxonomic methods and contemporary fatty acid analysis techniques were used to establish the position of this species. the hyphae fragment extensively when the organism is cultured in liquid media. the organism is characterized by white aerial hyphae that bear long chains of cylindrical conidia. the reverse side is yellowish brown; a faint light brown soluble pigment is occasi ... | 1993 | 8240953 |
| characterization of the rhodococcus sp. ni86/21 gene encoding alcohol: n,n'-dimethyl-4-nitrosoaniline oxidoreductase inducible by atrazine and thiocarbamate herbicides. | a protein with a mol.mass of 51,000 (thce) that was induced in rhodococcus sp. ni86/21 during assimilation of thiocarbamate herbicides, atrazine, ethanol, propanol, glycerol, propionaldehyde or ethanolamine was identified by two-dimensional electrophoresis. the thce gene was cloned and sequenced. the deduced amino acid sequence revealed thce as a member of group iii alcohol dehydrogenases. thce displayed strong homology with sequenced subunit fragments of the homodecameric n,n'-dimethyl-4-nitros ... | 1995 | 7575099 |
| balhimycin, a new glycopeptide antibiotic produced by amycolatopsis sp. y-86,21022. taxonomy, production, isolation and biological activity. | a new glycopeptide antibiotic, balhimycin, has been isolated from the fermentation broth of a amycolatopsis sp. y-86,21022. balhimycin belongs to the vancomycin class of glycopeptides and contains a dehydrovancosamine sugar. the biological activity of balhimycin has been compared extensively with that of vancomycin against methicillin resistant staphylococci and also against anaerobes. balhimycin is marginally superior to vancomycin in its in vitro activity against anaerobes and in its bacterici ... | 1994 | 8175486 |
| nicotinoprotein [nad(p)-containing] alcohol/aldehyde oxidoreductases. purification and characterization of a novel type from amycolatopsis methanolica. | extracts of gram-positive bacteria like rhodococcus rhodochrous, rhodococcus erythropolis and amycolatopsis methanolica, but not those of several gram-negative ones, showed dehydrogenase activity for ethanol as well as for methanol when 4-nitroso-n,n-dimethylaniline (ndma) was used as electron acceptor. chromatography of extracts of the first two organisms revealed one activity for both substrates, that of a. methanolica two activities, one of which is able to oxidize methanol and has been purif ... | 1993 | 8385013 |
| 31-homorifamycin w, a novel metabolite from amycolatopsis mediterranei. | | 1994 | 8040064 |
| chorismate mutase and 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase of the methylotrophic actinomycete amycolatopsis methanolica. | chorismate mutase (cm) and 3-deoxy-d-arabino-heptulosonate 7-phosphate (dahp) synthase (ds) are key regulatory enzymes in l-phe and l-tyr biosynthesis in amycolatopsis methanolica. at least two cm proteins, cmia and cmib, are required for the single chorismate mutase activity in the wild type. component cmia (a homodimeric protein with 16-kda subunits) was purified to homogeneity (2,717-fold) and kinetically characterized. the partially purified cmib preparation obtained also contained the singl ... | 1995 | 8526488 |
| characterization and phylogeny of the pfp gene of amycolatopsis methanolica encoding ppi-dependent phosphofructokinase. | the actinomycete amycolatopsis methanolica employs a ppi-dependent phosphofructokinase (ppi-pfk) (ec 2.7.1.90) with biochemical characteristics similar to those of both atp- and ppi-dependent enzymes during growth on glucose. a 2.3-kb pvuii fragment hybridizing to two oligonucleotides based on the amino-terminal amino acid sequence of ppi-pfk was isolated from a genomic library of a. methanolica. nucleotide sequence analysis of this fragment revealed the presence of an open reading frame encodin ... | 1996 | 8550409 |
| a second molybdoprotein aldehyde dehydrogenase from amycolatopsis methanolica ncib 11946. | methanol-grown amycolatopsis methanolica ncib 11946 contains a molybdoprotein dehydrogenase, active with aldehydes and formate esters as substrates and with wurster's blue as electron acceptor, the so-called formate ester dehydrogenase (fedh) (van ophem et al., 1992, eur. j. biochem. 206, 519-525). it appears now that another molybdoprotein dehydrogenase is present in this organism. this enzyme, indicated here as dye-linked aldehyde dehydrogenase (dl-aldh), has the same set of cofactors and conv ... | 1996 | 8554333 |
| transformation of the methylotrophic actinomycete amycolatopis methanolica with plasmid dna: stimulatory effect of a pmea300-encoded gene. | amycolatopsis methanolica contains a 13.29-kb plasmid (pmea300) present both in the free state and integrated at a unique genomic location. a pmea300-free derivative (strain wv1) was selected, allowing further analysis of pmea300-encoded functions. whole cells of strain wv1 could be transformed at high frequencies (approximately 10(6) transformants per microgram of plasmid dna) with both circular and linear plasmid dna, provided that the pmea300-encoded stf (stimulation of transformation frequen ... | 1995 | 8559807 |
| electron microscopic analysis and structural characterization of novel nadp(h)-containing methanol: n,n'-dimethyl-4-nitrosoaniline oxidoreductases from the gram-positive methylotrophic bacteria amycolatopsis methanolica and mycobacterium gastri mb19. | the quaternary protein structure of two methanol:n,n'-dimethyl-4-nitrosoaniline (ndma) oxidoreductases purified from amycolatopsis methanolica and mycobacterium gastri mb19 was analyzed by electron microscopy and image processing. the enzymes are decameric proteins (displaying fivefold symmetry) with estimated molecular masses of 490 to 500 kda based on their subunit molecular masses of 49 to 50 kda. both methanol:ndma oxidoreductases possess a tightly but noncovalently bound nadp(h) cofactor at ... | 1993 | 8449887 |
| azicemicin a, a new antimicrobial antibiotic from amycolatopsis. | | 1993 | 8270504 |
| new 4-oxovancosamine-containing glycopeptide antibiotics from amycolatopsis sp. y-86,21022. | | 1996 | 8609078 |
| epoxyquinomicins a and b, new antibiotics from amycolatopsis. | | 1996 | 8626253 |
| isolation of trehalamine, the aglycon of trehazolin, from microbial broths and characterization of trehazolin related compounds. | trehalamine, (3ar,4r,5s,6s,6as)-2-amino-4-(hydroxymethyl)-3a,5,6,6a- tetrahydro-4h-cyclo-pent[d]oxazole-4,5,6-triol (1) and d-glucose were obtained by acid hydrolysis of trehazolin (3), a trehalase inhibitor produced by actinomycetes. more vigorous hydrolytic treatment of trehazolin afforded an aminocyclitol, (1r,2s,3r,4s,5r)-5-amino-1- (hydroxymethyl)cyclopentane-1,2,3,4-tetraol (2). trehalamine, the aglycon of trehazolin, was also found in the culture broths of two trehazolin producing strains ... | 1993 | 8360108 |
| microbial conversion of em574 and em523, gastrointestinal motor stimulating agents. | em574 exerts gastrointestinal motor stimulating (gms) activity even after being converted to its metabolites p1 and p2 in dogs. these metabolites were isolated from dog liver using a series of chromatographic procedures. their structures were determined to be the 15- and 14-hydroxyl derivatives of em574, respectively, by spectral analysis. large scale preparation by microbial transformation was investigated for further evaluation of the metabolites, because the amounts obtained by oxidation with ... | 1996 | 8823514 |
| overexpression of the gene for n-acylamino acid racemase from amycolatopsis sp. ts-1-60 in escherichia coli and continuous produciton of optically active methionine by a bioreactor. | a dna sequence encoding n-acylamino acid racemase (aar) was inserted downstream from the t7 promoter in pet3c. the recombinant plasmid was introduced into escherichia coli mm 294 lysogenized with a bacteriophage lambda having a t7 rna polymerase gene. the amount of aar produced by the e. coli transformant was 1100-fold more than that produced by amycolatopsis sp. ts-1-60, the dna donor strain. the aar was purified to homogeneity from the crude extract of the e. coli transformant by two steps: he ... | 1996 | 8867636 |
| identification of atp-dependent phosphofructokinase as a regulatory step in the glycolytic pathway of the actinomycete streptomyces coelicolor a3(2). | the atp-dependent phosphofructokinase (atp-pfk) of streptomyces coelicolor a3(2) was purified to homogeneity (1,600-fold) and characterized (110 kda, with a single type of subunit of 40 kda); it is allosterically inhibited by phosphoenolpyruvate. cloning of the pfk gene of s. coelicolor a3(2) and analysis of the deduced amino acid sequence (343 amino acids; 36,667 da) revealed high similarities to the ppi-pfk enzyme from amycolatopsis methanolica (tetramer, nonallosteric; 70%) and to the alloste ... | 1997 | 9055413 |
| production of hybrid glycopeptide antibiotics in vitro and in streptomyces toyocaensis. | the glycopeptide antibiotics vancomycin and teicoplanin are currently the last line of defence against some microorganisms that are resistant to many drugs. the emergence of vancomycin-resistant and teicoplanin-resistant enterococci underscores the need for more potent antibiotics. the glycosylation patterns of glycopeptides and chemical modifications of the glycosyl moieties have been shown to greatly influence their antibiotic activity, and certain combinations have resulted in highly active n ... | 1997 | 9115410 |
| identification of the minimal replicon of plasmid pmea300 of the methylotrophic actinomycete amycolatopsis methanolica. | the actinomycete amycolatopsis methanolica contains a 13.3 kb plasmid (pmea300), capable of enhancing the spontaneous mutation frequency of its host. depending on the growth medium pmea300 is not only maintained as an integrated element but can additionally be present as a multicopy, autonomously replicating plasmid. the minimal replicon of pmea300 was identified. two unlinked dna fragments of 2.6 kb and 0.8 kb were required for pmea300 maintenance. sequence analysis of the 2.6 kb fragment revea ... | 1995 | 8596458 |
| new method for rna isolation from actinomycetes: application to the transcriptional analysis of the alcohol oxidoreductase gene thce in rhodococcus and mycobacterium. | a new protocol for the isolation of rna from rhodococcus and other actinomycetes such as mycobacterium and amycolatopsis was developed. the method is based on rapid lysis of cells in a high-speed reciprocal shaker using small abrasive particles followed by spin column purification of the lysate. this quick procedure yields rna preparations suitable for functional studies. this was shown for the thce gene of r. erythropolis ni86/21, which encodes a n,n'-dimethyl-4-nitrosoaniline-dependent alcohol ... | 1997 | 9248086 |
| tetrazolium-dye-linked alcohol dehydrogenase of the methylotrophic actinomycete amycolatopsis methanolica is a three-component complex. | tetrazolium-dye-linked alcohol dehydrogenase (td-adh) of amycolatopsis methanolica could be resolved into three protein components, which have been purified. each of the components has the ability to reconstitute td-adh activity when combined with the other two. component 1 is identical to the previously characterized methanol:n,n'-dimethyl-4-nitrosoaniline oxidoreductase (mno), a decameric protein with 50-kda subunits, each carrying a tightly bound nadph. component 2 is a high molecular mass (> ... | 1997 | 9249038 |
| cloning and analysis of a peptide synthetase gene of the balhimycin producer amycolatopsis mediterranei dsm5908 and development of a gene disruption/replacement system. | a gene cloning system for amycolatopsis mediterranei dsm5908, the producer of the glycopeptide antibiotic balhimycin, was developed for analysis of peptide synthetase genes. a modified direct transformation procedure was used to introduce dna. the efficiency of dna uptake depended on the age of the culture: mycelium of early stationary phase (52-55 h) cultures resulted in optimal transformation frequencies. using the novel non-replicative integration vector psp1, gene disruption plasmids were co ... | 1997 | 9304873 |
| occurrence and identification of microorganisms in compacted clay-based buffer material designed for use in a nuclear fuel waste disposal vault. | a full-scale nuclear fuel waste disposal container experiment was carried out 240 m below ground in an underground granitic rock research laboratory in canada. an electric heater was surrounded by buffer material composed of sand and bentonite clay and provided heat equivalent to what is anticipated in a canadian nuclear fuel waste repository. during the experiment, the heat caused a mass transport of water and moisture content gradients developed in the buffer ranging from 13% closest to the he ... | 1997 | 9476350 |
| studies of rifamycin production by amycolatopsis mediterranei cells immobilized on glass wool. | cells of amycolatopsis mediterranei cbs 42575 were immobilized on glass wool for the production of rifamycins b and sv. glass wool (corning type) of 8 microns in diameter has a better entrapment capacity for microbial cells of microorganism than the other types of glass wool used. the most suitable amount of glass wool was 0.8 g/50 ml. the best initial cell concentration used as inoculum was 40 mg cells/50 ml. repeated batch production of rifamycins by immobilized cells on glass wool was carried ... | 1995 | 8568638 |
| 3-amino-5-hydroxybenzoic acid synthase, the terminal enzyme in the formation of the precursor of mc7n units in rifamycin and related antibiotics. | the biosynthesis of ansamycin antibiotics, like rifamycin b, involves formation of 3-amino-5-hydroxybenzoic acid (ahba) by a novel variant of the shikimate pathway. ahba then serves as the starter unit for the assembly of a polyketide which eventually links back to the amino group of ahba to form the macrolactam ring. the terminal enzyme of ahba formation, which catalyzes the aromatization of 5-deoxy-5-amino-3-dehydroshikimic acid, has been purified to homogeneity from amycolatopsis mediterranei ... | 1998 | 9497318 |
| cloning and sequence analysis of the putative rifamycin polyketide synthase gene cluster from amycolatopsis mediterranei. | the 54-kbp type i polyketide synthase gene cluster, most probably involved in rifamycin biosynthesis by amycolatopsis mediterranei, was cloned in e. coli and completely sequenced. the dna encodes five closely packed, very large open reading frames reading in one direction. as expected from the chemical structure of rifamycins, ten polyketide synthase modules and a coa ligase domain were identified in the five open reading frames which contain one to three polyketide synthase modules each. the or ... | 1998 | 9503613 |
| a new esterase for the cleavage of pivalic acid-containing prodrug esters of cephalosporins. | an extracellular esterase from the actinomycetes amycolatopsis orientalis was found by screening. it is capable of splitting the isomeric mixture (k/j) of (i, scheme 1) into 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid, pivalic acid, and acetaldehyde with a high yield. the purified enzyme of 55.4 kd by sds-page shows an n-terminal sequence of vrtcadlvrtydlpgavth. the isoelectric point is 8.9 +/- 0.1. it can be immobilized with good yield to va-epoxy biosynth. besides the above-mentioned re ... | 1996 | 8672280 |
| overproduction of rifamycin b by amycolatopsis mediterranei and its relationship with the toxic effect of barbital on growth. | a novel method for selecting overproducing strains of rifamycin b was developed. this technique involves the use of lysozyme and the effect of barbital on the growth of a. mediterranei. complete medium added with glycine and barbital was inoculated with mutagenized mycelium, incubated for 48 hours and treated with lysozyme. the lysozyme resistant mycelium was washed with dilute detergent. complete medium with glycine but without barbital was inoculated with the washed mycelium. protoplasts were ... | 1998 | 9531988 |
| optical spectroscopy of nicotinoprotein alcohol dehydrogenase from amycolatopsis methanolica: a comparison with horse liver alcohol dehydrogenase and udp-galactose epimerase. | the nadh absorbance spectrum of nicotinoprotein (nadh-containing) alcohol dehydrogenase from amycolatopsis methanolica has a maximum at 326 nm. reduced enzyme-bound pyridine dinucleotide could be reversibly oxidized by acetaldehyde. the fluorescence excitation spectrum for nadh bound to the enzyme has a maximum at 325 nm. upon excitation at 290 nm, energy transfer from tryptophan to enzyme-bound nadh was negligible. the fluorescence emission spectrum (excitation at 325 nm) for nadh bound to the ... | 1998 | 9485460 |
| d-ala-d-ala ligases from glycopeptide antibiotic-producing organisms are highly homologous to the enterococcal vancomycin-resistance ligases vana and vanb. | the crisis in antibiotic resistance has resulted in an increasing fear of the emergence of untreatable organisms. resistance to the glycopeptide antibiotic vancomycin in the enterococci, and the spread of these pathogens throughout the environment, has shown that this scenario is a matter of fact rather than fiction. the basis for vancomycin resistance is the manufacture of the depsipeptide d-ala-d-lactate, which is incorporated into the peptidoglycan cell wall in place of the vancomycin target ... | 1997 | 9177243 |
| ppi-dependent phosphofructokinase from thermoproteus tenax, an archaeal descendant of an ancient line in phosphofructokinase evolution. | flux into the glycolytic pathway of most cells is controlled via allosteric regulation of the irreversible, committing step catalyzed by atp-dependent phosphofructokinase (pfk) (atp-pfk; ec 2.7.1.11), the key enzyme of glycolysis. in some organisms, the step is catalyzed by ppi-dependent pfk (ppi-pfk; ec 2.7.1.90), which uses ppi instead of atp as the phosphoryl donor, conserving atp and rendering the reaction reversible under physiological conditions. we have determined the enzymic properties o ... | 1998 | 9555897 |
| epoxyquinomicins a, b, c and d, new antibiotics from amycolatopsis. i. taxonomy, fermentation, isolation and antimicrobial activities. | a new structural class of the antibiotic, epoxyquinomicins a, b, c and d were isolated from the culture broth of the strain mk299-95f4, which was related to amycolatopsis sulphurea. antimicrobial activity of epoxyquinomicins a and b were weak against gram-positive bacteria, and epoxyquinomicins c and d showed almost no antimicrobial activity and no cytotoxicity. all these antibiotics showed improvement of collagen induced arthritis in vivo. | 1997 | 9592560 |
| epoxyquinomicins a, b, c and d, new antibiotics from amycolatopsis. ii. effect on type ii collagen-induced arthritis in mice. | the anti-arthritic effects of epoxyquinomicins on type ii collagen-induced arthritis in dba/1j mice were examined. prophylactic treatment with epoxyquinomicins a, b, c and d (1-4 mg/kg) had potent inhibitory effects on type ii collagen-induced arthritis. in contrast to nonsteroidal anti-inflammatory drugs (nsaids), epoxyquinomicin c (1-30 mg/kg) had neither an anti-inflammatory effect on carrageenan-induced paw edema in rats nor an analgesic effect on acetic acid-induced writhing in mice. these ... | 1997 | 9592561 |
| epoxyquinomicins a, b, c and d, new antibiotics from amycolatopsis. iii. physico-chemical properties and structure determination. | the structures of epoxyquinomicins a (1), b (2), c (3) and d (4) were determined by spectroscopic studies. compound 1 was determined to be (5r,6s)-2-(3-chloro-2-hydroxybenzoylamino)-5-hydroxymethyl-5,6-epo xy- 2-cyclohexene-1,4-dione. compound 2 was revealed to be the dechlorinated derivative of 1. compounds 3 and 4 were determined to be the reduced derivative of 2 and 1, respectively. | 1997 | 9592562 |
| molybdopterin radical in bacterial aldehyde dehydrogenases. | the epr spectra of three different molybdoprotein aldehyde dehydrogenases, one purified from comamonas testosteroni and two purified from amycolatopsis methanolica, showed in their oxidized state a novel type of signal. these three enzymes contain two different [2fe-2s] centers, one flavin and one molybdopterin cytosine dinucleotide, as cofactors all of which are expected to be epr silent in the oxidized state. the new epr signal is isotropic with g = 2.004 both at x-band and q-band frequencies, ... | 1998 | 9698384 |
| sequencing and analysis of genes involved in the biosynthesis of a vancomycin group antibiotic. | the emergence of resistance to vancomycin, the drug of choice against methicillin-resistant staphylococcus aureus, in enterococci has increased the need for new antibiotics. as chemical modification of the antibiotic structure is not trivial, we have initiated studies towards enzymatic modification by sequencing the dna coding for the biosynthesis of chloroeremomycin (also known as a82846b and ly264826). | 1998 | 9545426 |
| biosynthesis of the ansamycin antibiotic rifamycin: deductions from the molecular analysis of the rif biosynthetic gene cluster of amycolatopsis mediterranei s699. | the ansamycin class of antibiotics are produced by various actinomycetes. their carbon framework arises from the polyketide pathway via a polyketide synthase (pks) that uses an unusual starter unit. rifamycin (rif), produced by amycolatopsis mediterranei, is the archetype ansamycin and it is medically important. although its basic precursors (3-amino-5-hydroxy benzoic acid ahba, and acetic and propionic acids) had been established, and several biosynthetic intermediates had been identified, very ... | 1998 | 9512878 |
| mj347-81f4 a & b, novel antibiotics from amycolatopsis sp.: taxonomic characteristics, fermentation, and antimicrobial activity. | strain mj347-81f4 has been found to produce two new cyclic thiazolyl peptide antibiotics, components a and b. taxonomic studies including morphological and physiological characteristics and chemical analysis of whole cells of the producing strain revealed this microorganism to belong to genus amycolatopsis, and so we designated the strain amycolatopsis sp. mj347-81f4. after 10 to 12 days of fermentation, most of the antibacterial activity was present mainly in the mycelial cake and reached its m ... | 1998 | 9766463 |
| ddln from vancomycin-producing amycolatopsis orientalis c329.2 is a vana homologue with d-alanyl-d-lactate ligase activity. | vancomycin-resistant enterococci acquire high-level resistance to glycopeptide antibiotics through the synthesis of peptidoglycan terminating in d-alanyl-d-lactate. a key enzyme in this process is a d-alanyl-d-alanine ligase homologue, vana or vanb, which preferentially catalyzes the synthesis of the depsipeptide d-alanyl-d-lactate. we report the overexpression, purification, and enzymatic characterization of ddln, a vana and vanb homologue encoded by a gene of the vancomycin-producing organism ... | 1998 | 9791137 |
| selection of suitable marker genes for the development of cloning vectors and electroporation in different strains of amycolatopsis mediterranei. | to select suitable genetic markers for optimizing electroporation efficiency in amycolatopsis mediterranei, thiostrepton (tsr), erythromycin (erme) and apramycin (am) resistance genes were used. although tsr could not be suitably expressed in a. mediterranei, the cloning of erme in prl1 or its derivative (containing am) resulted in the development of cloning vectors prlm20, prlm30 and prl90. in contrast to tsr and km (kanamycin resistance gene), erme and am were suitably expressed in a. mediterr ... | 1998 | 9880927 |
| structure of actinotetraose hexatiglate, a unique glucotetraose from an actinomycete bacterium. | an actinomycete strain a499 belonging to the genera amycolatopsis or amycolata isolated from a western australian soil sample produced the cyclic decapeptide antibiotic quinaldopeptin (1), together with the actinotetraose hexatiglate (2), the hexa-ester of a novel non-reducing glucotetraose. | 1998 | 10048568 |
| genetic localization and molecular characterization of two key genes (mitab) required for biosynthesis of the antitumor antibiotic mitomycin c. | mitomycin c (mc) is an antitumor antibiotic derived biosynthetically from 3-amino-5-hydroxybenzoic acid (ahba), d-glucosamine, and carbamoyl phosphate. a gene (mita) involved in synthesis of ahba has been identified and found to be linked to the mc resistance locus, mrd, in streptomyces lavendulae. nucleotide sequence analysis showed that mita encodes a 388-amino-acid protein that has 71% identity (80% similarity) with the rifamycin ahba synthase from amycolatopsis mediterranei, as well as with ... | 1999 | 10094699 |
| vancomycin production is enhanced in chemostat culture with biomass-recycle. | production of the glycopeptide antibiotic vancomycin by amycolatopsis orientalis atcc 19795 was examined in phosphate-limited chemostat cultures with biomass-recycle, employing an oscillating membrane separator, at a constant dilution rate (d= 0. 14 h-1). experiments made under low agitation conditions (600 rpm) showed that the biomass concentration could be increased 3.9-fold with vancomycin production kinetics very similar to that of chemostat culture without biomass-recycle. the specific prod ... | 1999 | 10099566 |
| reclassification of amycolatopsis rugosa lechevalier et al. 1986 as prauserella rugosa gen. nov., comb. nov. | an almost complete sequence of the 16s rdna of the type strain of amycolatopsis rugosa was determined following direct sequencing of the amplified gene. the sequence was aligned with those of representatives of the family pseudonocardiaceae and related actinomycetes and phylogenetic trees were inferred by using three tree-making algorithms. the organism formed a distinct clade within the evolutionary radiation occupied by the family pseudonocardiaceae. it was also readily distinguished from all ... | 1999 | 10319471 |
| development of an improved cloning vector and transformation system in amycolatopsis mediterranei (nocardia mediterranei). | a versatile plasmid cloning vector prl60 carrying kanamycin/neomycin resistance (km/neo), erythromycin resistance (erme) and alpha-amylase (alpha-amy) marker genes that replicates in various amycolatopsis mediterranei strains and escherichia coli has been constructed. this cloning vector has been derived from a hybrid plasmid prl50, which was developed by cloning erme from pij4026 into a prl1 derivative pulam2. while cloning erme into the bamhi site of pulam2, only a hybrid plasmid prl50 with an ... | 1998 | 9544937 |
| actinomycetes in karstic caves of northern spain (altamira and tito bustillo). | a variety of isolation procedures were carried out to study the involvement of bacteria in the colonisation and biodeterioration of spanish caves with paleolithic rock art (altamira and tito bustillo). the applied techniques mainly aimed to isolate heterotrophic bacteria such as streptomycetes, nocardioform and coryneform actinomycetes, and other gram-positive and gram-negative bacteria. the results demonstrated that actinomycetes were the most abundant gram-positive bacteria in the caves. actin ... | 1999 | 10353805 |
| purification and properties of the pyrophosphate-dependent phosphofructokinase from dictyoglomus thermophilum rt46 b.1. | the distribution of phosphofructokinase phosphoryl donor subtypes (atp-, adp-, and pyrophosphate) in the deeply rooted phylogenetic lineages of thermophiles is of interest with regard to the evolution of phosphofructokinase activity and of the embden-meyerhof pathway. in this article we present the first biochemical description of a thermostable pyrophosphate-dependent phosphofructokinase from the hyperthermophilic bacterium dictyoglomus thermophilum. the enzyme was not allosterically controlled ... | 1999 | 10356999 |
| identification and analysis of the balhimycin biosynthetic gene cluster and its use for manipulating glycopeptide biosynthesis in amycolatopsis mediterranei dsm5908. | seven complete genes and one incomplete gene for the biosynthesis of the glycopeptide antibiotic balhimycin were isolated from the producer, amycolatopsis mediterranei dsm5908, by a reverse-cloning approach and characterized. using oligonucleotides derived from glycosyltransferase sequences, a 900-bp glycosyltransferase gene fragment was amplified and used to identify a dna fragment of 9,882 bp. of the identified open reading frames, three (oxya to -c) showed significant sequence similarities to ... | 1999 | 10390204 |
| crystal structure of 3-amino-5-hydroxybenzoic acid (ahba) synthase. | the biosynthesis of ansamycin antibiotics, including rifamycin b, involves the synthesis of an aromatic precursor, 3-amino-5-hydroxybenzoic acid (ahba), which serves as starter for the assembly of the antibiotics' polyketide backbone. the terminal enzyme of ahba formation, ahba synthase, is a dimeric, pyridoxal 5'-phosphate (plp) dependent enzyme with pronounced sequence homology to a number of plp enzymes involved in the biosynthesis of antibiotic sugar moieties. the structure of ahba synthase ... | 1999 | 10433690 |
| microbial proline 4-hydroxylase screening and gene cloning. | microbial proline 4-hydroxylases, which hydroxylate free l-proline to trans-4-hydroxy-l-proline, were screened in order to establish an industrial system for biotransformation of l-proline to trans-4-hydroxy-l-proline. enzyme activities were detected in eight strains, including strains of dactylosporangium spp. and amycolatopsis spp. the dactylosporangium sp. strain rh1 enzyme was partially purified 3,300-fold and was estimated to be a monomer polypeptide with an apparent molecular mass of 31 kd ... | 1999 | 10473412 |
| degradation of polycarbonate by a polyester-degrading strain, amycolatopsis sp. strain ht-6. | amycolatopsis sp. strain ht-6, a poly(tetramethylene succinate) (ptms)-degrading actinomycete, was observed to degrade poly(tetramethylene carbonate) (ptmc). in a liquid culture with 150 mg of ptmc film, 59% degradation was achieved, but with a low yield of cell growth. on the other hand, ptms copolymerized with a small amount of ptmc, forming a copolyester carbonate (pec) that was completely and rapidly degraded with a high yield of cell growth. | 1999 | 10473438 |
| a host-vector system for analysis and manipulation of rifamycin polyketide biosynthesis in amycolatopsis mediterranei. | modular polyketide synthases (pkss) are a large family of multifunctional enzymes responsible for the biosynthesis of numerous bacterial natural products such as erythromycin and rifamycin. advanced genetic analysis of these remarkable systems is often seriously hampered by the large size (>40 kb) of pks gene clusters, and, notwithstanding their considerable fundamental and biotechnological significance, by the lack of suitable methods for engineering non-selectable modifications in chromosomall ... | 1999 | 10517586 |
| glycopeptide antibiotic resistance genes in glycopeptide-producing organisms. | the mechanism of high-level resistance to vancomycin in enterococci consists of the synthesis of peptidoglycan terminating in d-alanyl-d-lactate instead of the usual d-alanyl-d-alanine. this alternate cell wall biosynthesis pathway is ensured by the collective actions of three enzymes: vanh, vana, and vanx. the origin of this resistance mechanism is unknown. we have cloned three genes encoding homologs of vanh, vana, and vanx from two organisms which produce glycopeptide antibiotics: the a47934 ... | 1998 | 9736537 |
| amycolatopsis thermoflava sp. nov., a novel soil actinomycete from hainan island, china. | a soil isolate, which had been assigned to the genus nocardia, was shown to have properties consistent with its classification in the genus amycolatopsis. an almost complete nucleotide sequence of the 16s rdna of the strain was determined following cloning and sequencing of the amplified gene. the sequence was aligned with those available for members of the family pseudonocardiaceae and related taxa and phylogenetic trees were inferred using three tree-making algorithms. the organism consistentl ... | 1999 | 10555314 |
| three new species of the genus actinobispora of the family pseudonocardiaceae, actinobispora alaniniphila sp. nov., actinobispora aurantiaca sp. nov. and actinobispora xinjiangensis sp. nov. | the genus actinobispora jiang et al. is characterized by the formation of longitudinally paired spores on both the vegetative and the aerial mycelium, absence of mycolic acid, cell wall chemotype iv (containing meso-diaminopimelic acid as the diamino acid, galactose and arabinose), pvi and mk-9(h2). comparative studies of morphology, chemical classification and phylogenetic analysis based on the 16s rrna sequences among the four type strains of the genus actinobispora and type strains of related ... | 1999 | 10319514 |
| phylogenetic analysis of the genera pseudonocardia and actinobispora based on 16s ribosomal dna sequences. | the 16s rdna sequences of 11 strains, nine type strains of validated pseudonocardia species and actinobispora yunnanensis, and two strains of unnamed pseudonocardia species, were determined and compared with those of representatives of the family pseudonocardiaceae. the phylogenetic analysis indicated that all of the validated species of the genera pseudonocardia and actinobispora consistently formed a monophyletic unit and separated well from the other genera of the family pseudonocardiaceae. o ... | 2000 | 10612743 |
| intermediates of rifamycin polyketide synthase produced by an amycolatopsis mediterranei mutant with inactivated riff gene. | rifamycin b biosynthesis in amycolatopsis mediterranei n/813 was inactivated by introducing a small deletion in the riff gene situated directly downstream of the rifamycin polyketide synthase (pks) gene cluster. the corresponding mutant strain produced a series of linear intermediates of rifamycin b biosynthesis that are most probably generated by obstruction of the normal release of the end product of the rifamycin pks. this result provides evidence that the riff gene product catalyses the rele ... | 1999 | 10627035 |