共查询到20条相似文献,搜索用时 15 毫秒
1.
D. Ostrovsky G. Diomina E. Lysak E. Matveeva O. Ogrel S. Trutko 《Archives of microbiology》1998,171(1):69-72
In this study, the gram-negative bacteria Xanthomonas campestris, Xanthomonas maltophilia, and Pseudomonas putida, facultative parasites of plants and animals, were shown to accumulate 2-C-methyl-d-erythritol-2,4-cyclopyrophosphate (MEC) in response to benzyl-viologen-induced oxidative stress. Corynebacterium ammoniagenes mutants capable of accumulating MEC in the absence of an exogenous oxidative stress inducer were obtained. Isoprenoid synthesis
and MEC synthesis in these and other bacteria were shown to be alternative processes, while biosynthesis of brominated polyene
xanthomonadin (an antioxidant pigment of X. campestris) increased concomitantly with the accumulation of MEC.
Received: 30 March 1998 / Accepted: 16 October 1998 相似文献
2.
Seok-Myung Lee Joo-Young Lee Kwang-Jin Park Jun-Sung Park Un-Hwan Ha Younhee Kim Heung-Shick Lee 《Current microbiology》2010,61(2):92-100
RamA plays a regulatory role for acetate utilization and S-layer biosynthesis in Corynebacterium glutamicum. Looking for any additional role, the function of RamA was analyzed in Corynebacterium ammoniagenes, which is closely related to C. glutamicum. In this study, we showed that the ΔramA mutant constructed by a markerless knockout strategy possessed increased cell surface hydrophobicity, leading to the formation
of aggregated cell masses in liquid media. In addition, the mutant exhibited an elongated cell shape as observed by SEM, suggesting
that cell wall-associated proteins might be influenced. Furthermore, cell surface proteome analysis revealed that the expression
of cmytA gene encoding corynomycoloyl transferase required for cell wall biosynthesis was down-regulated in the mutant, supporting
the regulatory role of RamA in cell wall assembly. These studies support a novel regulatory role of RamA in inducing the expression
of proteins required for cell wall assembly. 相似文献
3.
Koizumi S Yonetani Y Maruyama A Teshiba S 《Applied microbiology and biotechnology》2000,53(6):674-679
Improved strains for the production of riboflavin (vitamin B2) were constructed through metabolic engineering using recombinant DNA techniques in Corynebacterium ammoniagenes. A C. ammoniagenes strain harboring a plasmid containing its riboflavin biosynthetic genes accumulated 17-fold as much riboflavin as the host
strain. In order to increase the expression of the biosynthetic genes, we isolated DNA fragments that had promoter activities
in C. ammoniagenes. When the DNA fragment (P54-6) showing the strongest promoter activity in minimum medium was introduced into the upstream
region of the riboflavin biosynthetic genes, the accumulation of riboflavin was 3-fold elevated. In that strain, the activity
of guanosine 5′-triphosphate (GTP) cyclohydrolase II, the first enzyme in riboflavin biosynthesis, was 2.4-fold elevated whereas
that of riboflavin synthase, the last enzyme in the biosynthesis, was 44.1-fold elevated. Changing the sequence containing
the putative ribosome-binding sequence of 3,4-dihydroxy-2-butanone 4-phosphate synthase/GTP cyclohydrolase II gene led to
higher GTP cyclohydrolase II activity and strong enhancement of riboflavin production. Throughout the strain improvement,
the activity of GTP cyclohydrolase II correlated with the productivity of riboflavin. In the highest producer strain, riboflavin
was produced at the level of 15.3 g l−1 for 72 h in a 5-l jar fermentor without any end product inhibition.
Received: 23 August 1999 / Received revision: 13 October 1999 / Accepted: 5 November 1999 相似文献
4.
Usuda Yoshihiro Shimaoka Megumi Kawasaki Hisashi Utagawa Takashi 《World journal of microbiology & biotechnology》2011,27(3):709-712
The guanosine-inosine kinase gene (gsk) isolated from Exiguobacterium acetylicum was expressed in an ATP-regenerating strain, Corynebacterium ammoniagenes. In order to induce its expression, three promoters (those for the Escherichia coli tac, Escherichia coli trp, and Corynebacterium glutamicum odhA gene) with the corresponding ribosome-binding sequences were examined. The E. coli trp promoter was most efficient with regard to inducing the expression of gsk in C. ammoniagenes. Further, the resulting strain, which has both inosine kinase activity and ATP-regenerating activity, was used to induce
the phosphorylation of inosine to produce inosine 5′-monophosphate (5′-IMP), which is widely used as a flavor enhancer; approximately
80 g of 5′-IMP/l was produced with a molar conversion ratio of 80%. 相似文献
5.
A production system of UDP-N-acetylglucosamine (UDP-GlcNAc) was established by using recombinant Escherichia coli and Corynebacterium ammoniagenes in combination. E. coli overexpressed the UDP-GlcNAc biosynthetic genes, glmM, glmU, glk, ppa, ack, and pta, whereas C. ammoniagenes contributed to the formation of UTP from orotic acid. Glucose 1,6-diphosphate (Glc-1,6-P2), which was required for the activity of phosphoglucosamine mutase involved in UDP-GlcNAc biosynthesis, was supplied by phosphoglucomutase and phosphofructokinase. Starting with orotic acid (65 mM) and glucosamine (400 mM), UDP-GlcNAc accumulated at 11.4 mM (7.4 g l–1) after 8 h. 相似文献
6.
To evaluate the strategy of supplying ribose 5-phosphate to the purine-nucleotide pathway exclusively via the nonoxidative
route, the glucose 6-phosphate dehydrogenase gene zwf was disrupted in inosine- and 5′-xanthylic acid-producers of Corynebacterium ammoniagenes. In both producers, interruption of the oxidative route caused a decrease in production yields of about 50%. Attempts to
increase the capacity of the nonoxidative route through overexpression of the transketolase or transaldolase gene in the zwf mutants led to no discernable effects on production, indicating that, in C. ammoniagenes, the nonoxidative route alone cannot provide sufficient ribose 5-phosphate for high-level production, although nonoxidative
synthesis of the precursor is possible.
Electronic Publication 相似文献
7.
8.
The diversion of 2‐C‐methyl‐d‐erythritol‐2,4‐cyclodiphosphate from the 2‐C‐methyl‐d‐erythritol 4‐phosphate pathway to hemiterpene glycosides mediates stress responses in Arabidopsis thaliana
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Christian Paetz Nawaporn Onkokesung Jonathan Gershenzon Manuel Rodríguez‐Concepción Michael A. Phillips 《The Plant journal : for cell and molecular biology》2015,82(1):122-137
2‐C‐Methyl‐d ‐erythritol‐2,4‐cyclodiphosphate (MEcDP) is an intermediate of the plastid‐localized 2‐C‐methyl‐d ‐erythritol‐4‐phosphate (MEP) pathway which supplies isoprenoid precursors for photosynthetic pigments, redox co‐factor side chains, plant volatiles, and phytohormones. The Arabidopsis hds‐3 mutant, defective in the 1‐hydroxy‐2‐methyl‐2‐(E)‐butenyl‐4‐diphosphate synthase step of the MEP pathway, accumulates its substrate MEcDP as well as the free tetraol 2‐C‐methyl‐d ‐erythritol (ME) and glucosylated ME metabolites, a metabolic diversion also occurring in wild type plants. MEcDP dephosphorylation to the free tetraol precedes glucosylation, a process which likely takes place in the cytosol. Other MEP pathway intermediates were not affected in hds‐3. Isotopic labeling, dark treatment, and inhibitor studies indicate that a second pool of MEcDP metabolically isolated from the main pathway is the source of a signal which activates salicylic acid induced defense responses before its conversion to hemiterpene glycosides. The hds‐3 mutant also showed enhanced resistance to the phloem‐feeding aphid Brevicoryne brassicae due to its constitutively activated defense response. However, this MEcDP‐mediated defense response is developmentally dependent and is repressed in emerging seedlings. MEcDP and ME exogenously applied to adult leaves mimics many of the gene induction effects seen in the hds‐3 mutant. In conclusion, we have identified a metabolic shunt from the central MEP pathway that diverts MEcDP to hemiterpene glycosides via ME, a process linked to balancing plant responses to biotic stress. 相似文献
9.
S. Nakagawa T. Hagihara T. Fujio K. Aisaka 《Applied microbiology and biotechnology》1995,43(2):325-329
Using the bifunctional FAD synthetase from Corynebacterium ammoniagenes, which has the two sequential activities of flavokinase and FMN adenylyl-transferase in FAD biosynthesis, a method of production of the intermediate FMN without any accumulation of FAD was investigated. Various phosphate polymers having no adenylyl moiety were tested for their ability to phosphorylate riboflavin to FMN, using a crude enzyme from C. ammoniagenes/pKH46, which is an FAD-synthetase-gene-dosed strain. Only metaphosphate, other than ATP, could phosphorylate riboflavin to FMN, but FAD did not accumulate at all. The conditions for the conversion of riboflavin to FMN were optimized. The metaphosphate-dependent phosphorylation reaction required Mg2+ as the most effective divalent cation. The best concentrations were 10 mM for MgCl2 and 3mg/ml for metaphosphate. The riboflavin added to the reaction mixture was almost completely converted into FMN after 6 h incubation in the presence of high concentrations of the enzyme preparation. 相似文献
10.
The aerobic saprophyte Mycobacterium smegmatis, like its pathogenic counterpart M. tuberculosis, has the ability to adapt to anaerobiosis by shifting down to a dormant state. Here, we report the identification and molecular
genetic characterisation of the first dormancy-induced protein in M. smegmatis. Comparative SDS-polyacrylamide gel electrophoresis of protein extracts of aerobically growing and dormant anaerobic M. smegmatis cultures revealed the upregulation of a 27-kDa protein in the dormant state. Peptide sequencing showed that the induced protein
is a homologue of the histone-like protein Hlp, predicted by the M. tuberculosis genome project. The corresponding hlp gene was cloned from M. smegmatis and sequenced. Disruption of the hlp gene eliminated the histone-like protein but did not affect the viability of the dormant culture.
Received: 3 June 1998 / Accepted: 22 September 1998 相似文献
11.
We previously reported on the secretion of Streptomyces mobaraensis transglutaminase by Corynebacterium glutamicum ATCC13869 (formerly classified as Brevibacterium lactofermentum). In the present work, we investigated whether any other coryneform bacteria showed higher productivity than C. glutamicum ATCC13869. We found that most coryneform species secreted pro-transglutaminase efficiently. Moreover, we confirmed that Corynebacterium ammoniagenes ATCC6872 produced about 2.5 g/l pro-transglutaminase over a 71-h period in a jar fermentor. Our findings suggest that some
other coryneform bacteria, especially C. ammoniagenes ATCC6872, are potential hosts for industrial scale protein production. 相似文献
12.
Hee-Sung Shin Yong-Jae Kim In-Hwa Yoo Heung-Shick Lee Shouguang Jin Un-Hwan Ha 《Biotechnology letters》2011,33(1):97-102
A genetic locus, encoding putative acyltransferase, was induced by autoinducers in Corynebacterium glutamicum. The autoinducers were maximally produced by the bacterium after 24 h culture. Those molecules are resistant to proteinase
K treatment (300 μg ml−1) for 30 min at 37°C or at 121°C for 15 min, and remained stable after extensive storage at 4°C. Autoinducers in the cell-free
culture fluids from Corynebacterium ammoniagenes and Pseudomonas aeruginosa also induced the expression of acyltransferase in C. glutamicum, suggesting possible cross-recognition of the autoinducers by C. glutamicum. C. glutamicum thus possesses an autoinduction system which secretes autoinducers during growth, triggering the expression of downstream
genes, exemplified by the putative acyltransferase gene. 相似文献
13.
The mechanism of glutathione (GSH) depletion by isoniazid (INH) was studied inM. smegmatis. INH increased the activity of γ-glutamyl transferase (GGT) whether added before medium inoculation or to actively growing
cells. The activity of GGT in cells grown from the beginning in INH-containing medium increased significantly on growth days
2–6. Three-day oldM. smegmatis cells treated with INH exhibited a 30–65 % increase in the activity of GGT. The activities of γ-glutamyl-cysteine synthase
(GGCS) and GSH synthase (GS) were lowered by 50 and 56 % respectively on the second day of growth whenM. smegmatis was grown in a medium supplemented with 1.5 mg INH per L. In 3-day oldM. smegmatis, INH significantly inhibited the activities of GSH biosynthetic enzymes. The results demonstrate that the increased activity
of GGT and decreased activities of GSH biosynthetic enzymes are responsible for GSH depletion by INH inM. smegmatis. 相似文献
14.
Leirla Salazar Hafida Fsihi Edda de Rossi Giovanna Riccardi Carmen Rios Stewart T. Cole Howard E. Takiff 《Molecular microbiology》1996,20(2):283-293
The genus Mycobacterium is composed of species with widely differing growth rates ranging from approximately three hours in Mycobacterium smegmatis to two weeks in Mycobacterium leprae. As DNA replication is coupled to cell duplication, it may be regulated by common mechanisms. The chromosomal regions surrounding the origins of DNA replication from M. smegmatis, M. tuberculosis, and M. leprae have been sequenced, and show very few differences. The gene order, rnpA-rpmH-dnaA-dnaN-recF-orf-gyrB-gyrA, is the same as in other Gram-positive organisms. Although the general organization in M. smegmatis is very similar to that of Streptomyces spp., a closely related genus, M. tuberculosis and M. leprae differ as they lack an open reading frame, between dnaN and recF, which is similar to the gnd gene of Escherichia coli. Within the three mycobacterial species, there is extensive sequence conservation in the intergenic regions flanking dnaA, but more variation from the consensus DnaA box sequence was seen than in other bacteria. By means of subcloning experiments, the putative chromosomal origin of replication of M. smegmatis, containing the dnaA-dnaN region, was shown to promote autonomous replication in M. smegmatis, unlike the corresponding regions from M. tuberculosis or M. leprae. 相似文献
15.
16.
Chemical mutagenesis of the nucleotide-producing strain Corynebacterium ammoniagenes ATCC 6872 with N-methyl-N-nitro-N-nitrosoguanidine followed by an enrichment protocol yielded 46 temperature-sensitive (ts) clones. A rapid assay for the allosterically
regulated Mn-ribonucleotide reductase (RRase) was developed with nucleotide-permeable cells of C. ammoniagenes in order to screen for possible defects in DNA precursor biosynthesis at elevated temperature. Three mutants (CH 31, CH 32,
and CH 33) grew well at 30° C but did not proliferate at 40° C because they did not reduce ribonucleotides to 2′-deoxyribonucleotides.
They were designated nrd
ts
(nucleotide reduction defective). When the cultures were shifted from 30 to 40° C, the nrd
ts
mutants immediately ceased to incorporate radiolabeled nucleic acid precursors into the DNA fraction, while DNA chain elongation
was barely affected. Thus, exhaustion of the deoxyribonucleotide pool ultimately inhibited cell division, leading to a filamentous
growth morphology. In contrast to the wild-type, all three nrd
ts
mutants displayed a distinctly enhanced sensitivity of ribonucleotide reduction towards hydroxyurea (in permeabilized cells
and in vitro) at 30° C. The results from assays for biochemical complementation of heat-inactivated (2 min, 37° C) mutant
enzyme with either the small or the large subunit of wild-type Mn-RRase located the mutational defect on the large subunit.
Received: 28 December 1995 / Revision received: 22 January 1997 / Accepted: 29 January 1997 相似文献
17.
S Koizumi T Endo K Tabata H Nagano J Ohnishi A Ozaki 《Journal of industrial microbiology & biotechnology》2000,25(4):213-217
A large-scale production system of GDP-fucose (GDP-Fuc) and fucosylated oligosaccharides was established by the combination
of recombinant Escherichia coli cells overexpressing GDP-Fuc biosynthetic genes and Corynebacterium ammoniagenes cells. E. coli cells overexpressed the genes for glucokinase, phosphomannomutase, mannose-1-phosphate guanylyltransferase, GDP-mannose (GDP-Man)
dehydratase, and GDP-4-keto-6-deoxy-mannose (GKDM) epimerase/reductase as well as phosphoglucomutase and phosphofructokinase.
C. ammoniagenes contributed to the formation of GTP from GMP. GDP-Fuc accumulated to 29 mM (18.4 g l−1) after a 22-h reaction starting with GMP and mannose through introducing the two-step reaction to overcome the inhibition
of GDP-Fuc on GDP-Man dehydratase activity. When E. coli cells overexpressing the α1,3-fucosyltransferase gene of Helicobacter pylori were put into the GDP-Fuc production system, Lewis X [Galβ1–4(Fucα1–3)GlcNAc] was produced at an amount of 40 mM (21 g l−1) for 30 h from GMP, mannose, and N-acetyl lactosamine. The production system through bacterial coupling can be applied to the industrial manufacture of fucosylated
oligosaccharides. Journal of Industrial Microbiology & Biotechnology (2000) 25, 213–217.
Received 01 May 2000/ Accepted in revised form 20 July 2000 相似文献
18.
A novel process for producing inosine 5′-monophosphate (5′-IMP) has been demonstrated. The process consists of two sequential
bioreactions; the first is a fermentation of inosine by a mutant of Corynebacterium ammoniagenes, and the second is a unique phosphorylating reaction of inosine by guanosine/inosine kinase (GIKase). GIKase was produced
by an Escherichia coli recombinant strain, MC1000(pIK75), which overexpressed the enzyme up to 50% of the total cellular protein. The overproducing
plasmid, pIK75, which was randomly screened out from deletion plasmids with various lengths of intermediate sequence between
the E. coli trpL Shine-Dalgarno sequence, derived from the vector plasmid, and the start codon of the GIKase structural gene. In pIK75, the
start ATG was placed 16 bp downstream of the trpL Shine-Dalgarno sequence under the control of the E. coli trp promoter. Fermentation of inosine and its phosphorylation were sequentially performed in a 5-l jar fermenter. At the end
of inosine fermentation by C. ammoniagenes KY13761, culture broth of MC1000(pIK75) was mixed with that of KY13761 to start the phosphorylating reaction. Inosine in
the reaction mixture was stoichiometrically phosphorylated, and 91 mM 5′-IMP accumulated in a 12-h reaction. This new biological
process has advantages over traditional methods for producing 5′-IMP.
Received: 7 April 1997 / Received last revision: 18 July 1997 / Accepted: 27 July 1997 相似文献
19.
The cyanobacterium Oscillatoria brevis (Kütz.) Gom., strain NIVA CYA 7, was used to investigate how geosmin production is related to the synthesis of chlorophyll
a, phycobiliproteins and β-carotene under nitrogen (NH
4
+
) and light limiting conditions. Chemostat samples were used to inoculate batch cultures that were treated with inhibitors
of isoprenoid synthesis, norflurazon and dimethazone, and gabaculine that inhibits tetrapyrrole synthesis. Dimethazone decreased
and norflurazon increased geosmin production under light limited conditions, as was expected due to their sites of action
in the isoprenoid pathway. This effect was not so pronounced in nitrogen limited cultures due to the additional effect of
increasing nitrogen deficiency during the experimental period. Norflurazon was the only inhibitor that uncoupled geosmin production
completely from β-carotene formation which indicates a strikt coupling between geosmin and β-carotene biosynthesis. From the
observed increase of geosmin production relative to pigment synthesis after norflurazon treatment it was suggested that isoprenoid
precursors are directed to geosmin synthesis when the demand for pigment precursors is very low. Within the framework of this
study the data strongly support the hypothesis of geosmin formation via the isoprenoid pathway in Oscillatoria brevis as was found for actinomycetes.
This research was performed at the Department of Microbiology, University of Amsterdam, with financial support provided by
the royal Norwegian Ministry of Foreign Affairs and the Royal Norwegian Council for Scientific and Industrial Research 相似文献
20.
A. V. Goncharenko Yu. V. Ershov E. G. Salina J. Wiesner G. N. Vostroknutova A. A. Sandanov A. S. Kaprelyants D. N. Ostrovsky 《Microbiology》2007,76(2):147-152
2-C-Methyl-D-erythritol-2,4-cyclopyrophosphate (MEC), an intermediate of the biosynthesis of isoprenoid compounds in bacteria, was found to be capable of exerting a resuscitating effect on resting Mycobacterium smegmatis cells. The introduction of an additional copy of the ispE gene encoding cytidyl-methyl-erythritol kinase, an enzyme involved in MEC synthesis in M. smegmatis, resulted in the emergence of a capacity for spontaneous reactivation of “nonculturable” M. smegmatis cells, which is not characteristic of the wild-type cells of this species. The involvement of MEC in the transition from the “nonculturable” state to the state of active growth is indicative of a previously unknown function of MEC, assumed to consist in regulation of the bacterial genome activity. 相似文献