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1.
Juan Soliveri María-Enriqueta Arias Fernando Laborda 《Applied microbiology and biotechnology》1987,25(4):366-371
Summary Two antifungal antibiotics, named PA-5 and PA-7 were produced by an actinomycete strain, characterized and identified as Streptoverticillium sp 43/16. These antibiotics were extracted from mycelial cake with methanol and purified using different organic solvents and LH-20 Sephadex column chromatography. PA-5 and PA-7 were characterized as, a pentaene and a heptaene macrolide antibiotic, respectively. These antibiotics exhibit strong antifungal activity against pathogen yeasts and molds. 相似文献
2.
D. Klein P. Yanai R. Hofstein B. Fridlender S. Braun 《Applied microbiology and biotechnology》1989,30(6):580-584
Summary A range of industrial peptones in combination with other carbon and nitrogen sources were investigated in order to define a medium for production of insecticide from Bacillus sphaericus, strain 2362. Industrial protein hydrolysates with an average peptide chain length above 30 were found to be poor substrates. Fermentation of B. sphaericus on protein-based media supplemented with glycerol resulted in production of 4–5x103 units of larvicide per ml fermentation broth, and toxicity of the larvicide up to 104 units per mg. Equally high larvicide production was obtained, when peptone was substituted with 30 mM l-glutamate and 2 mM proline. Addition of 2 mM l-arginine to this medium prevented sporulation and larvicide production. 相似文献
3.
The effect of nitrogen and carbon sources, vitamins, antibiotics and metabolic inhibitors on growth and differentiation ofPaecilomyces viridis was investigated. Sodium nitrate,l-asparagine,l-proline and peptone were found to be suitable nitrogen sources for mycelial growth (M) in a synthetic medium with glucose.Paecilomyces viridis could also grow slowly in a synthetic medium containing benzylpenicillin or bacitracin as the only nitrogen sources and very
slowly even in a medium with polymyxin as the nitrogen source. Ammonium salts, area,l-arginine,d, l-aspartic acid andl,-serine were found to support intensive sporulation. Partially yeast-like growth (Y) was facilitated by NaNO2, (NH4)2SO4, NH4NO3, urea,d, l-alanine,l-arginine,d, l-aspartic acid,l-cysteine,l-glutamic acid andl-serine. Partially yeastlike growth could be observed in a medium with peptone and at an initial pH of 2. The following compounds
appear as suitable carbon sources for mycelial growth:d-glucose,d-galactose,d-mannose, maltose, sucrose, chitin andd-mannitol. No changes in morphology could be detected on any of the 25 used carbon sources in a synthetic medium with NaNO3. Yeast-like growth was induced by the antibiotics azalomycin F, cyanein (brefeldin A), griseofulvin and monorden (radicicol).
After removal of the antibiotics, mycelial growth was restored. Sporulation was stimulated by chloramphenicol, 2-deoxy-d-glucose, furancarboxylic acid and stipitatic acid. Deformation of phialides was observed after treatment with actinomycin
D, amphotericin B, boromycin, citrinin, cycloheximide, cytochalasin D, fungicidin and scopathricin. Microcyclic conidiation
or growth of phialides directly from conidia were induced by cycloheximide, desertomycin, ethidium bromide and 5-fluorouracil. 相似文献
4.
This paper describes the effect of different nutrients on the production of pyrazoloisoquinolinone antibiotics (APHE) by
Streptomyces griseocarneus. In a chemically defined medium with glucose as carbon and l-lysine as nitrogen source all APHE antibiotics (APHE-1 to -3) are produced, APHE-3 being the most abundant. Propionate and
butyrate used as precursors with glucose as main carbon source increased the production of APHE-1 and -2, respectively. The
presence of propionate or butyrate reduced the production of APHE-3. Results obtained in minimal medium supplemented with
l-valine and l-histidine indicate a relationship between these amino acids and APHE biosynthesis. These data, together with those obtained
in the presence of precursors of fatty acids, also show possible links with fatty acid biosynthesis. Different nutritional
requirements were found for APHE-3 production in comparison with APHE-1 and APHE-2.
Received: 15 April 1999 / Received revision: 21 June 1999 / Accepted: 27 June 1999 相似文献
5.
Rhodopseudomonas acidophila strain 7050 assimilated ammonia via a constitutive glutamine synthetase/glutamate synthase enzyme system.Glutamine synthetase had a K
m
for NH
4
+
of 0.38 mM whilst the nicotinamide adenine dinucleotide linked glutamate synthase had a K
m
for glutamine of 0.55 mM. R. acidophila utilized only a limited range of amino acids as sole nitrogen sources: l-alanine, glutamine and asparagine. The bacterium did not grow on glutamate as sole nitrogen source and lacked glutamate dehydrogenase. When R. acidophila was grown on l-alanine as the sole nitrogen source in the absence of N2 low levels of a nicotinamide adenine dinucleotide linked l-alanine dehydrogenase were produced. It is concluded, therefore, that this reaction was not a significant route of ammonia assimilation in this bacterium except when glutamine synthetase was inhibited by methionine sulphoximine. In l-alanine grown cells the presence of an active alanine-glyoxylate aminotransferase and, on occasions, low levels of an alanine-oxaloacetate aminotransferase were detected. Alanine-2-oxo-glutarate aminotransferase could not be demonstrated in this bacterium.Abreviations ADH
alanine dehydrogenase
- GDH
glutamate dehydrogenase
- GS
glutamine synthetase
- GOGAT
glutamate synthase
- MSO
methionine sulphoximine 相似文献
6.
A chemically defined medium was developed for the biosynthesis of cephalosporin C by Paecilomyces persicinus Nicot strain P-10. Glucose served as the major carbon source and nitrogen was supplied by five amino acids, l-arginine, l-aspartic acid, l-glutamic acid, glycine and dl-methionine. Omission of any of the first four diminished or prevented production of cephalosporin C; omission of methionine did not. Methionine is not critical for the production of cephalosporin C in this defined medium. Production of the antibiotic was affected by the concentrations of inorganic salts employed. Biotin was required for growth and cephalosporin C synthesis. The addition of l-lysine precursors to the medium did not influence cephalosporin C levels and l-lysine itself inhibited antibiotic production. Known precursors of -lactam antibiotics as well as oleic acid did not affect biosynthesis of cephalosporin C. Chemical changes occurring in the defined medium revealed that glucose was efficiently utilized after 96 hours incubation whereas total soluble nitrogen levels increased following an initial sharp decrease. Mycelial weight and cephalosporin C production were both maximal after 96 hours incubation. Mycelial nitrogen was highest after 48 hours incubation whereas mycelial lipid levels were greatest after 72 hours. 相似文献
7.
Summary
Streptomyces clavuligerus produced simultaneously cephamycin C and clavulanic acid in defined medium in long-term fermentations and in resting-cell cultures. Biosynthesis of cephamycin by phosphate-limited resting cells was dissociated from clavulanic acid formation by removing either glycerol or sulphate from the culture medium. In absence of glycerol no clavulanic acid was formed but cephamycin production occurred, whereas in absence of sulphate no cephamycin was synthesized but clavulanic biosynthesis took place. Sulphate, sulphite and thiosulphate were excellent sulphur sources for cephamycin biosynthesis while l-methionine and l-cysteine were poor precursors of this antibiotic. Increasing concentrations of sulphate also stimulated clavulanic acid formation. The biosynthesis of clavulanic acid was much more sensitive to phosphate (10–100 mM) regulation than that of cephamycin. Therefore, the formation of both metabolites was pertially dissociated at 25 mM phosphate. By contrast, nitrogen regulation by ammonium salts or glutamic acid strongly reduced the biosynthesis of both cephamycin and clavulanic acid. 相似文献
8.
Technikova-Dobrova Z Damiano F Tredici SM Vigliotta G di Summa R Palese L Abbrescia A Labonia N Gnoni GV Alifano P 《Applied microbiology and biotechnology》2004,65(6):671-677
Actinomadura sp. ATCC 39727 produces the glycopeptide antibiotic A40926, structurally similar to teicoplanin, with significant activity against Neisseria gonorrhoeae and precursor of the semi-synthetic antibiotic dalbavancin. In this study the production of A40926 by Actinomadura under a variety of growth conditions was investigated. The use of chemically defined mineral media allowed us to analyze the influence of carbon and nitrogen sources, phosphate, ammonium and calcium on the growth and the antibiotic productivity of Actinomadura. We confirm recent data [Gunnarsson et al. (2003) J Ind Microbiol Biotechnol 30:150–156] that low initial concentrations of phosphate and ammonium are beneficial for growth and A40926 production, and we provide new evidence that the production of A40926 is depressed by calcium, but promoted when l-glutamine or l-asparagine are used as nitrogen sources instead of ammonium salts. 相似文献
9.
10.
Francisco Javier Caballero Isabel Igeño Jacobo Cárdenas Francisco Castillo 《Archives of microbiology》1989,152(5):508-511
The phototrophic bacterium Rhodobacter capsulatus E1F1 assimilates ammonia and other forms of reduced nitrogen either through the GS/GOGAT pathway or by the concerted action of l-alanine dehydrogenase and aminotransferases. These routes are light-independent and very responsive to the carbon and nitrogen sources used for cell growth. GS was most active in cells grown on nitrate or l-glutamate as nitrogen sources, whereas it was heavily adenylylated and siginificantly repressed by ammonium, glycine, l-alanine, l-aspartate, l-asparagine and l-glutamine, under which conditions specific aminotransferases were induced. GOGAT activity was kept at constitutive levels in cells grown on l-amino acids as nitrogen sources except on l-glutamine where it was significantly induced during the early phase of growth. In vitro, GOGAT activity was strongly inhibited by l-tyrosine and NADPH. In cells using l-asparagine or l-aspartate as nitrogen source, a concerted induction of l-aspartate aminotransferase and l-asparaginase was observed. Enzyme level enhancements in response to nitrogen source variation involved de novo protein synthesis and strongly correlated with the cell growth phase.Abbreviations ADH
l-alanine dehydrogenase
- AOAT
l-alanine:2-oxoglutarate aminotransferase
- Asnase
l-asparaginase
- GOAT
Glycine: oxaloacetate aminotransferase
- GOGAT
Glutamate synthase
- GOT
l-aspartate: 2-oxoglutarate aminotransferase
- GS
Glutamine synthetase
- HPLC
High-Pressure Liquid Chromatography
- MOPS
2-(N-morpholino)propanesulfonic acid
- MSX
l-methionine-d,l-sulfoximine 相似文献
11.
Iris Eggeling Christiana Cordes Lothar Eggeling Hermann Sahm 《Applied microbiology and biotechnology》1987,25(4):346-351
Summary
Corynebacterium glutamicum ATCC 13 032 produces 13 g/l l-isoleucine from 200 mM -ketobutyrate as a synthetic precursor. In fed batch cultures up to 19 g/l l-isoleucine is formed. For optimal conversion the addition of 0.3 mM l-valine plus 0.3 mM l-leucine to the fermentation medium is required. The affinity constants for the acetohydroxy acid synthase (AHAS) were determined. (This enzyme directs the flow of -ketobutyrate plus pyruvate towards l-isoleucine and that of two moles of pyruvate to l-valine and l-leucine, respectively.) For -ketobutyrate the K
m is 4.8×10-3 M, and V
max 0.58 U/mg, for pyruvate the K
m is 8.4×10-3 M, and V
max 0.37 U/mg. Due to these characteristics the presence of high -ketobutyrate concentrations apparently results in a l-valine, l-leucine deficiency. This in turn leads to a derepression of the AHAS synthesis from 0.03 U/mg to 0.29 U/mg and high l-isoleucine production is favoured. The derepression of the AHAS synthesis induced by the l-valine, l-leucine shortage was directly proven with a l-valine, l-leucine, l-isoleucine auxotrophic mutant where the starvation of each amino acid resulted in an increased AHAS level. This is in accordance with the fact that only one AHAS enzyme could be verified by chromatographic and electrophoretic separations as being responsible for the synthesis of all three branched-chain amino-acids. 相似文献
12.
Yinan Zhang Fei Tao Miaofen Du Cuiqing Ma Jianhua Qiu Lichuan Gu Xiaofei He Ping Xu 《Applied microbiology and biotechnology》2010,86(2):481-489
N-Acetyl-d-neuraminic acid (Neu5Ac) is a precursor for producing many pharmaceutical drugs such as zanamivir which have been used in
clinical trials to treat and prevent the infection with influenza virus, such as the avian influenza virus H5N1 and the current
2009 H1N1. Two recombinant Escherichia coli strains capable of expressing N-acetyl-d-glucosamine 2-epimerase and N-acetyl-d-neuraminic acid aldolase were constructed based on a highly efficient temperature-responsive expression system which is safe
compared to chemical-induced systems and coupled in Neu5Ac production. Carbon sources were optimized for Neu5Ac production,
and the concentration effects of carbon sources on the production were investigated. With 2,200 mM pyruvate as carbon source
and substrate, 61.9 mM (19.1 g l−1) Neu5Ac was produced from 200 mM N-acetyl-d-glucosamine (GlcNAc) in 36 h by the coupled cells. Our Neu5Ac biosynthetic process is favorable compared with natural product
extraction, chemical synthesis, or even many other biocatalysis processes. 相似文献
13.
Gopinath V Meiswinkel TM Wendisch VF Nampoothiri KM 《Applied microbiology and biotechnology》2011,92(5):985-996
Corynebacterium glutamicum wild type lacks the ability to utilize the pentose fractions of lignocellulosic hydrolysates, but it is known that recombinants
expressing the araBAD operon and/or the xylA gene from Escherichia coli are able to grow with the pentoses xylose and arabinose as sole carbon sources. Recombinant pentose-utilizing strains derived
from C. glutamicum wild type or from the l-lysine-producing C. glutamicum strain DM1729 utilized arabinose and/or xylose when these were added as pure chemicals to glucose-based minimal medium or
when they were present in acid hydrolysates of rice straw or wheat bran. The recombinants grew to higher biomass concentrations
and produced more l-glutamate and l-lysine, respectively, than the empty vector control strains, which utilized the glucose fraction. Typically, arabinose and
xylose were co-utilized by the recombinant strains along with glucose either when acid rice straw and wheat bran hydrolysates
were used or when blends of pure arabinose, xylose, and glucose were used. With acid hydrolysates growth, amino acid production
and sugar consumption were delayed and slower as compared to media with blends of pure arabinose, xylose, and glucose. The
ethambutol-triggered production of up to 93 ± 4 mM l-glutamate by the wild type-derived pentose-utilizing recombinant and the production of up to 42 ± 2 mM l-lysine by the recombinant pentose-utilizing lysine producer on media containing acid rice straw or wheat bran hydrolysate
as carbon and energy source revealed that acid hydrolysates of agricultural waste materials may provide an alternative feedstock
for large-scale amino acid production. 相似文献
14.
The effect of different amounts of supplemented l-isoleucine and pantothenate has been analysed with the auxotrophic strain Corynebacterium glutamicum
ΔilvA
ΔpanB, showing that the final biomass concentration of this preliminary l-valine production strain can be controlled by the amount of added l-isoleucine. One gramme cell dry weight is formed from 48 μmol l-isoleucine. Different amounts of available pantothenate affect the intracellular pyruvate concentration. By limiting pantothenate
supplementation from 0.8 to 0.1 μM, a 35-fold increase of cytoplasmic pyruvate up to 14.2 mM can be observed, resulting in
the increased formation of l-valine, l-alanine and organic acids in the presence of low pantothenate concentrations. These findings can be used to redirect the
carbon flux from glycolysis via pyruvate to the TCA cycle towards the desired product l-valine. 相似文献
15.
Wejksza K Rzeski W Okuno E Kandefer-Szerszen M Albrecht J Turski WA 《Neurochemical research》2005,30(8):963-968
In the present study we demonstrate for the first time that both kynurenine aminotransferase (KAT) isoforms I and II are present
in the permanent immature rat oligodendrocytes cell line (OLN-93). Moreover, we provide evidence that OLN-93 cells are able
to synthesize kynurenic acid (KYNA) from exogenously added l-kynurenine and we characterize its regulation by extrinsic factors. KYNA production in OLN-93 cells was depressed in the
presence of aminotransferase inhibitor, aminooxyacetic acid and was not affected by depolarizing agents such as 50 mM K+ and 4-aminopyridine. Glutamate agonists, l-glutamate and d,l-homocysteine significantly decreased KYNA production. Selective agonist of ionotropic glutamate receptors Amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropionic
acid (AMPA) lowered KYNA production in OLN-93 cell line, whereas N-methyl-d-aspartate (NMDA) had no influence on KYNA production. Furthermore, KYNA synthesis in OLN-93 cells was decreased in a concentration-dependent
manner by amino acids transported by l-system, l-leucine, l-cysteine and l-tryptophan. The role of KYNA synthesis in oligodendrocytes needs further investigation. 相似文献
16.
A bacterium isolated from Burdwan (India) soil was found to accumulatel-lysine in the growth medium and was identified asArthrobacter globiformis. The strain grew and accumulated lysine in a purely synthetic medium. Supplementation of the synthetic medium stimulated
growth but did not improve the yield. The entire fermentation period could be divided into a growth phase and a production
phase, which could be prolonged by adjustment of pH to the neutral range. Among the different hydrocarbon and nitrogen sources
tested SR gas oil at 4 % and ammonium sulphate at 0.4 %, respectively, were found most to be suitable. Different vitamins
and antibiotics stimulated growth and lysine yield; inoculum of 7 % (V/V) of the medium was found to be optimal. The yield of lysine under optimal conditions was 3.4 g per litre medium. Lysine was
isolated in crystalline form from the fermented broth by IEC and found to be a purel-isomer. 相似文献
17.
Homocysteine affects cardiomyocyte viability: concentration-dependent effects on reversible flip-flop, apoptosis and necrosis 总被引:1,自引:0,他引:1
Sipkens JA Krijnen PA Meischl C Cillessen SA Smulders YM Smith DE Giroth CP Spreeuwenberg MD Musters RJ Muller A Jakobs C Roos D Stehouwer CD Rauwerda JA van Hinsbergh VW Niessen HW 《Apoptosis : an international journal on programmed cell death》2007,12(8):1407-1418
Background Hyperhomocysteinaemia (HHC) is thought to be a risk factor for cardiovascular disease including heart failure. While numerous
studies have analyzed the role of homocysteine (Hcy) in the vasculature, only a few studies investigated the role of Hcy in
the heart. Therefore we have analyzed the effects of Hcy on isolated cardiomyocytes.
Methods H9c2 cells (rat cardiomyoblast cells) and adult rat cardiomyocytes were incubated with Hcy and were analyzed for cell viability.
Furthermore, we determined the effects of Hcy on intracellular mediators related to cell viability in cardiomyocytes, namely
NOX2, reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨ
m) and ATP concentrations.
Results We found that incubation of H9c2 cells with 0.1 mM D,L-Hcy (= 60 μM l-Hcy) resulted in an increase of ΔΨ
m as well as ATP concentrations. 1.1 mM d,l-Hcy (= 460 μM l-Hcy) induced reversible flip-flop of the plasma membrane phospholipids, but not apoptosis. Incubation with 2.73 mM d,l-Hcy (= 1.18 mM l-Hcy) induced apoptosis and necrosis. This loss of cell viability was accompanied by a thread-to-grain transition of the mitochondrial
reticulum, ATP depletion and nuclear NOX2 expression coinciding with ROS production as evident from the presence of nitrotyrosin
residues. Notably, only at this concentration we found a significant increase in S-adenosylhomocysteine which is considered
the primary culprit in HHC.
Conclusion We found concentration-dependent effects of Hcy in cardiomyocytes, varying from induction of reversible flip-flop of the plasma
membrane phospholipids, to apoptosis and necrosis. 相似文献
18.
Isao Umemura Satoru Takamatsu Tadashi Sato Tetsuya Tosa Ichiro Chibata 《Applied microbiology and biotechnology》1984,20(5):291-295
Summary In our laboratory, EAPc-7 a strain having higher aspartase activity was derived from Escherichia coli ATCC 11303. For the improvement of l-aspartic acid productivity using EAPc-7 cells immobilized in -carrageenan, it was necessary to eliminate the fumarase activity which converts fumaric acid to l-malic acid. Several treatments for specifically eliminating fumarase activity from EAPc-7 cells were tested and it was found that when EAPc-7 cells were treated in a culture broth (pH 4.9) containing 50 mM l-aspartic acid at 45° C for 1 h, fumarase activity was almost completely eliminated without inactivation of the aspartase.The treated cells, immobilized in -carrageenan, were used for continuous production of l-aspartic acid from ammonium fumarate. The formation of l-malic acid was negligible and the half-life of the immobilized preparation was 126 days.Productivity of immobilized preparation of treated EAPc-7 cells in l-aspartic acid production was six times of that of the parent cell preparation. 相似文献
19.
Kawaguchi H Sasaki M Vertès AA Inui M Yukawa H 《Applied microbiology and biotechnology》2008,77(5):1053-1062
Corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar l-arabinose, a product of the degradation of lignocellulosic biomass. The resultant CRA1 recombinant strain expressed the Escherichia coli genes araA, araB, and araD encoding l-arabinose isomerase, l-ribulokinase, and l-ribulose-5-phosphate 4-epimerase, respectively, under the control of a constitutive promoter. Unlike the wild-type strain,
CRA1 was able to grow on mineral salts medium containing l-arabinose as the sole carbon and energy source. The three cloned genes were expressed to the same levels whether cells were
cultured in the presence of d-glucose or l-arabinose. Under oxygen deprivation and with l-arabinose as the sole carbon and energy source, strain CRA1 carbon flow was redirected to produce up to 40, 37, and 11%,
respectively, of the theoretical yields of succinic, lactic, and acetic acids. Using a sugar mixture containing 5% d-glucose and 1% l-arabinose under oxygen deprivation, CRA1 cells metabolized l-arabinose at a constant rate, resulting in combined organic acids yield based on the amount of sugar mixture consumed after
d-glucose depletion (83%) that was comparable to that before d-glucose depletion (89%). Strain CRA1 is, therefore, able to utilize l-arabinose as a substrate for organic acid production even in the presence of d-glucose. 相似文献
20.
Eco-Efficiency Analysis of biotechnological processes 总被引:1,自引:0,他引:1
Saling P 《Applied microbiology and biotechnology》2005,69(1):1-8
For almost 50 years now, biotechnological production processes have been used for industrial production of amino acids. Market development has been particularly dynamic for the flavor-enhancer glutamate and the animal feed amino acids l-lysine, l-threonine, and l-tryptophan, which are produced by fermentation processes using high-performance strains of Corynebacterium glutamicum and Escherichia coli from sugar sources such as molasses, sucrose, or glucose. But the market for amino acids in synthesis is also becoming increasingly important, with annual growth rates of 5–7%. The use of enzymes and whole cell biocatalysts has proven particularly valuable in production of both proteinogenic and nonproteinogenic l-amino acids, d-amino acids, and enantiomerically pure amino acid derivatives, which are of great interest as building blocks for active ingredients that are applied as pharmaceuticals, cosmetics, and agricultural products. Nutrition and health will continue to be the driving forces for exploiting the potential of microorganisms, and possibly also of suitable plants, to arrive at even more efficient processes for amino acid production. 相似文献