Influence of ammonium on the biosynthesis of the macrolide antibiotic tylosin

Vu-Trong, K.; Gray, P. P.

doi:10.1016/0141-0229(87)90110-4

Cited by 23 publications

(8 citation statements)

References 14 publications

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“…The results suggested that although the enzyme activity in control condition was low, it might be enough to catalyze the substrate (isobutanol). The inhibition target of ammonium on valine dehydrogenase was reported earlier [17][18][19], but in our study (Fig. 4B) no distinct difference of this enzyme activity was observed in the medium with or without ammonium.…”

Section: Effect Of Ammonium On Activities Of Isobutanol Dehydrogenasecontrasting

confidence: 52%

“…On the other hand, there are several reports claiming that antibiotic production was inhibited by high concentration of ammonium in medium [17,18] and the inhibition mechanism was explained as depression of enzymes in primary or secondary pathways related to the specific antibiotic biosynthesis [19,20]. However, the effect of ammonium in medium on gene transcription for antibiotic biosynthesis has not yet reported.…”

Section: Introductionmentioning

confidence: 90%

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Effect of ammonium in medium on ansamitocin P-3 production by Actinosynnema pretiosum

Lin

Bai

Deng

et al. 2010

Biotechnol Bioproc E

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Ansamitocin P-3 (AP-3) is an antitumor agent produced by ^ÅíáåçëóååÉã~=éêÉíáçëìã with a market demand for large and cheap supply, but its productivity is yet low. This work investigated the effects of ammonium in medium on the productivity, enzyme activities, and gene transcription for AP-3 biosynthesis. As observed, AP-3 production was depressed by medium ammonium, although the dry cell weight and the consumption of total sugar and isobutanol were not influenced obviously. From the onset of AP-3 accumulation, isobutyrate accumulation showed a different behavior in medium with or without ammonium. Isobutanol dehydrogenase activity was enhanced during production phase in medium with ammonium, but valine dehydrogenase activity was not substantially changed. qRT-PCR analysis revealed that transcriptional levels of structure genes=~ëãNQI ~ëãOQI ~ëãQP, and ~ëãNV were down-regulated by medium ammonium. The transcription of regulatory gene ~ëãO,=~ëãOVI=and=~ëãPN were slightly up-regulated while that of ~ëãPV was down-regulated by ammonium. The results indicated that inhibition of AP-3 production by ammonium might be related to the AP-3 ester side chain supply and the repression of gene transcription responsible for 3-amino-5-hydroxybenzoic acid and methoxymalonyl-ACP biosynthesis. The information is useful for future AP-3 productivity enhancement. © KSBB hÉóïçêÇëW=^åë~ãáíçÅáå=mJPI=ãÉÇáìã=~ããçåáìã=ÉÑÑÉÅíI=ÖÉåÉ=íê~åëÅêáéíáçåI=ÉåòóãÉ=~Åíáîáíó= = = = =

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Section: Effect Of Ammonium On Activities Of Isobutanol Dehydrogenasecontrasting

confidence: 52%

Section: Introductionmentioning

confidence: 90%

Effect of ammonium in medium on ansamitocin P-3 production by Actinosynnema pretiosum

Lin

Bai

Deng

et al. 2010

Biotechnol Bioproc E

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“…Many workers have noted a variety of repressors of secondary metabolism which may be responsible for this. These include the nature of the carbon source (Hu et al, 1984;Payne & Wang, 1989), and levels of ammonia which tends to repress many antibiotic biosynthetic pathways (Vu-trong & Gray, 1987;Dekleva et al, 1985;Tanaka et al, 1985) or the synthesis of some of antibiotic pathway enzymes (Zhang et al, 1989;Cimburkova et al, 1988;Shapiro & Vining, 1983). The levels of growth substrates in the growth medium did not appear to exert any direct catabolite repression or inhibition of granaticin synthesis when S .…”

Section: Discussionmentioning

confidence: 99%

The effects of temperature, pH and growth rate on secondary metabolism in Streptomyces thermoviolaceus grown in a chemostat

James

Edwards

Dawson³

1991

Journal of General Microbiology

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Streptomyces thermoviolaceus was grown in a chemostat under conditions of glutamate limitation. The effects of growth rate on production of the antibiotic granaticin, extracellular protein and protease activity as components of secondary metabolism were studied at 37,45 and 50 "C. The amount of each secondary metabolite synthesized was highly dependent on growth rate and temperature. Granaticin yields were highest at growth rates of 0.1 to 0.15 h-l at 37 "C, 0.175 h-l at 45 "C and 0.045 h-l at 50 "C. Protease activity of culture supernatants responded to low nutrient concentration and/or low growth rate. Measurements of extracellular protein revealed complex changes in amount which were dependent on growth rate and temperature. At 45 "C and a growth rate of 0.15 h-l, biomass yield was highest between pH 5.5 to 6.5 whereas granaticin synthesis was low at pH 5-5 and rose to highest values at between pH 6.5 and 7-5.

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“…controlling secondary-metabolite formation in streptomycetes appears to involve nitrogen catabolite regulation (see Kleinkauf et al 1986). In the case of tylosin production in cultures of S. fradiae, the titres of antibiotic, and of valine dehydrogenase activity in cell extracts, have both been shown to be dramatically lowered during growth in the presence of elevated levels of NH3 (Omura et al, 1983a(Omura et al, , 1984Omura & Tanaka, 1986;Vu-Trong & Gray, 1987), suggesting that antibiotic production is directly influenced by the flow of essential building blocks from this primary metabolic pathway. Secondly, the pathway of valine catabolism in these organisms must occur by a route that is different to that found in Pseudomonas (Massey et al, 1976) and mammals (Wolf & Ackers, 1986).…”

Section: Introductionmentioning

confidence: 99%

Purification and catalytic properties of l-valine dehydrogenase from Streptomyces cinnamonensis

Priestley

1989

Biochemical Journal

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NAD+-dependent L-valine dehydrogenase was purified 180-fold from Streptomyces cinnamonensis, and to homogeneity, as judged by gel electrophoresis. The enzyme has an Mr of 88,000, and appears to be composed of subunits of Mr 41,200. The enzyme catalyses the oxidative deamination of L-valine, L-leucine, L-2-aminobutyric acid, L-norvaline and L-isoleucine, as well as the reductive amination of their 2-oxo analogues. The enzyme requires NAD+ as the only cofactor, which cannot be replaced by NADP+. The enzyme activity is significantly decreased by thiol-reactive reagents, although purine and pyrimidine bases, and nucleotides, do not affect activity. Initial-velocity and product-inhibition studies show that the reductive amination proceeds through a sequential ordered ternary-binary mechanism; NADH binds to the enzyme first, followed by 2-oxoisovalerate and NH3, and valine is released first, followed by NAD+. The Michaelis constants are as follows; L-valine, 1.3 mM; NAD+, 0.18 mM; NADH, 74 microM; 2-oxoisovalerate, 0.81 mM; and NH3, 55 mM. The pro-S hydrogen at C-4' of NADH is transferred to the substrate; the enzyme is B-stereospecific. It is proposed that the enzyme catalyses the first step of valine catabolism in this organism.

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Influence of ammonium on the biosynthesis of the macrolide antibiotic tylosin

Cited by 23 publications

References 14 publications

Effect of ammonium in medium on ansamitocin P-3 production by Actinosynnema pretiosum

Effect of ammonium in medium on ansamitocin P-3 production by Actinosynnema pretiosum

The effects of temperature, pH and growth rate on secondary metabolism in Streptomyces thermoviolaceus grown in a chemostat

Purification and catalytic properties of l-valine dehydrogenase from Streptomyces cinnamonensis

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