Nutrient effects on growth and the production of 5-hydroxy-4-oxonorvaline by Streptomyces akiyoshiensis

1993 ◽  
Vol 39 (5) ◽  
pp. 536-542 ◽  
Author(s):  
M. A. Glazebrook ◽  
L. C. Vining ◽  
R. L. White ◽  
K. C. Smith ◽  
E. G. Chedrawy
Keyword(s):  
Nitrogen Sources ◽  
Potassium Nitrate ◽  
Nutrient Effects ◽  
Magnesium Ammonium ◽  
Initial Ph ◽  
Physiological Analysis ◽  
Poorly Soluble ◽  
High Concentrations ◽  
High Level ◽  
Inorganic Constituents

5-Hydroxy-4-oxonorvaline (HON) was produced optimally by Streptomyces akiyoshiensis in media containing starch and casein supplemented with high concentrations of phosphate and magnesium sulfate; cultures grown at initial pH values between 6.3 and 6.6 yielded HON titres of 13–14 mM. Physiological analysis of HON production provided evidence that the excess inorganic constituents in this medium played an important role in optimizing production. In simple defined media buffered at pH 5.5–6.0 and inoculated with either a spore suspension or washed vegetative mycelium, formation of HON was less than one-third the amount produced in the starch–casein–salts medium. Production was markedly affected by the carbon and nitrogen sources used; media containing starch and potassium nitrate or aspartate supported the highest yields of HON. In starch–nitrate media, production was suppressed by excess nitrogen source, and the HON titre decreased 3-fold as the phosphate content was increased from 0.5 to 5 mM; growth was not appreciably altered. The results suggest that the high level of HON production in the complex starch–casein–salts medium is associated with sequestration of metabolic ammonium and reduced availability of phosphate through formation of the poorly soluble magnesium ammonium phosphate.Key words: Streptomyces akiyoshiensis, 5-hydroxy-4-oxonorvaline, nitrogen catabolite regulation, phosphate suppression.

scholarly journals GENETIC AND PHYSIOLOGICAL ANALYSIS OF SUCROSE ACCUMULATION IN TOMATO FRUIT

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 584b-584
Author(s):  
John R. Stommnel
Keyword(s):  
Tomato Fruit ◽  
Sugar Content ◽  
Recessive Gene ◽  
Sucrose Phosphate Synthase ◽  
Soluble Solids ◽  
Sucrose Accumulation ◽  
Backcross Populations ◽  
Physiological Analysis ◽  
High Concentrations ◽  
High Level

Fruit of the cultivated tomato, Lycopersicon esculentum, accumulate the reducing sugars glucose and fructose as the primary storage carbohydrates. In contrast, fruit of several wild green-fruited species store high concentrations of sucrose. Analysis of invertase, sucrose synthase (SS) and sucrose phosphate synthase (SPS) enzyme activity throughout fruit development in the sucrose accumulating species L. peruvianum, indicated low levels of invertase and SS during the period of significant sucrose accumulation. Increased SPS activity was noted during the sucrose accumulation phase but was not coincident with maximum rates of sucrose accumulation. The percent soluble solids in ripe L. peruvianum fruit was more than twice that present in L. esculentum and attributed primarily to the high level of sucrose accumulated in L. peruvianum. Analysis of fruit sugar content in F1, F2 and backcross populations derived from an initial cross between plants of sucrose and hexose accumulators suggests that recessive gene(s) are responsible for sucrose accumulation.

scholarly journals A family of ammonium transporters in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (8) ◽  
pp. 4282-4293 ◽  
Author(s):  
A M Marini ◽  
S Soussi-Boudekou ◽  
S Vissers ◽  
B Andre
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nitrogen Source ◽  
Transcriptional Activation ◽  
Nitrogen Sources ◽  
Yeast Cells ◽  
Dependent Manner ◽  
Feeding Experiments ◽  
High Concentrations ◽  
High Level

Ammonium is a nitrogen source supporting growth of yeast cells at an optimal rate. We recently reported the first characterization of an NH4+ transport protein (Mep1p) in Saccharomyces cerevisiae. Here we describe the characterization of two additional NH4+ transporters, Mep2p and Mep3p, both of which are highly similar to Mep1p. The Mep2 protein displays the highest affinity for NH4+ (Km, 1 to 2 microM), followed closely by Mep1p (Km, 5 to 10 microM) and finally by Mep3p, whose affinity is much lower (Km, approximately 1.4 to 2.1 mM). A strain lacking all three MEP genes cannot grow on media containing less than 5 mM NH4+ as the sole nitrogen source, while the presence of individual NH4+ transporters enables growth on these media. Yet, the three Mep proteins are not essential for growth on NH4+ at high concentrations (>20 mM). Feeding experiments further indicate that the Mep transporters are also required to retain NH4+ inside cells during growth on at least some nitrogen sources other than NH4+. The MEP genes are subject to nitrogen control. In the presence of a good nitrogen source, all three MEP genes are repressed. On a poor nitrogen source, MEP2 expression is much higher than MEP1 and MEP3 expression. High-level MEP2 transcription requires at least one of the two GATA family factors Gln3p and Nil1p, which are involved in transcriptional activation of many other nitrogen-regulated genes. In contrast, expression of either MEP1 or MEP3 requires only Gln3p and is unexpectedly down-regulated in a Nil1p-dependent manner. Analysis of databases suggests that families of NH4+ transporters exist in other organisms as well.

scholarly journals High level production of laccases and peroxidases from the newly isolated white-rot basidiomycete Marasmiellus palmivorus VE111 in a stirred-tank bioreactor in response to different carbon and nitrogen sources

2018 ◽  
Vol 69 ◽  
pp. 1-11 ◽  
Author(s):  
Willian Daniel Hahn Schneider ◽  
Roselei Claudete Fontana ◽  
Simone Mendonça ◽  
Félix Gonçalves de Siqueira ◽  
Aldo José Pinheiro Dillon ◽  
...  
Keyword(s):  
Nitrogen Sources ◽  
White Rot ◽  
Stirred Tank ◽  
Carbon And Nitrogen Sources ◽  
Stirred Tank Bioreactor ◽  
Carbon And Nitrogen ◽  
High Level ◽  
Level Production

The effect of salinity on the growth, water status, and ion content on Common bean (Phaseolus vulgaris. L. var. El-Djadida)

2018 ◽  
Vol 7 (4) ◽  
pp. 147-156
Author(s):  
Laredj-Zazou Rahma ◽  
Toumi Benali Fawzia ◽  
Bouazza Sofiane
Keyword(s):  
Sodium Chloride ◽  
Water Status ◽  
Phaseolus Vulgaris L ◽  
Salt Stress Tolerance ◽  
Ion Content ◽  
Organic Growth ◽  
Growth Attributes ◽  
High Concentrations ◽  
High Level ◽  
Post Stress

Stress salinity has an important effect on crops physiology. The scope of our study was to evaluate the effect of salt stress tolerance as determined through growth attributes, water status and ion content in (Phaseolus vul-garis. L), the variety of El-Djadida in 6 weeks post stress application. The ex-periment was performed under glasshouse, in controlled conditions, in pots and irrigated with nutrient solution of Hoagland. Plants were irrigated with water containing sodium chloride alone (100 and 200 meq.l-1) combined with sodium chloride (NaCl) and calcium chloride (CaCl2) (100 and 150 meq.l-1). The results obtained showed that the salt application had a depressive effect on the organic growth however, this trend was dependant on the intensity of the stress. The hydric state of the plant varied with the concentration of sub-strate, thus exhibiting the ability to moderate the sensitive plant to adjust gradually to their osmotic pressure even by maintaining high concentrations of K+. The distribution of Na+, K+ and Ca++ in plant organs leaves and roots highlighted that the high level of salinity increased with levels of Na+ which inhibited the absorption of Ca++ and K+ ions.

scholarly journals Recycling and Conversion of Yeasts into Organic Nitrogen Sources for Wine Fermentation: Effects on Molecular and Sensory Attributes

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 313
Author(s):  
Paula Rojas ◽  
Daniel Lopez ◽  
Francisco Ibañez ◽  
Camila Urbina ◽  
Wendy Franco ◽  
...  
Keyword(s):  
Organic Nitrogen ◽  
Protein Hydrolysate ◽  
Principal Component ◽  
Nitrogen Sources ◽  
Isoamyl Alcohol ◽  
Positive Influence ◽  
Higher Alcohols ◽  
Fermentation Performance ◽  
High Concentrations ◽  
Significant Positive Influence

Organic nitrogen plays a significant role in the fermentation performance and production of esters and higher alcohols. This study assessed the use of yeast protein hydrolysate (YPH) as a nitrogen source for grape must fermentation. In this study, we prepared an enzymatic protein hydrolysate using yeasts recovered from a previous fermentation of wine. Three treatments were performed. DAP supplementation was used as a control, while two YPH treatments were used. Low (LDH) and high degrees of hydrolysis (HDH), 3.5% and 10%, respectively, were chosen. Gas chromatography and principal component analysis indicated a significant positive influence of YPH-supplementations on the production of esters and higher alcohols. Significantly high concentrations of 3-methyl-1-penthanol, isoamyl alcohol, isobutanol, and 2-phenylethanol were observed. Significant odorant activity was obtained for 3-methyl-1-pentanol and ethyl-2-hexenoate. The use of YPH as nitrogen supplementation is justified as a recycling yeasts technique by the increase in volatile compounds.

scholarly journals Yearly microbial cycle of human exposed surfaces in show caves

2019 ◽  
Vol 31 ◽  
pp. 1-14
Author(s):  
Silviu Bercea ◽  
Ruxandra Năstase-Bucur ◽  
Oana Teodora Moldovan ◽  
Marius Kenesz ◽  
Silviu Constantin
Keyword(s):  
Microbial Communities ◽  
Rapid Test ◽  
Coliform Bacteria ◽  
Culturable Bacteria ◽  
Indirect Contact ◽  
Cave Environment ◽  
Show Caves ◽  
High Concentrations ◽  
Bacteria And Fungi ◽  
High Level

The human impact upon the subterranean microbiomes is not only a peril to the cave environment but might also affect future visitors. We focused on the changes that humans induced on the surfaces they came in direct or indirect contact with inside two intensely visited Romanian show caves, by means of commercially available microbial rapid test kits and molecular identification. Overall culturable bacteria abundance in the caves maintained high levels year-round while Enterobacteriaceae, coliform bacteria and Escherichiacoli levels peaked during the touristic season, reaching levels that could pose a threat to the health of the visitors. Culturable fungi abundance usually peaked in the spring, remained at a high level in the summer and started to slowly decrease towards the winter months. Differences were observed between the direct and indirect exposed surfaces, as the later had lower overall levels of bacteria and fungi, with increased Enterobacteriaceae loads. Most of the taxa identified are known biodeteriorants of subterranean surfaces and were previously associated with human altered caves. A Dothideomycete sp. previously unknown to the cave environments was detected. This was the first study to analyse the dynamics of the microbial communities of delicate subterranean surfaces in show caves through the use of commercially available test kits. We revealed that exposed surfaces in show caves, in direct or indirect contact with tourists, are host to high concentrations of cultivable microbes. The touristic activity was shown to influence the abundance and dynamics of the microbial communities inhabiting surfaces of show caves.

EFFECTS OF pH AND NITROGEN SOURCES ON GROWTH OF MICROCYSTIS AERUGINOSA KÜTZ.

1962 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Jack McLachlan ◽  
P. R. Gorham
Keyword(s):  
Growth Inhibition ◽  
Microcystis Aeruginosa ◽  
Nitrate Nitrogen ◽  
Nitrogen Sources ◽  
Cesium Chloride ◽  
Potassium Nitrate ◽  
Degree Of Ionization ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range

Microcystis aeruginosa Kütz. (strain NRC-1) grew equally well throughout the pH range 6.5 to 10 when provided with suitable media. Toxicity of tris(hydroxymethyl)aminomethane (TRIS) towards the alga was found to decrease as the pH decreased and could be correlated with the degree of ionization of the TRIS molecule. Other organic buffers examined were either toxic at all concentrations and pH values tested or promoted lysis. When TRIS was used as a buffer, higher concentrations of cesium chloride and potassium nitrate were tolerated without growth inhibition at pH 6.5 than at 7.5. In the presence of TRIS, Microcystis grew equally well with nitrate, ammonium, or urea as nitrogen sources. Eight out of 20 amino compounds examined served as nitrogen sources in TRIS-buffered medium, but growth was poorer than with nitrate nitrogen.

Long-Term Exposure to Air Pollutants and Cognitive Function in Taiwanese Community-Dwelling Older Adults: A Four-Year Cohort Study

2021 ◽  
Author(s):  
Jen-Hau Chen ◽  
Tsung-Yu Kuo ◽  
Hwa-Lung Yu ◽  
Charlene Wu ◽  
Su-Ling Yeh ◽  
...  
Keyword(s):  
Older Adults ◽  
Cohort Study ◽  
Executive Function ◽  
Verbal Fluency ◽  
Air Pollutants ◽  
Community Dwelling ◽  
High Concentrations ◽  
High Level ◽  
Community Dwelling Older Adults

Background: Previous studies have assessed limited cognitive domains with relatively short exposure to air pollutants, and studies in Asia are limited. Objective: This study aims to explore the association between long-term exposure to air pollutants and cognition in community-dwelling older adults. Methods: This four-year prospective cohort study recruited 605 older adults at baseline (2011–2013) and 360 participants remained at four-year follow-up. Global and domain-specific cognition were assessed biennially. Data on PM2.5 (particulate matter ≤ 2.5 μm diameter, 2005–2015), PM10 (1993–2015), and nitrogen dioxide (NO2, 1993–2015) were obtained from Taiwan Environmental Protection Administration (TEPA). Bayesian Maximum Entropy was utilized to estimate the spatiotemporal distribution of levels of these pollutants. Results: Exposure to high-level PM2.5 (>29.98 μg/m3) was associated with an increased risk of global cognitive impairment (adjusted odds ratio = 4.56; β = −0.60). High-level PMcoarse exposure (>26.50 μg/m3) was associated with poor verbal fluency (β = −0.19). High-level PM10 exposure (>51.20 μg/m3) was associated with poor executive function (β = −0.24). Medium-level NO2 exposure (>28.62 ppb) was associated with better verbal fluency (β = 0.12). Co-exposure to high concentrations of PM2.5, PMcoarse or PM10 and high concentration of NO2 were associated with poor verbal fluency (PM2.5 and NO2: β = −0.17; PMcoarse and NO2: β = −0.23; PM10 and NO2: β = −0.21) and poor executive function (PM10 and NO2: β = −0.16). These associations became more evident in women, apolipoprotein ε4 non-carriers, and those with education > 12 years. Conclusion: Long-term exposure to PM2.5 (higher than TEPA guidelines), PM10 (lower than TEPA guidelines) or co-exposure to PMx and NO2 were associated with poor global, verbal fluency, and executive function over 4 years.

scholarly journals Programmed spatial organization of biomacromolecules into discrete, coacervate-based protocells

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wiggert J. Altenburg ◽  
N. Amy Yewdall ◽  
Daan F. M. Vervoort ◽  
Marleen H. M. E. van Stevendaal ◽  
Alexander F. Mason ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Nitrilotriacetic Acid ◽  
Binding Motif ◽  
Biologically Relevant ◽  
Enzyme Cascade ◽  
Synthetic Cell ◽  
Synthetic Cells ◽  
Membrane Bound ◽  
High Concentrations ◽  
High Level

AbstractThe cell cytosol is crowded with high concentrations of many different biomacromolecules, which is difficult to mimic in bottom-up synthetic cell research and limits the functionality of existing protocellular platforms. There is thus a clear need for a general, biocompatible, and accessible tool to more accurately emulate this environment. Herein, we describe the development of a discrete, membrane-bound coacervate-based protocellular platform that utilizes the well-known binding motif between Ni2+-nitrilotriacetic acid and His-tagged proteins to exercise a high level of control over the loading of biologically relevant macromolecules. This platform can accrete proteins in a controlled, efficient, and benign manner, culminating in the enhancement of an encapsulated two-enzyme cascade and protease-mediated cargo secretion, highlighting the potency of this methodology. This versatile approach for programmed spatial organization of biologically relevant proteins expands the protocellular toolbox, and paves the way for the development of the next generation of complex yet well-regulated synthetic cells.

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