The effect of ammonium ions and pH on the elaboration of the fungal extracellular polysaccharide, pullulan, by Aureobasidium pullulans

1987 ◽  
Vol 25 (4) ◽  
Author(s):  
MarcA. Bulmer ◽  
BrianJ. Catley ◽  
PatrickJ. Kelly
Keyword(s):  
Aureobasidium Pullulans ◽  
Extracellular Polysaccharide ◽  
Ammonium Ions

Morphogenesis and adhesion of Aureobasidium pullulans

1994 ◽  
Vol 40 (1) ◽  
pp. 6-17 ◽  
Author(s):  
John H. Andrews ◽  
Robin F. Harris ◽  
Russell N. Spear ◽  
Gee W. Lau ◽  
Erik V. Nordheim
Keyword(s):  
Batch Culture ◽  
Aureobasidium Pullulans ◽  
Cell Attachment ◽  
Extracellular Polysaccharide ◽  
Quantitative Detection ◽  
Total Biomass ◽  
Dimorphic Fungus ◽  
Solid Media ◽  
Carbon And Nitrogen Content ◽  
Cellulose Membranes

Two strains of the dimorphic fungus Aureobasidium pullulans were grown in liquid and on solid media varying in carbon and nitrogen content, and on leaf surfaces. Hyphae were observed in all systems but comprised a very low proportion (often below quantitative detection) of the total biomass. In liquid media, hyphae were found sparsely and only in the wash-zone on walls of the culture flasks. Yeast phase growth (blastospores) occurred in pH-buffered media that were nutrient balanced, or continuously carbon-limited (fed-batch culture), or carbon-exhausted (batch culture). Blastospores exposed to conditions with limited nitrogen but sufficient organic carbon, or to acidified media, converted to swollen cells and chlamydospores. The latter morphotypes accumulated carbon internally as lipid granules, and then externally as capsular and soluble extracellular polysaccharide. They were cohesive and also adhered more strongly to cellulose membranes overlying agar media or to leaves than did blastospores. Pullulanase treatment diminished the capsules, cohesion, and adhesion. Addition of soluble extracellular polysaccharide to blastospores enhanced their adhesion to leaves. We conclude that extracellular polysaccharide can play a role in adhesion of A. pullulans.Key words: phylloplane, leaf surface, epiphytic growth, extracellular polysaccharide, cell attachment.

Extracellular polysaccharide (EPS) production by a novel strain of yeast-like fungus Aureobasidium pullulans

2010 ◽  
Vol 82 (3) ◽  
pp. 728-732 ◽  
Author(s):  
Sreenivas Rao Ravella ◽  
Teresa Suárez Quiñones ◽  
Andy Retter ◽  
Monika Heiermann ◽  
Thomas Amon ◽  
...  
Keyword(s):  
Aureobasidium Pullulans ◽  
Extracellular Polysaccharide

Pullulan elaboration and differentiation of the resting forms in Aureobasidium pullulans

1995 ◽  
Vol 41 (1) ◽  
pp. 35-45 ◽  
Author(s):  
L. Simon ◽  
B. Bouchet ◽  
C. Caye-Vaugien ◽  
D. J. Gallant
Keyword(s):  
Cell Wall ◽  
Aureobasidium Pullulans ◽  
Culture Medium ◽  
Extracellular Polysaccharide ◽  
Growth Conditions ◽  
Cellular Level ◽  
Wall Thickening ◽  
Resting Forms ◽  
Polysaccharide Synthesis ◽  
Swollen Cell

To identify the cellular forms that are responsible for the synthesis of pullulan produced by Aureobasidium pullulans, we performed cytochemical and ultrastructural localizations of glucan in the cellular forms of this microorganism (blastospores and resting forms). Growth conditions, cell populations, and pullulan production were studied concurrently. Our results are consistent with a model in which the resting forms (swollen cells and chlamydospores) might be primarily involved in this extracellular polysaccharide elaboration. At the cellular level, pullulan production could be the result of three main stages: (i) cell wall thickening and extracellular polysaccharide synthesis by the swollen cell, (ii) fibrillar arrangement of this polysaccharide into pullulan along a capsular network around the chlamydospore, and (iii) subcellular hydrolysis separating the capsule from the periplasmic zone and consequently permitting the solubilization of pullulan in the culture medium. A melanization process in the outer layer of the cell wall and the capsule accompanies these patterns.Key words: Aureobasidium pullulans, capsule, cytochemistry, polysaccharide, pullulan, resting forms.

Aureobasidium thailandense sp. nov. isolated from leaves and wooden surfaces

2013 ◽  
Vol 63 (Pt_2) ◽  
pp. 790-795 ◽  
Author(s):  
Stephen W. Peterson ◽  
Pennapa Manitchotpisit ◽  
Timothy D. Leathers
Keyword(s):  
Salt Tolerance ◽  
Aureobasidium Pullulans ◽  
18S Rrna ◽  
Extracellular Polysaccharide ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
Type I ◽  
Type Isolate

Aureobasidium thailandense sp. nov. is described from cultures of material collected on leaves and wooden surfaces in Thailand and the type isolate is NRRL 58539T. Phylogenetically it is distinct from other species of the genus Aureobasidium. Phenotypically it is distinguished by its cardinal growth temperatures, salt tolerance and production of reddish brown hyphal pigmentation in PDA cultures, but micro-morphologically it is not clearly distinguishable from Aureobasidium pullulans. Unlike A. pullulans, A. thailandense sp. nov. produces a non-pullulan extracellular polysaccharide whose characteristics are unknown. The two known isolates of A. thailandense sp. nov. possess an approx. 500 bp type I intron in the 18S rRNA gene that is present in ITS amplifications using primers ITS4 and ITS5. A. pullulans isolates uniformly lack this intron.

scholarly journals Ability of the fungus Aureobasidium pullulans to produce polysaccharide (pullulan) with presence of different Carbon and Nitrogen sources

2014 ◽  
Vol 8 (1) ◽  
pp. 67-70
Author(s):  
Zahraa Ibraheem Muhammed Al_dabbagh ◽  
Muhammed Basheer Ismaeil Kassim
Keyword(s):  
Amino Acid ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Incubation Period ◽  
Aureobasidium Pullulans ◽  
Nitrogen Sources ◽  
Extracellular Polysaccharide ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Amino Acid Glycine

The effect of incubation period, different carbon and nitrogen sources on the production of the extracellular polysaccharide pullulan by Aureobasidium pullulansNRRL58560 was examined. The results showed that the maximum production of pullulan was obtained 13.76 after 96 hours of incubation. Sucrose as a carbon source gave the highest production of pullulan 31.92 g/l while the highest biomass was obtained when starch was used as a carbon source 16.30 g/l. The amino acid glycine as a nitrogen source gave the highest production of pullulan 34.61 g/l and the highest production of biomass 14.49 g/l was obtained when ammonium chloride was used.

ALDOSTERONE STIMULATION IN VITRO

1965 ◽  
Vol 50 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Jürg Müller
Keyword(s):  
Ammonium Chloride ◽  
Human Urine ◽  
Incubation Medium ◽  
The Other ◽  
Ammonium Ions ◽  
Response Curves ◽  
Urine Extract ◽  
Similar Dose ◽  
Aldosterone Production

ABSTRACT An extract of human urine, which was previously shown to stimulate aldosterone production by rat adrenal sections, was further purified. Evidence was obtained that its aldosterone-stimulating effect was due to the presence of ammonium ions. Addition of ammonium chloride and of urine extract to the incubation medium caused identical increases in aldosterone production in vitro. In addition to ammonium ions, rubidium and caesium ions also stimulated aldosterone production up to 250% that of control values without a significant effect on corticosterone production. Similar dose-response curves were obtained when increasing concentrations of potassium, ammonium, rubidium and caesium ions were tested. Aldosterone production was maximal at concentrations of 7 mval/1 and was significantly lower at higher concentrations. When ammonium chloride and ACTH were simultaneously added to the incubation medium, the production of aldosterone and of corticosterone was lower than with ACTH alone. On the other hand, the stimulating activity on aldosterone and corticosterone production by »TPN« (NADP) and glucose-6-phosphate was enhanced by the simultaneous addition of ammonium chloride.

Sorption of Heavy Metals by Bed Silts in the Presence of Ammonium Ions

2016 ◽  
Vol 38 (2) ◽  
pp. 96-100
Author(s):  
V. Shkapenko ◽  
V. Kadoshnikov ◽  
E. Musich ◽  
I. Pisanskaya
Keyword(s):  
Heavy Metals ◽  
Ammonium Ions

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

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