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Production of beta-1,4-xylanase by Aureobasidium pullulans DSM-73015: stimulatory effect of ethylene diamine tetraacetic acid [EDTA]

100%

Udeh K. O., Janas P., Targonski Z.

Polish Journal of Food and Nutrition Sciences

1999

tom 08

nr 2

253-262

Aureobasidium pullulans DSM-73015 grown on modified Biely's medium with different carbon sources at 1% concentration secreted very low levels of β-1,4-xylanase (148.4-4680.9 nkat mL-1; 675.1-9752.0 nkat/mg protein). Xylose was the best carbon source inducer upon addition of EDTA and NH4NOh simultaneously into the culture medium. In this case, both the volumetric and specific activities increased up to 4680.9 nkat mL-1 and 9752.0 nkat/mg protein. The highest volumetric ( 13080.9 nkat mL-1 ) and specific activity (14964.6 nkat/mg protein) were obtained after 96 h of cultivation on 3% xylose-containing medium supplemented with EDTA and NH4NO:ł at 0.06% and 0.6% (w/v) concentrations, respectively, at an initial pH value of 4. Added EDTA showed concentration-dependent stimulatory effect on β-l,4-xylanase synthesis and about 16.7-22 and 1.5-22-folds increase in both volumetric and specific activities were achieved compared to that obtained initially on Biely's medium at 1% xylose concentration.

Effect of different inorganic nitrogen sources on the production of cellulase-free beta-1,4-xylanase by Aureobasidium pullulans

100%

Udeh K. O.

Polish Journal of Food and Nutrition Sciences

1999

tom 08

nr 3

39-48

The effect of different levels of inorganic nitrogen sources (0.15,0.21 and 0.25% nitrogen content) on the synthesis of cellulase-free ß-1,4-xylanase by Aureobasidium pullulans DSM-73015 was examined. Among inorganic nitrogen compounds tested, ammonium nitrate (NH4NO3) was the best inorganic nitrogen source at 0.21% nitrogen content that gave the highest volumetric and specific activities (8830.09 nkat mL-1; 10767.15 nkat/mg protein) after 96 h of cultivation, while urea displayed the lowest effect. Partial characterization of this crude enzyme produced after optimization processes on two different buffer systems showed that its optimum pH activity was 4, while the thermoactivity had its maximum at 50°C in both buffers. The highest volumetric and specific activities obtained were 20102.35 nkat mL-1; 23000.40 nkat/mg protein for sodium acetate buffer and 19852.30 nkat mL-1; 22714.31 nkat/mg protein for sodium citrate buffer.

Ograniczanie wyników

2 Polish Journal of Food and Nutrition Sciences

2 Udeh K. O.

1 Janas P.

1 Targonski Z.

2 1999

Wyniki wyszukiwania

Production of beta-1,4-xylanase by Aureobasidium pullulans DSM-73015: stimulatory effect of ethylene diamine tetraacetic acid [EDTA]

Effect of different inorganic nitrogen sources on the production of cellulase-free beta-1,4-xylanase by Aureobasidium pullulans