Production and characterization of cellulolytic enzymes from the thermophilic fungus Thermoascus aurantiacus under solid state cultivation of agricultural wastes

A thermostable endo-β-D-xylanase (1,4-β-D-xylan xylanohydrolase, EC 3.2.1.8) was purified from the culture filtrate of a thermophilic fungus Thermoascus aurantiacus C436, using a single chromatographic step on SP-Sephadex C50. The purified preparation was homogeneous based on denaturing polyacrylamide and isoelectric focusing gels. The xylanase had a subunit molecular mass of 32 000 daltons, isoelectric point at pH 7.1, apparent Km and Vmax of 0.17% (w/v) xylan and 61.3IU/mg protein, respectively, at 50 °C. The pH and temperature optima for xylan hydrolysis were pH 5.1 and 80 °C, respectively. The xylanase retained full activity following incubation at 60 °C for 97 h or 70 °C for 24 h. At 80 °C, the half-life of the enzyme was 54 min. The xylanase was not affected by copper sulfate, zinc sulfate, calcium chloride, cobalt chloride, barium chloride, magnesium sulfate, and EDTA at concentrations of 2 mM. Mercury chloride at 2 mM concentration abolished all xylanase activity, while lead acetate at the same concentration reduced xylanase activity by approximately 25%. From the initial hydrolysis products of xylan, the xylanase was deduced to hydrolyse xylan through an endo-acting mechanism.

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Cellulolytic Enzymes Production by Utilizing Agricultural Wastes Under Solid State Fermentation and its Application for Biohydrogen Production

Applied Biochemistry and Biotechnology ◽

10.1007/s12010-014-1227-1 ◽

2014 ◽

Vol 174 (8) ◽

pp. 2801-2817 ◽

Cited By ~ 39

Author(s):

Ganesh D. Saratale ◽

Siddheshwar D. Kshirsagar ◽

Vilas T. Sampange ◽

Rijuta G. Saratale ◽

Sang-Eun Oh ◽

...

Keyword(s):

Solid State ◽

Solid State Fermentation ◽

Agricultural Wastes ◽

Biohydrogen Production ◽

Cellulolytic Enzymes

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Purification and characterization of alkaline xylanase from Thermoascus aurantiacus var. levisporus KKU-PN-I2-1 cultivated by solid-state fermentation

Mycoscience ◽

10.1016/j.myc.2014.09.003 ◽

2015 ◽

Vol 56 (3) ◽

pp. 309-318 ◽

Cited By ~ 19

Author(s):

Nantawan Chanwicha ◽

Somporn Katekaew ◽

Tadanori Aimi ◽

Sophon Boonlue

Keyword(s):

Solid State ◽

Solid State Fermentation ◽

Thermoascus Aurantiacus ◽

Purification And Characterization

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Partially purified and characterization of the α-glucosidase produced by thermophilic fungus Thermoascus aurantiacus CBMAI 756 in submerged fermentation

Journal of Biotechnology ◽

10.1016/j.jbiotec.2007.07.422 ◽

2007 ◽

Vol 131 (2) ◽

pp. S232 ◽

Cited By ~ 1

Author(s):

Ana Flávia Azevedo Carvalho ◽

Rodrigo Simões Ribeiro Leite ◽

Eduardo Martins ◽

Natália Martin ◽

Roberto Silva ◽

...

Keyword(s):

Submerged Fermentation ◽

Thermophilic Fungus ◽

Thermoascus Aurantiacus

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Purification and Properties of Polygalacturonase Produced by Thermophilic Fungus Thermoascus aurantiacus CBMAI-756 on Solid-State Fermentation

Enzyme Research ◽

10.1155/2013/438645 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 14

Author(s):

Eduardo da Silva Martins ◽

Rodrigo Simões Ribeiro Leite ◽

Roberto da Silva ◽

Eleni Gomes

Keyword(s):

Solid State ◽

Solid State Fermentation ◽

Culture Media ◽

Hydrolysis Product ◽

Exchange Chromatography ◽

Thermophilic Fungus ◽

Thermoascus Aurantiacus ◽

Textile Processing ◽

Original Activity ◽

Ph Values

Polygalacturonases are enzymes involved in the degradation of pectic substances, being extensively used in food industries, textile processing, degumming of plant rough fibres, and treatment of pectic wastewaters. Polygalacturonase (PG) production by thermophilic fungus Thermoascus aurantiacus on solid-state fermentation was carried out in culture media containing sugar cane bagasse and orange bagasse in proportions of 30% and 70% (w/w) at 45°C for 4 days. PG obtained was purified by gel filtration and ion-exchange chromatography. The highest activity was found between pH 4.5 and 5.5, and the enzyme preserved more than 80% of its activity at pH values between 5.0 and 6.5. At pH values between 3.0 and 4.5, PG retained about 73% of the original activity, whereas at pH 10.0 it remained around 44%. The optimum temperature was 60–65°C. The enzyme was completely stable when incubated for 1 hour at 50°C. At 55°C and 60°C, the activity decreased 55% and 90%, respectively. The apparent molecular weight was 29.3 kDa, Km of 1.58 mg/mL and Vmax of 1553.1 μmol/min/mg. The presence of Zn+2, Mn+2, and Hg+2 inhibited 59%, 77%, and 100% of enzyme activity, respectively. The hydrolysis product suggests that polygalacturonase was shown to be an endo/exoenzyme.

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