Activity and thermostability of carboxymethylcellulase from Aspergillus niger is strongly influenced by noncovalently attached polysaccharides

Siddiqui, Khawar Sohail; Azhar, M. J.; Rashid, Mohammad Hamid; Rajoka, Muhammad Ibrahim

doi:10.1007/bf00360917

Cited by 27 publications

(10 citation statements)

References 13 publications

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“…While the differences in the optimum temperatures of the endoglucanases may be due to the difference in their amino acid sequences, the carbohydrate moieties non-covalently attached to the enzymes have also been shown to affect the optimum temperature of an enzyme. The endoglucanase from Aspergillus niger had its temperature optimum at 60 8C which was decreased to 50 8C when the enzyme was made carbohydrate-free through a technique called compartmental gel electrophoresis [37].…”

Section: Effect Of Temperature On Substrate Hydrolysismentioning

confidence: 99%

Thermostability of crude endoglucanase from Aspergillus fumigatus grown under solid state fermentation (SSF) and submerged fermentation (SmF)

Saqib

Hassan

Khan

et al. 2010

Process Biochemistry

125

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Section: Effect Of Temperature On Substrate Hydrolysismentioning

confidence: 99%

Thermostability of crude endoglucanase from Aspergillus fumigatus grown under solid state fermentation (SSF) and submerged fermentation (SmF)

Saqib

Hassan

Khan

et al. 2010

Process Biochemistry

125

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“…The strain was maintained on potato-dextrose agar (PDA) plates and slants as described earlier (Siddiqui et al 1997). Lactose, the best inducer of a-galactosidase (a-Gal) among disaccharides was used in these studies and was procured from Sigma Chemical Company USA.…”

Section: Organism and Growth Conditionsmentioning

confidence: 99%

Solid-state fermentation-supported enhanced production of α-galactosidase by a deoxyglucose-resistant mutant of Aspergillus niger and thermostabilization of the production process

Rajoka

Awan

Saleem

et al. 2008

World J Microbiol Biotechnol

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The aim of the present investigation was to comparatively evaluate the behaviour of A. niger and its derepressed mutant in production of a-galactosidase in submerged (SmF) and solid state fermentation (SSF) using basal Vogel's medium or corn steep liquor as nitrogen source and observe the response of latter source under both cultural techniques under different temperature regimes, and determine if SSF can be exploited in a wide range of temperature expected to vary in this fermentation system. All studies were performed in both systems under preoptimized cultural conditions. Higher melting temperature and negative values of entropy of activation in SSF indicated that the genetic system of both organisms was thermodynamically resistant in the presence of corn steep liquor but sensitive to inactivation in the presence of Vogel's nitrogen sources in submerged fermentation. This was reflected as the organisms demanded higher magnitudes of energy for product formation in the presence of ammonium salts. Studies on influence of corn steep liquor revealed that it had stabilizing effect too in both fermentation systems but the mutant strain was more stable in both fermentation systems. Because of these properties, the mutant organism may be exploited for bulk production of a-galactosidase in SSF under condition where temperature may fluctuate during fermentation.

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“…Aspergillus niger was grown in glucosesalt medium supplemented with 0.2% yeast extract (Siddiqui et al 1997) containing acid-washed glass beads. The latter were added to achieve uniform turbidity.…”

Section: Chemicals and Growth Mediamentioning

confidence: 99%

“…The strain was maintained on potato-dextrose agar plates and slants as described earlier (Siddiqui et al 1997).…”

Section: Organismmentioning

confidence: 99%

Improved productivity of β-fructofuranosidase by a derepressed mutant of Aspergillus niger from conventional and non-conventional substrates

Rajoka

Yasmeen

2005

World J Microbiol Biotechnol

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Wild-type cultures of Aspergillus niger produced a basal level of b-fructofuranosidase on glucose of 1 IU l )1 h )1 . In contrast, a catabolite-derepressed mutant strain of the same organism produced a markedly higher level (25 IU l )1 h )1 ) of this enzyme when grown on the same carbon source. Wheat bran induced both the wild type (252 IU l )1 h )1 ) and the mutant strain (516 IU l )1 h )1 ) to produce 252-to 516-fold higher levels of this enzyme than was observed with the wild-type grown on glucose and was the best carbon source. When corn steep liquor served as a nitrogen source, the wild-type organism showed a higher activity of enzyme on monosaccharides and disaccharides comparable to that produced by corncobs in the basal medium and that mutant was a potentially improved (>2-fold) organism for the production of b-fructofuranosidase on all carbon sources. Enhanced substrate consumption and product formation kinetic parameters suggest that the mutant organism may be exploited for bulk production of this useful enzyme.

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Activity and thermostability of carboxymethylcellulase from Aspergillus niger is strongly influenced by noncovalently attached polysaccharides

Cited by 27 publications

References 13 publications

Thermostability of crude endoglucanase from Aspergillus fumigatus grown under solid state fermentation (SSF) and submerged fermentation (SmF)

Thermostability of crude endoglucanase from Aspergillus fumigatus grown under solid state fermentation (SSF) and submerged fermentation (SmF)

Solid-state fermentation-supported enhanced production of α-galactosidase by a deoxyglucose-resistant mutant of Aspergillus niger and thermostabilization of the production process

Improved productivity of β-fructofuranosidase by a derepressed mutant of Aspergillus niger from conventional and non-conventional substrates

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