Effect of glutaraldehyde on oligosaccharide production by β-galactosidase from Bacillus circulans

Mozaffar, Zahid; Nakanishi, Koji; Matsuno, Ryuichi

doi:10.1007/bf00253312

Cited by 18 publications

(16 citation statements)

References 8 publications

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“…Some researchers reported a smaller yield of GalOS when immobilized enzymes were used for lactose conversion in packed-bed reactors (Mahoney, 1998;Prenosil et al, 1987aPrenosil et al, ,1987b), but it is not clear why. The chemical modi®cation of the enzyme during covalent immobilization may also alter the GalOS formation capability of the biocatalyst (Mozaar et al, 1987(Mozaar et al, ,1989. Ecient continuous process design requires, however, that the interaction of the various process parameters be well understood to enable the transformation of lactose into a sugar mixture of well programmable composition.…”

Section: Hydrolysis Versus Transgalactosylation During Lactose Convermentioning

confidence: 99%

Development of an ultrahigh‐temperature process for the enzymatic hydrolysis of lactose. IV. Immobilization of two thermostable β‐glycosidases and optimization of a packed‐bed reactor for lactose conversion

Petzelbauer

Kühn

Splechtna

et al. 2002

Biotech & Bioengineering

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Recombinant hyperthermostable beta-glycosidases from the archaea Sulfolobus solfataricus (Ss beta Gly) and Pyrococcus furiosus (CelB) were covalently attached onto the insoluble carriers chitosan, controlled pore glass (CPG), and Eupergit C. For each enzyme/carrier pair, the protein-binding capacity, the immobilization yield, the pH profiles for activity and stability, the activity/temperature profile, and the kinetic constants for lactose hydrolysis at 70 degrees C were determined. Eupergit C was best among the carriers in regard to retention of native-like activity and stability of Ss beta Gly and CelB over the pH range 3.0-7.5. Its protein binding capacity of approximately 0.003 (on a mass basis) was one-third times that of CPG, while immobilization yields were typically 80% in each case. Activation energies for lactose conversion by the immobilized enzymes at pH 5.5 were in the range 50-60 kJ/mol. This is compared to values of approximately 75 kJ/mol for the free enzymes. Immobilization expands the useful pH range for CelB and Ss beta Gly by approximately 1.5 pH units toward pH 3.5 and pH 4.5, respectively. A packed-bed enzyme reactor was developed for the continuous conversion of lactose in different media, including whey and milk, and operated over extended reaction times of up to 14 days. The productivities of the Eupergit C-immobilized enzyme reactor were determined at dilution rates between 1 and 12 h(-1), and using 45 and 170 g/L initial lactose. Results of kinetic modeling for the same reactor, assuming plug flow and steady state, suggest the presence of mass-transfer limitation of the reaction rate under the conditions used. Formation of galacto-oligosaccharides in the continuous packed-bed reactor and in the batch reactor using free enzyme was closely similar in regard to yield and individual saccharide components produced.

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Section: Hydrolysis Versus Transgalactosylation During Lactose Convermentioning

confidence: 99%

Development of an ultrahigh‐temperature process for the enzymatic hydrolysis of lactose. IV. Immobilization of two thermostable β‐glycosidases and optimization of a packed‐bed reactor for lactose conversion

Petzelbauer

Kühn

Splechtna

et al. 2002

Biotech & Bioengineering

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“…Immobilized enzyme reactors also can give higher productivities and minimize downtime, enzyme costs, and reactor size, and thus generally are more economical than free enzyme reactors (Axelsson and Zacchi, 1990;Mozaar et al, 1986). However, GOS production from immobilized enzymes has not been addressed very well (Berger et al, 1995a;Mozaar et al, 1987). Many of the carriers used for enzyme immobilization are some types of microparticles, such as ion-exchange resins (Matsumoto et al, 1989;Mozaar et al, 1986), chitosan beads (Sheu et al, 1998;, cellulose beads (Kminkova et al, 1988), and agarose beads (Berger et al, 1995b).…”

Section: Introductionmentioning

confidence: 97%

Production of galacto‐oligosaccharides from lactose by Aspergillus oryzae β‐galactosidase immobilized on cotton cloth

Albayrak

Yang²

2001

Biotech & Bioengineering

175

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The production of galacto-oligosaccharides (GOS) from lactose by A. oryzae beta-galactosidase immobilized on cotton cloth was studied. The total amounts and types of GOS produced were mainly affected by the initial lactose concentration in the reaction media. In general, more and larger GOS can be produced with higher initial lactose concentrations. A maximum GOS production of 27% (w/w) of initial lactose was achieved at 50% lactose conversion with 500 g/L of initial lactose concentration. Tri-saccharides were the major types of GOS formed, accounting for more than 70% of the total GOS produced in the reactions. Temperature and pH affected the reaction rate, but did not result in any changes in GOS formation. The presence of galactose and glucose at the concentrations encountered near maximum GOS greatly inhibited the reactions and reduced GOS yield by as much as 15%. The cotton cloth as the support matrix for enzyme immobilization did not affect the GOS formation characteristics of the enzyme, suggesting no diffusion limitation in the enzyme carrier. The thermal stability of the enzyme increased approximately 25-fold upon immobilization on cotton cloth. The half-life for the immobilized enzyme on cotton cloth was more than 1 year at 40 degrees C and 48 days at 50 degrees C. Stable, continuous operation in a plugflow reactor was demonstrated for 2 weeks without any apparent problem. A maximum GOS production of 21 and 26% (w/w) of total sugars was attained with a feed solution containing 200 and 400 g/L of lactose, respectively, at pH 4.5 and 40 degrees C. The corresponding reactor productivities were 80 and 106 g/L/h, respectively, which are at least several-fold higher than those previously reported.

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“…However, GOS production from immobilized enzymes has not been addressed very well (21,22). Many of the carriers used for immobilization of -galactosidases applied in GOS production are some types of microparticles, such as ionexchange resins (23,24), chitosan beads (18,25), cellulose beads (26), and agarose beads (27).…”

Section: Introductionmentioning

confidence: 99%

Immobilization of β‐Galactosidase on Fibrous Matrix by Polyethyleneimine for Production of Galacto‐Oligosaccharides from Lactose

Albayrak

Yang

2002

Biotechnology Progress

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The production of galacto-oligosaccharides (GOS) from lactose by Aspergillus oryzae beta-galactosidase immobilized on cotton cloth was studied. A novel method of enzyme immobilization involving PEI-enzyme aggregate formation and growth of aggregates on individual fibrils of cotton cloth leading to multilayer immobilization of the enzyme was developed. A large amount of enzyme was immobilized (250 mg/g support) with about 90-95% efficiency. A maximum GOS production of 25-26% (w/w) was achieved at near 50% lactose conversion from 400 g/L of lactose at pH 4.5 and 40 degrees C. Tri- and tetrasaccharides were the major types of GOS formed, accounting for about 70% and 25% of the total GOS produced in the reactions, respectively. Temperature and pH affected not only the reaction rate but also GOS yield to some extend. A reaction pH of 6.0 increased GOS yield by as much as 10% compared with that of pH 4.5 while decreased the reaction rate of immobilized enzyme. The cotton cloth as the support matrix for enzyme immobilization did not affect the GOS formation characteristics of the enzyme under the same reaction conditions, suggesting diffusion limitation was negligible in the packed bed reactor and the enzyme carrier. Increase in the thermal stability of PEI-immobilized enzyme was also observed. The half-life for the immobilized enzyme on cotton cloth was close to 1 year at 40 degrees C and 21 days at 50 degrees C. Stable, continuous operation in a plug-flow reactor was demonstrated for about 3 days without any apparent problem. A maximum GOS production of 26% (w/w) of total sugars was attained at 50% lactose conversion with a feed containing 400 g/L of lactose at pH 4.5 and 40 degrees C. The corresponding reactor productivity was 6 kg/L/h, which is several-hundred-fold higher than those previously reported.

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Effect of glutaraldehyde on oligosaccharide production by β-galactosidase from Bacillus circulans

Cited by 18 publications

References 8 publications

Development of an ultrahigh‐temperature process for the enzymatic hydrolysis of lactose. IV. Immobilization of two thermostable β‐glycosidases and optimization of a packed‐bed reactor for lactose conversion

Development of an ultrahigh‐temperature process for the enzymatic hydrolysis of lactose. IV. Immobilization of two thermostable β‐glycosidases and optimization of a packed‐bed reactor for lactose conversion

Production of galacto‐oligosaccharides from lactose by Aspergillus oryzae β‐galactosidase immobilized on cotton cloth

Immobilization of β‐Galactosidase on Fibrous Matrix by Polyethyleneimine for Production of Galacto‐Oligosaccharides from Lactose

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