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Chang, Chih Cheng; Tseng, Szu‐Kung

doi:10.1023/a:1008895525476

Cited by 43 publications

(2 citation statements)

References 6 publications

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“…Even though it has been mainly used for cell immobilization [8], it has been successfully applied to the immobilization of enzymepolymer composites [9,10] and enzyme aggregates [11]. The most common immobilization method is performed by mixing the biocatalyst with a solution of commercial PVA, and the promotion of gelification is accomplished by dripping the mixture over a surface, allowing for partial drying [8,12] by freezing and thawing [13] or by UV light [14], or otherwise by dripping the mixture to an extrusion solution such as boric acid or sodium sulfate to promote the cross-link between PVA molecules [15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Immobilization of Naringinase in PVA–Alginate Matrix Using an Innovative Technique

Nunes

Vila-Real

Fernandes

et al. 2009

Appl Biochem Biotechnol

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A synthetic polymer, polyvinyl alcohol (PVA), a cheap and nontoxic synthetic polymer to organism, has been ascribed for biocatalyst immobilization. In this work PVA-alginate beads were developed with thermal, mechanical, and chemical stability to high temperatures (<80 degrees C). The combination of alginate and bead treatment with sodium sulfate not only prevented agglomeration but produced beads of high gel strength and conferred enzyme protection from inactivation by boric acid. Naringinase from Penicillium decumbens was immobilized in PVA (10%)-alginate beads with three different sizes (1-3 mm), at three different alginate concentrations (0.2-1.0%), and these features were investigated in terms of swelling ratio within the beads, enzyme activity, and immobilization yield during hydrolysis of naringin. The pH and temperature optimum were 4.0 and 70 degrees C for the PVA-alginate-immobilized naringinase. The highest naringinase activity yield in PVA (10%)-alginate (1%) beads of 2 mm was 80%, at pH 4.0 and 70 degrees C. The Michaelis constant (K(Mapp)) and the maximum reaction velocity (V(maxapp)) were evaluated for both free (K(Mapp) = 0.233 mM; V(maxapp) = 0.13 mM min(-1)) and immobilized naringinase (K(Mapp) = 0.349 mM; V(maxapp) = 0.08 mM min(-1)). The residual activity of the immobilized enzyme was followed in eight consecutive batch runs with a retention activity of 70%. After 6 weeks, upon storage in acetate buffer pH 4 at 4 degrees C, the immobilized biocatalyst retained 90% of the initial activity. These promising results are illustrative of the potential of this immobilization strategy for the system evaluated and suggest that its application may be effectively performed for the entrapment of other biocatalysts.

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Section: Introductionmentioning

confidence: 99%

Immobilization of Naringinase in PVA–Alginate Matrix Using an Innovative Technique

Nunes

Vila-Real

Fernandes

et al. 2009

Appl Biochem Biotechnol

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“…Crystalline regions are impermeable to solute diffusion and have been shown to hinder solute diffusion, while amorphous regions are more flexible but act as roadblocks to solute diffusion. Poly(vinyl alcohol) (PVA) hydrogels are commonly used in cryogel and chemically crosslinked hydrogel studies. − Previous work by Schuszter et al investigated hydronium diffusion in non-PVA hydrogels, and Choudhury et al , Ajith et al , and Wang et al measured hydronium conductivity in PVA hydrogels but did not quantify hydronium diffusivity, a critical knowledge gap in these materials. NMR analysis of hydronium diffusion in aqueous systems is common, but this technique is infeasible in hydrogel systems because the high water content in the hydrogel would mask the hydronium signal …”

Section: Introductionmentioning

confidence: 99%

Investigation of Hydronium Diffusion in Poly(vinyl alcohol) Hydrogels: A Critical First Step to Describe Acid Transport for Encapsulated Bioremediation

et al. 2022

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Bioremediation of chlorinated aliphatic hydrocarbon-contaminated aquifers can be hindered by high contaminant concentrations and acids generated during remediation. Encapsulating microbes in hydrogels may provide a protective, tunable environment from inhibiting compounds; however, current approaches to formulate successful encapsulated systems rely on trial and error rather than engineering approaches because fundamental information on mass-transfer coefficients is lacking. To address this knowledge gap, hydronium ion mass-transfer rates through two commonly used hydrogel materials, poly(vinyl alcohol) and alginic acid, under two solidification methods (chemical and cryogenic) were measured. Variations in hydrogel crosslinking conditions, polymer composition, and solvent ionic strength were investigated to understand how each influenced hydronium ion diffusivity. A three-way ANOVA indicated that the ionic strength, membrane type, and crosslinking method significantly (p < 0.001) contributed to changes in hydronium ion mass transfer. Hydronium ion diffusion increased with ionic strength, counter to what is observed in aqueous-only (no polymer) solutions. Co-occurring mechanisms correlated to increased hydronium ion diffusion with ionic strength included an increased water fraction within hydrogel matrices and hydrogel contraction. Measured diffusion rates determined in this study provide first principal design information to further optimize encapsulating hydrogels for bioremediation.

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Mass transfer efficiency inside the polyvinyl alcohol‐sodium alginate carriers: kinetic changes of immobilized anammox bacteria

Chen

Lin

Wei

et al. 2020

J of Chemical Tech & Biotech

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BACKGROUND: Mass transfer inside the plain polyvinyl alcohol (PVA)-sodium alginate (SA) carriers was determined to correlate with nitrogen removal by anaerobic ammonium-oxidation (anammox) bacteria in this study. The anammox bacteria immobilized by the PVA-SA material for nitrogen removal were inoculated into a sequencing batch reactor (SBR) operated at a hydraulic retention time of 4 days and a temperature of 35 ± 1°C while another identical reactor inoculated with the un-immobilized biomass was run for comparison. RESULTS: Results show that the total nitrogen removals were 81 and 92% for the immobilized and un-immobilized biomass, respectively, when the ammonium-and nitrite-nitrogen, both at 200 mg N L −1 , were fed into the SBRs. The poorer performance observed from the immobilized biomass was due to the lower mass transfer efficiency. The obtained diffusion coefficient of the ammonium-nitrogen and specific surface area were 15.2 × 10 −6 cm 2 s −1 and 29.35 m 2 g −1 gel beads, respectively. In addition, the mass transfer efficiency influenced the kinetics of the immobilized anammox bacteria. Results indicate that the ammoniumnitrogen removal rate of the un-immobilized biomass was 28 to 34% greater than that of the immobilized biomass, while the nitrite-nitrogen removal rate was greater by 9 to 24% for the un-immobilized biomass. This influence was more significant at high levels of ammonium-and nitrite-nitrogen concentrations. CONCLUSION: Increasing the mass transfer efficiency inside the plain PVA-SA carriers was needed before using the PVA-SA carriers to immobilize anammox bacteria.

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Cited by 43 publications

References 6 publications

Immobilization of Naringinase in PVA–Alginate Matrix Using an Innovative Technique

Immobilization of Naringinase in PVA–Alginate Matrix Using an Innovative Technique

Investigation of Hydronium Diffusion in Poly(vinyl alcohol) Hydrogels: A Critical First Step to Describe Acid Transport for Encapsulated Bioremediation

Mass transfer efficiency inside the polyvinyl alcohol‐sodium alginate carriers: kinetic changes of immobilized anammox bacteria

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