Comparative study of immobilized Trametes versicolor laccase on nanoparticles and kaolinite

Hu, Xiaoke; Zhao, Xueheng; Hwang, Huey‐Min

doi:10.1016/j.chemosphere.2006.08.004

Cited by 113 publications

(54 citation statements)

References 35 publications

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“…The extracellular proteins were determined using the Bradford assay with bovine serum albumin as the standard [22], and reducing sugars remaining in the medium were quantified using Miller's method with glucose as the standard [23]. Laccase activity in the medium was quantified spectrophotometrically in a reaction medium containing a 100 mM tartaric acid buffer (pH 3.0) with 0.1% (w/v) catechol as the substrate at 25°C [24]. A suitable amount of the cellfree supernatant was added to the substrate solution for 5 min, and the increase in the absorbance at 450 nm was measured using a UV-2100 spectrophotometer (Shanghai, China).…”

Section: Discussionmentioning

confidence: 99%

“…To test the effect of treatment duration, the T. versicolor mycelial pellets were exposed to one ultrasonic treatment for a given time period (1, 3, 5, 7 and 10 min) after they had been in culture for either 2 days or 5 days. To test the effect of repeated exposure, the T. versicolor mycelial pellets were repeatedly exposed to a 5 min ultrasonic treatment at different intervals (6,12,24,48 and 72 h) after they had been in culture for either 2 days or 5 days. Following the ultrasonic treatments, the flasks with the mycelial pellets were returned to the shaker for continued cultivation.…”

Section: Ultrasonic Treatmentmentioning

confidence: 99%

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Ultrasound-intensified laccase production from Trametes versicolor

Wang

Chen

et al. 2013

Ultrasonics Sonochemistry

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a b s t r a c tAn efficient intermittent ultrasonic treatment strategy was developed to improve laccase production from Trametes versicolor mycelia cultures. The optimized strategy consisted of exposing 2-day-old mycelia cultures to 5-min ultrasonic treatments for two times with a 12-h interval at the fixed ultrasonic power and frequency (120 W, 40 kHz). After 5 days of culture, this strategy produced the highest extracellular laccase activity of 588.9 U/L among all treatments tested which was 1.8-fold greater than the control without ultrasound treatment. The ultrasonic treatment resulted in a higher pellet porosity that facilitated the mass transfer of nutrients and metabolites from the pellets to the surrounding liquid. Furthermore, the ultrasonic treatment induced the expression of the laccase gene (lcc), which correlated with a sharp increase in both extracellular and intracellular laccase activity. This is the first study to find positive effects of ultrasound on gene expression in fungal cells. These results provide a basis for understanding the stimulation of metabolite production and process intensification by ultrasonic treatment in filamentous fungal culture.

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Section: Discussionmentioning

confidence: 99%

Section: Ultrasonic Treatmentmentioning

confidence: 99%

Ultrasound-intensified laccase production from Trametes versicolor

Wang

Chen

et al. 2013

Ultrasonics Sonochemistry

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“…When enzymes immobilized on support, materials create a kind of protection and provide a resistance against the conformational changes of enzyme structure, which results in an increased thermal stability of laccase nano-conjugates [31]. Hu et al [32] reported that laccase immobilized on nanoparticle and kaolinite was more stable as compared to the free laccase when laccase nano-conjugates incubated in a temperature range of 40-70°C. Laccase nanoparticles depicted more than 55% residual laccase activity at all tested pH values after 24 h of incubation, as shown in Fig.…”

Section: Temperature and Ph Stabilitymentioning

confidence: 99%

Laccase-conjugated amino-functionalized nanosilica for efficient degradation of Reactive Violet 1 dye

Gahlout

Rudakiya

Gupte³

2017

Int Nano Lett

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Immobilization of enzyme with nanostructures enhances its ideal characteristics, which may allow the enzyme to become more stable and resistant. The present investigation deals with the formulation of laccase nanosilica conjugates to overcome the problems associated with its stability and reusability. Synthesized nanosilica and laccase nanoparticles were spherical shaped, with the mean size of 220 and 615 nm, respectively. Laccase nanoparticles had an optimum temperature of 55°C and pH 4.0 for the oxidation of ABTS. Laccase nanoparticle retained 79% of residual activity till 20th cycle. It also showed 91% of its initial activity at lower temperatures even after 60 days. Laccase nanoparticles were applied for Reactive Violet 1 degradation wherein 96.76% of decolourization was obtained at pH 5.0 and 30°C within 12 h. Toxicity studies on microbes and plants suggested that the degraded metabolites were less toxic than control dye. Thus, the method applied for immobilization increased storage stability and reusability of laccase, and therefore, it can be utilized for efficient degradation of azo dyes.

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“…There are many different materials which have been proposed to immobilize enzymes, including Ca-alginate, agar, K-Carrageenin, polyacrylamide, nylon, cellulose, polysulfone, alumina, silica, porous glass, ceramics, diatomaceous earth, clay and bentonite (Hu et al, 2007). Among these materials, mesoporous silica is the most commonly used supporter for the immobilized enzyme because of its advantages (Hu et al, 2007;Wang et al, 2009). Siso et al (1990) have reported that after a-amylase was immobilized on porous silica, external diffusional resistances to mass transfer were minimized when the immobilized enzyme was operated in a packed bed reactor.…”

Section: Introductionmentioning

confidence: 99%

“…Different carriers can provide different external backbone for the enzyme molecules, which is expected to improve the stability of enzyme molecules at reaction conditions (Temoçin and Yiğitoğlu, 2009). There are many different materials which have been proposed to immobilize enzymes, including Ca-alginate, agar, K-Carrageenin, polyacrylamide, nylon, cellulose, polysulfone, alumina, silica, porous glass, ceramics, diatomaceous earth, clay and bentonite (Hu et al, 2007). Among these materials, mesoporous silica is the most commonly used supporter for the immobilized enzyme because of its advantages (Hu et al, 2007;Wang et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Immobilization of cellulase on modified mesoporous silica shows improved thermal stability and reusability

Yin¹,

Su²,

Shao³

et al. 2013

Afr. J. Microbiol. Res.

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Cellulase was covalently immobilized using modified mesoporous silica as carrier, and the characters of immobilized cellulase were investigated including the optimum pH, the optimum temperature, thermal stability, reusability, storage stability and enzyme kinetics. As compared to the free enzyme, the optimum pH of the immobilized cellulase showed no changes, the optimum temperature showed a slight increase to 60°C. The immobilized enzymes demonstrated enhanced thermal stability, while the free enzymes lost almost 40% initial activity, the immobilized forms lost only 9% initial activity within a period of 120 min at 60°C. The immobilized cellulase showed excellent reusability. After 11 cycles, the cellulase immobilized on modified mesoporous silica still retained 89% of its initial activity. At optimized conditions, Km and Vmax values for the immobilized enzyme were slightly increased when compared with those of free enzyme. The characters of cellulase immobilized on modified mesoporous silica suggest that the immobilized enzyme has high potential for application in the industrial degradation of cellulose.

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Comparative study of immobilized Trametes versicolor laccase on nanoparticles and kaolinite

Cited by 113 publications

References 35 publications

Ultrasound-intensified laccase production from Trametes versicolor

Ultrasound-intensified laccase production from Trametes versicolor

Laccase-conjugated amino-functionalized nanosilica for efficient degradation of Reactive Violet 1 dye

Immobilization of cellulase on modified mesoporous silica shows improved thermal stability and reusability

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