A novel method to prepare chitosan powder and its application in cellulase immobilization

Mao, Xuepu; Guo, Gangjun; Huang, Jinfeng; Du, Zhiyun; Huang, Zhi‐Shu; Ma, Lin; Li, Pei; Gu, Lian‐Quan

doi:10.1002/jctb.1378

Cited by 48 publications

(29 citation statements)

References 23 publications

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“…Pre-and postincubation enzyme concentrations (C 0 and C t , respectively) were determined using a Bradford protein assay with BSA as the protein standard. 27 Lastly, the enzyme loading (mg of cellulose/g of sample) was calculated from the difference in preand postincubation enzyme concentration and plotted vs the cellulose equilibrium concentration to give the adsorption isotherm. The data points were fitted using a Langmuir equation.…”

Section: Synthesis Of Nonfunctionalized Andmentioning

confidence: 99%

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Functionalized Mesoporous Silica with Very Large Pores for Cellulase Immobilization

et al. 2010

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Organo-functionalized FDU-12 type silicas exhibiting large pore sizes and ordered mesoporous structures were synthesized at low reaction (15°C) and high hydrothermal (160°C) temperatures via the co-condensation of tetraethoxysilane (TEOS) with a suite of organosilanes, i.e., 3-aminopropyltriethoxysilane (APTES), 3-mercaptopropyltrimethoxysilane (MPTMS), vinyltrimethoxysilane (VTMS), and phenyltrimethoxysilane (PTMS), in the presence of structure directing micelles formed using the surfactant pluronic F127 and the pore enlarging reagent trimethylbenzene (TMB). Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) confirmed that all synthesized materials possessed a face-centered cubic mesostructure (space group Fm3 j m), while nitrogen sorption analyses showed that the synthesized materials had extra large pores with cavity sizes of up to 25.4 nm and entrance sizes of up to 10.8 nm. X-ray photoelectron spectroscopy (XPS) and 13 C solid-state magic-angle spinning nuclear magnetic resonance ( 13 C-MAS NMR) measurements verified the incorporation of the different organosilanes into the silica network and more importantly on the inner and outer surfaces of the materials. As-obtained mesoporous silicas were tested in protein immobilization studies using bovine serum albumin and the cellulose-hydrolyzing enzyme cellulase, which in itself is a mixture of three large enzymes. Enzyme immobilization efficiency, activity, and stability varied significantly with organic functionality due to size exclusion effects at pore entries, electrostatic and hydrophobic interactions between the organo-functionalized surfaces and the enzymes, and conformational changes of the enzymes which can occur on some of the material surfaces. As a result, phenyl (PTMS)-and thiol (MPTMS)-functionalized FDU-12 mesoporous silicas had a very low adsorption capacity of proteins because of their small pore sizes. Amino (APTES)-functionalized FDU-12 mesoporous silica showed the highest adsorption amount of proteins yet the lowest activity of immobilized cellulase. Cellulase immobilization on vinyl (VTMS)-functionalized FDU-12 mesoporous silica appeared to be the most promising approach, since it occurred with high efficiency, maintained enzyme activity, and provided temporal enzyme stability.

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Section: Synthesis Of Nonfunctionalized Andmentioning

confidence: 99%

“…27,46 XPS analysis was used to determine the presence of the amide bonds. Figure 9 shows the C1s region of the high resolution XPS spectra of S-APTES samples with and without immobilized cellulase.…”

Section: Bsa Adsorptionmentioning

confidence: 99%

Functionalized Mesoporous Silica with Very Large Pores for Cellulase Immobilization

et al. 2010

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“…키토산은 유용한 형태 (필름, 섬유질, 비 드, 분말, 용액 등)로의 변환 능력과 독특한 화학적, 생물학적 특성으로 인해 효소 고정화에 이용되어 왔다 [13]. PVA는 비 용이 저렴한 합성 고분자로서 미생물에 무독성이어서 세포 와 효소 고정화에 사용될 수 있다 [14].…”

Section: Methodsunclassified

Properties of Cellulase Immobilized on Chitosan Beads

Lee¹,

Ha²,

Kim³

et al. 2014

KSBB Journal

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Abstract:Recently, there is a growing interest in efficient biomass pretreatment and saccharification processes to produce biofuels and biochemicals from renewable non-food biomass resources. In this study, glucose was produced from cellulose by immobilizing cellulase enzyme on chitosan beads which was reported to have high pH and temperature stability. The immobilized amounts of cellulase on chitosan beads linearly increased with increasing the concentrations of cellulase solution. The glucose production increased to 7.2 g/L from 1% carboxymethyl cellulose (CMC) substrate when immobilized at 20% cellulase solution. The maximum specific activity was 0.37 unit/mg protein when immobilized at 8% cellulase solution. At pH 7 and 37 o C, the optimum reaction composition was 0.5 g beads/L from 1% CMC substrate. At this condition, the conversion to glucose completed at ca. 20 min.

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“…고정화 효소를 사용하면 안정성이 높고 재사 용이 가능하기 때문에 전체 공정의 비용을 줄일 수 있다. 고정 화 방법으로는 가두기(entrapment)에 의한 방법 [5,27], 담체로 키토산과 PVA을 사용하는 방법 [6,14,18], 가교에 의한 공유 결합 방법 [9], 실리카 겔과 같은 무기물이나 polyacrylamide와 같이 고분자에 의한 고정화 방법 [22,29] 등이 있다. 효소 고정 화의 단점인 기질의 물질전달에 의한 확산 저항을 감소시키기 위한 연구도 진행되었다 [1,26].…”

Section: 서 론 바이오매스를 당(Sugar)으로 전환한 후 발효 혹은 화학적 변환에 의해 에탄올과 같은 액체 연료나 unclassified

Hydrolysis of Cellulose by Immobilized Cellulase in a Packed Bed Reactor

Kang¹,

Lee²

2013

Journal of Life Science

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Immobilized cellulase on weak ion exchange resin showed a typical Langmuir adsorption isotherm. Immobilized cellulase had better stability with respect to pH and temperature than free cellulase. Kinetics of thermal inactivation on free and immobilized cellulase followed first order rate, and immobilized cellulase had a longer half-life than free cellulase. The initial rate method was used to characterize the kinetic parameters of free and immobilized enzyme. The Michaelis-Menten constant Km was higher for the immobilized enzyme than it was for the free enzyme. The effect of the recirculation rate on cellulose degradation was studied in a recycling packed-bed reactor. In a continuous packed-bed reactor, the increasing flow rate of cellulose decreased the conversion efficiency of cellulose at different input lactose concentrations. Continuous operation for five days was conducted to investigate the stability of long term operation. The retained activity of the immobilized enzymes was 48% after seven days of operation.

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A novel method to prepare chitosan powder and its application in cellulase immobilization

Cited by 48 publications

References 23 publications

Functionalized Mesoporous Silica with Very Large Pores for Cellulase Immobilization

Functionalized Mesoporous Silica with Very Large Pores for Cellulase Immobilization

Properties of Cellulase Immobilized on Chitosan Beads

Hydrolysis of Cellulose by Immobilized Cellulase in a Packed Bed Reactor

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