Removal of lignin and reuse of cellulases for continuous saccharification of lignocelluloses

Tanaka, Mitsuo; Fukui, Masahide; Matsuno, Ryuichi

doi:10.1002/bit.260320708

Cited by 30 publications

(8 citation statements)

References 20 publications

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“…Further, the lignin remaining after the enzymatic hydrolysis might support the residual enzymes and, therefore, could be reused (Tanaka et al, 1988); this aspect could be a focus area from the standpoint of the biomass refinery process. In addition, since the residual lignin might have high molecular weight without remarkable degradation and retain a similar structure to proto-lignin, there is a possibility that it can be utilized as structural materials.…”

Section: Discussionmentioning

confidence: 99%

Pretreatment of eucalyptus wood chips for enzymatic saccharification using combined sulfuric acid‐free ethanol cooking and ball milling

Teramoto¹,

Tanaka²,

Lee³

et al. 2007

Biotech & Bioengineering

127

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A combined sulfuric acid-free ethanol cooking and pulverization process was developed in order to achieve the complete saccharification of the cellulosic component of woody biomass, thereby avoiding the problems associated with the use of strong acid catalysts. Eucalyptus wood chips were used as a raw material and exposed to an ethanol/water/acetic acid mixed solvent in an autoclave. This process can cause the fibrillation of wood chips. During the process, the production of furfural due to an excessive degradation of polysaccharide components was extremely low and delignification was insignificant. Therefore, the cooking process is regarded not as a delignification but as an activation of the original wood. Subsequently, the activated solid products were pulverized by ball-milling in order to improve their enzymatic digestibility. Enzymatic hydrolysis experiments demonstrated that the conversion of the cellulosic components into glucose attained 100% under optimal conditions. Wide-angle X-ray diffractometry and particle size distribution analysis revealed that the scale affecting the improvement of enzymatic digestibility ranged from 10 nm to 1 microm. Field emission scanning electron microscopy depicted that the sulfuric acid-free ethanol cooking induced a pore formation by the removal of part of the lignin and hemicellulose fractions in the size range from a few of tens nanometers to several hundred nanometers.

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Section: Discussionmentioning

confidence: 99%

Pretreatment of eucalyptus wood chips for enzymatic saccharification using combined sulfuric acid‐free ethanol cooking and ball milling

Teramoto¹,

Tanaka²,

Lee³

et al. 2007

Biotech & Bioengineering

127

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“…Ultrafiltration [25][26][27] -To recycle micro-organisms and other value-added chemicals such as cellulase in the enzymatic hydrolysate Q . K a n g e t a l .…”

Section: Membrane Technique Applicationmentioning

confidence: 99%

A novel sintered metal fiber microfiltration of bio-ethanol fermentation broth

Kang

Baeyens

Tan

et al. 2015

Korean J. Chem. Eng.

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In bio-ethanol fermentation, the broth consists of mainly water and ethanol, together with particulate residues of unreacted feedstock and additives (mostly yeast). Prior to further processing (distillation), and to avoid fouling of heat exchangers and distillation columns, the solids residues of the broth need to be removed to as low a concentration as possible. The current mechanical separation (belt filter or centrifuge) can only remove +10 µm particles representing about 90% of the total solids content. The remaining 10% is usually recovered in the bottom stream of the first distillation column, and forms the stillage that is further treated. To avoid fouling and even eliminate the first distillation column where the ethanol fraction is only increased from 12% (feed) to 16% (top), a better particulate removal is required. Novel sintered metal fiber (SFM) fleeces are highly efficient for microfiltration, and the removal of suspended solids largely exceeds 99%. The paper (i) positions microfiltration in the overall bio ethanol process; (ii) describes the novel sintered metal fiber microfiltration application; (iii) experimentally determines the major operating characteristics of SFM and (iv) predicts the up-scaled operation by using a simplified filtration model. At an ambient feed temperature, the flux of permeate exceeds 5 m 3 /m 2 h for a TMP of 1.5 bar and a yeast concentration of 15 g/l, as commonly encountered in the fermenter broth.

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“…Note that the amount of OKP, cellulose, and The standard curve of cellulase loading versus glucose production rate between 24 and 48 h is shown in Fig. 2 and expressed by Equation (1). Cellulase activity in 0.1 g of the OKP hydrolyzed residue was estimated using the standard curve and then cellulase activity in the total OKP hydrolyzed residue was calculated.…”

Section: Substratementioning

confidence: 99%

Evaluation of Cellulase Activity in Enzymatic Hydrolysis Residues for Efficient Enzyme Reuse

Hasegawa

Inoue

Yano

et al. 2016

J. Jpn. Inst. Energy

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Enzymatic hydrolysis by cellulase has potential as an environment-friendly technology for producing bioethanol from lignocelluloses, but its production cost remains expensive. Therefore, several studies have examined methods in reducing the cost of enzymatic hydrolysis, and one of the most effective ways is to reuse enzymes. In this study, we developed a method for evaluating the cellulase activity in enzymatic hydrolysis residues for efficient enzyme reuse. Approximately 70% the of cellulase activity remained in the solid residue after 70% of the glucan was hydrolyzed, and 22% of cellulase activity still remained in the solid residue after 99% of glucan was hydrolyzed.Other experiments were performed in order to examine the application of our proposed method for practical reuse of enzymes. The results indicate that enzymes were recovered from the residues as we estimated by our method.Thus our method is efficient for evaluating cellulase activity in enzymatic hydrolysis residues.

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Removal of lignin and reuse of cellulases for continuous saccharification of lignocelluloses

Cited by 30 publications

References 20 publications

Pretreatment of eucalyptus wood chips for enzymatic saccharification using combined sulfuric acid‐free ethanol cooking and ball milling

Pretreatment of eucalyptus wood chips for enzymatic saccharification using combined sulfuric acid‐free ethanol cooking and ball milling

A novel sintered metal fiber microfiltration of bio-ethanol fermentation broth

Evaluation of Cellulase Activity in Enzymatic Hydrolysis Residues for Efficient Enzyme Reuse

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