scholarly journals Study on the Anti-Biodegradation Property of Tunicate Cellulose

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3071
Author(s):  
Yanan Cheng ◽  
Ajoy Kanti Mondal ◽  
Shuai Wu ◽  
Dezhong Xu ◽  
Dengwen Ning ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Conversion Rate ◽  
Crystallinity Index ◽  
Functional Materials ◽  
Degree Of Polymerization ◽  
Crystalline Size ◽  
Crystalline Cellulose ◽  
Marine Animal ◽  
Amorphous Cellulose ◽  
Cellulose Conversion

Tunicate is a kind of marine animal, and its outer sheath consists of almost pure Iβ crystalline cellulose. Due to its high aspect ratio, tunicate cellulose has excellent physical properties. It draws extensive attention in the construction of robust functional materials. However, there is little research on its biological activity. In this study, cellulose enzymatic hydrolysis was conducted on tunicate cellulose. During the hydrolysis, the crystalline behaviors, i.e., crystallinity index (CrI), crystalline size and degree of polymerization (DP), were analyzed on the tunicate cellulose. As comparisons, similar hydrolyses were performed on cellulose samples with relatively low CrI, namely α-cellulose and amorphous cellulose. The results showed that the CrI of tunicate cellulose and α-cellulose was 93.9% and 70.9%, respectively; and after 96 h of hydrolysis, the crystallinity, crystalline size and DP remained constant on the tunicate cellulose, and the cellulose conversion rate was below 7.8%. While the crystalline structure of α-cellulose was significantly damaged and the cellulose conversion rate exceeded 83.8% at the end of 72 h hydrolysis, the amorphous cellulose was completely converted to glucose after 7 h hydrolysis, and the DP decreased about 27.9%. In addition, tunicate cellulose has high anti-mold abilities, owing to its highly crystalized Iβ lattice. It can be concluded that tunicate cellulose has significant resistance to enzymatic hydrolysis and could be potentially applied as anti-biodegradation materials.

scholarly journals Effect of Subsequent Dilute Acid and Enzymatic Hydrolysis on Reducing Sugar Production from Sugarcane Bagasse and Spent Citronella Biomass

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Robinson Timung ◽  
Narendra Naik Deshavath ◽  
Vaibhav V. Goud ◽  
Venkata V. Dasu
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugarcane Bagasse ◽  
Crystallinity Index ◽  
Sem Analysis ◽  
Reducing Sugar ◽  
Dilute Acid Pretreatment ◽  
Crystalline Cellulose ◽  
Dilute Acid ◽  
Acid Pretreatment ◽  
Hydrolysis Of

This work was aimed at investigating the effect of process parameters on dilute acid pretreatment and enzymatic hydrolysis of spent citronella biomass (after citronella oil extraction) and sugarcane bagasse on total reducing sugar (TRS) yield. In acid pretreatment, the parameters studied were acid concentration, temperature, and time. At the optimized condition (0.1 M H2SO4, 120°C, and 120 min), maximum TRS obtained was 452.27 mg·g−1and 487.50 mg·g−1for bagasse and citronella, respectively. Enzymatic hydrolysis of the pretreated biomass usingTrichoderma reesei26291 showed maximum TRS yield of 226.99 mg·g−1for citronella and 282.85 mg·g−1for bagasse at 10 FPU, 50°C, and 48 hr. The maximum crystallinity index (CI) of bagasse and citronella after acid pretreatment obtained from X-ray diffraction analysis was 64.41% and 56.18%, respectively. Decreased CI after enzymatic hydrolysis process to 37.28% and 34.16% for bagasse and citronella, respectively, revealed effective conversion of crystalline cellulose to glucose. SEM analysis of the untreated and treated biomass revealed significant hydrolysis of holocellulose and disruption of lignin.

scholarly journals EVALUATION OF ALKALINE PRETREATMENT ON THE ENZYMATIC HYDROLYSIS OF CARNAUBA STRAW RESIDUE

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Alan De Oliveira Campos ◽  
Francinaldo Leite Da Silva ◽  
Emilianny Rafaely Batista Magalhães ◽  
Gorete Ribeiro De Macedo ◽  
Everaldo Silvino Dos Santos
Keyword(s):  
Enzymatic Hydrolysis ◽  
Cellulosic Ethanol ◽  
Chemical Characterization ◽  
Crystallinity Index ◽  
Biomass Pretreatment ◽  
Cellulose Conversion ◽  
Hydrolysis Of ◽  
Potential Use ◽  
Second Generation Ethanol

Carnauba (Copernicia prunifera) straw residue generated from production of its wax is rich in cellulose, thus showing a potential use in the production of second generation ethanol. However, the high lignin and hemicellulose load associated with cellulose makes it difficult the enzymatic attack, thus having the need of an adequate pretreatment of this material. The objective of this study was to optimize the enzymatic hydrolysis of carnauba straw residue, focusing on the alkaline biomass pretreatment. Therefore, NaOH solutions at concentrations of 1.0% (w/v) (PA1), 2.0% (w/v) (PA2), 3.0% (w/v) (PA3) and 4.0% (w/v) (PA4) were used. The chemical and physical characterization of natural and pre-treated carnauba straw were according to the NREL, and DRX and FTIR performed analyzes. The materials chemical characterization showed that all the used pretreatments were able to remove a significant amount of lignin and hemicellulose, which can improve the enzymes access, favoring the increase of cellulose conversion. In relation to DRX analysis an increase in crystallinity index happens reaching up to 55.15% after the pretreatment PA4, which may be associated to the removal of hemicellulose and amorphous lignin, related to cellulose. After a period of 96 hours of enzymatic hydrolysis, the PA4 pretreated residue showed the best performance with a cellulosic conversion of 78%. Spite of a slightly lower performance of the residue that presented higher cellulose conversion, the pretreated material PA2 is an alternative to reduce costs in the cellulosic ethanol production.

Effects of Treatments on Cellulosic Biomass Structure in Ethanol Manufacturing: A Literature Review

2011 ◽  
Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
Linda Pei
Keyword(s):  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Literature Review ◽  
Crystallinity Index ◽  
Degree Of Polymerization ◽  
Cellulosic Biomass ◽  
Experimental Investigations ◽  
Structure Parameters ◽  
Transportation Fuels ◽  
Biomass Structure

Ethanol made from cellulosic biomass is an alternative to petroleum-based liquid transportation fuels. Enzymatic hydrolysis uses enzymes to convert cellulosic biomass into sugars that are fermented into ethanol. In order to increase sugar yield, various treatments (such as biomass size reduction and pretreatment) are applied to cellulosic biomass before enzymatic hydrolysis. These treatments will alter structure parameters of cellulosic biomass, such as crystallinity index, degree of polymerization, particle size, pore volume, and specific surface area. There are currently no review papers on these structure parameters of cellulosic biomass in ethanol manufacturing. This paper reviews experimental investigations in the literature about effects of various treatments on the structure parameters of cellulosic biomass.

scholarly journals The effect of the natural degradation process on the cellulose structure of Moroccan hardwood fiber: a survey on spectroscopy and structural properties

2019 ◽  
Vol 8 (3) ◽  
pp. 179 ◽  
Author(s):  
Abdellatif Boukir ◽  
Ikram Mehyaoui ◽  
Somia Fellak ◽  
Laurence Asia ◽  
Pierre Doumenq
Keyword(s):  
Raman Spectroscopy ◽  
Crystallinity Index ◽  
Crystalline Cellulose ◽  
Cellulose Fibres ◽  
Amorphous Cellulose ◽  
Cellulose Structure ◽  
Ft Raman Spectroscopy ◽  
Long Time ◽  
Natural Degradation ◽  
Ft Raman

<p>The aim of this work is to study the effect of natural degradation on the cellulose structure conformation changes of 2 ageing Moroccan hardwoods (400 and 500 years) compared to recent one considered as a reference; and to provide information on the polymorphs content variability from two-phases material (crystalline and amorphous) influenced by a long time of ageing and environmental degradation effects. In order to investigate the effects of both natural degradation conditions and a long time of exposure on cellulose structure conformation (examined samples) with estimating their content (crystalline and amorphous cellulose), three combined techniques XRD, ATR-FTIR and FT-Raman spectroscopy were used. XRD results associated with the crystallographic planes and Miller indices provide information on the presence of a mixture of celluloses polymorphs (crystalline cellulose I, II, I<sub>b</sub> and amorphous phase). The decrease in crystallinity-index values from recent to aged ones (38 to 19.5%) confirms well the occurred alteration of crystalline cellulose fibres and their evolution towards a high content of the amorphous form. The prominent regression in the intensities of three FTIR fingerprint cellulose regions evolving towards an overall increase in the intensities of C=O area (1733-1630 cm<sup>-1</sup>) is a sign on the introduced changes on cellulose conformation and cellulose fibres degradation more accentuated in the case of the very aged sample (500 years). Similar results were confirmed by combining FT-Raman spectroscopy as a vibrational technique. No work has been done on this genus of degraded Moroccan hardwood and the relevance of this study is to investigate the compositional content and structural conformation, to determine the variability in the forms of both crystalline and amorphous cellulose phases with estimating the evolution of their polymorphism, and to monitor the degree of crystalline cellulose fibres deterioration.</p>

scholarly journals The effect of the natural degradation process on the cellulose structure of Moroccan hardwood fiber: a survey on spectroscopy and structural properties

2019 ◽  
Vol 8 (3) ◽  
pp. 179-190 ◽  
Author(s):  
Abdellatif Boukir ◽  
Ikram Mehyaoui ◽  
Somia Fellak ◽  
Laurence Asia ◽  
Pierre Doumenq
Keyword(s):  
Raman Spectroscopy ◽  
Crystallinity Index ◽  
Crystalline Cellulose ◽  
Cellulose Fibres ◽  
Amorphous Cellulose ◽  
Cellulose Structure ◽  
Ft Raman Spectroscopy ◽  
Long Time ◽  
Natural Degradation ◽  
Ft Raman

The aim of this work is to study the effect of natural degradation on the cellulose structure conformation changes of 2 ageing Moroccan hardwoods (400 and 500 years) compared to recent one considered as a reference; and to provide information on the polymorphs content variability from two-phases material (crystalline and amorphous) influenced by a long time of ageing and environmental degradation effects. In order to investigate the effects of both natural degradation conditions and a long time of exposure on cellulose structure conformation (examined samples) with estimating their content (crystalline and amorphous cellulose), three combined techniques XRD, ATR-FTIR and FT-Raman spectroscopy were used. XRD results associated with the crystallographic planes and Miller indices provide information on the presence of a mixture of celluloses polymorphs (crystalline cellulose I, II, Ib and amorphous phase). The decrease in crystallinity-index values from recent to aged ones (38 to 19.5%) confirms well the occurred alteration of crystalline cellulose fibres and their evolution towards a high content of the amorphous form. The prominent regression in the intensities of three FTIR fingerprint cellulose regions evolving towards an overall increase in the intensities of C=O area (1733-1630 cm-1) is a sign on the introduced changes on cellulose conformation and cellulose fibres degradation more accentuated in the case of the very aged sample (500 years). Similar results were confirmed by combining FT-Raman spectroscopy as a vibrational technique. No work has been done on this genus of degraded Moroccan hardwood and the relevance of this study is to investigate the compositional content and structural conformation, to determine the variability in the forms of both crystalline and amorphous cellulose phases with estimating the evolution of their polymorphism, and to monitor the degree of crystalline cellulose fibres deterioration.

scholarly journals Diketopiperazine Gels: New Horizons from the Self-Assembly of Cyclic Dipeptides

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3376
Author(s):  
Marco Scarel ◽  
Silvia Marchesan
Keyword(s):  
Drug Discovery ◽  
Enzymatic Hydrolysis ◽  
Self Assembly ◽  
Biological Activities ◽  
Functional Materials ◽  
The Self ◽  
Cyclic Dipeptides ◽  
New Horizons ◽  
Concise Review

Cyclodipeptides (CDPs) or 2,5-diketopiperazines (DKPs) can exert a variety of biological activities and display pronounced resistance against enzymatic hydrolysis as well as a propensity towards self-assembly into gels, relative to the linear-dipeptide counterparts. They have attracted great interest in a variety of fields spanning from functional materials to drug discovery. This concise review will analyze the latest advancements in their synthesis, self-assembly into gels, and their more innovative applications.

scholarly journals Toward Biochemical Conversion of Lignocellulose On-Farm: Pretreatment and Hydrolysis of Corn Stover in Situ

2017 ◽  
Vol 60 (4) ◽  
pp. 1025-1033
Author(s):  
Alicia A. Modenbach ◽  
Sue E. Nokes ◽  
Michael D. Montross ◽  
Barbara L. Knutson
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Conversion Efficiency ◽  
High Solids ◽  
Cellulose Conversion ◽  
Biochemical Conversion ◽  
High Solids Loading ◽  
Combined Pretreatment ◽  
Pretreatment Conditions ◽  
On Farm

Abstract. High-solids lignocellulosic pretreatment using NaOH followed by high-solids enzymatic hydrolysis was evaluated for an on-farm biochemical conversion process. Increasing the solids loadings for these processes has the potential for increasing glucose concentrations and downstream ethanol production; however, sequential processing at high-solids loading similar to an on-farm cellulose conversion system has not been studied. This research quantified the effects of high-solids pretreatment with NaOH and subsequent high-solids enzymatic hydrolysis on cellulose conversion. As expected, conversion efficiency was reduced; however, the highest glucose concentration (40.2 g L-1), and therefore the highest potential ethanol concentration, resulted from the high-solids combined pretreatment and hydrolysis. Increasing the enzyme dosage improved cellulose conversion from 9.6% to 36.8% when high-solids loadings were used in both unit operations; however, increasing NaOH loading and pretreatment time did not increase the conversion efficiency. The enzyme-to-substrate ratio had a larger impact on cellulose conversion than the NaOH pretreatment conditions studied, resulting in recommendations for an on-farm bioconversion system. Keywords: Corn stover, Enzymatic hydrolysis, Enzyme loading, High solids, Low solids, Sodium hydroxide.

scholarly journals Conditions of hydrolysis with a specific pair of endo- and exo-cellulases

2021 ◽  
Author(s):  
Yoshiki Kitano
Keyword(s):  
Synergistic Effect ◽  
Crystalline Cellulose ◽  
Carbohydrate Binding ◽  
Amorphous Cellulose ◽  
Potential Synergy ◽  
Hydrolysis Of Cellulose ◽  
Potential Alternative ◽  
Specific Pair ◽  
Hydrolysis Of ◽  
Increased Activity

Enzymatic hydrolysis of cellulose is a technology involved in the production of bioethanol, a potential alternative renewable energy. Many cellulases with endo- and exo- type of activity are known to hydrolyze cellulose synergistically. In this thesis, potential synergy between an endo-cellulase, Cel5B, with and without a carbohydrate- binding module (CBM6), and a new exo-cellulase, CBH1, from Trichoderma harzianum FP108 were examined during the hydrolysis of semi- crystalline cellulose (Avicel). Since CBM6 is recognized as having a high affinity for amorphous cellulose, it was hypothesized that this affinity could enhance the synergistic effect between the endo- and exo-cellulases by focusing the action to Cel5B+CBM6 on the amorphous regions of the Avicel substrate. The increased activity of Cel5B+CBM6 over Cel5B alone was confirmed. However, in contrast to our expectations, a synergistic effect was not observed between either endo- and exo-cellulase pairs. From the obtained hydrolysis yield, it was inferred that Cel5B+CBM6 may have exo-type activity that caused a competitive interaction with the exo-cellulase, which resulted in no synergy.

scholarly journals A Novel Inulin-Mediated Ethanol Precipitation Method for Separating Endo-Inulinase From Inulinases for Inulooligosaccharides Production From Inulin

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Li ◽  
Qiannan Zhang ◽  
Wei Wang ◽  
Shang-Tian Yang
Keyword(s):  
Enzymatic Hydrolysis ◽  
Aspergillus Niger ◽  
Functional Food ◽  
Degree Of Polymerization ◽  
Precipitation Method ◽  
High Yield ◽  
Process Conditions ◽  
Food Ingredients ◽  
Ethanol Precipitation ◽  
Novel Method

Inulin is a kind of polysaccharide that can be obtained various biomass. Inulooligosaccharides (IOS), a kind of oligosaccharides that can be obtained from inulin by enzymatic hydrolysis using inulinases, have been regarded as the functional food ingredients. Commercially available inulinases produced by natural Aspergillus niger contained both endo- and exo-inulinase activities. For IOS production from inulin, it is desirable to use only endo-inulinase as exo-inulinase would produce mainly the monosacchairde fructose from inulin. In the present study, a simple inulin-mediated ethanol precipitation method was developed to separate endo- and exo-inulinases present in natural inulinases. IOS production from inulin using the enriched endo-inulinase was then optimized in process conditions including pH and temperature, achieving a high yield of ∼94%. The resultant IOS products had a degree of polymerization ranging from 2 to 7. The study demonstrated a novel method for obtaining partially purified or enriched endo-inulinase for IOS production from inulin in an efficient process.

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