Hydroxypropyl sulfomethylation modification of lignin and its effect on cellulase hydrolysis

doi:10.11949/0438-1157.20220184

Abstract

Abstract:

The hydroxypropyl sulfomethylated lignin was modified by a two-step method, and the effect of hydroxypropyl sulfomethyl lignin on cellulase hydrolysis and its interaction mechanism with the enzyme were studied. The structure and surface properties of modified lignin were characterized by infrared spectroscopy, proton nuclear magnetic resonance spectra, surface charge measurement and contact angle analysis. The non-productive adsorption of cellulases on the modified lignin were investigated by using quartz crystal microbalance with dissipation (QCM-D). The results showed that compared with unmodified lignin, hydroxypropylation and sulfomethylation could block the phenolic hydroxyl groups with introduction of hydrophilic sulfonic acid groups. The modified lignin had high surface electronegativity and low hydrophobicity, which led to the decrease in the non-productive adsorption capacity of cellulase thus promoting the efficiency of enzymatic hydrolysis of cellulose.

Key words: biomass, lignin, hydroxypropylation, sulfomethylation, adsorption, cellulose hydrolysis

摘要：

通过两步法对木质素进行了羟丙基磺甲基化改性，研究了羟丙基磺甲基木质素对纤维素酶水解的影响及其与酶的相互作用机制。采用红外光谱、核磁氢谱、表面电荷测定、接触角测定等方法对改性木质素的结构和表面特性进行了表征；采用耗散型石英晶体微天平(quartz crystal microbalance with dissipation， QCM-D)研究了改性木质素对纤维素酶非生产性吸附的影响。结果表明：与未改性木质素相比，羟丙基磺甲基化改性封闭了酚羟基，引入了亲水性的磺酸基团。羟丙基磺甲基化木质素具有较高的表面负电性和较低的疏水性，减少了其对纤维素酶的非生产性吸附，从而提高了纤维素的酶水解效率。

关键词: 生物质, 木质素, 羟丙基化, 磺甲基化, 吸附, 纤维素酶水解

CLC Number:

TQ 35

Lijing HUANG, Jijiao HUANG, Penghui LI, Zhinuo LIU, Kangjie JIANG, Wenjuan WU. Hydroxypropyl sulfomethylation modification of lignin and its effect on cellulase hydrolysis[J]. CIESC Journal, 2022, 73(7): 3232-3239.

黄丽菁, 黄继娇, 李鹏辉, 刘芷诺, 蒋康杰, 吴文娟. 木质素羟丙基磺甲基化改性及其对纤维素酶水解的影响[J]. 化工学报, 2022, 73(7): 3232-3239.

Figures/Tables 9

Fig.1 Preparation process of modified lignin

Fig.2 FT-IR spectra of modified lignin and original lignin

Fig.3 1H NMR spectra of modified lignin and original lignin

Table 1 Surface properties of lignin and hydroxypropyl sulfonmethyl lignin

样品	元素组成/%			酚羟基含量/(mmol/g)	表面电荷/(mmol/g)
样品	C	O	S	酚羟基含量/(mmol/g)	表面电荷/(mmol/g)
木质素	77.97±0.03	21.65±0.01	0.38±0.02	5.28±0.21	-0.33±0.04
羟丙基磺甲基木质素	77.33±0.03	21.89±0.02	0.78±0.05	0.36±0.01	-0.58±0.02

Fig.4 The contact angle of lignin (a) and hydroxypropyl sulfonmethyl lignin (b)

Fig.5 Adsorption of cellulase on lignin film

Table 2 Adsorption parameters of cellulase on lignin films

样品	$- Δ F m a x$ /Hz	（ $1 / τ$ ）/min^-1	R²	最大吸附量/（ng/cm²）	不可逆吸附量/（ng/cm²）	解吸量/（ng/cm²）
木质素膜	57.81	0.064	0.92	341.1	311.9	29.2
羟丙基磺甲基木质素膜	50.59	0.053	0.95	298.5	255.4	43.1

Table 2 Adsorption parameters of cellulase on lignin films

样品	$- Δ F m a x$ /Hz	（ $1 / τ$ ）/min^-1	R²	最大吸附量/（ng/cm²）	不可逆吸附量/（ng/cm²）	解吸量/（ng/cm²）
木质素膜	57.81	0.064	0.92	341.1	311.9	29.2
羟丙基磺甲基木质素膜	50.59	0.053	0.95	298.5	255.4	43.1

Fig.6 Change of dissipation (ΔD) versus frequency (ΔF) during the enzymatic adsorption of lignin films

Fig.7 Effects of lignin on enzymatic hydrolysis efficiency

References 43

1	Lai C H, Yang B, Lin Z H, et al. New strategy to elucidate the positive effects of extractable lignin on enzymatic hydrolysis by quartz crystal microbalance with dissipation[J]. Biotechnology for Biofuels, 2019, 12: 57.
2	Yuan Y F, Jiang B, Chen H, et al. Recent advances in understanding the effects of lignin structural characteristics on enzymatic hydrolysis[J]. Biotechnology for Biofuels, 2021, 14(1): 205.
3	Cheng L, Hu X H, Gu Z B, et al. Characterization of physicochemical properties of cellulose from potato pulp and their effects on enzymatic hydrolysis by cellulase[J]. International Journal of Biological Macromolecules, 2019, 131: 564-571.
4	Li X, Zheng Y. Lignin-enzyme interaction: mechanism, mitigation approach, modeling, and research prospects[J]. Biotechnology Advances, 2017, 35(4): 466-489.
5	Sheng Y Q, Lam S S, Wu Y J, et al. Enzymatic conversion of pretreated lignocellulosic biomass: a review on influence of structural changes of lignin[J]. Bioresource Technology, 2021, 324: 124631.
6	Djajadi D T, Jensen M M, Oliveira M, et al. Lignin from hydrothermally pretreated grass biomass retards enzymatic cellulose degradation by acting as a physical barrier rather than by inducing nonproductive adsorption of enzymes[J]. Biotechnology for Biofuels, 2018, 11: 85.
7	Li X, Li M, Pu Y Q, et al. Inhibitory effects of lignin on enzymatic hydrolysis: the role of lignin chemistry and molecular weight[J]. Renewable Energy, 2018, 123: 664-674.
8	Ponnusamy V K, Nguyen D D, Dharmaraja J, et al. A review on lignin structure, pretreatments, fermentation reactions and biorefinery potential[J]. Bioresource Technology, 2019, 271: 462-472.
9	Pan X J. Role of functional groups in lignin inhibition of enzymatic hydrolysis of cellulose to glucose[J]. Journal of Biobased Materials and Bioenergy, 2008, 2(1): 25-32.
10	赵存异, 应文俊, 史正军, 等. 羟丙基化碱木质素的制备及其对纤维素酶水解的影响[J]. 林产化学与工业, 2019, 39(2): 109-114.
	Zhao C Y, Ying W J, Shi Z J, et al. Preparation of hydroxypropylated alkali lignin and its effect on hydrolysis efficiency of cellulase[J]. Chemistry and Industry of Forest Products, 2019, 39(2): 109-114.
11	Nakagame S, Chandra R P, Kadla J F, et al. Enhancing the enzymatic hydrolysis of lignocellulosic biomass by increasing the carboxylic acid content of the associated lignin[J]. Biotechnology and Bioengineering, 2011, 108(3): 538-548.
12	Yang Q, Pan X J. Correlation between lignin physicochemical properties and inhibition to enzymatic hydrolysis of cellulose[J]. Biotechnology and Bioengineering, 2016, 113( 6): 1213-1224.
13	金永灿, 陈慧, 吴文娟,等.水溶性木质素对纤维原料酶水解的影响研究进展[J]. 林业工程学报, 2020, 5(4): 12-19.
	Jin Y C, Chen H, Wu W J, et al. Investigations of the effect of water-soluble lignin on enzymatic hydrolysis of lignocellulose[J]. Journal of Forestry Engineering, 2020, 5(4): 12-19.
14	Wu J, Chandra R P, Takada M, et al. Enhancing enzyme-mediated cellulose hydrolysis by incorporating acid groups onto the lignin during biomass pretreatment[J]. Frontiers in Bioengineering and Biotechnology, 2020, 8: 608835.
15	Zheng W Q, Lan T Q, Li H, et al. Exploring why sodium lignosulfonate influenced enzymatic hydrolysis efficiency of cellulose from the perspective of substrate-enzyme adsorption[J]. Biotechnology for Biofuels, 2020, 13: 19.
16	梁文学, 邱学青, 杨东杰, 等. 麦草碱木质素的氧化和磺甲基化改性[J]. 华南理工大学学报(自然科学版), 2007, 35(5): 117-121.
	Liang W X, Qiu X Q, Yang D J, et al. Modificaion of wheat straw alkali lignin by oxidation and sulfomethylation[J]. Journal of South China University of Technology (Natural Science Edition), 2007, 35(5): 117-121.
17	Filipe D S, Anders R. Estimating the amount of phenolic hydroxyl groups in lignins[C]// Proceedings of 11th ISWPC. Nice, France, 2001.
18	Rahikainen J L, Evans J D, Mikander S, et al. Cellulase-lignin interactions—the role of carbohydrate-binding module and pH in non-productive binding[J]. Enzyme and Microbial Technology, 2013, 53(5): 315-321.
19	Nada A A M A, El-Sakhawy M, Kamel S M. Infra-red spectroscopic study of lignins[J]. Polymer Degradation and Stability, 1998, 60(2/3): 247-251.
20	麻秀星. 木质素磺酸钠减水剂改性实验研究[J]. 福建建筑, 2010(1): 123-124, 134.
	Ma X X. The modified research of the sodium lignosulfonate water-reducer[J]. Fujian Architecture & Construction, 2010(1): 123-124, 134.
21	Busse-Wicher M, Gomes T C F, Tryfona T, et al. The pattern of xylan acetylation suggests xylan may interact with cellulose microfibrils as a twofold helical screw in the secondary plant cell wall of Arabidopsis thaliana [J]. The Plant Journal, 2014, 79(3): 492-506.
22	Xu C, Zhang J, Zhang Y, et al. Lignin prepared from different alkaline pretreated sugarcane bagasse and its effect on enzymatic hydrolysis[J]. International Journal of Biological Macromolecules, 2019, 141: 484-492.
23	赖玉荣, 张曾, 黄干强, 等. FC法测定木素和纸浆中的酚羟基[J]. 中国造纸学报, 2007, 22(1): 54-58.
	Lai Y R, Zhang Z, Huang G Q, et al. Determination of the content of phenolic hydroxyl groups in lignin and pulp with FC-method[J]. Transactions of China Pulp and Paper, 2007, 22(1): 54-58.
24	Mou H Y, Wu X, Huang J, et al. Eucalyptus lignin modification for dynamic adsorption with lignocellulose-degradation enzymes dependent on pH values[J]. Industrial Crops and Products, 2021, 169: 113650.
25	Nakagame S, Chandra R P, Saddler J N. The effect of isolated lignins, obtained from a range of pretreated lignocellulosic substrates, on enzymatic hydrolysis[J]. Biotechnology and Bioengineering, 2010, 105(5): 871-879.
26	Yu H L, Xu Y Q, Ni Y H, et al. Enhanced enzymatic hydrolysis of cellulose from waste paper fibers by cationic polymers addition[J]. Carbohydrate Polymers, 2018, 200: 248-254.
27	Song Y L, Chandra R P, Zhang X, et al. Non-productive celluase binding onto deep eutectic solvent (DES) extracted lignin from willow and corn stover with inhibitory effects on enzymatic hydrolysis of cellulose[J]. Carbohydrate Polymers, 2020, 250: 116956.
28	Zhang Y Q, Jiang X, Wan S Q, et al. Adsorption behavior of two glucanases on three lignins and the effect by adding sulfonated lignin[J]. Journal of Biotechnology, 2020, 323: 1-8.
29	Chen X M, Ma Y, Gui Q W, et al. An antifouling polymer for dynamic anti-protein adhesion analysis by a quartz crystal microbalance[J]. The Analyst, 2021, 146(14): 4636-4641.
30	Qi P J, Xu Z W, Zhou T T, et al. Study on a quartz crystal microbalance sensor based on chitosan-functionalized mesoporous silica for humidity detection[J]. Journal of Colloid and Interface Science, 2021, 583: 340-350.
31	Agrawal R, Verma A, Singhania R R, et al. Current understanding of the inhibition factors and their mechanism of action for the lignocellulosic biomass hydrolysis[J]. Bioresource Technology, 2021, 332: 125042.
32	Chen G Q, Song W J, Qi B K, et al. Recycling cellulase from enzymatic hydrolyzate of acid treated wheat straw by electroultrafiltration[J]. Bioresource Technology, 2013, 144: 186-193.
33	Sun S L, Huang Y, Sun R C, et al. The strong association of condensed phenolic moieties in isolated lignins with their inhibition of enzymatic hydrolysis[J]. Green Chemistry, 2016, 18(15): 4276-4286.
34	Li Y, Qi B K, Luo J Q, et al. Effect of alkali lignins with different molecular weights from alkali pretreated rice straw hydrolyzate on enzymatic hydrolysis[J]. Bioresource Technology, 2016, 200: 272-278.
35	Mou H Y, Wu S B, He M Y, et al. Study of the difference between enzyme adsorption onto hydrotropic and alkali lignin separated from eucalyptus and bamboo[J]. BioResources, 2018, 13(1): 1441-1456.
36	Yuan Y F, Jiang B, Chen H, et al. Recent advances in understanding the effects of lignin structural characteristics on enzymatic hydrolysis[J]. Biotechnology for Biofuels, 2021, 14(1): 205.
37	Yu H L, Hou J J, Yu S T, et al. Comprehensive understanding of the non-productive adsorption of cellulolytic enzymes onto lignins isolated from furfural residues[J]. Cellulose, 2019, 26(5): 3111-3125.
38	Huang Y, Sun S L, Huang C, et al. Stimulation and inhibition of enzymatic hydrolysis by organosolv lignins as determined by zeta potential and hydrophobicity[J]. Biotechnology for Biofuels, 2017, 10: 162.
39	Lin X L, Wu L J, Huang S Q, et al. Effect of lignin-based amphiphilic polymers on the cellulase adsorption and enzymatic hydrolysis kinetics of cellulose[J]. Carbohydrate Polymers, 2019, 207: 52-58.
40	Rodahl M, Höök F, Krozer A, et al. Quartz crystal microbalance setup for frequency and Q-factor measurements in gaseous and liquid environments[J]. Review of Scientific Instruments, 1995, 66(7): 3924-3930.
41	Min D Y, Yang C M, Shi R, et al. The elucidation of the lignin structure effect on the cellulase-mediated saccharification by genetic engineering poplars (Populus nigra L.×Populus maximowiczii A.)[J]. Biomass and Bioenergy, 2013, 58: 52-57.
42	Li H J, Pu Y Q, Kumar R, et al. Investigation of lignin deposition on cellulose during hydrothermal pretreatment, its effect on cellulose hydrolysis, and underlying mechanisms[J]. Biotechnology and Bioengineering, 2014, 111(3): 485-492.
43	Xu C, Liu F, Alam M A, et al. Comparative study on the properties of lignin isolated from different pretreated sugarcane bagasse and its inhibitory effects on enzymatic hydrolysis[J]. International Journal of Biological Macromolecules, 2020, 146: 132-140.

[1]	Jiali ZHENG, Zhihui LI, Xinqiang ZHAO, Yanji WANG. Kinetics of ionic liquid catalyzed synthesis of 2-cyanofuran [J]. CIESC Journal, 2023, 74(9): 3708-3715.
[2]	Shaoqi YANG, Shuheng ZHAO, Lungang CHEN, Chenguang WANG, Jianjun HU, Qing ZHOU, Longlong MA. Hydrodeoxygenation of lignin-derived compounds to alkanes in Raney Ni-protic ionic liquid system [J]. CIESC Journal, 2023, 74(9): 3697-3707.
[3]	Yan GAO, Peng WU, Chao SHANG, Zejun HU, Xiaodong CHEN. Preparation of magnetic agarose microspheres based on a two-fluid nozzle and their protein adsorption properties [J]. CIESC Journal, 2023, 74(8): 3457-3471.
[4]	Bingchun SHENG, Jianguo YU, Sen LIN. Study on lithium resource separation from underground brine with high concentration of sodium by aluminum-based lithium adsorbent [J]. CIESC Journal, 2023, 74(8): 3375-3385.
[5]	Ruihang ZHANG, Pan CAO, Feng YANG, Kun LI, Peng XIAO, Chun DENG, Bei LIU, Changyu SUN, Guangjin CHEN. Analysis of key parameters affecting product purity of natural gas ethane recovery process via ZIF-8 nanofluid [J]. CIESC Journal, 2023, 74(8): 3386-3393.
[6]	Jiaqi CHEN, Wanyu ZHAO, Ruichong YAO, Daolin HOU, Sheying DONG. Synthesis of pistachio shell-based carbon dots and their corrosion inhibition behavior on Q235 carbon steel [J]. CIESC Journal, 2023, 74(8): 3446-3456.
[7]	Jie WANG, Xiaolin QIU, Ye ZHAO, Xinyang LIU, Zhongqiang HAN, Yong XU, Wenhan JIANG. Preparation and properties of polyelectrolyte electrostatic deposition modified PHBV antioxidant films [J]. CIESC Journal, 2023, 74(7): 3068-3078.
[8]	Ji CHEN, Ze HONG, Zhao LEI, Qiang LING, Zhigang ZHAO, Chenhui PENG, Ping CUI. Study on coke dissolution loss reaction and its mechanism based on molecular dynamics simulations [J]. CIESC Journal, 2023, 74(7): 2935-2946.
[9]	Wentao WU, Liangyong CHU, Lingjie ZHANG, Weimin TAN, Liming SHEN, Ningzhong BAO. High-efficient preparation of cardanol-based self-healing microcapsules [J]. CIESC Journal, 2023, 74(7): 3103-3115.
[10]	Zhenghao YANG, Zhen HE, Yulong CHANG, Ziheng JIN, Xia JIANG. Research progress in downer fluidized bed reactor for biomass fast pyrolysis [J]. CIESC Journal, 2023, 74(6): 2249-2263.
[11]	Maolin DONG, Lidong CHEN, Liulian HUANG, Weibing WU, Hongqi DAI, Huiyang BIAN. Research progress in preparation of lignonanocellulose by acid hydrotropes and their functional applications [J]. CIESC Journal, 2023, 74(6): 2281-2295.
[12]	Jing LI, Conghao SHEN, Daliang GUO, Jing LI, Lizheng SHA, Xin TONG. Research progress in the application of lignin-based carbon fiber composite materials in energy storage components [J]. CIESC Journal, 2023, 74(6): 2322-2334.
[13]	Caihong LIN, Li WANG, Yu WU, Peng LIU, Jiangfeng YANG, Jinping LI. Effect of alkali cations in zeolites on adsorption and separation of CO₂/N₂O [J]. CIESC Journal, 2023, 74(5): 2013-2021.
[14]	Chenxin LI, Yanqiu PAN, Liu HE, Yabin NIU, Lu YU. Carbon membrane model based on carbon microcrystal structure and its gas separation simulation [J]. CIESC Journal, 2023, 74(5): 2057-2066.
[15]	Shaoyun CHEN, Dong XU, Long CHEN, Yu ZHANG, Yuanfang ZHANG, Qingliang YOU, Chenglong HU, Jian CHEN. Preparation and adsorption properties of monolayer polyaniline microsphere arrays [J]. CIESC Journal, 2023, 74(5): 2228-2238.