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Zhang Y, Xin D, Wen P, Chen X, Jia L, Lu Z, Zhang J. Comparison of Alkaline Sulfite Pretreatment and Acid Sulfite Pretreatment with Low Chemical Loading in Saccharification of Poplar. Appl Biochem Biotechnol 2023; 195:4414-4428. [PMID: 36696039 DOI: 10.1007/s12010-023-04351-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2023] [Indexed: 01/26/2023]
Abstract
Sulfite pretreatment is a productive process for lignin dissolution in lignocelluloses and to reduce the hydrophobicity of lignin by sulfonation, thus promoting the hydrolyzability of the substrate. Previously, sulfite pretreatment needs high dosages of chemicals and thus results in the high cost of the pretreatment and the great pressure of environmental pollution. To overcome these problems, it was crucial to research whether alkaline sulfite pretreatment (ALS) and acid sulfite pretreatment (ACS) with low chemical loading could enhance the saccharification of poplar. In this work, the results indicated that with low loading of chemicals in sulfite pretreatment, ALS pretreatment (1.6% Na2SO3 and 0.5% NaOH) at 180 °C removed more lignin, resulted in lower hydrophobicity and higher cellulase adsorption capacity of poplar than ACS pretreatment (1.6% Na2SO3 and 0.5% H2SO4) at 180 °C. A satisfying glucose yield of 84.9% and a xylose yield of 76.0% were obtained from poplar after ALS pretreatment with 1.6% Na2SO3 and 0.5% NaOH at 180 °C for 1 h using 10 FPU cellulase/g dry matter, saving sodium sulfite by 60.0% compared to the loading of sulfite in traditional sulfite pretreatment. The strategy developed in this work reduced chemical loading and cellulase loading in alkali sulfite pretreatment for the saccharification of poplar.
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Affiliation(s)
- Ying Zhang
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi, 712100, China
| | - Donglin Xin
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Peiyao Wen
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi, 712100, China
| | - Xiang Chen
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi, 712100, China
| | - Lili Jia
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi, 712100, China
| | - Zhoumin Lu
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi, 712100, China.
| | - Junhua Zhang
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi, 712100, China
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Yang L, Jiang G, Chen J, Xu Z, Yang Y, Zheng B, Yang Y, Huang H, Tian Y. Production of 1,3-propanediol using enzymatic hydrolysate derived from pretreated distillers' grains. BIORESOURCE TECHNOLOGY 2023; 374:128773. [PMID: 36828224 DOI: 10.1016/j.biortech.2023.128773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/17/2023] [Accepted: 02/19/2023] [Indexed: 06/18/2023]
Abstract
To minimize environmental pollution and waste of resources, distillers' grains (DG) was used to produce 1,3-propanediol. Biological, physical, and chemical methods were used for pretreatment. The correlation between features of pretreated samples and enzymatic digestibility was analyzed. The results showed that the glucan and xylan conversion of dilute sulfuric acid pretreated DG increased by 69.59% and 413.68%, respectively. The glucan conversion of microwave pretreated and xylan conversion of laccase pretreated DG increased by 14.22% and 34.19%, respectively. Pretreatment enhanced enzymatic digestibility through changing the dense structure and features of DG making them conductive to enzymatic hydrolysis. The production of 1,3-propanediol using enzymatic hydrolysate of pretreated DG and glycerol in shake-flask was 17 g/L. The utilization of DG not only provides plentiful raw materials replacing fossil fuels to produce biofuels and other chemicals but efficiently reduces environmental waste.
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Affiliation(s)
- Li Yang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - Guangyang Jiang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - Jia Chen
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - Zhe Xu
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - Yichen Yang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - Bijun Zheng
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - Yi Yang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Yongqiang Tian
- College of Biomass Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Ministry of Education, Chengdu, Sichuan 610065, China.
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Xie X, Chen M, Tong W, Song K, Wang J, Wu S, Hu J, Jin Y, Chu Q. Comparative study of acid- and alkali-catalyzed 1,4-butanediol pretreatment for co-production of fermentable sugars and value-added lignin compounds. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:52. [PMID: 36978121 PMCID: PMC10045053 DOI: 10.1186/s13068-023-02303-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/12/2023] [Indexed: 03/30/2023]
Abstract
BACKGROUND Organosolv pretreatment is one of the most efficient methods for delignification and boosting biomass saccharification. As compared to typical ethanol organosolv pretreatments, 1,4-butanediol (BDO) organosolv pretreatment is a high-boiling-point solvent pretreatment, which can generate low pressure in the reactor during high temperature cooking that improves the operation safety. Although several studies showed that organosolv pretreatment can lead to effective delignification and enhancement in glucan hydrolysis, there has been no studies on acid- and alkali-catalyzed BDO pretreatment, as well as their comparison on promoting biomass saccharification and lignin utilization. RESULTS It was shown that BDO organosolv pretreatment was more effective in removing lignin from poplar as compared with typical ethanol organosolv pretreatment under the same pretreatment conditions. HCl-BDO pretreatment with 40 mM acid loading led to 82.04% of original lignin removed from biomass, as compared to the lignin removal of 59.66% in HCl-Ethanol pretreatment. Besides, acid-catalyzed BDO pretreatment was more effective in improving the enzymatic digestibility of poplar than alkali-catalyzed BDO pretreatment. As a result, HCl-BDO with acid loading of 40 mM provided a good enzymatic digestibility of cellulose (91.16%) and the maximum sugar yield of 79.41% from original woody biomass. The linear correlations between physicochemical structure (e.g., fiber swelling, cellulose crystallinity, crystallite size, surface lignin coverage and cellulose accessibility) changes of BDO pretreated poplar and enzymatic hydrolysis were plotted to figure out the main factors that influenced biomass saccharification. Moreover, acid-catalyzed BDO pretreatment mainly brought about the phenolic hydroxyl (PhOH) groups formation in lignin structure, while alkali-catalyzed BDO pretreatment mostly led to the lower molecular weight of lignin. CONCLUSIONS Results indicated that the acid-catalyzed BDO organosolv pretreatment could significantly improve enzymatic digestibility of the highly recalcitrant woody biomass. The great enzymatic hydrolysis of glucan resulted from increased cellulose accessibility, which mostly associated with the higher degree of delignification and hemicellulose solubilization, as well as the more increase in fiber swelling. Besides, lignin was recovered from the organic solvent, which could be used as natural antioxidants. The formation of phenolic hydroxyl groups in lignin structure and the lower molecular weight of lignin contributed to its greater radical scavenging capacity.
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Affiliation(s)
- Xinyu Xie
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Mingjun Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Wenyao Tong
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Kai Song
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Jing Wang
- Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization, Guangdong Academy of Forestry, Guangzhou, 510520, China
| | - Shufang Wu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Jinguang Hu
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1Z4, Canada
| | - Yongcan Jin
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Qiulu Chu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, 210037, China.
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Wu X, Tang W, Huang C, Huang C, Lai C, Yong Q. The effects of exogenous ash on the autohydrolysis and enzymatic hydrolysis of wheat straw. BIORESOURCE TECHNOLOGY 2019; 286:121411. [PMID: 31078979 DOI: 10.1016/j.biortech.2019.121411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 05/24/2023]
Abstract
The effects of exogenous ash (EA) from harvest wheat straw and its internal components on wheat straw autohydrolysis efficiency and subsequent enzymatic hydrolysis were investigated. Results showed that when EA and its insoluble mineral components were included in the autohydrolysis, the enzymatic efficiencies of pretreated residues were significantly reduced from 84.9% to 66.3% and 58.4%, respectively. This was found to be largely attributable to the buffering of free H+ in the pretreatment medium which took place due to the ash. Specifically, the insoluble mineral fraction of said ash exerted strongest buffering capacity in EA. Furthermore, this decrease was found to linearly correlate with decreases to substrate enzymatic accessibility and hydrophobicity. These results demonstrate that the penalties of ash upon autohydrolysis are borne of specific fractions comprising the ash, making the case for ash removal processes or supplementation of processes with additives that will counter the negative effects of ash.
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Affiliation(s)
- Xinxing Wu
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Wei Tang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Chen Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Caoxing Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Chenhuan Lai
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Qiang Yong
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China.
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Tang S, Liu W, Huang C, Lai C, Fan Y, Yong Q. Improving the enzymatic hydrolysis of larch by coupling water pre-extraction with alkaline hydrogen peroxide post-treatment and adding enzyme cocktail. BIORESOURCE TECHNOLOGY 2019; 285:121322. [PMID: 30965281 DOI: 10.1016/j.biortech.2019.121322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
Soluble arabinogalactan (AG) in larch leads to reagent waste during its biorefining using oxidative pretreatment strategies. A two-stage pretreatment of water pre-extraction followed by alkaline hydrogen peroxide (AHP) pretreatment was investigated to more efficiently convert larch cellulose into glucose, while also obtaining a value-added AG product stream. The results showed that water pre-extraction increases the lignin selectivity of both NaOH and H2O2 reagents, translating to improved lignin removal and enzymatic hydrolysis yields. This was found to be related to cellulose accessibility alongside the effective consumption of the reagents. Moreover, the addition of mannanase also significantly enhanced enzymatic digestibility of pretreated solid from 81.0% to 97.7% (4% H2O2 charge and 180 °C) when 40 U/g mannanase was supplemented with 20 FPU/g cellulase. In all, it was demonstrated that coupling mannanase with cellulase could improve larch's enzymatic digestibility and overall viability for biorefining processes.
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Affiliation(s)
- Shuo Tang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Wanying Liu
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Caoxing Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Chenhuan Lai
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Yimin Fan
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Qiang Yong
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China.
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Huang C, Lin W, Lai C, Li X, Jin Y, Yong Q. Coupling the post-extraction process to remove residual lignin and alter the recalcitrant structures for improving the enzymatic digestibility of acid-pretreated bamboo residues. BIORESOURCE TECHNOLOGY 2019; 285:121355. [PMID: 31004950 DOI: 10.1016/j.biortech.2019.121355] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/14/2019] [Accepted: 04/15/2019] [Indexed: 05/08/2023]
Abstract
In this work, a mild and facile post-extraction using different reagents was evaluated to overcome these recalcitrance for improving the enzymatic digestibility of acid-pretreated bamboo residues by removing the lignin and disrupting its inhibitory properties. Results showed that the enzymatic digestibility of acid-pretreated bamboo residues can be improved from 15.4% to 61.4%, 59.7%, and 42.8% by room temperature post-extraction with phosphoric acid, urea, and ethanol, respectively. Several compelling correlations (R2 > 0.5) were observable between enzymatic digestibility and structural changes, including delignification, reducing of substrate hydrophobicity, altering cellulose crystallinity, and elevations to the residual lignin syringyl-to-guaiacyl (S/G) ratio and functional groups. The results serve as a demonstration of the downstream value that can be gained when coupling a post-extraction process with acid pretreatment of bamboo residues, resulting in greater fermentable sugar production.
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Affiliation(s)
- Caoxing Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Wenqian Lin
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Chenhuan Lai
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Xin Li
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Yongcan Jin
- Department of Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China
| | - Qiang Yong
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
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Alam A, Zhang R, Liu P, Huang J, Wang Y, Hu Z, Madadi M, Sun D, Hu R, Ragauskas AJ, Tu Y, Peng L. A finalized determinant for complete lignocellulose enzymatic saccharification potential to maximize bioethanol production in bioenergy Miscanthus. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:99. [PMID: 31057665 PMCID: PMC6486690 DOI: 10.1186/s13068-019-1437-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/13/2019] [Indexed: 05/18/2023]
Abstract
BACKGROUND Miscanthus is a leading bioenergy crop with enormous lignocellulose production potential for biofuels and chemicals. However, lignocellulose recalcitrance leads to biomass process difficulty for an efficient bioethanol production. Hence, it becomes essential to identify the integrative impact of lignocellulose recalcitrant factors on cellulose accessibility for biomass enzymatic hydrolysis. In this study, we analyzed four typical pairs of Miscanthus accessions that showed distinct cell wall compositions and sorted out three major factors that affected biomass saccharification for maximum bioethanol production. RESULTS Among the three optimal (i.e., liquid hot water, H2SO4 and NaOH) pretreatments performed, mild alkali pretreatment (4% NaOH at 50 °C) led to almost complete biomass saccharification when 1% Tween-80 was co-supplied into enzymatic hydrolysis in the desirable Miscanthus accessions. Consequently, the highest bioethanol yields were obtained at 19% (% dry matter) from yeast fermentation, with much higher sugar-ethanol conversion rates by 94-98%, compared to the other Miscanthus species subjected to stronger pretreatments as reported in previous studies. By comparison, three optimized pretreatments distinctively extracted wall polymers and specifically altered polymer features and inter-linkage styles, but the alkali pretreatment caused much increased biomass porosity than that of the other pretreatments. Based on integrative analyses, excellent equations were generated to precisely estimate hexoses and ethanol yields under various pretreatments and a hypothetical model was proposed to outline an integrative impact on biomass saccharification and bioethanol production subjective to a predominate factor (CR stain) of biomass porosity and four additional minor factors (DY stain, cellulose DP, hemicellulose X/A, lignin G-monomer). CONCLUSION Using four pairs of Miscanthus samples with distinct cell wall composition and varied biomass saccharification, this study has determined three main factors of lignocellulose recalcitrance that could be significantly reduced for much-increased biomass porosity upon optimal pretreatments. It has also established a novel standard that should be applicable to judge any types of biomass process technology for high biofuel production in distinct lignocellulose substrates. Hence, this study provides a potential strategy for precise genetic modification of lignocellulose in all bioenergy crops.
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Affiliation(s)
- Aftab Alam
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Ran Zhang
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Peng Liu
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Jiangfeng Huang
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Yanting Wang
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Zhen Hu
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Meysam Madadi
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Dan Sun
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan, 430068 China
| | - Ruofei Hu
- College of Food Science and Technology, Hubei University of Arts and Science, Xiangyang, 441053 China
| | - Arthur J. Ragauskas
- Department of Chemical and Biomolecular Engineering, University of Tennessee-Knoxville, Knoxville, TN 37996-2200 USA
| | - Yuanyuan Tu
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Liangcai Peng
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070 China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
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Tang W, Wu X, Huang C, Huang C, Lai C, Yong Q. Enhancing enzymatic digestibility of waste wheat straw by presoaking to reduce the ash-influencing effect on autohydrolysis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:222. [PMID: 31534481 PMCID: PMC6747752 DOI: 10.1186/s13068-019-1568-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/11/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND The acid buffering capacity of high free ash in waste wheat straw (WWS) has been revealed to be a significant hindrance on the efficiency of autohydrolysis pretreatment. Previous researches have mainly relied on washing to eliminate the influence of ash, and the underlying mechanism of the ash influencing was not extensively investigated. Presently, studies have found that cations can destroy the acid buffering capacity of ash through cation exchange. Herein, different cations were applied to presoak WWS with the aim to overcome the negative effects of ash on autohydrolysis efficiency, further improving its enzymatic digestibility. RESULTS Results showed that cations can be adsorbed on the surface of the material by electrostatic adsorption to change the acid buffering capacity of WWS. The acid buffering capacity of 120 mM Fe2+ presoaked WWS is reduced from 226.3 mmol/pH-kg of original WWS to 79.3 mmol/pH-kg. This reduced the autohydrolysis pretreatment medium pH from 5.7 to 3.8 and promoted the removal of xylan from 61.7 to 83.7%. In addition, the enzymatic digestibility of WWS was enhanced from 49.7 to 86.3% by presoaking with 120 mM Fe2+ solution. The relationship between enzymatic accessibility and hydrophobicity with enzymatic digestibility of the autohydrolyzed WWS was analyzed. CONCLUSIONS The results showed that the acid buffering capacity of the high free ash was detrimental for the autohydrolysis efficiency of WWS. After WWS was presoaked with different cations, the acid buffering capacity of ash was weakened by cation exchange and electrostatic adsorption, which improved the autohydrolysis efficiency. The results expound that the enzymatic digestibility of WWS can be enhanced through presoaking to reduce the ash-influencing effect on autohydrolysis.
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Affiliation(s)
- Wei Tang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037 People’s Republic of China
| | - Xinxing Wu
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037 People’s Republic of China
| | - Chen Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037 People’s Republic of China
| | - Caoxing Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037 People’s Republic of China
| | - Chenhuan Lai
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037 People’s Republic of China
| | - Qiang Yong
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, 210037 People’s Republic of China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, 210037 People’s Republic of China
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