1
|
Kasegn MM, Simachew A, Redda YT, Gebremedhn HM. Production of bioethanol from sweet sorghum [Sorghum bicolor L.] juice using yeast isolated from fermented sweet sorghum juice. Int Microbiol 2024; 27:491-504. [PMID: 37498435 DOI: 10.1007/s10123-023-00403-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/30/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023]
Abstract
As a sugar-rich plant with no impact on global warming and food security, sweet sorghum can be exploited as an alternative source of renewable bioenergy. This study aimed to examine the potential of sweet sorghum juice for the generation of bioethanol using yeast isolated from the juice. The °Brix of sweet sorghum juice was measured using a digital refractometer. Additionally, 18 wild yeasts isolated from fermented sweet sorghum juice were subjected to various biochemical tests to describe them to identify potential yeast for ethanol production. The morphological and biochemical analyses of the yeasts revealed that all of the yeast isolates were most likely members of the genus Saccharomyces. The most ethanol-tolerant yeast isolate SJU14 was employed for sweet sorghum juice fermentation. A completely randomized factorial design was used with various fermentation parameters, primarily pH, temperature, and incubation period. Then ethanol content was determined using a potassium dichromate solution. According to the ANOVA, the highest ethanol content (18.765%) was produced at 30/26 °C, pH 4.5, and incubated for 96 h. Sweet sorghum juice was found to be an excellent source of potent yeasts, which have important industrial properties like the capacity to grow at high ethanol and glucose concentrations. Moreover, it can be utilized as a substitute substrate for the manufacturing of bioethanol production to lessen the environmental threat posed by fossil fuels. Further research is, therefore, recommended to develop strategically valuable applications of sweet sorghum for enhancing the food system and mitigating climate change.
Collapse
Affiliation(s)
- Melaku Mekonen Kasegn
- Department of Biotechnology, College of Dryland Agriculture and Natural Resources, Mekelle University, Mekelle, Ethiopia.
| | - Addis Simachew
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - Hailay Mehari Gebremedhn
- Department of Biotechnology, College of Dryland Agriculture and Natural Resources, Mekelle University, Mekelle, Ethiopia
| |
Collapse
|
2
|
Yousef NMH, Mawad AMM. Characterization of thermo/halo stable cellulase produced from halophilic Virgibacillus salarius BM-02 using non-pretreated biomass. World J Microbiol Biotechnol 2023; 39:22. [PMID: 36422734 PMCID: PMC9691493 DOI: 10.1007/s11274-022-03446-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 10/21/2022] [Indexed: 11/27/2022]
Abstract
The production of extremozymes from halophilic bacteria has increased significantly due to their stability and efficiency in catalyzing a reaction, as well as their capacity to display optimum activity at various salt concentrations. In the current study, the halophilic bacterium Virgibacillus salarius strain BM-02 could utilize many non-pretreated substrates including cellulose, corn stover, sugarcane bagasse and wheat bran as a sole carbon source. However, wheat bran was the best substrate for achieving optimum saccharification yield (90.1%). The partially purified cellulase was active and stable at a wide range of pH (5-8) with residual activities > 58%. Moreover, it was stable at 5-12% of NaCl. Metal ions have a variable impact on the activity of partially purified cellulase however, Fe+3 exhibited the highest increase in the cellulase activity. The enzyme exhibited a thermal stability at 40, 50 and 60 °C with half-lives of 1049.50, 168.14 and 163.5 min, respectively. The value of Vmax was 22.27 U/mL while Km was 2.1 mM. The activation energy of denaturation Ed 69.81 kJ/mol, the enthalpy values (ΔHd) were positive, and the entropy values (ΔS) were negative. Therefore, V. Salarius is recommended as a novel promising halophilic extremozyme producer and agricultural waste remover in the bio-industrial applications.
Collapse
Affiliation(s)
- Naeima M. H. Yousef
- grid.252487.e0000 0000 8632 679XBotany and Microbiology Department, Faculty of Science, Assiut University, Assiut, 71516 Egypt
| | - Asmaa M. M. Mawad
- grid.252487.e0000 0000 8632 679XBotany and Microbiology Department, Faculty of Science, Assiut University, Assiut, 71516 Egypt
| |
Collapse
|
3
|
Bioethanol Production from Lignocellulosic Biomass-Challenges and Solutions. Molecules 2022; 27:molecules27248717. [PMID: 36557852 PMCID: PMC9785513 DOI: 10.3390/molecules27248717] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Regarding the limited resources for fossil fuels and increasing global energy demands, greenhouse gas emissions, and climate change, there is a need to find alternative energy sources that are sustainable, environmentally friendly, renewable, and economically viable. In the last several decades, interest in second-generation bioethanol production from non-food lignocellulosic biomass in the form of organic residues rapidly increased because of its abundance, renewability, and low cost. Bioethanol production fits into the strategy of a circular economy and zero waste plans, and using ethanol as an alternative fuel gives the world economy a chance to become independent of the petrochemical industry, providing energy security and environmental safety. However, the conversion of biomass into ethanol is a challenging and multi-stage process because of the variation in the biochemical composition of biomass and the recalcitrance of lignin, the aromatic component of lignocellulose. Therefore, the commercial production of cellulosic ethanol has not yet become well-received commercially, being hampered by high research and production costs, and substantial effort is needed to make it more widespread and profitable. This review summarises the state of the art in bioethanol production from lignocellulosic biomass, highlights the most challenging steps of the process, including pretreatment stages required to fragment biomass components and further enzymatic hydrolysis and fermentation, presents the most recent technological advances to overcome the challenges and high costs, and discusses future perspectives of second-generation biorefineries.
Collapse
|
4
|
Production of Citric Acid by Aspergillus niger Cultivated in Olive Mill Wastewater Using a Two-Stage Packed Column Bioreactor. FERMENTATION 2022. [DOI: 10.3390/fermentation8040153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
For building a sustainable fermentation process, it is essential to reduce dependence on natural resources and lower the amount of pollution that is created. The reuse of agro-industrial wastewater after possible treatment leads to the achievement of these goals concurrently. This study investigates the production of citric acid and the cellulase enzyme by A. niger cultivated in olive mill wastewater (OMW) using a loofa sponge-packed column bioreactor. The process was conducted under batch conditions using a single-stage packed bioreactor and under continuous operation using two-stage packed-column bioreactors. Citric acid and cellulase enzyme production were enhanced when the culture was supplied with cellulose. Employing loofa sponge slices for cell entrapment/immobilization improved the efficiency of the process. The maximum citric acid concentration achieved was 16 g/L with a yield (YCit.A/BOD) of 38.5% and a productivity of 2.5 g/L/day. When the process parameters were translated into continuous operation employing two loofa sponge-packed column bioreactors, citric acid production was improved significantly to 25 g/L in a steady-state period of 5 days at a production rate of 3.6 g/L/day and an allover yield (YCit.A/BOD) of 57.5%. Cellulases and reducing sugars were continuously supplied to the second-stage bioreactor by the first-stage bioreactor, which in turn enhanced fungal growth and citric acid production.
Collapse
|
5
|
Dutta S, Bhat NS. Chemocatalytic value addition of glucose without carbon-carbon bond cleavage/formation reactions: an overview. RSC Adv 2022; 12:4891-4912. [PMID: 35425469 PMCID: PMC8981328 DOI: 10.1039/d1ra09196d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/02/2022] [Indexed: 01/22/2023] Open
Abstract
As the monomeric unit of the abundant biopolymer cellulose, glucose is considered a sustainable feedstock for producing carbon-based transportation fuels, chemicals, and polymers. The chemocatalytic value addition of glucose can be broadly classified into those involving C-C bond cleavage/formation reactions and those without. The C6 products obtained from glucose are particularly satisfying because their syntheses enjoy a 100% carbon economy. Although multiple derivatives of glucose retaining all six carbon atoms in their moiety are well-documented, they are somewhat dispersed in the literature and never delineated coherently from the perspective of their carbon skeleton. The glucose-derived chemical intermediates discussed in this review include polyols like sorbitol and sorbitan, diols like isosorbide, furanic compounds like 5-(hydroxymethyl)furfural, and carboxylic acids like gluconic acid. Recent advances in producing the intermediates mentioned above from glucose following chemocatalytic routes have been elaborated, and their derivative chemistry highlighted. This review aims to comprehensively understand the prospects and challenges associated with the catalytic synthesis of C6 molecules from glucose.
Collapse
Affiliation(s)
- Saikat Dutta
- Department of Chemistry, National Institute of Technology Karnataka (NITK) Surathkal Mangalore-575025 Karnataka India
| | - Navya Subray Bhat
- Department of Chemistry, National Institute of Technology Karnataka (NITK) Surathkal Mangalore-575025 Karnataka India
| |
Collapse
|
6
|
Mohsin A, Hussain MH, Zaman WQ, Mohsin MZ, Zhang J, Liu Z, Tian X, Salim-Ur-Rehman, Khan IM, Niazi S, Zhuang Y, Guo M. Advances in sustainable approaches utilizing orange peel waste to produce highly value-added bioproducts. Crit Rev Biotechnol 2021; 42:1284-1303. [PMID: 34856847 DOI: 10.1080/07388551.2021.2002805] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Orange peel waste (OPW), a discarded part of orange fruit, is a rich source of essential constituents that can be transformed into highly value-added bioproducts. OPW is being generated in million tonnes globally and returns to the environment without complete benefit. Thus, a high volume of annually produced OPW in the industry requires effective valorization. In this regard, limited data is available that summarizes the broader spectrum for the sustainable fate of OPW to produce value-added bioproducts. The main objective of this treatise is to explore the sustainable production of bioproducts from OPW. Therefore, this review covers all the aspects of OPW, from its production to complete valorization. The review encompasses the extraction technologies employed for extracting different valuable bioactive compounds, such as: essential oil (EO), pectin, and carotenoids, from OPW. Furthermore, the suitability of bioconversion technologies (digestion/fermentation) in transforming OPW to other useful bioproducts, such as: biochemicals (lactic acid and succinic acid), biopolysaccharides (xanthan and curdlan gum), and bioenergy (biomethane and bioethanol) is discussed. Also, it includes the concept of OPW-based biorefineries and their development that shall play a definite role in future to cover demands for: food, chemicals, materials, fuels, power, and heat. Lastly, this review focuses on OPW-supplemented functional food products such as: beverages, yogurts, and extruded products. In conclusion, insights provided in this review maximize the potential of OPW for commercial purposes, leading to a safe, and waste-free environment.
Collapse
Affiliation(s)
- Ali Mohsin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Muhammad Hammad Hussain
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Waqas Qamar Zaman
- Institute of Environment Science and Engineering, School of Civil and Environment Engineering, National University of Sciences and Technology, Islamabad, Pakistan
| | - Muhammad Zubair Mohsin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Junhong Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Zebo Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Xiwei Tian
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Salim-Ur-Rehman
- National Institute of Food Science and Technology, University of Agriculture, Faisalabad, Pakistan
| | - Imran Mehmood Khan
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, P.R. China
| | - Sobia Niazi
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, P.R. China
| | - Yingping Zhuang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Meijin Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| |
Collapse
|
7
|
Zhang H, Wu J. Statistical optimization of aqueous ammonia pretreatment and enzymatic hydrolysis of corn cob powder for enhancing sugars production. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
8
|
Anu, Kumar S, Kumar A, Kumar V, Singh B. Optimization of cellulase production by Bacillus subtilis subsp. subtilis JJBS300 and biocatalytic potential in saccharification of alkaline-pretreated rice straw. Prep Biochem Biotechnol 2020; 51:697-704. [PMID: 33302792 DOI: 10.1080/10826068.2020.1852419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Optimization of cellulase production by Bacillus subtilis subsp. subtilis JJBS300 resulted in maximum cellulase (CMCase 9.7 U/g substrate) using wheat bran and rice straw in 1:1 ratio at substrate to moisture ratio of 1:3 at 35 °C and pH 4.0 after 48 h. Partially purified cellulase of B. subtilis subsp. subtilis showed optimal activity at 50 °C and pH 5.0. Among the metal ions, Na+, Ca2+ and Fe2+ stimulated the cellulase activity. Glutaraldehyde and 1-butanol also enhanced the cellulase activity as compared to other solvents. Bacterial cellulase hydrolyzed ammonia-pretreated rice straw more efficiently as compared to sodium-carbonate pretreated and untreated biomass. Optimization of saccharification of untreated and pretreated (sodium carbonate and ammonia) rice straw by bacterial cellulase resulted in high liberation of reducing sugars with enzyme dose of 100 U/g substrate (221 mg/g substrate) at pH 5.0 (103 mg/g substrate) and 50 °C (142 mg/g substrate) after 6 h in ammonia-pretreated rice straw. Furthermore, liberation of reducing sugars increased with incubation time showing maximum reducing sugars (171 mg/g substrate) after 24 h in ammonia-pretreated rice straw. HPLC analysis of enzymatic hydrolysate of ammonia-pretreated rice straw verified the ability of bacterial cellulase in liberation of various monomeric and oligomeric sugars.
Collapse
Affiliation(s)
- Anu
- Laboratory of Bioprocess Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Sumit Kumar
- Laboratory of Bioprocess Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Anil Kumar
- Department of Botany, Pt. N.R.S. Govt. College, Rohtak, Haryana, India
| | - Vinod Kumar
- Department of Chemistry, Central University of Haryana, Mahendergarh, Haryana, India
| | - Bijender Singh
- Laboratory of Bioprocess Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India.,Department of Biotechnology, Central University of Haryana, Mahendergarh, Haryana, India
| |
Collapse
|
9
|
Ramaiah SK, Thimappa GS, Nataraj LK, Dasgupta P. Optimization of oxalic acid pre-treatment and enzymatic saccharification in Typha latifolia for production of reducing sugar. J Genet Eng Biotechnol 2020; 18:28. [PMID: 32648065 PMCID: PMC7347720 DOI: 10.1186/s43141-020-00042-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/05/2020] [Indexed: 12/29/2022]
Abstract
Background Plants with high biomass can be manipulated for their reducing sugar content which ultimately upon fermentation produces ethanol. This concept was used to enhance the production of reducing sugar from cattail (Typha latifolia) by oxalic acid (OAA) pre-treatment followed by enzymatic saccharification. Result The optimum condition of total reducing sugar released from OAA pre-treatment was found to be 22.32 mg/ml (OAA—1.2%; substrate concentration (SC)—6%; reaction time (RT)—20 min) using one variable at a time (OVAT). Enzymatic saccharification yielded 45.21 mg/ml of reducing sugar (substrate concentration (SC)—2.4%; enzymatic dosage—50 IU/g; pH 7.0; temp—50 °C) using response surface methodology (RSM). Conclusion We conclude that Typha can be used as a potential substrate for large-scale biofuel production, employing economical bioprocessing strategies.
Collapse
Affiliation(s)
- Sunil Kodishetty Ramaiah
- Bioenergy Lab, Department of Biotechnology, Bangalore University, Bengaluru, Karnataka, 560056, India
| | | | | | - Proteek Dasgupta
- Department of Zoology, Bangalore University, Bengaluru, Karnataka, 560056, India
| |
Collapse
|
10
|
Liu C, Zou G, Yan X, Zhou X. Screening of multimeric β-xylosidases from the gut microbiome of a higher termite, Globitermes brachycerastes. Int J Biol Sci 2018; 14:608-615. [PMID: 29904275 PMCID: PMC6001650 DOI: 10.7150/ijbs.22763] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 01/03/2018] [Indexed: 11/24/2022] Open
Abstract
Termite gut microbiome is a rich reservoir for glycoside hydrolases, a suite of enzymes critical for the degradation of lignocellulosic biomass. To search for hemicellulases, we screened 12,000 clones from a fosmid gut library of a higher termite, Globitermes brachycerastes. As a common Southeastern Asian genus, Globitermes distributes predominantly in tropical rain forests and relies on the lignocellulases from themselves and bacterial symbionts to digest wood. In total, 22 positive clones with β-xylosidase activity were isolated, in which 11 representing different restriction fragment length polymorphism (RFLP) patterns were pooled and subjected to 454 pyrosequencing. As a result, eight putative β-xylosidases were cloned and heterologously expressed in Escherichia coli BL21 competent cells. After purification using Ni-NTA affinity chromatography, recombinant G. brachycerastes symbiotic β-xylosidases were characterized enzymatically, including their pH and temperature optimum. In addition to β-xylosidase activity, four of them also exhibited either β-glucosidase or α-arabinosidases activities, suggesting the existence of bifunctional hemicellulases in the gut microbiome of G. brachycerastes. In comparison to multimeric protein engineering, the involvement of naturally occurring multifunctional biocatalysts streamlines the genetic modification procedures and simplifies the overall production processes. Alternatively, these multimeric enzymes could serve as the substitutes for β-glucosidase, β-xylosidase and α-arabinosidase to facilitate a wide range of industrial applications, including food processing, animal feed, environment and waste management, and biomass conversion.
Collapse
Affiliation(s)
- Chunyan Liu
- College of Plant Protection, Hunan Agricultural University, Changsha, 410128, China
| | - Gen Zou
- Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Xing Yan
- Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Xuguo Zhou
- College of Plant Protection, Hunan Agricultural University, Changsha, 410128, China.,Department of Entomology, University of Kentucky, Lexington, KY, 40546-0091, USA
| |
Collapse
|
11
|
Influence of Catalytic Formulation and Operative Conditions on Coke Deposition over CeO2-SiO2 Based Catalysts for Ethanol Reforming. ENERGIES 2017. [DOI: 10.3390/en10071030] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Nikolić S, Lazić V, Veljović Đ, Mojović L. Production of bioethanol from pre-treated cotton fabrics and waste cotton materials. Carbohydr Polym 2017; 164:136-144. [DOI: 10.1016/j.carbpol.2017.01.090] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 12/18/2022]
|
13
|
Li P, Zeng Y, Xie Y, Li X, Kang Y, Wang Y, Xie T, Zhang Y. Effect of pretreatment on the enzymatic hydrolysis of kitchen waste for xanthan production. BIORESOURCE TECHNOLOGY 2017; 223:84-90. [PMID: 27788431 DOI: 10.1016/j.biortech.2016.10.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/10/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
The study was carried out to gain insight into the effect of pretreatment on enzymatic hydrolysis of kitchen waste (KW) for xanthan fermentation. Herein, various pretreatments were applied and it was found that chemical pretreatment had positive effect on the following enzymatic or overall hydrolysis process. The highest reducing sugar concentration was obtained as 51.87g/L from 2% HCl (90°C) pretreated sample, while the Kjeldahl nitrogen (KDN) concentration was 7.79g/L. Kinetic study showed that first order kinetic model was suitable to describe the enzymatic hydrolysis process. The obtained kitchen waste hydrolysate (KWH) was successfully applied for xanthan fermentation. Xanthan concentration reached 4.09-6.46g/L when KWH with 2% HCl (90°C) pretreatment was applied as medium. In comparison, a xanthan concentration of 3.25-5.57g/L was obtained from KWH without pretreatment. Therefore, pretreatment of KW using diluted acid is favorable for the overall hydrolysis process and effective for xanthan fermentation.
Collapse
Affiliation(s)
- Panyu Li
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yu Zeng
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yi Xie
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Xiang Li
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yan Kang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yabo Wang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Tonghui Xie
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Yongkui Zhang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
| |
Collapse
|
14
|
Du SK, Su X, Yang W, Wang Y, Kuang M, Ma L, Fang D, Zhou D. Enzymatic saccharification of high pressure assist-alkali pretreated cotton stalk and structural characterization. Carbohydr Polym 2016; 140:279-86. [DOI: 10.1016/j.carbpol.2015.12.056] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 12/14/2015] [Accepted: 12/23/2015] [Indexed: 12/14/2022]
|
15
|
Ayeni AO, Omoleye JA, Hymore FK, Pandey RA. EFFECTIVE ALKALINE PEROXIDE OXIDATION PRETREATMENT OF SHEA TREE SAWDUST FOR THE PRODUCTION OF BIOFUELS: KINETICS OF DELIGNIFICATION AND ENZYMATIC CONVERSION TO SUGAR AND SUBSEQUENT PRODUCTION OF ETHANOL BY FERMENTATION USING Saccharomyces cerevisiae. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2016. [DOI: 10.1590/0104-6632.20160331s20140258] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- A. O. Ayeni
- National Environmental Engineering Research Institute, India; Covenant University, Nigeria
| | | | | | - R. A. Pandey
- National Environmental Engineering Research Institute, India
| |
Collapse
|
16
|
An Electrochemical Impedance Spectroscopy System for Monitoring Pineapple Waste Saccharification. SENSORS 2016; 16:188. [PMID: 26861317 PMCID: PMC4801565 DOI: 10.3390/s16020188] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/27/2016] [Accepted: 01/31/2016] [Indexed: 11/30/2022]
Abstract
Electrochemical impedance spectroscopy (EIS) has been used for monitoring the enzymatic pineapple waste hydrolysis process. The system employed consists of a device called Advanced Voltammetry, Impedance Spectroscopy & Potentiometry Analyzer (AVISPA) equipped with a specific software application and a stainless steel double needle electrode. EIS measurements were conducted at different saccharification time intervals: 0, 0.75, 1.5, 6, 12 and 24 h. Partial least squares (PLS) were used to model the relationship between the EIS measurements and the sugar determination by HPAEC-PAD. On the other hand, artificial neural networks: (multilayer feed forward architecture with quick propagation training algorithm and logistic-type transfer functions) gave the best results as predictive models for glucose, fructose, sucrose and total sugars. Coefficients of determination (R2) and root mean square errors of prediction (RMSEP) were determined as R2 > 0.944 and RMSEP < 1.782 for PLS and R2 > 0.973 and RMSEP < 0.486 for artificial neural networks (ANNs), respectively. Therefore, a combination of both an EIS-based technique and ANN models is suggested as a promising alternative to the traditional laboratory techniques for monitoring the pineapple waste saccharification step.
Collapse
|
17
|
Waghmare AG, Arya SS. Utilization of unripe banana peel waste as feedstock for ethanol production. ACTA ACUST UNITED AC 2016. [DOI: 10.1515/bioeth-2016-0011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractBanana is second largest produced fruit of total world’s fruits. Cooking banana or plantains processing industry is generating enormous amount of waste in the form of unripe banana peel at one place, thus important to study waste management and utilization. Therefore, unripe banana peel was investigated for ethanol production. This study involved chemical characterization, optimization of acid hydrolysis, selection of yeast strain and optimization of fermentative production of ethanol from dried unripe banana peel powder (DUBPP). Ethanol concentration was determined using gas chromatography flame ionization detector (GC-FID). Characterization of DUBPP revealed notably amount of starch (41% w/w), cellulose (9.3% w/w) and protein (8.4% w/w). 49.2% w/w of reducing sugar was produced by acid hydrolysis of DUBPP at optimized conditions. Three yeast strains of Saccharomyces cerevisiae were screened for ethanol conversion efficiency, osmotolerance, ethanol tolerance, thermotolerance, fermentation ability at high temperature and sedimentation rate. Further, fermentation conditions were optimized for maximum ethanol production from acid hydrolysate of DUBPP. At optimized fermentation conditions, 35.5 g/l ethanol was produced using selected strain of Saccharomyces cerevisiae NCIM 3095. Hence, unripe banana peel waste can be good feedstock for ethanol production.
Collapse
|
18
|
McKee LS, Sunner H, Anasontzis GE, Toriz G, Gatenholm P, Bulone V, Vilaplana F, Olsson L. A GH115 α-glucuronidase from Schizophyllum commune contributes to the synergistic enzymatic deconstruction of softwood glucuronoarabinoxylan. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:2. [PMID: 26734072 PMCID: PMC4700659 DOI: 10.1186/s13068-015-0417-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/15/2015] [Indexed: 05/11/2023]
Abstract
BACKGROUND Lignocellulosic biomass from softwood represents a valuable resource for the production of biofuels and bio-based materials as alternatives to traditional pulp and paper products. Hemicelluloses constitute an extremely heterogeneous fraction of the plant cell wall, as their molecular structures involve multiple monosaccharide components, glycosidic linkages, and decoration patterns. The complete enzymatic hydrolysis of wood hemicelluloses into monosaccharides is therefore a complex biochemical process that requires the activities of multiple degradative enzymes with complementary activities tailored to the structural features of a particular substrate. Glucuronoarabinoxylan (GAX) is a major hemicellulose component in softwood, and its structural complexity requires more enzyme specificities to achieve complete hydrolysis compared to glucuronoxylans from hardwood and arabinoxylans from grasses. RESULTS We report the characterisation of a recombinant α-glucuronidase (Agu115) from Schizophyllum commune capable of removing (4-O-methyl)-glucuronic acid ((Me)GlcA) residues from polymeric and oligomeric xylan. The enzyme is required for the complete deconstruction of spruce glucuronoarabinoxylan (GAX) and acts synergistically with other xylan-degrading enzymes, specifically a xylanase (Xyn10C), an α-l-arabinofuranosidase (AbfA), and a β-xylosidase (XynB). Each enzyme in this mixture showed varying degrees of potentiation by the other activities, likely due to increased physical access to their respective target monosaccharides. The exo-acting Agu115 and AbfA were unable to remove all of their respective target side chain decorations from GAX, but their specific activity was significantly boosted by the addition of the endo-Xyn10C xylanase. We demonstrate that the proposed enzymatic cocktail (Agu115 with AbfA, Xyn10C and XynB) achieved almost complete conversion of GAX to arabinofuranose (Araf), xylopyranose (Xylp), and MeGlcA monosaccharides. Addition of Agu115 to the enzymatic cocktail contributes specifically to 25 % of the conversion. However, traces of residual oligosaccharides resistant to this combination of enzymes were still present after deconstruction, due to steric hindrances to enzyme access to the substrate. CONCLUSIONS Our GH115 α-glucuronidase is capable of finely tailoring the molecular structure of softwood GAX, and contributes to the almost complete saccharification of GAX in synergy with other exo- and endo-xylan-acting enzymes. This has great relevance for the cost-efficient production of biofuels from softwood lignocellulose.
Collapse
Affiliation(s)
- Lauren S. McKee
- />Wallenberg Wood Science Centre, Division of Glycoscience, School of Biotechnology, KTH Royal Institute of Technology, AlbaNova University Centre, 106 91 Stockholm, Sweden
| | - Hampus Sunner
- />Wallenberg Wood Science Centre, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - George E. Anasontzis
- />Wallenberg Wood Science Centre, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Guillermo Toriz
- />Wallenberg Wood Science Centre, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- />Department of Wood, Cellulose and Paper Research, University of Guadalajara, Guadalajara, Mexico
| | - Paul Gatenholm
- />Wallenberg Wood Science Centre, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Vincent Bulone
- />Wallenberg Wood Science Centre, Division of Glycoscience, School of Biotechnology, KTH Royal Institute of Technology, AlbaNova University Centre, 106 91 Stockholm, Sweden
- />ARC Centre of Excellence in Plant Cell Walls and School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, Urrbrae, SA 5064 Australia
| | - Francisco Vilaplana
- />Wallenberg Wood Science Centre, Division of Glycoscience, School of Biotechnology, KTH Royal Institute of Technology, AlbaNova University Centre, 106 91 Stockholm, Sweden
| | - Lisbeth Olsson
- />Wallenberg Wood Science Centre, Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| |
Collapse
|
19
|
Alrumman SA. Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid. Braz J Microbiol 2016; 47:110-9. [PMID: 26887233 PMCID: PMC4822781 DOI: 10.1016/j.bjm.2015.11.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 07/09/2015] [Indexed: 11/18/2022] Open
Abstract
The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50°C, respectively, after 24h of incubation, with a yield of 31.56mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24h by using a two-step hydrolysis. Significant lactic acid production (27.8mg/mL) was obtained by separate saccharification and fermentation after 72h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate.
Collapse
Affiliation(s)
- Sulaiman A Alrumman
- Department of Biology, College of Science, King Khalid University, P.O. Box 3100, Abha 61417, Saudi Arabia.
| |
Collapse
|
20
|
L. Herring J, C. Narayanan V. A Comparative Study on the Utilization of Corn Pericarp and Peanut Hull in the Production of Ethanol and the Impact on Food Economics. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/fns.2016.711098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
21
|
Healey AL, Lee DJ, Furtado A, Simmons BA, Henry RJ. Efficient Eucalypt Cell Wall Deconstruction and Conversion for Sustainable Lignocellulosic Biofuels. Front Bioeng Biotechnol 2015; 3:190. [PMID: 26636077 PMCID: PMC4653827 DOI: 10.3389/fbioe.2015.00190] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/04/2015] [Indexed: 11/13/2022] Open
Abstract
In order to meet the world's growing energy demand and reduce the impact of greenhouse gas emissions resulting from fossil fuel combustion, renewable plant-based feedstocks for biofuel production must be considered. The first-generation biofuels, derived from starches of edible feedstocks, such as corn, create competition between food and fuel resources, both for the crop itself and the land on which it is grown. As such, biofuel synthesized from non-edible plant biomass (lignocellulose) generated on marginal agricultural land will help to alleviate this competition. Eucalypts, the broadly defined taxa encompassing over 900 species of Eucalyptus, Corymbia, and Angophora are the most widely planted hardwood tree in the world, harvested mainly for timber, pulp and paper, and biomaterial products. More recently, due to their exceptional growth rate and amenability to grow under a wide range of environmental conditions, eucalypts are a leading option for the development of a sustainable lignocellulosic biofuels. However, efficient conversion of woody biomass into fermentable monomeric sugars is largely dependent on pretreatment of the cell wall, whose formation and complexity lend itself toward natural recalcitrance against its efficient deconstruction. A greater understanding of this complexity within the context of various pretreatments will allow the design of new and effective deconstruction processes for bioenergy production. In this review, we present the various pretreatment options for eucalypts, including research into understanding structure and formation of the eucalypt cell wall.
Collapse
Affiliation(s)
- Adam L. Healey
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD, Australia
| | - David J. Lee
- Forest Industries Research Centre, University of the Sunshine Coast, Maroochydore, QLD, Australia
- Department of Agriculture and Fisheries, Forestry and Biosciences, Agri-Science Queensland, Gympie, QLD, Australia
| | - Agnelo Furtado
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD, Australia
| | - Blake A. Simmons
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD, Australia
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA
- Biological and Engineering Sciences Center, Sandia National Laboratories, Livermore, CA, USA
| | - Robert J. Henry
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD, Australia
| |
Collapse
|
22
|
Nachaiwieng W, Lumyong S, Yoshioka K, Watanabe T, Khanongnuch C. Bioethanol production from rice husk under elevated temperature simultaneous saccharification and fermentation using Kluyveromyces marxianus CK8. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2015. [DOI: 10.1016/j.bcab.2015.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
23
|
Hydrothermal Pretreatment of Date Palm (Phoenix dactylifera L.) Leaflets and Rachis to Enhance Enzymatic Digestibility and Bioethanol Potential. BIOMED RESEARCH INTERNATIONAL 2015; 2015:216454. [PMID: 26347878 PMCID: PMC4549489 DOI: 10.1155/2015/216454] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/18/2015] [Accepted: 03/28/2015] [Indexed: 11/18/2022]
Abstract
Date palm residues are one of the most promising lignocellulosic biomass for bioethanol production in the Middle East. In this study, leaflets and rachis were subjected to hydrothermal pretreatment to overcome the recalcitrance of the biomass for enzymatic conversion. Evident morphological, structural, and chemical changes were observed by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy after pretreatment. High glucan (>90% for both leaflets and rachis) and xylan (>75% for leaflets and >79% for rachis) recovery were achieved. Under the optimal condition of hydrothermal pretreatment (210°C/10 min) highly digestible (glucan convertibility, 100% to leaflets, 78% to rachis) and fermentable (ethanol yield, 96% to leaflets, 80% to rachis) solid fractions were obtained. Fermentability test of the liquid fractions proved that no considerable inhibitors to Saccharomyces cerevisiae were produced in hydrothermal pretreatment. Given the high sugar recovery, enzymatic digestibility, and ethanol yield, production of bioethanol by hydrothermal pretreatment could be a promising way of valorization of date palm residues in this region.
Collapse
|
24
|
Shi Z, Yang Q, Kuga S, Matsumoto Y. Dissolution of Wood Pulp in Aqueous NaOH/Urea Solution via Dilute Acid Pretreatment. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:6113-6119. [PMID: 26101792 DOI: 10.1021/acs.jafc.5b01714] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Wood pulps with certain amounts of lignin were successfully dissolved in aqueous NaOH/urea solution by subjecting them to the dilute acid pretreatment. After the acid hydrolysis, viscosity-average degree of polymerization (DPv) of the pulps decreased. The results revealed that both the DPv and lignin contents influenced the dissolved proportions of wood pulps. When they were not so high, the wood pulps could almost completely dissolve with dissolved proportions >90%. In particular, the acid-pretreated unbleached kraft pulp with DPv of about 500 and lignin content of 6.9% could dissolve in NaOH/urea solvent and achieve a maximum pulp concentration of 4 wt % in the obtained lignocellulose solution. Moreover, the acid-pretreated bleached thermomechanical pulp with a high lignin content of 14.2% also almost completely dissolved. The lignocellulose films prepared from these wood pulp/NaOH/urea solutions exhibited good transparency and bendability, thus maybe promising as new biobased materials.
Collapse
Affiliation(s)
- Zhuqun Shi
- Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Quanling Yang
- Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shigenori Kuga
- Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuji Matsumoto
- Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| |
Collapse
|
25
|
Narra M, James JP, Balasubramanian V. Simultaneous saccharification and fermentation of delignified lignocellulosic biomass at high solid loadings by a newly isolated thermotolerant Kluyveromyces sp. for ethanol production. BIORESOURCE TECHNOLOGY 2015; 179:331-338. [PMID: 25553563 DOI: 10.1016/j.biortech.2014.11.116] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 11/27/2014] [Accepted: 11/28/2014] [Indexed: 05/09/2023]
Abstract
Simultaneous saccharification and fermentation studies were carried out using thermotolerant newly isolated Kluyveromyces sp. with three different delignified lignocellulosic biomass viz. rice straw, wheat straw and sugarcane bagasse at 5-15% solid loading and 6-12 FPU g(-1) substrate enzyme loading for different time intervals 0-72 h at 42°C. Maximum ethanol achieved from rice straw, wheat straw and sugarcane bagasse with in-house crude cellulases from Aspergillus terreus was 23.23, 18.29 and 17.91 mg mL(-1) at 60 h with 10% solid load and 9 FPU g(-1) substrate enzyme loading. Tween 80 1% (v/v) enhanced the ethanol yield by 8.39%, 9.26% and 8.14% in rice straw, wheat straw and sugarcane bagasse, respectively. External supplementation of β-glucosidase to the crude as well commercial cellulases produced maximum theoretical ethanol yield of 71.76%, 63.77%, 57.15% and 84.56%, 72.47%, 70.55% from rice straw, wheat straw and sugarcane bagasse, respectively.
Collapse
Affiliation(s)
- Madhuri Narra
- Sardar Patel Renewable Energy Research Institute, P. Box No. 2, Vallabh Vidyanagar, 388 120 Gujarat, India.
| | - Jisha P James
- Sardar Patel Renewable Energy Research Institute, P. Box No. 2, Vallabh Vidyanagar, 388 120 Gujarat, India
| | - Velmurugan Balasubramanian
- Sardar Patel Renewable Energy Research Institute, P. Box No. 2, Vallabh Vidyanagar, 388 120 Gujarat, India
| |
Collapse
|
26
|
Khattak WA, Ul-Islam M, Ullah MW, Yu B, Khan S, Park JK. Yeast cell-free enzyme system for bio-ethanol production at elevated temperatures. Process Biochem 2014. [DOI: 10.1016/j.procbio.2013.12.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
27
|
Du SK, Zhu X, Wang H, Zhou D, Yang W, Xu H. High pressure assist-alkali pretreatment of cotton stalk and physiochemical characterization of biomass. BIORESOURCE TECHNOLOGY 2013; 148:494-500. [PMID: 24080288 DOI: 10.1016/j.biortech.2013.09.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 09/01/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
Ground cotton stalks were pretreated with sodium hydroxide (NaOH) at concentrations of 1-4% (w/v), pressures of 30-130 kPa, durations of 15-75 min, and liquid/solid ratios of 10:1-30:1. Modeling of the high pressure assist-alkali pretreatment (HPAP) of cotton stalk was attempted. The levels of NaOH concentration, pressure, and duration were optimized using a Box-Behnken design to enhance the cellulose content of treated solid residue. The optimum pretreatment conditions were as follows: liquid/solid ratio, 20:1; pressure, 130 kPa; NaOH concentration, 3.0%; duration, 40 min. During the conditions, cellulose content of pretreated cotton stalk residue was 64.07%. The maximum cellulose conversion of 45.82% and reducing sugar yield of 0.293 g/g upon hydrolysis were obtained. Significant differences were observed in biomass composition and physiochemical characteristics between native and alkali-treated biomass. High NaOH concentration and pressure were conducive to lignin dissolution and resulted in increased cellulose content and conversion.
Collapse
Affiliation(s)
- Shuang-kui Du
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | | | | | | | | | | |
Collapse
|
28
|
Efficient production of ethanol from empty palm fruit bunch fibers by fed-batch simultaneous saccharification and fermentation using Saccharomyces cerevisiae. Appl Biochem Biotechnol 2013; 170:1807-14. [PMID: 23754558 DOI: 10.1007/s12010-013-0314-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 05/27/2013] [Indexed: 10/26/2022]
Abstract
The concentration of ethanol produced from lignocellulosic biomass should be at least 40 g l(-1) [about 5 % (v/v)] to minimize the cost of distillation process. In this study, the conditions for the simultaneous saccharification and fermentation (SSF) at fed-batch mode for the production of ethanol from alkali-pretreated empty palm fruit bunch fibers (EFB) were investigated. Optimal conditions for the production of ethanol were identified as temperature, 30 °C; enzyme loading, 15 filter paper unit g(-1) biomass; and yeast (Saccharomyces cerevisiae) loading, 5 g l(-1) of dry cell weight. Under these conditions, an economical ethanol concentration was achieved within 17 h, which further increased up to 62.5 g l(-1) after 95 h with 70.6 % of the theoretical yield. To our knowledge, this is the first report to evaluate the economic ethanol production from alkali-pretreated EFB in fed-batch SSF using S. cerevisiae.
Collapse
|
29
|
Cekmecelioglu D, Uncu ON. Kinetic modeling of enzymatic hydrolysis of pretreated kitchen wastes for enhancing bioethanol production. WASTE MANAGEMENT (NEW YORK, N.Y.) 2013; 33:735-739. [PMID: 22959156 DOI: 10.1016/j.wasman.2012.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 07/25/2012] [Accepted: 08/05/2012] [Indexed: 05/27/2023]
Abstract
It is well known that use of low cost and abundant waste materials in microbial fermentations can reduce product costs. Kitchen wastes disposed of in large amounts from cafeterias, restaurants, dining halls, food processing plants, and household kitchens contain high amounts of carbohydrate components such as glucose, starch, and cellulose. Efficient utilization of these sugars is another opportunity to reduce ethanol costs. In this study, the effect of pretreatment methods (hot water, acid solutions, and a control) on enzymatic hydrolysis of kitchen wastes was evaluated using a kinetic modeling approach. Fermentation experiments conducted with and without traditional fermentation nutrients were assessed at constant conditions of pH 4.5 and temperature of 30°C for 48h using commercial dry baker's yeast, Saccharomyces cerevisiae. The control, which involved no treatment, and hot water treated samples gave close glucose concentrations after 6h. The highest and lowest rates of glucose production were found as 0.644 and 0.128 (h(-1)) for the control (or no-pretreated (NPT)) and 1% acid solutions, respectively. The fermentation results indicated that final ethanol concentrations are not significantly improved by adding nutrients (17.2-23.3g/L). Thus, it was concluded that product cost can be lowered to a large extent if (1) kitchen wastes are used as a substrate, (2) no fermentation nutrient is used, and (3) hydrolysis time is applied for about 6h. Further optimization study is needed to increase the yield to higher levels.
Collapse
Affiliation(s)
- Deniz Cekmecelioglu
- Department of Food Engineering, Middle East Technical University, Dumlupinar Blvd., 06800 Ankara, Turkey.
| | | |
Collapse
|
30
|
Statistical optimization, partial purification, and characterization of coffee pulp β-glucosidase and its application in ethanol production. Food Sci Biotechnol 2013. [DOI: 10.1007/s10068-013-0068-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
31
|
Chang JJ, Ho FJ, Ho CY, Wu YC, Hou YH, Huang CC, Shih MC, Li WH. Assembling a cellulase cocktail and a cellodextrin transporter into a yeast host for CBP ethanol production. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:19. [PMID: 23374631 PMCID: PMC3599373 DOI: 10.1186/1754-6834-6-19] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/08/2013] [Indexed: 05/07/2023]
Abstract
BACKGROUND Many microorganisms possess enzymes that can efficiently degrade lignocellulosic materials, but do not have the capability to produce a large amount of ethanol. Thus, attempts have been made to transform such enzymes into fermentative microbes to serve as hosts for ethanol production. However, an efficient host for a consolidated bioprocess (CBP) remains to be found. For this purpose, a synthetic biology technique that can transform multiple genes into a genome is instrumental. Moreover, a strategy to select cellulases that interact synergistically is needed. RESULTS To engineer a yeast for CBP bio-ethanol production, a synthetic biology technique, called "promoter-based gene assembly and simultaneous overexpression" (PGASO), that can simultaneously transform and express multiple genes in a kefir yeast, Kluyveromyces marxianus KY3, was recently developed. To formulate an efficient cellulase cocktail, a filter-paper-activity assay for selecting heterologous cellulolytic enzymes was established in this study and used to select five cellulase genes, including two cellobiohydrolases, two endo-β-1,4-glucanases and one beta-glucosidase genes from different fungi. In addition, a fungal cellodextrin transporter gene was chosen to transport cellodextrin into the cytoplasm. These six genes plus a selection marker gene were one-step assembled into the KY3 genome using PGASO. Our experimental data showed that the recombinant strain KR7 could express the five heterologous cellulase genes and that KR7 could convert crystalline cellulose into ethanol. CONCLUSION Seven heterologous genes, including five cellulases, a cellodextrin transporter and a selection marker, were simultaneously transformed into the KY3 genome to derive a new strain, KR7, which could directly convert cellulose to ethanol. The present study demonstrates the potential of our strategy of combining a cocktail formulation protocol and a synthetic biology technique to develop a designer yeast host.
Collapse
Affiliation(s)
- Jui-Jen Chang
- Biodiversity Research Center, Academia Sinica, 115, Taipei, Taiwan
- Genomics Research Center, Academia Sinica, 115, Taipei, Taiwan
| | - Feng-Ju Ho
- Biodiversity Research Center, Academia Sinica, 115, Taipei, Taiwan
| | - Cheng-Yu Ho
- Department of Life Sciences, National Chung Hsing University, 402, Taichung, Taiwan
| | - Yueh-Chin Wu
- Biodiversity Research Center, Academia Sinica, 115, Taipei, Taiwan
| | - Yu-Han Hou
- Biodiversity Research Center, Academia Sinica, 115, Taipei, Taiwan
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, 402, Taichung, Taiwan
| | - Ming-Che Shih
- Agricultural Biotechnology Research, Center, Academia Sinica, 115, Taipei, Taiwan
| | - Wen-Hsiung Li
- Biodiversity Research Center, Academia Sinica, 115, Taipei, Taiwan
- Genomics Research Center, Academia Sinica, 115, Taipei, Taiwan
- Department of Ecology and Evolution, University of Chicago, 60637, Chicago, IL, USA
| |
Collapse
|
32
|
Rodrigues EC, Bezerra BTC, Farias BV, Adriano WS, Vieira RS, Azevedo DCS, Silva IJ. Adsorption of Cellulase Isolated fromAspergillus Nigeron Chitosan/Alginate Particles Functionalized with Epichlorohydrin. ADSORPT SCI TECHNOL 2013. [DOI: 10.1260/0263-6174.31.1.17] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Elaine C. Rodrigues
- Chemical Engineering Department, Federal University of Ceará, Grupo de Pesquisa em Separações por Adsorção - GPSA, Campus do Pici, Bl. 709, CEP 60455-760, Fortaleza - CE - Brazil
| | - Bruna T. C. Bezerra
- Chemical Engineering Department, Federal University of Ceará, Grupo de Pesquisa em Separações por Adsorção - GPSA, Campus do Pici, Bl. 709, CEP 60455-760, Fortaleza - CE - Brazil
| | - Barbara V. Farias
- Chemical Engineering Department, Federal University of Ceará, Grupo de Pesquisa em Separações por Adsorção - GPSA, Campus do Pici, Bl. 709, CEP 60455-760, Fortaleza - CE - Brazil
| | - Wellington S. Adriano
- Laboratory of Pharmaceutical Science - CES/UAS, Campina Grande Federal University, 58175-000, Cuite - PB - Brazil
| | - Rodrigo S. Vieira
- Chemical Engineering Department, Federal University of Ceará, Grupo de Pesquisa em Separações por Adsorção - GPSA, Campus do Pici, Bl. 709, CEP 60455-760, Fortaleza - CE - Brazil
| | - Diana C. S. Azevedo
- Chemical Engineering Department, Federal University of Ceará, Grupo de Pesquisa em Separações por Adsorção - GPSA, Campus do Pici, Bl. 709, CEP 60455-760, Fortaleza - CE - Brazil
| | - Ivanildo J. Silva
- Chemical Engineering Department, Federal University of Ceará, Grupo de Pesquisa em Separações por Adsorção - GPSA, Campus do Pici, Bl. 709, CEP 60455-760, Fortaleza - CE - Brazil
| |
Collapse
|
33
|
Prévot V, Lopez M, Copinet E, Duchiron F. Comparative performance of commercial and laboratory enzymatic complexes from submerged or solid-state fermentation in lignocellulosic biomass hydrolysis. BIORESOURCE TECHNOLOGY 2013; 129:690-693. [PMID: 23352484 DOI: 10.1016/j.biortech.2012.11.135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 11/27/2012] [Accepted: 11/30/2012] [Indexed: 06/01/2023]
Abstract
The aim of this study was to compare the hydrolysis performances of four lignocellulolytic complexes from commercial or laboratory origin and produced either by solid-state fermentation or by submerged fermentation. To evaluate their potential, saccharification tests were performed on cellulose, as model substrate, and wheat bran, as lignocellulosic substrate, using either the same filter paper unit or the same amount of protein to introduce these enzymatic complexes. A great difference was observed for the laboratory enzymatic complex produced by solid-state fermentation, which has shown a greater efficiency of cellobiohydrolase on cellulose and better conversion capacity on wheat bran, probably due to the presence of side activities. This comparison has proved that solid-state fermentation could be a promising technology to overcome the biomass recalcitrance and lower the cost of conversion step.
Collapse
Affiliation(s)
- Vincent Prévot
- Université de Reims Champagne-Ardenne, UMR614 Fractionnement des AgroRessources et Environnement, B.P. 1039, F-51687 Reims cedex 2, France
| | | | | | | |
Collapse
|
34
|
Suhardi VSH, Prasai B, Samaha D, Boopathy R. Combined biological and chemical pretreatment method for lignocellulosic ethanol production from energy cane. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2052-6237-1-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
35
|
Awan AT, Tsukamoto J, Tasic L. Orange waste as a biomass for 2G-ethanol production using low cost enzymes and co-culture fermentation. RSC Adv 2013. [DOI: 10.1039/c3ra43722a] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
36
|
Khattak WA, Ul-Islam M, Park JK. Prospects of reusable endogenous hydrolyzing enzymes in bioethanol production by simultaneous saccharification and fermentation. KOREAN J CHEM ENG 2012. [DOI: 10.1007/s11814-012-0174-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
37
|
Ghorbanpour Khamseh AA, Miccio M. Comparison of batch, fed-batch and continuous well-mixed reactors for enzymatic hydrolysis of orange peel wastes. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
38
|
Combination of wet disk milling and hydrogen peroxide treatments for enhancing saccharification of sugarcane bagasse. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2012.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
39
|
Han L, Feng J, Zhang S, Ma Z, Wang Y, Zhang X. Alkali pretreated of wheat straw and its enzymatic hydrolysis. Braz J Microbiol 2012; 43:53-61. [PMID: 24031803 PMCID: PMC3768998 DOI: 10.1590/s1517-83822012000100006] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 06/29/2011] [Accepted: 01/16/2012] [Indexed: 11/22/2022] Open
Abstract
The efficiency of enzymatic hydrolysis of cellulose can be improved by various pretreatments of the substrate. In order to increase the efficiency of enzymatic saccharification of the wheat straw, we determined the effect of different pretreatments on the physical structure, chemical components and enzymatic saccharification of wheat straw. Our results showed that combination of grinding and sodium hydroxide (NaOH) treatment had high effect on the enzymatic hydrolysis of wheat straws. The optimal pretreatment condition was to grind the wheat straws into the sizes of 120 meshes followed by treatment with 1.0% NaOH for 1.5 h (121°C/15psi). Under this condition, the cellulose content of wheat straw was increased by 44.52%, while the content of hemicellulose and lignin was decreased by 44.15% and 42.52%, respectively. Scanning Electronic Microscopy and infrared spectrum analyses showed that significant changes occurred in the structure of wheat straws after pretreatment, which is favorable for the hydrolysis and saccharification. Cellulase produced by Penicillium waksmanii F10–2 was used to hydrolyze the pretreated wheat straw and the optimal condition was determined to be 30 h of enzymatic reaction under the temperature of 55°C, pH 5.5 and substrate concentration of 3%.
Collapse
Affiliation(s)
- Lirong Han
- R&D Center of Biorational Pesticides, Northwest A & F University , 22 Xinong Road, Yangling, Shaanxi 712100 , China
| | | | | | | | | | | |
Collapse
|
40
|
Ma MG, Jia N, Zhu JF, Li SM, Peng F, Sun RC. Isolation and characterization of hemicelluloses extracted by hydrothermal pretreatment. BIORESOURCE TECHNOLOGY 2012; 114:677-83. [PMID: 22487132 DOI: 10.1016/j.biortech.2012.03.048] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 03/14/2012] [Accepted: 03/16/2012] [Indexed: 05/08/2023]
Abstract
The dewaxed sample from Triploid of Populus tomentosa Carr. was extracted by using organic alkaline solvent (Dimethylformamide, DMF) via hydrothermal pretreatment. Neutral sugar compositions and molecular weight analysis demonstrated that the hemicellulosic fractions with a higher Uro/Xyl ratio, namely the more branched hemicelluloses, had higher molecular weights. Interestingly, these results were different from the previous report, in which the ratio of Uro/Xyl in the water-soluble hemicellulosic fraction was more than that of the alkali-soluble hemicellulosic fraction. Spectroscopy (FTIR, (1)H NMR, (13)C NMR, and HSQC) analysis indicated that the hemicellulosic fractions were mainly composed of (1→4)-linked α-D-glucan from starch and (1→4)-linked β-D-xylan attached with minor amounts of branched sugars from hemicelluloses. In addition, thermal analysis implied that linear hemicelluloses showed more thermal stability than the branched ones during pyrolysis.
Collapse
Affiliation(s)
- Ming-Guo Ma
- Institute of Biomass Chemistry and Technology, College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, PR China.
| | | | | | | | | | | |
Collapse
|
41
|
Mukhtar H, Ikram-Ul-Haq. Concomitant production of two proteases and alpha-amylase by a novel strain of Bacillus subtilis in a microprocessor controlled bioreactor. Braz J Microbiol 2012; 43:1072-9. [PMID: 24031930 PMCID: PMC3768893 DOI: 10.1590/s1517-838220120003000033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 09/30/2011] [Accepted: 06/07/2012] [Indexed: 11/30/2022] Open
Abstract
We describe the simultaneous production of Bacillus subtilis based proteases and alpha amylase using a computer controlled laboratory scale 7.5 L batch bioreactor. The present strain is the first to be reported that concomitantly produces these two industrially important enzymes. The growth and sporulation of Bacillus subtilis was monitored and maximum production of alkaline protease and alpha amylase was found to coincide with maximum sporulation. Two types of proteases were detected in the fermentation broth; a neutral and an alkaline protease most active in a pH range of 7.0–8.0 and 8.0–10, respectively. Maximum production of proteases was observed at an incubation temperature of 37°C while that of alpha amylase was observed at 40°C. The optimum aeration and agitation levels for protease production were 0.6 L/L/min and 200rpm, respectively, and for alpha amylase were 0.6 L/L/min and 150 rpm. The kinetic parameters Yp/x and qp were also found to be significant at the given fermentation conditions.
Collapse
Affiliation(s)
- Hamid Mukhtar
- Institute of Industrial Biotechnology, Government College University , Lahore, 54000 , Pakistan
| | | |
Collapse
|
42
|
Vani S, Binod P, Kuttiraja M, Sindhu R, Sandhya SV, Preeti VE, Sukumaran RK, Pandey A. Energy requirement for alkali assisted microwave and high pressure reactor pretreatments of cotton plant residue and its hydrolysis for fermentable sugar production for biofuel application. BIORESOURCE TECHNOLOGY 2012; 112:300-307. [PMID: 22420987 DOI: 10.1016/j.biortech.2012.02.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/15/2012] [Accepted: 02/17/2012] [Indexed: 05/31/2023]
Abstract
In the present work, alkali assisted microwave pretreatment (AAMP) of cotton plant residue (CPR) with high pressure reactor pretreatment was compared. Further, modeling of AAMP was attempted. AAMP, followed by enzymatic saccharification was evaluated and the critical parameters were identified to be exposure time, particle size and enzyme loading. The levels of these parameters were optimized using response surface methodology (RSM) to enhance sugar yield. AAMP of CPR (1mm average size) for 6 min at 300 W yielded solid fractions that on hydrolysis resulted in maximum reducing sugar yield of 0.495 g/g. The energy required for AAMP at 300 W for 6 min was 108 kJ whereas high pressure pretreatment (180°C, 100 rpm for 45 min) requires 5 times more energy i.e., 540 kJ. Physiochemical characterization of native and pretreated feedstock revealed differences between high pressure pretreatment and AAMP.
Collapse
Affiliation(s)
- Sankar Vani
- Centre for Biofuels, National Institute for Interdisciplinary Science and Technology, CSIR Trivandrum 695019, India
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Karagöz P, Rocha IV, Özkan M, Angelidaki I. Alkaline peroxide pretreatment of rapeseed straw for enhancing bioethanol production by Same Vessel Saccharification and Co-Fermentation. BIORESOURCE TECHNOLOGY 2012; 104:349-57. [PMID: 22104093 DOI: 10.1016/j.biortech.2011.10.075] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 09/12/2011] [Accepted: 10/21/2011] [Indexed: 05/09/2023]
Abstract
Alkaline peroxide pretreatment of rapeseed straw was evaluated for conversion of cellulose and hemicellulose to fermentable sugars. After pretreatment, a liquid phase called pretreatment liquid and a solid phase were separated by filtration. The neutralized pretreatment liquids were used in a co-fermentation process, with Saccharomyces cerevisiae and Pichia stipitis. The solid fraction was used for simultaneous saccharification and co-fermentation process in the same vessel. The effects of various operating variables were investigated. Pretreatment with 5% (v/v) H(2)O(2) at 50 °C for 1h was found to be the optimal pretreatment combination with respect to overall ethanol production. At this condition, 5.73 g ethanol was obtained from pretreatment liquid and 14.07 g ethanol was produced by co-fermentation of solid fraction with P. stipitis. Optimum delignification was observed when 0.5 M MgSO(4) was included in the pretreatment mixture, and it resulted in 0.92% increase in ethanol production efficiency.
Collapse
Affiliation(s)
- Pinar Karagöz
- Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, 2800 Kongens Lyngby, Denmark
| | | | | | | |
Collapse
|
44
|
Uncu ON, Cekmecelioglu D. Cost-effective approach to ethanol production and optimization by response surface methodology. WASTE MANAGEMENT (NEW YORK, N.Y.) 2011; 31:636-43. [PMID: 21220196 DOI: 10.1016/j.wasman.2010.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 12/13/2010] [Accepted: 12/14/2010] [Indexed: 05/23/2023]
Abstract
Food wastes disposed from residential and industrial kitchens have gained attention as a substrate in microbial fermentations to reduce product costs. In this study, the potential of simultaneously hydrolyzing and subsequently fermenting the mixed carbohydrate components of kitchen wastes were assessed and the effects of solid load, inoculum volume of baker's yeast, and fermentation time on ethanol production were evaluated by response surface methodology (RSM). The enzymatic hydrolysis process was complete within 6h. Fermentation experiments were conducted at pH 4.5, a temperature of 30°C, and agitated at 150 rpm without adding the traditional fermentation nutrients. The statistical analysis of the model developed by RSM suggested that linear effects of solid load, inoculum volume, and fermentation time and the quadratic effects of inoculum volume and fermentation time were significant (P<0.05). The verification experiments indicated that the developed model could be successfully used to predict ethanol concentration at >90% accuracy. An optimum ethanol concentration of 32.2g/l giving a yield of 0.40g/g, comparable to yields reported to date, was suggested by the model with 20% solid load, 8.9% inoculum volume, and 58.8h of fermentation. The results indicated that the production costs can be lowered to a large extent by using kitchen wastes having multiple carbohydrate components and eliminating the use of traditional fermentation nutrients from the recipe.
Collapse
Affiliation(s)
- Oya Nihan Uncu
- Department of Food Engineering, Middle East Technical University, METU, Inonu Blvd, 06531 Ankara, Turkey
| | | |
Collapse
|
45
|
Peng P, Peng F, Bian J, Xu F, Sun R. Studies on the starch and hemicelluloses fractionated by graded ethanol precipitation from bamboo Phyllostachys bambusoides f. shouzhu Yi. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:2680-8. [PMID: 21341802 DOI: 10.1021/jf1045766] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Starch from bamboo Phyllostachys bambusoides f. shouzhu Yi evaluated by means of solid-state 13C CP/MAS NMR and X-ray diffraction showed a typical B-type pattern with a very low degree of crystallinity (10.9%). In addition to starch, alkali-soluble hemicelluloses were further fractionated by graded precipitation at ethanol concentrations of 0 (HA), 15, 30, 45, 60, and 75% (v/v). Chemical composition and structural features of the six hemicellulosic subfractions were investigated by a combination of sugar analysis, GPC, FT-IR, GC-MS, 1D (1H and 13C) and 2D (HSQC) NMR spectra, and thermal analysis. The results showed that the bamboo hemicelluloses were O-acetylated 4-O-methyl-glucuronoarabinoxylans (GAX) consisting of a linear (1→4)-β-D-xylopyranosyl backbone decorated with branches at O-3 of α-L-arabinofuranosyl (5-12 mol%) or at O-2 of 4-O-methylglucuronic acid units and acetyl groups (0.8-11 mol%). The molecular weights of these polysaccharides ranged between 13400 and 67500 g/mol, and the molar ratios of A/X and G/X increased with ascending ethanol concentrations. Moreover, xylo-oligosaccharides (XOS) with DP 1-6 were produced by enzymatic hydrolysis of hemicelluloses and the total yields of XOS were range of 21.5 to 40.6%. The structure-property relationships were also established in order to improve enzyme accessibility.
Collapse
Affiliation(s)
- Pai Peng
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China
| | | | | | | | | |
Collapse
|
46
|
Ferreira S, Gil N, Queiroz JA, Duarte AP, Domingues FC. Bioethanol from the Portuguese forest residue Pterospartum tridentatum--an evaluation of pretreatment strategy for enzymatic saccharification and sugars fermentation. BIORESOURCE TECHNOLOGY 2010; 101:7797-7803. [PMID: 20965126 DOI: 10.1016/j.biortech.2010.05.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 05/10/2010] [Accepted: 05/17/2010] [Indexed: 05/30/2023]
Abstract
Under the current energy scenario, the development of alternatives to fossil fuels, like bioethanol from lignocellulosic materials, is highly relevant. Therefore it is important to search and study new raw materials and to optimize the different steps that lead to bioethanol production. In this work, acid diluted pretreatment was optimized considering the release of sugars. Under the optimal conditions, the reducing sugars yield was of 293.4mg/g of dry biomass in liquid fraction. The tested pretreated samples of Pterospartum tridentatum that presented a higher glucose yield in enzymatic saccharification where those that were subject to a pretreatment at 180°C for 75min with 2.75% (w/w) of sulfuric acid when using a biomass/liquid ratio of 2.25g/10mL leading to a maximum yield of glucose that was 92% of the theoretical maximum. From the fermentation of filtrates it was possible to obtain a maximum ethanol yield of 0.26g ethanol/g total sugars, without previous detoxification.
Collapse
Affiliation(s)
- S Ferreira
- Research Unit of Textile and Paper Materials, University of Beira Interior, Av. Marquês D' Ávila e Bolama, 6201-001 Covilhã, Portugal
| | | | | | | | | |
Collapse
|
47
|
Fuentes LLG, Rabelo SC, Filho RM, Costa AC. Kinetics of Lime Pretreatment of Sugarcane Bagasse to Enhance Enzymatic Hydrolysis. Appl Biochem Biotechnol 2010; 163:612-25. [DOI: 10.1007/s12010-010-9067-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 08/12/2010] [Indexed: 10/19/2022]
|
48
|
Oberoi HS, Vadlani PV, Madl RL, Saida L, Abeykoon JP. Ethanol production from orange peels: two-stage hydrolysis and fermentation studies using optimized parameters through experimental design. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:3422-3429. [PMID: 20158208 DOI: 10.1021/jf903163t] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Orange peels were evaluated as a fermentation feedstock, and process conditions for enhanced ethanol production were determined. Primary hydrolysis of orange peel powder (OPP) was carried out at acid concentrations from 0 to 1.0% (w/v) at 121 degrees C and 15 psi for 15 min. High-performance liquid chromatography analysis of sugars and inhibitory compounds showed a higher production of hydroxymethyfurfural and acetic acid and a decrease in sugar concentration when the acid level was beyond 0.5% (w/v). Secondary hydrolysis of pretreated biomass obtained from primary hydrolysis was carried out at 0.5% (w/v) acid. Response surface methodology using three factors and a two-level central composite design was employed to optimize the effect of pH, temperature, and fermentation time on ethanol production from OPP hydrolysate at the shake flask level. On the basis of results obtained from the optimization experiment and numerical optimization software, a validation study was carried out in a 2 L batch fermenter at pH 5.4 and a temperature of 34 degrees C for 15 h. The hydrolysate obtained from primary and secondary hydrolysis processes was fermented separately employing parameters optimized through RSM. Ethanol yields of 0.25 g/g on a biomass basis (YP/X) and 0.46 g/g on a substrate-consumed basis (YP/S) and a promising volumetric ethanol productivity of 3.37 g/L/h were attained using this process at the fermenter level, which shows promise for further scale-up studies.
Collapse
Affiliation(s)
- Harinder Singh Oberoi
- Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas 66506, USA
| | | | | | | | | |
Collapse
|
49
|
Tu M, Zhang X, Paice M, MacFarlane P, Saddler JN. The potential of enzyme recycling during the hydrolysis of a mixed softwood feedstock. BIORESOURCE TECHNOLOGY 2009; 100:6407-6415. [PMID: 19632826 DOI: 10.1016/j.biortech.2009.06.108] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 03/19/2009] [Accepted: 06/27/2009] [Indexed: 05/28/2023]
Abstract
Despite recent improvement in cellulase enzymes properties, the high cost associated with the hydrolysis step remains a major impediment to the commercialization of full-scale lignocellulose-to-ethanol bioconversion process. As part of a research effort to develop a commercial process for bioconversion of softwood residues, we have examined the potential for recycling enzymes during the hydrolysis of mixed softwood substrate pretreated by organosolv process. We have used response surface methodology to determine the optimal temperature, pH, ionic strength, and surfactant (Tween 80) concentration for maximizing the recovery of bound protein and enzyme activity from the residual substrates after hydrolysis. Data analysis showed that the temperature, pH and surfactant concentration were the major factors governing enzyme desorption from residual substrate. The optimized conditions were temperature 44.4 degrees C, pH 5.3 and 0.5% Tween 80. The optimal conditions significantly increased the hydrolysis yield by 25% after three rounds of hydrolysis. This bound enzyme desorption combining with free enzyme re-adsorption is a potential method to recover cellulase enzymes and reduce the cost of enzymatic hydrolysis.
Collapse
Affiliation(s)
- Maobing Tu
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849-5418, USA.
| | | | | | | | | |
Collapse
|
50
|
Jeya M, Zhang YW, Kim IW, Lee JK. Enhanced saccharification of alkali-treated rice straw by cellulase from Trametes hirsuta and statistical optimization of hydrolysis conditions by RSM. BIORESOURCE TECHNOLOGY 2009; 100:5155-61. [PMID: 19540109 DOI: 10.1016/j.biortech.2009.05.040] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 05/17/2009] [Accepted: 05/20/2009] [Indexed: 05/24/2023]
Abstract
A white rot fungus, identified as Trametes hirsuta based on morphological and phylogenetic analysis, was found to contain efficient cellulose degrading enzymes. The strain showed maximum endoglucanase (EG), cellobiohydrolase (CBH) and beta-glucosidase (BGL) activities of 55, 0.28 and 5.0 U/mg-protein, respectively. Rice straw was found to be a potentially good substrate for growth of T. hirsuta for cellulase production. Statistical experimental design was used to optimize hydrolysis parameters such as pH, temperature, and concentrations of substrates and enzymes to achieve the highest saccharification yield. Enzyme concentration was identified as the limiting factor for saccharification of rice straw. A maximum saccharification rate of 88% was obtained at an enzyme concentration of 37.5 FPU/g-substrate after optimization of the hydrolysis parameters. The results of a confirmation experiment under the optimum conditions agreed well with model predictions. T. hirsuta may be a good choice for the production of reducing sugars from cellulosic biomass.
Collapse
Affiliation(s)
- Marimuthu Jeya
- Department of Chemical Engineering, Konkuk University, Seoul 143-701, Republic of Korea
| | | | | | | |
Collapse
|