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Kumar N, Yadav A, Singh G, Singh A, Kumar P, Aggarwal NK. Comparative study of ethanol production from sodium hydroxide pretreated rice straw residue using Saccharomyces cerevisiae and Zymomonas mobilis. Arch Microbiol 2023; 205:146. [PMID: 36971832 DOI: 10.1007/s00203-023-03468-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/23/2023] [Accepted: 03/04/2023] [Indexed: 03/29/2023]
Abstract
Rice straw is a suitable alternative to a cheaper carbohydrate source for the production of ethanol. For pretreatment efficiency, different sodium hydroxide concentrations (0.5-2.5% w/v) were tested. When compared to other concentrations, rice straw processed with 2% NaOH (w/v) yielded more sugar (8.17 ± 0.01 mg/ml). An alkali treatment induces effective delignification and swelling of biomass. The pretreatment of rice straw with 2% sodium hydroxide (w/v) is able to achieve 55.34% delignification with 53.30% cellulose enrichment. The current study shows the effectiveness of crude cellulolytic preparation from Aspergillus niger resulting in 80.51 ± 0.4% cellulose hydrolysis. Rice straw hydrolysate was fermented using ethanologenic Saccharomyces cerevisiae (yeast) and Zymomonas mobilis (bacteria). Overall, superior efficiency of sugar conversion to ethanol 70.34 ± 0.3% was obtained with the yeast compared to bacterial strain 39.18 ± 0.5%. The current study showed that pretreatment with sodium hydroxide is an effective method for producing ethanol from rice straw and yeast strain S. cerevisiae having greater fermentative potential for bioethanol production than bacterial strain Z. mobilis.
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Affiliation(s)
- Naveen Kumar
- Laboratory of Fermentation Technology, Department of Microbiology, Kurukshetra University, Kurukshetra, Haryana, 136119, India
| | - Anita Yadav
- Department of Biotechnology, Kurukshetra University, Kurukshetra, Haryana, 136119, India
| | - Gulab Singh
- Department of Biotechnology, Maharaja Agrasen University, Baddi, Himachal Pradesh, 174103, India
| | - Ajay Singh
- Department of Food Technology, Mata Gujri College, Fatehgarh Sahib, Punjab, 140406, India
| | - Pankaj Kumar
- Department of Microbiology, Dolphin (PG) Institute of Biomedical and Natural Sciences, Dehradun, Uttarakhand, 248007, India.
| | - Neeraj K Aggarwal
- Laboratory of Fermentation Technology, Department of Microbiology, Kurukshetra University, Kurukshetra, Haryana, 136119, India.
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2
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Sun C, Meng X, Sun F, Zhang J, Tu M, Chang JS, Reungsang A, Xia A, Ragauskas AJ. Advances and perspectives on mass transfer and enzymatic hydrolysis in the enzyme-mediated lignocellulosic biorefinery: A review. Biotechnol Adv 2023; 62:108059. [PMID: 36402253 DOI: 10.1016/j.biotechadv.2022.108059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/04/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
Abstract
Enzymatic hydrolysis is a critical process for the cellulase-mediated lignocellulosic biorefinery to produce sugar syrups that can be converted into a whole range of biofuels and biochemicals. Such a process operating at high-solid loadings (i.e., scarcely any free water or roughly ≥ 15% solids, w/w) is considered more economically feasible, as it can generate a high sugar concentration at low operation and capital costs. However, this approach remains restricted and incurs "high-solid effects", ultimately causing the lower hydrolysis yields with increasing solid loadings. The lack of available water leads to a highly viscous system with impaired mixing that exhibits strong transfer resistance and reaction limitation imposed on enzyme action. Evidently, high-solid enzymatic hydrolysis involves multi-scale mass transfer and multi-phase enzyme reaction, and thus requires a synergistic perspective of transfer and biotransformation to assess the interactions among water, biomass components, and cellulase enzymes. Porous particle characteristics of biomass and its interface properties determine the water form and distribution state surrounding the particles, which are summarized in this review aiming to identify the water-driven multi-scale/multi-phase bioprocesses. Further aided by the cognition of rheological behavior of biomass slurry, solute transfer theories, and enzyme kinetics, the coupling effects of flow-transfer-reaction are revealed under high-solid conditions. Based on the above basic features, this review lucidly explains the causes of high-solid hydrolysis hindrances, highlights the mismatched issues between transfer and reaction, and more importantly, presents the advanced strategies for transfer and reaction enhancements from the viewpoint of process optimization, reactor design, as well as enzyme/auxiliary additive customization.
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Affiliation(s)
- Chihe Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xianzhi Meng
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Junhua Zhang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China
| | - Maobing Tu
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan
| | - Alissara Reungsang
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China
| | - Arthur J Ragauskas
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, The University of Tennessee, Knoxville, TN 37996, USA; Joint Institute of Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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3
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Condor BE, de Luna MDG, Chang YH, Chen JH, Leong YK, Chen PT, Chen CY, Lee DJ, Chang JS. Bioethanol production from microalgae biomass at high-solids loadings. BIORESOURCE TECHNOLOGY 2022; 363:128002. [PMID: 36155816 DOI: 10.1016/j.biortech.2022.128002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/14/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Industrial adoption of microalgae biofuel technology has always been hindered by its economic viability. To increase the feasibility of bioethanol production from microalgae, fermentation was applied to Chlorella vulgaris FSP-E biomass at high-solids loading conditions. First, Chlorella vulgaris FSP-E was cultivated to produce microalgae biomass with high carbohydrate content. Next, different ethanol-producing microorganisms were screened. Saccharomyces cerevisiae FAY-1 showed no inhibition when fermenting high initial glucose concentrations and was selected for the fermentation experiments at high-solids loadings. Optimization of acid hydrolysis at high biomass loading was also performed. The fermentation of microalgal biomass hydrolysate produced a final ethanol concentration and yield higher than most reported literature using microalgae feedstock. In addition, the kinetics of bioethanol fermentation of microalgae hydrolysate under high-solids loading were evaluated. These results showed the potential of fermenting microalgae biomass at high-solids loading in improving the viability of microalgae bioethanol production.
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Affiliation(s)
- Billriz E Condor
- Energy Engineering Program, National Graduate School of Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Mark Daniel G de Luna
- Energy Engineering Program, National Graduate School of Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines; Department of Chemical Engineering, College of Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Yu-Han Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Jih-Heng Chen
- Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, Taiwan
| | - Yoong Kit Leong
- Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan
| | - Po-Ting Chen
- Department of Biotechnology and Food Technology, Southern Taiwan University of Science and Technology, Tainan 71005, Taiwan
| | - Chun-Yen Chen
- University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tang, Hong Kong
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, Taiwan; Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 32003, Taiwan.
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4
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Coprocessing Corn Germ Meal for Oil Recovery and Ethanol Production: A Process Model for Lipid-Producing Energy Crops. Processes (Basel) 2022. [DOI: 10.3390/pr10040661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Efforts to engineer high-productivity crops to accumulate oils in their vegetative tissue present the possibility of expanding biodiesel production. However, processing the new crops for lipid recovery and ethanol production from cell wall saccharides is challenging and expensive. In a previous study using corn germ meal as a model substrate, we reported that liquid hot water (LHW) pretreatment enriched the lipid concentration by 2.2 to 4.2 fold. This study investigated combining oil recovery with ethanol production by extracting oil following LHW and simultaneous saccharification and co-fermentation (SSCF) of the biomass. Corn germ meal was again used to model the oil-bearing energy crops. Pretreated germ meal hydrolysate or solids (160 and 180 °C for 10 min) were fermented, and lipids were extracted from both the spent fermentation whole broth and fermentation solids, which were recovered by centrifugation and convective drying. Lipid contents in spent fermentation solids increased 3.7 to 5.7 fold compared to the beginning germ meal. The highest lipid yield achieved after fermentation was 36.0 mg lipid g−1 raw biomass; the maximum relative amount of triacylglycerol (TAG) was 50.9% of extracted oil. Although the fermentation step increased the lipid concentration of the recovered solids, it did not improve the lipid yields of pretreated biomass and detrimentally affected oil compositions by increasing the relative concentrations of free fatty acids.
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Tareen A, Punsuvon V, Sultan IN, Khan MW, Parakulsuksatid P. Cellulase Addition and Pre-hydrolysis Effect of High Solid Fed-Batch Simultaneous Saccharification and Ethanol Fermentation from a Combined Pretreated Oil Palm Trunk. ACS OMEGA 2021; 6:26119-26129. [PMID: 34660972 PMCID: PMC8515579 DOI: 10.1021/acsomega.1c03111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
In the current study, alkaline hydrogen peroxide pretreated oil palm trunk fibers were subjected to ethanol production via simultaneous saccharification and fermentation (SSF). The effect of high substrate loading, enzyme and substrate feeding strategy, and influence of a pre-hydrolysis step in SSF was studied to scale up ethanol production. In the enzyme feeding strategy, the addition of an enzyme at the start of fed-batch SSF significantly (p < 0.05) increased ethanol concentration to 51.05 g/L, ethanol productivity (QP ) to 0.61 g/L·h, and ethanol yield (Y P/S) to 0.31 g/g, with a theoretical ethanol yield of 60.65%. Furthermore, the initial velocity of the enzyme (V 0) in the first 8 h was 2.27 (g/h) with a glucose concentration of 18.17 g/L. On the other hand, the substrate feeding strategy and pre-hydrolysis simultaneous saccharification and fermentation (PSSF) process were studied in a 1 L fermenter. PSSF in fed batch with 10 and 20% (w/v) significantly improved enzyme hydrolysis, circumvent the problems of high viscosity, reduced overall fermentation time, and gave the highest ethanol concentration of 51.66 g/L, ethanol productivity (QP ) of 0.72 g/L·h, ethanol yield (Y P/S) of 0.31 g/g, and theoretical ethanol yield of 60.66%. In addition, PSSF with 10 and 20% significantly increased the initial velocity of the enzyme (V 0) to 4.64 and 4.40 (g/h) and glucose concentration to 37.14 and 35.27 g/L, respectively. This result indicated that ethanol production by PSSF along with substrate feeding could enhance ethanol production efficiently.
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Affiliation(s)
- Afrasiab
Khan Tareen
- Department
of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Rd, Ladyao, Chatuchak, Bangkok 10900, Thailand
| | - Vittaya Punsuvon
- Department
of Chemistry, Faculty of Science, Kasetsart
University, 50 Ngam Wong Wan Rd, Ladyao, Chatuchak, Bangkok 10900, Thailand
| | - Imrana Niaz Sultan
- Department
of Biotechnology, Faculty of Life Sciences and Informatics, BUITEMS, Quetta 87300, Pakistan
| | - Muhammad Waseem Khan
- Department
of Biotechnology, Faculty of Life Sciences and Informatics, BUITEMS, Quetta 87300, Pakistan
| | - Pramuk Parakulsuksatid
- Department
of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Rd, Ladyao, Chatuchak, Bangkok 10900, Thailand
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6
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Vancov T, Palmer J, Keen B. Pilot scale demonstration of a two-stage pretreatment and bioethanol fermentation process for cotton gin trash. BIORESOURCE TECHNOLOGY 2021; 335:125224. [PMID: 33984554 DOI: 10.1016/j.biortech.2021.125224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 06/12/2023]
Abstract
A two-stage dilute acid and steam explosion (SE) pretreatment process was developed and evaluated at pilot scale for ethanol production from cotton gin trash (CGT). Optimal conditions for CGT processing were defined as 1:6 solids to liquids ratio with 9% H2SO4 wt. on solids at 180 °C for 15 min. during stage 1 with ensuing pressed fibres successively exposed to SE at 200 °C for 5 min during stage 2. SE fibres were highly acquiescent to enzyme hydrolysis (76%) in the presence of PEG 6000, yielding 381 g glucose kg-1 fibre. Simultaneous saccharification and fermentation (SSF) trials validated the selected process option and additional fed-batch SSFs confirmed titres above the minimum 4% ww-1 benchmark for economically viable distillation. The practicality of converting CGT to ethanol was demonstrated at pilot scale with titres above 4% ww-1 and a conversion efficiency of 60% t-1 dry GCT.
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Affiliation(s)
- T Vancov
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, NSW, Australia.
| | - J Palmer
- NSW Department of Primary Industries, Wollongbar Primary Industries Institute, NSW, Australia
| | - B Keen
- NSW Department of Primary Industries, Wollongbar Primary Industries Institute, NSW, Australia
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7
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Wang R, Lorantfy B, Fusco S, Olsson L, Franzén CJ. Analysis of methods for quantifying yeast cell concentration in complex lignocellulosic fermentation processes. Sci Rep 2021; 11:11293. [PMID: 34050249 PMCID: PMC8163860 DOI: 10.1038/s41598-021-90703-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/10/2021] [Indexed: 11/09/2022] Open
Abstract
Cell mass and viability are tightly linked to the productivity of fermentation processes. In 2nd generation lignocellulose-based media quantitative measurement of cell concentration is challenging because of particles, auto-fluorescence, and intrinsic colour and turbidity of the media. We systematically evaluated several methods for quantifying total and viable yeast cell concentrations to validate their use in lignocellulosic media. Several automated cell counting systems and stain-based viability tests had very limited applicability in such samples. In contrast, manual cell enumeration in a hemocytometer, plating and enumeration of colony forming units, qPCR, and in situ dielectric spectroscopy were further investigated. Parameter optimization to measurements in synthetic lignocellulosic media, which mimicked typical lignocellulosic fermentation conditions, resulted in statistically significant calibration models with good predictive capacity for these four methods. Manual enumeration of cells in a hemocytometer and of CFU were further validated for quantitative assessment of cell numbers in simultaneous saccharification and fermentation experiments on steam-exploded wheat straw. Furthermore, quantitative correlations could be established between these variables and in situ permittivity. In contrast, qPCR quantification suffered from inconsistent DNA extraction from the lignocellulosic slurries. Development of reliable and validated cell quantification methods and understanding their strengths and limitations in lignocellulosic contexts, will enable further development, optimization, and control of lignocellulose-based fermentation processes.
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Affiliation(s)
- Ruifei Wang
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.,Nouryon, Hamnvägen 2, 444 85, Stenungsund, Sweden
| | - Bettina Lorantfy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.,BioPhero ApS, Lersø Parkallé 42-44, 4. th., 2100, Copenhagen Ø, Denmark
| | - Salvatore Fusco
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.,Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Lisbeth Olsson
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Carl Johan Franzén
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
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8
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Olkiewicz M, Tylkowski B, Montornés JM, Garcia-Valls R, Gulaczyk I. Modelling of enzyme kinetics: cellulose enzymatic hydrolysis case. PHYSICAL SCIENCES REVIEWS 2020. [DOI: 10.1515/psr-2020-0039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Enzymes as industrial biocatalysts offer numerous advantages over traditional chemical processes resulting on improvements in process economy and environmental sustainability. Because enzymes are extensively used in different industrial areas, the enzyme kinetics is an important factor for industry as it is able to estimate the extent of substrate conversion under known conditions and evaluate reactor performance. Furthermore, kinetic modelling is useful in the analysis, prediction, and optimization of an enzymatic process. Thus, kinetic modelling is a powerful tool for biochemical reaction engineering. In addition to the aforementioned, in the industrial technology, modelling together with simulation play a key role because they help to understand how a system behaves under specific conditions, and thus they allow saving on costs and lead times. Enzymatic conversion of renewable cellulosic biomass into biofuels is at the heart of advanced bioethanol production. In the production of bioethanol from cellulosic biomass, enzymatic hydrolysis of cellulose to fermentable sugars accounts for a large portion (∼30%) of the total production costs. Therefore, a thorough understanding of enzymatic hydrolysis is necessary to create a robust model which helps designing optimal conditions and economical system. Nevertheless, it is a challenging task because cellulose is a highly complex substrate and its enzymatic hydrolysis is heterogeneous in nature, and thus the whole process of cellulose conversion to glucose involves more steps than classical enzyme kinetics. This chapter describes the bases of enzyme kinetic modelling, focussing on Michaelis-Menten kinetics, and presents the models classification based on the fundamental approach and methodology used. Furthermore, the modelling of cellulose enzymatic hydrolysis is described, also reviewing some model examples developed for cellulose hydrolysis over the years. Finally, the application of enzyme kinetics modelling in food, pharmaceutical and bioethanol industry is presented.
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Affiliation(s)
- Magdalena Olkiewicz
- Eurecat Technology Centre of Catalonia , Chemical Technology Unit , C/ Marcel·lí Domingo 2 , 43007 Tarragona , Spain
| | - Bartosz Tylkowski
- Eurecat Technology Centre of Catalonia , Chemical Technology Unit , C/ Marcel·lí Domingo 2 , 43007 Tarragona , Spain
| | - Josep M. Montornés
- Eurecat Technology Centre of Catalonia , Chemical Technology Unit , C/ Marcel·lí Domingo 2 , 43007 Tarragona , Spain
| | - Ricard Garcia-Valls
- Eurecat Technology Centre of Catalonia , Chemical Technology Unit , C/ Marcel·lí Domingo 2 , 43007 Tarragona , Spain
- Universitat Rovira i Virgili , Department of Chemical Engineering , Av. Països Catalans 26 , 43007 Tarragona , Spain
| | - Iwona Gulaczyk
- Faculty of Chemistry , Adam Mickiewicz University in Poznan , ul. Uniwersytetu Poznańskiego 8 , 61-614 Poznań , Poland
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Sun L, Wang L, Chen H. High Productivity Ethanol from Solid-State Fermentation of Steam-Exploded Corn Stover Using Zymomonas mobilis by N 2 Periodic Pulsation Process Intensification. Appl Biochem Biotechnol 2020; 192:466-481. [PMID: 32399840 DOI: 10.1007/s12010-020-03318-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/23/2020] [Indexed: 01/06/2023]
Abstract
Solid-state fermentation, featured by water-saving, eco-friendly and high concentration product, is a promising technology in lignocellulosic ethanol industry. However, in solid-state fermentation system, large gas content inside the substrate directly leads to high oxygen partial pressure and inhibits ethanol fermentation. Z. mobilis can produce ethanol from glucose near the theoretical maximum value, but this ethanol yield would be greatly decreased by high oxygen partial pressure during solid-state fermentation. In this study, we applied N2 periodic pulsation process intensification (NPPPI) to ethanol solid-state fermentation, which displaced air with N2 and provided a proper anaerobic environment for Z. mobilis. Based on the water state distribution, the promotion effects of NPPPI on low solid loading and solid-state fermentation were analyzed to confirm the different degrees of oxygen inhibition in ethanol solid-state fermentation. During the simultaneous saccharification solid-state fermentation, the NPPPI group achieved 45.29% ethanol yield improvement and 30.38% concentration improvement compared with the control group. NPPPI also effectively decreased 58.47% of glycerol and 84.24% of acetic acid production and increased the biomass of Z. mobilis. By coupling the peristaltic enzymatic hydrolysis and fed-batch culture, NPPPI made the ethanol yield and concentration reach 80.11% and 55.06 g/L, respectively, in solid-state fermentation.
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Affiliation(s)
- Lele Sun
- State Key Laboratory of Biochemical Engineering, Beijing Key Laboratory of Biomass Refining Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Lan Wang
- State Key Laboratory of Biochemical Engineering, Beijing Key Laboratory of Biomass Refining Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
| | - Hongzhang Chen
- State Key Laboratory of Biochemical Engineering, Beijing Key Laboratory of Biomass Refining Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
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10
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Duan Z, Wilms T, Neubauer P, Kravaris C, Cruz Bournazou MN. Model reduction of aerobic bioprocess models for efficient simulation. Chem Eng Sci 2020. [DOI: 10.1016/j.ces.2020.115512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Ethanol Production from High Solid Loading of Rice Straw by Simultaneous Saccharification and Fermentation in a Non-Conventional Reactor. ENERGIES 2020. [DOI: 10.3390/en13082090] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Simultaneous saccharification and fermentation (SSF) at high solid loading is a potential approach to improve the economic feasibility of cellulosic ethanol. In this study, SSF using high loading of rice straw was assessed using a vertical ball mill reactor. First, the conditions of temperature and number of glass spheres were optimized at 8% (w/v) initial solids (41.5 °C, 18 spheres). Then, assays were carried out at higher solid loadings (16% and 24% w/v). At 8% or 16% solids, the fermentation efficiency was similar (ηF~75%), but the ethanol volumetric productivity (QP) reduced from 1.50 to 1.14 g/L.h. By increasing the solids to 24%, the process was strongly affected (ηF = 40% and QP = 0.7 g/L.h). To overcome this drawback, three different feeding profiles of 24% pre-treated rice straw were investigated. Gradual feeding of the substrate (initial load of 16% with additions of 4% at 10 and 24 h) and an inoculum level of 3 g/L resulted in a high ethanol titer (52.3 g/L) with QP of 1.1 g/L.h and ηF of 67%. These findings demonstrated that using a suitable fed-batch feeding strategy helps to overcome the limitations of SSF in batch mode caused by the use of high solid content.
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12
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Pérez-Pimienta JA, Papa G, Gladden JM, Simmons BA, Sanchez A. The effect of continuous tubular reactor technologies on the pretreatment of lignocellulosic biomass at pilot-scale for bioethanol production. RSC Adv 2020; 10:18147-18159. [PMID: 35517195 PMCID: PMC9053731 DOI: 10.1039/d0ra04031b] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/06/2020] [Indexed: 11/21/2022] Open
Abstract
A pilot-scale continuous tubular reactor increases enzymatic digestibility of four different feedstocks by removing xylan and effectively achieving economically viable ethanol concentrations.
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Affiliation(s)
- José A. Pérez-Pimienta
- Laboratorio de Futuros en Bioenergía
- Unidad Guadalajara de Ingeniería Avanzada
- Centro de Investigación y Estudios Avanzados (CINVESTAV)
- Zapopan
- Mexico
| | - Gabriela Papa
- Joint BioEnergy Institute
- Biological Systems and Engineering Division
- Lawrence Berkeley National Laboratory
- Emeryville
- USA
| | - John M. Gladden
- Joint BioEnergy Institute
- Biological Systems and Engineering Division
- Lawrence Berkeley National Laboratory
- Emeryville
- USA
| | - Blake A. Simmons
- Joint BioEnergy Institute
- Biological Systems and Engineering Division
- Lawrence Berkeley National Laboratory
- Emeryville
- USA
| | - Arturo Sanchez
- Laboratorio de Futuros en Bioenergía
- Unidad Guadalajara de Ingeniería Avanzada
- Centro de Investigación y Estudios Avanzados (CINVESTAV)
- Zapopan
- Mexico
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Draft Genome Sequence of Bacillus coagulans MA-13, a Thermophilic Lactic Acid Producer from Lignocellulose. Microbiol Resour Announc 2019; 8:8/23/e00341-19. [PMID: 31171617 PMCID: PMC6554604 DOI: 10.1128/mra.00341-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Bacillus coagulans MA-13 is an efficient lactic acid producer which withstands high concentrations of the growth inhibitors formed during the pretreatment of lignocellulosic feedstock. This draft genome sequence is expected to pave the way toward the understanding of mechanisms responsible for the robustness of MA-13 during simultaneous saccharification and fermentation. Bacillus coagulans MA-13 is an efficient lactic acid producer which withstands high concentrations of the growth inhibitors formed during the pretreatment of lignocellulosic feedstock. This draft genome sequence is expected to pave the way toward the understanding of mechanisms responsible for the robustness of MA-13 during simultaneous saccharification and fermentation.
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14
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Liu CG, Xiao Y, Xia XX, Zhao XQ, Peng L, Srinophakun P, Bai FW. Cellulosic ethanol production: Progress, challenges and strategies for solutions. Biotechnol Adv 2019; 37:491-504. [DOI: 10.1016/j.biotechadv.2019.03.002] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 02/18/2019] [Accepted: 03/03/2019] [Indexed: 11/16/2022]
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Aulitto M, Fusco S, Nickel DB, Bartolucci S, Contursi P, Franzén CJ. Seed culture pre-adaptation of Bacillus coagulans MA-13 improves lactic acid production in simultaneous saccharification and fermentation. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:45. [PMID: 30858882 PMCID: PMC6394018 DOI: 10.1186/s13068-019-1382-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/20/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Lignocellulosic biomass is an abundant and sustainable feedstock, which represents a promising raw material for the production of lactic acid via microbial fermentation. However, toxic compounds that affect microbial growth and metabolism are released from the biomass upon thermochemical pre-treatment. So far, susceptibility of bacterial strains to biomass-derived inhibitors still represents a major barrier to lactic acid production from lignocellulose. Detoxification of the pre-treated lignocellulosic material by water washing is commonly performed to alleviate growth inhibition of the production microorganism and achieve higher production rates. RESULTS In this study, we assessed the feasibility of replacing the washing step with integrated cellular adaptation during pre-culture of Bacillus coagulans MA-13 prior to simultaneous saccharification and lactic acid fermentation of steam exploded wheat straw. Using a seed culture pre-exposed to 30% hydrolysate led to 50% shorter process time, 50% higher average volumetric and 115% higher average specific productivity than when using cells from a hydrolysate-free seed culture. CONCLUSIONS Pre-exposure of B. coagulans MA-13 to hydrolysate supports adaptation to the actual production medium. This strategy leads to lower process water requirements and combines cost-effective seed cultivation with physiological pre-adaptation of the production strain, resulting in reduced lactic acid production costs.
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Affiliation(s)
- Martina Aulitto
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Salvatore Fusco
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - David Benjamin Nickel
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | | | - Patrizia Contursi
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Carl Johan Franzén
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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Boboescu IZ, Gélinas M, Beigbeder JB, Lavoie JM. High-efficiency second generation ethanol from the hemicellulosic fraction of softwood chips mixed with construction and demolition residues. BIORESOURCE TECHNOLOGY 2018; 266:421-430. [PMID: 29990759 DOI: 10.1016/j.biortech.2018.06.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
Using lignocellulosic residues for bioethanol production could provide an alternative solution to current approaches at competitive costs once challenges related to substrate recalcitrance, process complexity and limited knowledge are overcome. Thus, the impact of different process variables on the ethanol production by Saccharomyces cerevisiae using the hemicellulosic fraction extracted through the steam-treatment of softwood chips mixed with construction and demolition residues was assessed. A statistical design of experiments approach was developed and implemented in order to identify the influencing factors (various nutrient addition sources as well as yeast inoculum growth conditions and inoculation strategies) relevant for enhancing the ethanol production potential and substrate uptake. Ethanol yields of 74.12% and monomeric sugar uptakes of 82.12 g/L were predicted and experimentally confirmed in bench and bioreactor systems. This innovative approach revealed the factors impacting the ethanol yields and carbohydrate consumption allowing powerful behavioral predictions spanning different process inputs and outputs.
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Affiliation(s)
- Iulian-Zoltan Boboescu
- Departement of Chemical Engineering and Biotechnological Engineering, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - Malorie Gélinas
- Departement of Chemical Engineering and Biotechnological Engineering, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - Jean-Baptiste Beigbeder
- Departement of Chemical Engineering and Biotechnological Engineering, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - Jean-Michel Lavoie
- Departement of Chemical Engineering and Biotechnological Engineering, University of Sherbrooke, Sherbrooke, Québec, Canada.
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Dong C, Wang Y, Zhang H, Leu SY. Feasibility of high-concentration cellulosic bioethanol production from undetoxified whole Monterey pine slurry. BIORESOURCE TECHNOLOGY 2018; 250:102-109. [PMID: 29161568 DOI: 10.1016/j.biortech.2017.11.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 05/15/2023]
Abstract
The economic feasibility of high-concentration cellulosic bioethanol production remains challenging because it requires easily available feedstock and low energy consumption process. Simultaneous saccharification and fermentation (SSF) of sulfite pretreated Momentary pine slurry at 20% (w/w) loadings increased ethanol concentration from 59.3 g/L to 68.5 g/L by washing strategy. Effects of inhibitors in pretreatment liquor were further investigated. Besides HMF, furfural and acetic acid, other inhibitors and/or their synergistic effects proved to be responsible for a lower fermentability. To bypass the inhibition and achieve high-efficient bioethanol concentration, a fermentation temperature of 28 °C was optimized for both cell growth and ethanol production. Under the optimal conditions with prehydrolyzed 25% (w/w) whole undetoxified slurry, a high ethanol concentration (up to 82.1 g/L) were produced with a yield of 205 kg/ton Monterey pine in the SSF. Thus, this high cellulosic bioethanol production from Monterey pine makes it a potential strategy for biofuel production.
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Affiliation(s)
- Chengyu Dong
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Ying Wang
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
| | - Han Zhang
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Shao-Yuan Leu
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
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18
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Laluce C, Igbojionu LI, Dussán KJ. Fungal Enzymes Applied to Industrial Processes for Bioethanol Production. Fungal Biol 2018. [DOI: 10.1007/978-3-319-90379-8_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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19
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Boboescu IZ, Gélinas M, Beigbeder JB, Lavoie JM. A two-step optimization strategy for 2nd generation ethanol production using softwood hemicellulosic hydrolysate as fermentation substrate. BIORESOURCE TECHNOLOGY 2017; 244:708-716. [PMID: 28822282 DOI: 10.1016/j.biortech.2017.07.107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 06/07/2023]
Abstract
Ethanol production using waste biomass represents a very attractive approach. However, there are considerable challenges preventing a wide distribution of these novel technologies. Thus, a fractional-factorial screening of process variables and Saccharomyces cerevisiae yeast inoculum conditions was performed using a synthetic fermentation media. Subsequently, a response-surface methodology was developed for maximizing ethanol yields using a hemicellulosic solution generated through the chemical hydrolysis of steam treatment broth obtained from residual softwood biomass. In addition, nutrient supplementation using starch-based ethanol production by-products was investigated. An ethanol yield of 74.27% of the theoretical maximum was observed for an initial concentration of 65.17g/L total monomeric sugars. The two-step experimental strategy used in this work represents the first successful attempt to developed and use a model to make predictions regarding the optimal ethanol production using both softwood feedstock residues as well as 1st generation ethanol production by-products.
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Affiliation(s)
- Iulian-Zoltan Boboescu
- Department of Chemical Engineering and Biotechnology Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Malorie Gélinas
- Department of Chemical Engineering and Biotechnology Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Jean-Baptiste Beigbeder
- Department of Chemical Engineering and Biotechnology Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| | - Jean-Michel Lavoie
- Department of Chemical Engineering and Biotechnology Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada.
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Novy V, Wang R, Westman JO, Franzén CJ, Nidetzky B. Saccharomyces cerevisiae strain comparison in glucose-xylose fermentations on defined substrates and in high-gravity SSCF: convergence in strain performance despite differences in genetic and evolutionary engineering history. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:205. [PMID: 28878820 PMCID: PMC5584037 DOI: 10.1186/s13068-017-0887-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/12/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND The most advanced strains of xylose-fermenting Saccharomyces cerevisiae still utilize xylose far less efficiently than glucose, despite the extensive metabolic and evolutionary engineering applied in their development. Systematic comparison of strains across literature is difficult due to widely varying conditions used for determining key physiological parameters. Here, we evaluate an industrial and a laboratory S. cerevisiae strain, which has the assimilation of xylose via xylitol in common, but differ fundamentally in the history of their adaptive laboratory evolution development, and in the cofactor specificity of the xylose reductase (XR) and xylitol dehydrogenase (XDH). RESULTS In xylose and mixed glucose-xylose shaken bottle fermentations, with and without addition of inhibitor-rich wheat straw hydrolyzate, the specific xylose uptake rate of KE6-12.A (0.27-1.08 g gCDW-1 h-1) was 1.1 to twofold higher than that of IBB10B05 (0.10-0.82 g gCDW-1 h-1). KE6-12.A further showed a 1.1 to ninefold higher glycerol yield (0.08-0.15 g g-1) than IBB10B05 (0.01-0.09 g g-1). However, the ethanol yield (0.30-0.40 g g-1), xylitol yield (0.08-0.26 g g-1), and maximum specific growth rate (0.04-0.27 h-1) were in close range for both strains. The robustness of flocculating variants of KE6-12.A (KE-Flow) and IBB10B05 (B-Flow) was analyzed in high-gravity simultaneous saccharification and co-fermentation. As in shaken bottles, KE-Flow showed faster xylose conversion and higher glycerol formation than B-Flow, but final ethanol titres (61 g L-1) and cell viability were again comparable for both strains. CONCLUSIONS Individual specific traits, elicited by the engineering strategy, can affect global physiological parameters of S. cerevisiae in different and, sometimes, unpredictable ways. The industrial strain background and prolonged evolution history in KE6-12.A improved the specific xylose uptake rate more substantially than the superior XR, XDH, and xylulokinase activities were able to elicit in IBB10B05. Use of an engineered XR/XDH pathway in IBB10B05 resulted in a lower glycerol rather than a lower xylitol yield. However, the strain development programs were remarkably convergent in terms of the achieved overall strain performance. This highlights the importance of comparative strain evaluation to advance the engineering strategies for next-generation S. cerevisiae strain development.
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Affiliation(s)
- Vera Novy
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria
| | - Ruifei Wang
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Johan O Westman
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Carl Johan Franzén
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria
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Catal T, Gover T, Yaman B, Droguetti J, Yilancioglu K. Hydrogen production profiles using furans in microbial electrolysis cells. World J Microbiol Biotechnol 2017; 33:115. [PMID: 28488198 DOI: 10.1007/s11274-017-2270-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 04/22/2017] [Indexed: 10/19/2022]
Abstract
Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.
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Affiliation(s)
- Tunc Catal
- Department of Molecular Biology and Genetics, Uskudar University, Uskudar, 34662, Istanbul, Turkey.
- Biotechnology Application and Research Center, Uskudar University, Uskudar, 34662, Istanbul, Turkey.
| | - Tansu Gover
- Department of Molecular Biology and Genetics, Uskudar University, Uskudar, 34662, Istanbul, Turkey
| | - Bugra Yaman
- Department of Molecular Biology and Genetics, Uskudar University, Uskudar, 34662, Istanbul, Turkey
| | - Jessica Droguetti
- Department of Bioengineering, Uskudar University, Uskudar, 34662, Istanbul, Turkey
| | - Kaan Yilancioglu
- Department of Bioengineering, Uskudar University, Uskudar, 34662, Istanbul, Turkey
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Westman JO, Wang R, Novy V, Franzén CJ. Sustaining fermentation in high-gravity ethanol production by feeding yeast to a temperature-profiled multifeed simultaneous saccharification and co-fermentation of wheat straw. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:213. [PMID: 28919926 PMCID: PMC5596858 DOI: 10.1186/s13068-017-0893-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 08/24/2017] [Indexed: 05/17/2023]
Abstract
BACKGROUND Considerable progress is being made in ethanol production from lignocellulosic feedstocks by fermentation, but negative effects of inhibitors on fermenting microorganisms are still challenging. Feeding preadapted cells has shown positive effects by sustaining fermentation in high-gravity simultaneous saccharification and co-fermentation (SSCF). Loss of cell viability has been reported in several SSCF studies on different substrates and seems to be the main reason for the declining ethanol production toward the end of the process. Here, we investigate how the combination of yeast preadaptation and feeding, cell flocculation, and temperature reduction improves the cell viability in SSCF of steam pretreated wheat straw. RESULTS More than 50% cell viability was lost during the first 24 h of high-gravity SSCF. No beneficial effects of adding selected nutrients were observed in shake flask SSCF. Ethanol concentrations greater than 50 g L-1 led to significant loss of viability and prevented further fermentation in SSCF. The benefits of feeding preadapted yeast cells were marginal at later stages of SSCF. Yeast flocculation did not improve the viability but simplified cell harvest and improved the feasibility of the cell feeding strategy in demo scale. Cultivation at 30 °C instead of 35 °C increased cell survival significantly on solid media containing ethanol and inhibitors. Similarly, in multifeed SSCF, cells maintained the viability and fermentation capacity when the temperature was reduced from 35 to 30 °C during the process, but hydrolysis yields were compromised. By combining the yeast feeding and temperature change, an ethanol concentration of 65 g L-1, equivalent to 70% of the theoretical yield, was obtained in multifeed SSCF on pretreated wheat straw. In demo scale, the process with flocculating yeast and temperature profile resulted in 5% (w/w) ethanol, equivalent to 53% of the theoretical yield. CONCLUSIONS Multifeed SSCF was further developed by means of a flocculating yeast and a temperature-reduction profile. Ethanol toxicity is intensified in the presence of lignocellulosic inhibitors at temperatures that are beneficial to hydrolysis in high-gravity SSCF. The counteracting effects of temperature on cell viability and hydrolysis call for more tolerant microorganisms, enzyme systems with lower temperature optimum, or full optimization of the multifeed strategy with temperature profile.
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Affiliation(s)
- Johan O. Westman
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Present Address: Chr. Hansen A/S, Bøge Allé 10-12, 2970 Hørsholm, Denmark
| | - Ruifei Wang
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Vera Novy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria
- Present Address: Forest Products Biotechnology, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T1Z4 Canada
| | - Carl Johan Franzén
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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23
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Aulitto M, Fusco S, Bartolucci S, Franzén CJ, Contursi P. Bacillus coagulans MA-13: a promising thermophilic and cellulolytic strain for the production of lactic acid from lignocellulosic hydrolysate. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:210. [PMID: 28904563 PMCID: PMC5590179 DOI: 10.1186/s13068-017-0896-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/28/2017] [Indexed: 05/15/2023]
Abstract
BACKGROUND The transition from a petroleum-based economy towards more sustainable bioprocesses for the production of fuels and chemicals (circular economy) is necessary to alleviate the impact of anthropic activities on the global ecosystem. Lignocellulosic biomass-derived sugars are suitable alternative feedstocks that can be fermented or biochemically converted to value-added products. An example is lactic acid, which is an essential chemical for the production of polylactic acid, a biodegradable bioplastic. However, lactic acid is still mainly produced by Lactobacillus species via fermentation of starch-containing materials, the use of which competes with the supply of food and feed. RESULTS A thermophilic and cellulolytic lactic acid producer was isolated from bean processing waste and was identified as a new strain of Bacillus coagulans, named MA-13. This bacterium fermented lignocellulose-derived sugars to lactic acid at 55 °C and pH 5.5. Moreover, it was found to be a robust strain able to tolerate high concentrations of hydrolysate obtained from wheat straw pre-treated by acid-catalysed (pre-)hydrolysis and steam explosion, especially when cultivated in controlled bioreactor conditions. Indeed, unlike what was observed in microscale cultivations (complete growth inhibition at hydrolysate concentrations above 50%), B. coagulans MA-13 was able to grow and ferment in 95% hydrolysate-containing bioreactor fermentations. This bacterium was also found to secrete soluble thermophilic cellulases, which could be produced at low temperature (37 °C), still retaining an optimal operational activity at 50 °C. CONCLUSIONS The above-mentioned features make B. coagulans MA-13 an appealing starting point for future development of a consolidated bioprocess for production of lactic acid from lignocellulosic biomass, after further strain development by genetic and evolutionary engineering. Its optimal temperature and pH of growth match with the operational conditions of fungal enzymes hitherto employed for the depolymerisation of lignocellulosic biomasses to fermentable sugars. Moreover, the robustness of B. coagulans MA-13 is a desirable trait, given the presence of microbial growth inhibitors in the pre-treated biomass hydrolysate.
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Affiliation(s)
- Martina Aulitto
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Naples, Italy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Salvatore Fusco
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Naples, Italy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Simonetta Bartolucci
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Carl Johan Franzén
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Patrizia Contursi
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Naples, Italy
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Moreno AD, Alvira P, Ibarra D, Tomás-Pejó E. Production of Ethanol from Lignocellulosic Biomass. PRODUCTION OF PLATFORM CHEMICALS FROM SUSTAINABLE RESOURCES 2017. [DOI: 10.1007/978-981-10-4172-3_12] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Alfenore S, Molina-Jouve C. Current status and future prospects of conversion of lignocellulosic resources to biofuels using yeasts and bacteria. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.07.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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