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Sitara A, Hocq R, Horvath J, Pflügl S. Industrial biotechnology goes thermophilic: Thermoanaerobes as promising hosts in the circular carbon economy. BIORESOURCE TECHNOLOGY 2024; 408:131164. [PMID: 39069138 DOI: 10.1016/j.biortech.2024.131164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/19/2024] [Accepted: 07/24/2024] [Indexed: 07/30/2024]
Abstract
Transitioning away from fossil feedstocks is imperative to mitigate climate change, and necessitates the utilization of renewable, alternative carbon and energy sources to foster a circular carbon economy. In this context, lignocellulosic biomass and one-carbon compounds emerge as promising feedstocks that could be renewably upgraded by thermophilic anaerobes (thermoanaerobes) via gas fermentation or consolidated bioprocessing to value-added products. In this review, the potential of thermoanaerobes for cost-efficient, effective and sustainable bioproduction is discussed. Metabolic and bioprocess engineering approaches are reviewed to draw a comprehensive picture of current developments and future perspectives for the conversion of renewable feedstocks to chemicals and fuels of interest. Selected bioprocessing scenarios are outlined, offering practical insights into the applicability of thermoanaerobes at a large scale. Collectively, the potential advantages of thermoanaerobes regarding process economics could facilitate an easier transition towards sustainable bioprocesses with renewable feedstocks.
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Affiliation(s)
- Angeliki Sitara
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria
| | - Rémi Hocq
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria; Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria; CIRCE Biotechnologie GmbH, Kerpengasse 125, 1210 Vienna, Austria
| | - Josef Horvath
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria; Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria
| | - Stefan Pflügl
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria; Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060 Vienna, Austria.
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2
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Wilson AN, St John PC, Marin DH, Hoyt CB, Rognerud EG, Nimlos MR, Cywar RM, Rorrer NA, Shebek KM, Broadbelt LJ, Beckham GT, Crowley MF. PolyID: Artificial Intelligence for Discovering Performance-Advantaged and Sustainable Polymers. Macromolecules 2023; 56:8547-8557. [PMID: 38024155 PMCID: PMC10653284 DOI: 10.1021/acs.macromol.3c00994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 09/30/2023] [Indexed: 12/01/2023]
Abstract
A necessary transformation for a sustainable economy is the transition from fossil-derived plastics to polymers derived from biomass and waste resources. While renewable feedstocks can enhance material performance through unique chemical moieties, probing the vast material design space by experiment alone is not practically feasible. Here, we develop a machine-learning-based tool, PolyID, to reduce the design space of renewable feedstocks to enable efficient discovery of performance-advantaged, biobased polymers. PolyID is a multioutput, graph neural network specifically designed to increase accuracy and to enable quantitative structure-property relationship (QSPR) analysis for polymers. It includes a novel domain-of-validity method that was developed and applied to demonstrate how gaps in training data can be filled to improve accuracy. The model was benchmarked with both a 20% held-out subset of the original training data and 22 experimentally synthesized polymers. A mean absolute error for the glass transition temperatures of 19.8 and 26.4 °C was achieved for the test and experimental data sets, respectively. Predictions were made on polymers composed of monomers from four databases that contain biologically accessible small molecules: MetaCyc, MINEs, KEGG, and BiGG. From 1.4 × 106 accessible biobased polymers, we identified five poly(ethylene terephthalate) (PET) analogues with predicted improvements to thermal and transport performance. Experimental validation for one of the PET analogues demonstrated a glass transition temperature between 85 and 112 °C, which is higher than PET and within the predicted range of the PolyID tool. In addition to accurate predictions, we show how the model's predictions are explainable through analysis of individual bond importance for a biobased nylon. Overall, PolyID can aid the biobased polymer practitioner to navigate the vast number of renewable polymers to discover sustainable materials with enhanced performance.
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Affiliation(s)
- A. Nolan Wilson
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Peter C. St John
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Daniela H. Marin
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Caroline B. Hoyt
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Erik G. Rognerud
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mark R. Nimlos
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Robin M. Cywar
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Nicholas A. Rorrer
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Kevin M. Shebek
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Department
of Chemical and Biological Engineering and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry
of Life Processes Institute, Northwestern
University, Evanston, Illinois 60208, United States
| | - Linda J. Broadbelt
- Department
of Chemical and Biological Engineering and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Gregg T. Beckham
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Michael F. Crowley
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
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3
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Zhang L, Lin Y, Yi X, Huang W, Hu Q, Zhang Z, Wu F, Ye JW, Chen GQ. Engineering low-salt growth Halomonas Bluephagenesis for cost-effective bioproduction combined with adaptive evolution. Metab Eng 2023; 79:146-158. [PMID: 37543135 DOI: 10.1016/j.ymben.2023.08.001] [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: 06/26/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/07/2023]
Abstract
Halophilic Halomonas bluephagenesis has been engineered to produce various added-value bio-compounds with reduced costs. However, the salt-stress regulatory mechanism remained unclear. H. bluephagenesis was randomly mutated to obtain low-salt growing mutants via atmospheric and room temperature plasma (ARTP). The resulted H. bluephagenesis TDH4A1B5 was constructed with the chromosomal integration of polyhydroxyalkanoates (PHA) synthesis operon phaCAB and deletion of phaP1 gene encoding PHA synthesis associated protein phasin, forming H. bluephagenesis TDH4A1B5P, which led to increased production of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-4-hydrobutyrate) (P34HB) by over 1.4-fold. H. bluephagenesis TDH4A1B5P also enhanced production of ectoine and threonine by 50% and 77%, respectively. A total 101 genes related to salinity tolerance was identified and verified via comparative genomic analysis among four ARTP mutated H. bluephagenesis strains. Recombinant H. bluephagenesis TDH4A1B5P was further engineered for PHA production utilizing sodium acetate or gluconate as sole carbon source. Over 33% cost reduction of PHA production could be achieved using recombinant H. bluephagenesis TDH4A1B5P. This study successfully developed a low-salt tolerant chassis H. bluephagenesis TDH4A1B5P and revealed salt-stress related genes of halophilic host strains.
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Affiliation(s)
- Lizhan Zhang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yina Lin
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xueqing Yi
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wuzhe Huang
- PhaBuilder Biotech Co. Ltd., Shunyi District, Zhaoquan Ying, Beijing, 101309, China
| | - Qitiao Hu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhongnan Zhang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Fuqing Wu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jian-Wen Ye
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Guo-Qiang Chen
- School of Life Sciences, Tsinghua University, Beijing, 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing, China; MOE Key Lab of Industrial Biocatalysis, Dept Chemical Engineering, Tsinghua University, Beijing, 100084, China.
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Yankov D. Fermentative Lactic Acid Production From Lignocellulosic Feedstocks: From Source to Purified Product. Front Chem 2022; 10:823005. [PMID: 35308791 PMCID: PMC8931288 DOI: 10.3389/fchem.2022.823005] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/21/2022] [Indexed: 01/10/2023] Open
Abstract
The second (lignocellulosic biomass and industrial wastes) and third (algal biomass) generation feedstocks gained substantial interest as a source of various value-added chemicals, produced by fermentation. Lactic acid is a valuable platform chemical with both traditional and newer applications in many industries. The successful fractionation, separation, and hydrolysis of lignocellulosic biomass result in sugars’ rich raw material for lactic acid fermentation. This review paper aims to summarize the investigations and progress in the last 5 years in lactic acid production from inexpensive and renewable resources. Different aspects are discussed—the type of raw materials, pretreatment and detoxification methods, lactic acid-producers (bacteria, fungi, and yeasts), use of genetically manipulated microorganisms, separation techniques, different approaches of process organization, as well as main challenges, and possible solutions for process optimization.
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5
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Recent Advances in Lactic Acid Production by Lactic Acid Bacteria. Appl Biochem Biotechnol 2021; 193:4151-4171. [PMID: 34519919 DOI: 10.1007/s12010-021-03672-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/03/2021] [Indexed: 02/07/2023]
Abstract
Lactic acid can synthesize high value-added chemicals such as poly lactic acid. In order to further minimize the cost of lactic acid production, some effective strategies (e.g., effective mutagenesis and metabolic engineering) have been applied to increase productive capacity of lactic acid bacteria. In addition, low-cost cheap raw materials (e.g., cheap carbon source and cheap nitrogen source) are also used to reduce the cost of lactic acid production. In this review, we summarized the recent developments in lactic acid production, including efficient strain modification technology (high-efficiency mutagenesis means, adaptive laboratory evolution, and metabolic engineering), the use of low-cost cheap raw materials, and also discussed the future prospects of this field, which could promote the development of lactic acid industry.
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Wu M, Jiang Y, Liu Y, Mou L, Zhang W, Xin F, Jiang M. Microbial application of thermophilic Thermoanaerobacterium species in lignocellulosic biorefinery. Appl Microbiol Biotechnol 2021; 105:5739-5749. [PMID: 34283269 DOI: 10.1007/s00253-021-11450-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/04/2021] [Accepted: 07/06/2021] [Indexed: 12/13/2022]
Abstract
Recently, thermophilic Thermoanaerobacterium species have attracted increasing attentions in consolidated bioprocessing (CBP), which can directly utilize lignocellulosic materials for biofuels production. Compared to the mesophilic process, thermophilic process shows greater prospects in CBP due to its relatively highly efficiency of lignocellulose degradation. In addition, thermophilic conditions can avoid microbial contamination, reduce the cooling costs, and further facilitate the downstream product recovery. However, only few reviews specifically focused on the microbial applications of thermophilic Thermoanaerobacterium species in lignocellulosic biorefinery. Accordingly, this review will comprehensively summarize the recent advances of Thermoanaerobacterium species in lignocellulosic biorefinery, including their secreted xylanases and bioenergy production. Furthermore, the co-culture can significantly reduce the metabolic burden and achieve the more complex work, which will be discussed as the further perspectives. KEY POINTS: • Thermoanaerobacterium species, promising chassis for lignocellulosic biorefinery. • Potential capability of hemicellulose degradation for Thermoanaerobacterium species. • Efficient bioenergy production by Thermoanaerobacterium species through metabolic engineering.
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Affiliation(s)
- Mengdi Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Yansong Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Lu Mou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
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Qu C, Zhang Y, Dai K, Fu H, Wang J. Metabolic engineering of Thermoanaerobacterium aotearoense SCUT27 for glucose and cellobiose co-utilization by identification and overexpression of the endogenous cellobiose operon. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Mostafa YS, Alamri SA, Hashem M, Nafady NA, Abo-Elyousr KA, Mohamed ZA. Thermostable Cellulase Biosynthesis from Paenibacillus alvei and its Utilization in Lactic Acid Production by Simultaneous Saccharification and Fermentation. Open Life Sci 2020; 15:185-197. [PMID: 33987475 PMCID: PMC8114780 DOI: 10.1515/biol-2020-0019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 12/18/2019] [Indexed: 02/02/2023] Open
Abstract
Cellulosic date palm wastes may have beneficial biotechnological applications for eco-friendly utilization. This study reports the isolation of thermophilic cellulase-producing bacteria and their application in lactic acid production using date palm leaves. The promising isolate was identified as Paenibacillus alvei by 16S rRNA gene sequencing. Maximum cellulase production was acquired using alkaline treated date palm leaves (ATDPL) at 48 h and yielded 4.50 U.mL-1 FPase, 8.11 U.mL-1 CMCase, and 2.74 U.mL-1 β-glucosidase. The cellulase activity was optimal at pH 5.0 and 50°C with good stability at a wide temperature (40-70°C) and pH (4.0-7.0) range, demonstrating its suitability in simultaneous saccharification and fermentation. Lactic acid fermentation was optimized at 4 days, pH 5.0, 50°C, 6.0% cellulose of ATDPL, 30 FPU/ g cellulose, 1.0 g. L-1 Tween 80, and 5.0 g. L-l yeast extract using Lactobacillus delbrueckii. The conversion efficiency of lactic acid from the cellulose of ATDPL was 98.71%, and the lactic acid productivity was 0.719 g. L-1 h-1. Alkaline treatment exhibited a valuable effect on the production of cellulases and lactic acid by reducing the lignin content and cellulose crystallinity. The results of this study offer a credible procedure for using date palm leaves for microbial industrial applications.
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Affiliation(s)
- Yasser S. Mostafa
- King Khalid University, Faculty of Science, Biology Department, AbhaSaudi Arabia
| | - Saad A. Alamri
- King Khalid University, Faculty of Science, Biology Department, AbhaSaudi Arabia
- Prince Sultan Bin Abdulaziz Center for Environmental and Tourism Research and Studies, King Khalid University, AbhaSaudi Arabia
| | - Mohamed Hashem
- King Khalid University, Faculty of Science, Biology Department, AbhaSaudi Arabia
- Assiut University, Faculty of Science, Botany and Microbiology Department, Assiut, Egypt
| | - Nivien A. Nafady
- Assiut University, Faculty of Science, Botany and Microbiology Department, Assiut, Egypt
| | | | - Zakaria A. Mohamed
- King Abdulaziz University, Faculty of Meteorology, Environmental and Arid Land Agriculture, Department of Arid Land Agriculture, JeddahSaudi Arabia
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Li Y, Hu J, Qu C, Chen L, Guo X, Fu H, Wang J. Engineered Thermoanaerobacterium aotearoense with nfnAB knockout for improved hydrogen production from lignocellulose hydrolysates. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:214. [PMID: 31528202 PMCID: PMC6737674 DOI: 10.1186/s13068-019-1559-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND As a renewable and clean energy carrier, the production of biohydrogen from low-value feedstock such as lignocellulose has increasingly garnered interest. The NADH-dependent reduced ferredoxin:NADP+ oxidoreductase (NfnAB) complex catalyzes electron transfer between reduced ferredoxin and NAD(P)+, which is critical for production of NAD(P)H-dependent products such as hydrogen and ethanol. In this study, the effects on end-product formation of deletion of nfnAB from Thermoanaerobacterium aotearoense SCUT27 were investigated. RESULTS Compared with the parental strain, the NADH/NAD+ ratio in the ∆nfnAB mutant was increased. The concentration of hydrogen and ethanol produced increased by (41.1 ± 2.37)% (p < 0.01) and (13.24 ± 1.12)% (p < 0.01), respectively, while the lactic acid concentration decreased by (11.88 ± 0.96)% (p < 0.01) when the ∆nfnAB mutant used glucose as sole carbon source. No obvious inhibition effect was observed for either SCUT27 or SCUT27/∆nfnAB when six types of lignocellulose hydrolysate pretreated with dilute acid were used for hydrogen production. Notably, the SCUT27/∆nfnAB mutant produced 190.63-209.31 mmol/L hydrogen, with a yield of 1.66-1.77 mol/mol and productivity of 12.71-13.95 mmol/L h from nonsterilized rice straw and corn cob hydrolysates pretreated with dilute acid. CONCLUSIONS The T. aotearoense SCUT27/∆nfnAB mutant showed higher hydrogen yield and productivity compared with those of the parental strain. Hence, we demonstrate that deletion of nfnAB from T. aotearoense SCUT27 is an effective approach to improve hydrogen production by redirecting the electron flux, and SCUT27/∆nfnAB is a promising candidate strain for efficient biohydrogen production from lignocellulosic hydrolysates.
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Affiliation(s)
- Yang Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
| | - Jialei Hu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
| | - Chunyun Qu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
| | - Lili Chen
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
| | - Xiaolong Guo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
| | - Hongxin Fu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006 China
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640 China
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Kumar V, Binod P, Sindhu R, Gnansounou E, Ahluwalia V. Bioconversion of pentose sugars to value added chemicals and fuels: Recent trends, challenges and possibilities. BIORESOURCE TECHNOLOGY 2018; 269:443-451. [PMID: 30217725 DOI: 10.1016/j.biortech.2018.08.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/09/2018] [Accepted: 08/12/2018] [Indexed: 05/12/2023]
Abstract
Most of the crop plants contain about 30% of hemicelluloses comprising D-xylose and D-arabinose. One of the major limitation for the use of pentose sugars is that high purity grade D-xylose and D-arabinose are yet to be produced as commodity chemicals. Research and developmental activities are going on in this direction for their use as platform intermediates through economically viable strategies. During chemical pretreatment of biomass, the pentose sugars were generated in the liquid stream along with other compounds. This contains glucose, proteins, phenolic compounds, minerals and acids other than pentose sugars. Arabinose is present in small amounts, which can be used for the economic production of value added compound, xylitol. The present review discusses the recent trends and developments as well as challenges and opportunities in the utilization of pentose sugars generated from lignocellulosic biomass for the production of value added compounds.
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Affiliation(s)
- Vinod Kumar
- Center of Innovative and Applied Bioprocessing, Sector 81, Mohali 160071, Punjab, India
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695019, Kerala, India
| | - Raveendran Sindhu
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695019, Kerala, India
| | - Edgard Gnansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Vivek Ahluwalia
- Center of Innovative and Applied Bioprocessing, Sector 81, Mohali 160071, Punjab, India.
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11
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Riaz S, Fatima N, Rasheed A, Riaz M, Anwar F, Khatoon Y. Metabolic Engineered Biocatalyst: A Solution for PLA Based Problems. Int J Biomater 2018; 2018:1963024. [PMID: 30302092 PMCID: PMC6158955 DOI: 10.1155/2018/1963024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/29/2018] [Indexed: 11/18/2022] Open
Abstract
Polylactic acid (PLA) is a biodegradable thermoplastic polyester. In 2010, PLA became the second highest consumed bioplastic in the world due to its wide application. Conventionally, PLA is produced by direct condensation of lactic acid monomer and ring opening polymerization of lactide, resulting in lower molecular weight and lesser strength of polymer. Furthermore, conventional methods of PLA production require a catalyst which makes it inappropriate for biomedical applications. Newer method utilizes metabolic engineering of microorganism for direct production of PLA through fermentation which produces good quality and high molecular weight and yield as compared to conventional methods. PLA is used as decomposing packaging material, sheet casting, medical implants in the form of screw, plate, and rod pin, etc. The main focus of the review is to highlight the synthesis of PLA by various polymerization methods that mainly include metabolic engineering fermentation as well as salient biomedical applications of PLA.
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Affiliation(s)
- Sundus Riaz
- Department of Biomedical Engineering and Sciences, National University of Sciences & Technology, Islamabad, Pakistan
- Pakistan Agricultural Research Council, FQSRI, SARC, Karachi, Pakistan
| | - Nosheen Fatima
- Department of Biomedical Engineering and Sciences, National University of Sciences & Technology, Islamabad, Pakistan
| | - Ahmed Rasheed
- PhD. Scholar, Sun Yat-Sen University (East Campus), Higher Education Mega Centre North, Guangzhou, China
| | | | - Faiza Anwar
- Pakistan Agricultural Research Council, FQSRI, SARC, Karachi, Pakistan
| | - Yamna Khatoon
- Postgraduate Scholar, Department of Agriculture and Agribusiness Management, University of Karachi, Karachi, Pakistan
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12
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Microbial conversion of xylose into useful bioproducts. Appl Microbiol Biotechnol 2018; 102:9015-9036. [PMID: 30141085 DOI: 10.1007/s00253-018-9294-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/03/2018] [Accepted: 08/06/2018] [Indexed: 02/06/2023]
Abstract
Microorganisms can produce a number of different bioproducts from the sugars in plant biomass. One challenge is devising processes that utilize all of the sugars in lignocellulosic hydrolysates. D-xylose is the second most abundant sugar in these hydrolysates. The microbial conversion of D-xylose to ethanol has been studied extensively; only recently, however, has conversion to bioproducts other than ethanol been explored. Moreover, in the case of yeast, D-xylose may provide a better feedstock for the production of bioproducts other than ethanol, because the relevant pathways are not subject to glucose-dependent repression. In this review, we discuss how different microorganisms are being used to produce novel bioproducts from D-xylose. We also discuss how D-xylose could be potentially used instead of glucose for the production of value-added bioproducts.
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13
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Chen Z, Wan C. Non-sterile fermentations for the economical biochemical conversion of renewable feedstocks. Biotechnol Lett 2017; 39:1765-1777. [PMID: 28905262 DOI: 10.1007/s10529-017-2429-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/31/2017] [Indexed: 01/17/2023]
Abstract
Heavy reliance on petroleum-based products drives continuous exploitation of fossil fuels, and results in serious environmental and climate problems. To address such an issue, there is a shift from petroleum sources to renewable ones. Biochemical conversion via fermentation is a primary platform for converting renewable sources to biofuels and bulk chemicals. In order to provide cost-competitive alternatives, it is imperative to develop efficient, cost-saving, and robust fermentation processes. Non-sterile fermentation offers several benefits compared to sterile fermentation, including elimination of sterility, reduced maintenance requirements, relatively simple bioreactor design, and simplified operation. Thus, cost effectiveness of non-sterile fermentation makes it a practical platform for low cost, large volume production of biofuels and bulk chemicals. Many approaches have been developed to conduct non-sterile fermentation without sacrificing the yields and productivities of fermentation products. This review focuses on the strategies for conducting non-sterile fermentation. The challenges facing non-sterile fermentation are also discussed.
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Affiliation(s)
- Zhu Chen
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA
| | - Caixia Wan
- Department of Bioengineering, University of Missouri, Columbia, MO, 65211, USA.
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Zhu M, Fan W, Cha Y, Yang X, Lai Z, Li S, Wang X. Dynamic cell responses in Thermoanaerobacterium sp. under hyperosmotic stress. Sci Rep 2017; 7:10088. [PMID: 28855699 PMCID: PMC5577258 DOI: 10.1038/s41598-017-10514-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/09/2017] [Indexed: 12/17/2022] Open
Abstract
As a nongenetic engineering technique, adaptive evolution is an effective and easy-to-operate approach to strain improvement. In this work, a commercial Thermoanaerobacterium aotearoense SCUT27/Δldh-G58 was successfully isolated via sequential batch fermentation with step-increased carbon concentrations. Mutants were isolated under selective high osmotic pressures for 58 passages. The evolved isolate rapidly catabolized sugars at high concentrations and subsequently produced ethanol with good yield. A 1.6-fold improvement of ethanol production was achieved in a medium containing 120 g/L of carbon substrate using the evolved strain, compared to the start strain. The analysis of transcriptome and intracellular solute pools suggested that the adaptive evolution altered the synthesis of some compatible solutes and activated the DNA repair system in the two Thermoanaerobacterium sp. evolved strains. Overall, the results indicated the potential of adaptive evolution as a simple and effective tool for the modification and optimization of industrial microorganisms.
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Affiliation(s)
- Muzi Zhu
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Wudi Fan
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yaping Cha
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Xiaofeng Yang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Zhicheng Lai
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuang Li
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.
| | - Xiaoning Wang
- State Key Laboratory of Kidney, the Institute of Life Sciences, Chinese PLA General Hospital, Beijing, China
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15
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Bosma EF, Forster J, Nielsen AT. Lactobacilli and pediococci as versatile cell factories - Evaluation of strain properties and genetic tools. Biotechnol Adv 2017; 35:419-442. [PMID: 28396124 DOI: 10.1016/j.biotechadv.2017.04.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/29/2017] [Accepted: 04/03/2017] [Indexed: 12/14/2022]
Abstract
This review discusses opportunities and bottlenecks for cell factory development of Lactic Acid Bacteria (LAB), with an emphasis on lactobacilli and pediococci, their metabolism and genetic tools. In order to enable economically feasible bio-based production of chemicals and fuels in a biorefinery, the choice of product, substrate and production organism is important. Currently, the most frequently used production hosts include Escherichia coli and Saccharomyces cerevisiae, but promising examples are available of alternative hosts such as LAB. Particularly lactobacilli and pediococci can offer benefits such as thermotolerance, an extended substrate range and increased tolerance to stresses such as low pH or high alcohol concentrations. This review will evaluate the properties and metabolism of these organisms, and provide an overview of their current biotechnological applications and metabolic engineering. We substantiate the review by including experimental results from screening various lactobacilli and pediococci for transformability, growth temperature range and ability to grow under biotechnologically relevant stress conditions. Since availability of efficient genetic engineering tools is a crucial prerequisite for industrial strain development, genetic tool development is extensively discussed. A range of genetic tools exist for Lactococcus lactis, but for other species of LAB like lactobacilli and pediococci such tools are less well developed. Whereas lactobacilli and pediococci have a long history of use in food and beverage fermentation, their use as platform organisms for production purposes is rather new. By harnessing their properties such as thermotolerance and stress resistance, and by using emerging high-throughput genetic tools, these organisms are very promising as versatile cell factories for biorefinery applications.
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Affiliation(s)
- Elleke F Bosma
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet B220, 2800 Kgs. Lyngby, Denmark
| | - Jochen Forster
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet B220, 2800 Kgs. Lyngby, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet B220, 2800 Kgs. Lyngby, Denmark.
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16
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Abdel-Rahman MA, Sonomoto K. Opportunities to overcome the current limitations and challenges for efficient microbial production of optically pure lactic acid. J Biotechnol 2016; 236:176-92. [DOI: 10.1016/j.jbiotec.2016.08.008] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/11/2016] [Indexed: 10/21/2022]
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17
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Neu AK, Pleissner D, Mehlmann K, Schneider R, Puerta-Quintero GI, Venus J. Fermentative utilization of coffee mucilage using Bacillus coagulans and investigation of down-stream processing of fermentation broth for optically pure l(+)-lactic acid production. BIORESOURCE TECHNOLOGY 2016; 211:398-405. [PMID: 27035470 DOI: 10.1016/j.biortech.2016.03.122] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 06/05/2023]
Abstract
In this study, mucilage, a residue from coffee production, was investigated as substrate in fermentative l(+)-lactic acid production. Mucilage was provided as liquid suspension consisting glucose, galactose, fructose, xylose and sucrose as free sugars (up to 60gL(-1)), and used directly as medium in Bacillus coagulans batch fermentations carried out at 2 and 50L scales. Using mucilage and 5gL(-1) yeast extract as additional nitrogen source, more than 40gL(-1) lactic acid was obtained. Productivity and yield were 4-5gL(-1)h(-1) and 0.70-0.77g lactic acid per g of free sugars, respectively, irrespective the scale. Similar yield was found when no yeast extract was supplied, the productivity, however, was 1.5gL(-1)h(-1). Down-stream processing of culture broth, including filtration, electrodialysis, ion exchange chromatography and distillation, resulted in a pure lactic acid formulation containing 930gL(-1)l(+)-lactic acid. Optical purity was 99.8%.
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Affiliation(s)
- Anna-Katrin Neu
- Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany
| | - Daniel Pleissner
- Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany
| | - Kerstin Mehlmann
- Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany
| | - Roland Schneider
- Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany
| | - Gloria Inés Puerta-Quintero
- Cenicafé, National Coffee Research Center, Sede Planalto, km. 4 via Chinchiná-Manizales, Manizales (Caldas), Colombia
| | - Joachim Venus
- Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany.
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18
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Chirality Matters: Synthesis and Consumption of the d-Enantiomer of Lactic Acid by Synechocystis sp. Strain PCC6803. Appl Environ Microbiol 2015; 82:1295-1304. [PMID: 26682849 DOI: 10.1128/aem.03379-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/09/2015] [Indexed: 12/19/2022] Open
Abstract
Both enantiomers of lactic acid, l-lactic acid and d-lactic acid, can be produced in a sustainable way by a photosynthetic microbial cell factory and thus from CO2, sunlight, and water. Several properties of polylactic acid (a polyester of polymerized lactic acid) depend on the controlled blend of these two enantiomers. Recently, cyanobacterium Synechocystis sp. strain PCC6803 was genetically modified to allow formation of either of these two enantiomers. This report elaborates on the d-lactic acid production achieved by the introduction of a d-specific lactate dehydrogenase from the lactic acid bacterium Leuconostoc mesenteroides into Synechocystis. A typical batch culture of this recombinant strain initially shows lactic acid production, followed by a phase of lactic acid consumption, until production "outcompetes" consumption at later growth stages. We show that Synechocystis is able to use d-lactic acid, but not l-lactic acid, as a carbon source for growth. Deletion of the organism's putative d-lactate dehydrogenase (encoded by slr1556), however, does not eliminate this ability with respect to d-lactic acid consumption. In contrast, d-lactic acid consumption does depend on the presence of glycolate dehydrogenase GlcD1 (encoded by sll0404). Accordingly, this report highlights the need to match a product of interest of a cyanobacterial cell factory with the metabolic network present in the host used for its synthesis and emphasizes the need to understand the physiology of the production host in detail.
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19
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Yang X, Zhu M, Huang X, Lin CSK, Wang J, Li S. Valorisation of mixed bakery waste in non-sterilized fermentation for L-lactic acid production by an evolved Thermoanaerobacterium sp. strain. BIORESOURCE TECHNOLOGY 2015; 198:47-54. [PMID: 26363501 DOI: 10.1016/j.biortech.2015.08.108] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 08/21/2015] [Accepted: 08/22/2015] [Indexed: 06/05/2023]
Abstract
In this study, an advanced biorefinery technology that uses mixed bakery waste has been developed to produce l-lactic acid using an adaptively evolved Thermoanaerobacterium aotearoense LA1002-G40 in a non-sterilized system. Under these conditions, mixed bakery waste was directly hydrolysed by Aspergillus awamori and Aspergillus oryzae, resulting in a nutrient-rich hydrolysate containing 83.6g/L glucose, 9.5 g/L fructose and 612 mg/L free amino nitrogen. T. aotearoense LA1002-G40 was evaluated and then adaptively evolved to grow in this nutrient-rich hydrolysate. Using a 5-L fermenter, the overall lactic acid production from mixed bakery waste was 0.18 g/g with a titer, productivity and yield of 78.5 g/L, 1.63 g/L/h and 0.85 g/g, respectively. This is an innovative procedure involving a complete bioconversion process for l-lactic acid produced from mixed bakery waste under non-sterilized conditions. The proposed process could be potentially applied to turn food waste into l-lactic acid in an economically feasible way.
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Affiliation(s)
- Xiaofeng Yang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China; School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Muzi Zhu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Xiongliang Huang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Carol Sze Ki Lin
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Jufang Wang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Shuang Li
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
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20
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Substitutability of Electricity and Renewable Materials for Fossil Fuels in a Post-Carbon Economy. ENERGIES 2015. [DOI: 10.3390/en81212371] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Zhu M, Lu Y, Wang J, Li S, Wang X. Carbon Catabolite Repression and the Related Genes of ccpA, ptsH and hprK in Thermoanaerobacterium aotearoense. PLoS One 2015; 10:e0142121. [PMID: 26540271 PMCID: PMC4634974 DOI: 10.1371/journal.pone.0142121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/16/2015] [Indexed: 01/09/2023] Open
Abstract
The strictly anaerobic, Gram-positive bacterium, Thermoanaerobacterium aotearoense SCUT27, is capable of producing ethanol, hydrogen and lactic acid by directly fermenting glucan, xylan and various lignocellulosically derived sugars. By using non-metabolizable and metabolizable sugars as substrates, we found that cellobiose, galactose, arabinose and starch utilization was strongly inhibited by the existence of 2-deoxyglucose (2-DG). However, the xylose and mannose consumptions were not markedly affected by 2-DG at the concentration of one-tenth of the metabolizable sugar. Accordingly, T. aotearoense SCUT27 could consume xylose and mannose in the presence of glucose. The carbon catabolite repression (CCR) related genes, ccpA, ptsH and hprK were confirmed to exist in T. aotearoense SCUT27 through gene cloning and protein characterization. The highly purified Histidine-containing Protein (HPr) could be specifically phosphorylated at Serine 46 by HPr kinase/phosphatase (HPrK/P) with no need to add fructose-1,6-bisphosphate (FBP) or glucose-6-phosphate (Glc-6-P) in the reaction mixture. The specific protein-interaction of catabolite control protein A (CcpA) and phosphorylated HPr was proved via affinity chromatography in the absence of formaldehyde. The equilibrium binding constant (KD) of CcpA and HPrSerP was determined as 2.22 ± 0.36 nM by surface plasmon resonance (SPR) analysis, indicating the high affinity between these two proteins.
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Affiliation(s)
- Muzi Zhu
- Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Yanping Lu
- Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Jufang Wang
- Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Shuang Li
- Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
- * E-mail:
| | - Xiaoning Wang
- State Key Laboratory of Kidney, the Institute of Life Sciences, Chinese PLA General Hospital, Beijing, China
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22
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Huang X, Li Z, Du C, Wang J, Li S. Improved Expression and Characterization of a Multidomain Xylanase from Thermoanaerobacterium aotearoense SCUT27 in Bacillus subtilis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:6430-9. [PMID: 26132889 DOI: 10.1021/acs.jafc.5b01259] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A xylanase gene was cloned and characterized from Thermoanerobacterium aotearoense SCUT27, which was attested to consist of a signal peptide, one glycoside hydrolase family 10 domain, four carbohydrate binding modules, and three surface layer homology domains. The change of expression host from Escherichia coli to Bacillus subtilis resulted in a 4.1-fold increase of specific activity for the truncated XynAΔSLH. Five different versions of secretion signals in B. subtilis indicated that it was preferably routed via a Sec-dependent pathway. Purified XynAΔSLH showed a high activity of 379.8 U/mg on beechwood xylan. XynAΔSLH was optimally active at 80 °C, pH 6.5. Thin layer chromatography results showed that xylobiose and the presumed methylglucuronoxylotriose (MeGlcAXyl3) were the main products liberated from beechwood xylan catalyzed by the recombinant xylanase. All of the results suggest that XynAΔSLH is a suitable candidate for generating xylooligosaccharides from cellulosic materials for industrial uses.
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Affiliation(s)
- Xiongliang Huang
- †Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Zhe Li
- †Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Chenyu Du
- §School of Applied Sciences, The University of Huddersfield, Queensgate, Huddersfield, United Kingdom
| | - Jufang Wang
- †Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Shuang Li
- †Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
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23
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Bosma EF, van de Weijer AHP, van der Vlist L, de Vos WM, van der Oost J, van Kranenburg R. Establishment of markerless gene deletion tools in thermophilic Bacillus smithii and construction of multiple mutant strains. Microb Cell Fact 2015; 14:99. [PMID: 26148486 PMCID: PMC4494709 DOI: 10.1186/s12934-015-0286-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/18/2015] [Indexed: 01/22/2023] Open
Abstract
Background Microbial conversion of biomass to fuels or chemicals is an attractive alternative for fossil-based fuels and chemicals. Thermophilic microorganisms have several operational advantages as a production host over mesophilic organisms, such as low cooling costs, reduced contamination risks and a process temperature matching that of commercial hydrolytic enzymes, enabling simultaneous saccharification and fermentation at higher efficiencies and with less enzymes. However, genetic tools for biotechnologically relevant thermophiles are still in their infancy. In this study we developed a markerless gene deletion method for the thermophile Bacillus smithii and we report the first metabolic engineering of this species as a potential platform organism. Results Clean deletions of the ldhL gene were made in two B. smithii strains (DSM 4216T and compost isolate ET 138) by homologous recombination. Whereas both wild-type strains produced mainly l-lactate, deletion of the ldhL gene blocked l-lactate production and caused impaired anaerobic growth and acid production. To facilitate the mutagenesis process, we established a counter-selection system for efficient plasmid removal based on lacZ-mediated X-gal toxicity. This counter-selection system was applied to construct a sporulation-deficient B. smithii ΔldhL ΔsigF mutant strain. Next, we demonstrated that the system can be used repetitively by creating B. smithii triple mutant strain ET 138 ΔldhL ΔsigF ΔpdhA, from which also the gene encoding the α-subunit of the E1 component of the pyruvate dehydrogenase complex is deleted. This triple mutant strain produced no acetate and is auxotrophic for acetate, indicating that pyruvate dehydrogenase is the major route from pyruvate to acetyl-CoA. Conclusions In this study, we developed a markerless gene deletion method including a counter-selection system for thermophilic B. smithii, constituting the first report of metabolic engineering in this species. The described markerless gene deletion system paves the way for more extensive metabolic engineering of B. smithii. This enables the development of this species into a platform organism and provides tools for studying its metabolism, which appears to be different from its close relatives such as B. coagulans and other bacilli. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0286-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elleke F Bosma
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
| | - Antonius H P van de Weijer
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
| | - Laurens van der Vlist
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
| | - Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands. .,Corbion, Arkelsedijk 46, 4206 AC, Gorinchem, The Netherlands.
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24
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Yang F, Yang X, Li Z, Du C, Wang J, Li S. Overexpression and characterization of a glucose-tolerant β-glucosidase from T. aotearoense with high specific activity for cellobiose. Appl Microbiol Biotechnol 2015; 99:8903-15. [DOI: 10.1007/s00253-015-6619-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 04/07/2015] [Accepted: 04/10/2015] [Indexed: 12/20/2022]
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25
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Metabolic engineering as a tool for enhanced lactic acid production. Trends Biotechnol 2014; 32:637-44. [DOI: 10.1016/j.tibtech.2014.10.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 10/02/2014] [Accepted: 10/08/2014] [Indexed: 11/19/2022]
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26
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Peng L, Xie N, Guo L, Wang L, Yu B, Ma Y. Efficient open fermentative production of polymer-grade L-lactate from sugarcane bagasse hydrolysate by thermotolerant Bacillus sp. strain P38. PLoS One 2014; 9:e107143. [PMID: 25192451 PMCID: PMC4156441 DOI: 10.1371/journal.pone.0107143] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/06/2014] [Indexed: 11/18/2022] Open
Abstract
Lactic acid is one of the top 30 potential building-block chemicals from biomass, of which the most extensive use is in the polymerization of lactic acid to poly-lactic-acid (PLA). To reduce the cost of PLA, the search for cheap raw materials and low-cost process for lactic acid production is highly desired. In this study, the final titer of produced L-lactic acid reached a concentration of 185 g·L−1 with a volumetric productivity of 1.93 g·L−1·h−1 by using sugarcane bagasse hydrolysate as the sole carbon source simultaneously with cottonseed meal as cheap nitrogen sources under the open fed-batch fermentation process. Furthermore, a lactic acid yield of 0.99 g per g of total reducing sugars was obtained, which is very close to the theoretical value (1.0 g g−1). No D-isomer of lactic acid was detected in the broth, and thereafter resulted in an optical purity of 100%, which exceeds the requirement of lactate polymerization process. To our knowledge, this is the best performance of fermentation on polymer-grade L-lactic acid production totally using lignocellulosic sources. The high levels of optically pure l-lactic acid produced, combined with the ease of handling and low costs associated with the open fermentation strategy, indicated the thermotolerant Bacillus sp. P38 could be an excellent candidate strain with great industrial potential for polymer-grade L-lactic acid production from various cellulosic biomasses.
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Affiliation(s)
- Lili Peng
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Nengzhong Xie
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Science, Nanning, China
| | - Ling Guo
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Science, Nanning, China
| | - Limin Wang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Bo Yu
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
| | - Yanhe Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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27
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Lai Z, Zhu M, Yang X, Wang J, Li S. Optimization of key factors affecting hydrogen production from sugarcane bagasse by a thermophilic anaerobic pure culture. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:119. [PMID: 25184001 PMCID: PMC4147175 DOI: 10.1186/s13068-014-0119-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 07/28/2014] [Indexed: 05/25/2023]
Abstract
BACKGROUND Hydrogen is regarded as an attractive future energy carrier for its high energy content and zero CO2 emission. Currently, the majority of hydrogen is generated from fossil fuels. However, from an environmental perspective, sustainable hydrogen production from low-cost lignocellulosic biomass should be considered. Thermophilic hydrogen production is attractive, since it can potentially convert a variety of biomass-based substrates into hydrogen at high yields. RESULTS Sugarcane bagasse (SCB) was used as the substrate for hydrogen production by Thermoanaerobacterium aotearoense SCUT27/Δldh. The key parameters of acid hydrolysis were studied through the response surface methodology. The hydrogen production was maximized under the conditions of 2.3% of H2SO4 for 114.2 min at 115°C. Using these conditions, a best hydrogen yield of 1.86 mol H2/mol total sugar and a hydrogen production rate (HPR) of 0.52 L/L · h were obtained from 2 L SCB hydrolysates in a 5-L fermentor, showing a superior performance to the results reported in the literature. Additionally, no obvious carbon catabolite repression (CCR) was observed during the fermentation using the multi-sugars as substrates. CONCLUSIONS Considering these advantages and theimpressive HPR, the potential of hydrogen production using T. aotearoense SCUT27/Δldh is intriguing. Thermophilic, anaerobic fermentation using SCB hydrolysates as the medium by this strain would be a practical and eco-friendly process.
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Affiliation(s)
- Zhicheng Lai
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Panyu District, Guangzhou, 510006 China
| | - Muzi Zhu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Panyu District, Guangzhou, 510006 China
| | - Xiaofeng Yang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Panyu District, Guangzhou, 510006 China
| | - Jufang Wang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Panyu District, Guangzhou, 510006 China
| | - Shuang Li
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Panyu District, Guangzhou, 510006 China
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Draft Genome Sequence of an Anaerobic, Thermophilic Bacterium, Thermoanaerobacterium aotearoense SCUT27, Isolated from a Hot Spring in China. GENOME ANNOUNCEMENTS 2014; 2:2/1/e00041-14. [PMID: 24526632 PMCID: PMC3924364 DOI: 10.1128/genomea.00041-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Thermoanaerobacterium aotearoense SCUT27, isolated from a hot spring in China, is a strictly anaerobic, thermophilic bacterium capable of degrading xylan and converting both pentose and hexose to ethanol with high yields. Here, we report the draft genome sequence of SCUT27, which reveals insights into the mechanisms of carbon source coutilization and xylan degradation in this thermophilic microorganism.
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