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Saxena A, Hussain A, Parveen F, Ashfaque M. Current status of metabolic engineering of microorganisms for bioethanol production by effective utilization of pentose sugars of lignocellulosic biomass. Microbiol Res 2023; 276:127478. [PMID: 37625339 DOI: 10.1016/j.micres.2023.127478] [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: 05/08/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023]
Abstract
Lignocellulosic biomass, consisting of homo- and heteropolymeric sugars, acts as a substrate for the generation of valuable biochemicals and biomaterials. The readily available hexoses are easily utilized by microbes due to the presence of transporters and native metabolic pathways. But, utilization of pentose sugar viz., xylose and arabinose are still challenging due to several reasons including (i) the absence of the particular native pathways and transporters, (ii) the presence of inhibitors, and (iii) lower uptake of pentose sugars. These challenges can be overcome by manipulating metabolic pathways/glycosidic enzymes cascade by using genetic engineering tools involving inverse-metabolic engineering, ex-vivo isomerization, Adaptive Laboratory Evolution, Directed Metabolic Engineering, etc. Metabolic engineering of bacteria and fungi for the utilization of pentose sugars for bioethanol production is the focus area of research in the current decade. This review outlines current approaches to biofuel development and strategies involved in the metabolic engineering of different microbes that can uptake pentose for bioethanol production.
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Affiliation(s)
- Ayush Saxena
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
| | - Akhtar Hussain
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
| | - Fouziya Parveen
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
| | - Mohammad Ashfaque
- Lignocellulose & Biofuel Laboratory, Department of Biosciences, Integral University, Lucknow 226026, Uttar Pradesh, India.
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Qiu Y, Qiu Z, Xia J, Liu X, Zhang H, Yang Y, Hou W, Li X, He J. Co-expression of Xylose Transporter and Fructose-Bisphosphate Aldolase Enhances the Utilization of Xylose by Lactococcus lactis IO-1. Appl Biochem Biotechnol 2023; 195:816-831. [PMID: 36205844 DOI: 10.1007/s12010-022-04168-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 01/24/2023]
Abstract
The raw material cost of lactic acid fermentation accounts for the main part of the production cost, and this necessitates the exploration of the efficient use of cheap raw materials in lactic acid production. We compared the outcomes of the homologous expressions of xylose transporters (xylFGH, xylE, araE, and xylT), 6-phosphofructokinase (pfkA), fructose-bisphosphate aldolase (fbaA), and their co-expression in Lactococcus lactis IO-1 on lactic acid production using xylose as the raw material. We found that the production rate of lactic acid on xylose fermentation by L. lactis IO-1 overexpressing fbaA was the highest (14.42%). Among the xylose transporters investigated, XylT had the strongest xylose transport capacity in L. lactis IO-1, with an increase in the lactic acid production rate by 10.38%. The genes near the overexpression of fbaA or xylT in the metabolic pathway were more upregulated than the distant genes. The co-expression of fbaA and xylT increased the production rate of lactic acid by 27.84% on xylose fermentation by L. lactis IO-1. This work presents a novel strategy for the simultaneous enhancement of the expression of important genes at the beginning and midway of the xylose metabolic pathway of L. lactis IO-1, which could greatly improve the target production.
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Affiliation(s)
- Yejuan Qiu
- Jiangsu Provincial Key Construction Laboratory of Probiotics Preparation, Huaiyin Institute of Technology, 1 Meicheng Road, Huaian, 223003, Jiangsu Province, China
| | - Zhongyang Qiu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiang West Road, Huaian, 223300, Jiangsu Province, China
| | - Jun Xia
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiang West Road, Huaian, 223300, Jiangsu Province, China
| | - Xiaoyan Liu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiang West Road, Huaian, 223300, Jiangsu Province, China
| | - Hanwen Zhang
- Jiangsu Provincial Key Construction Laboratory of Probiotics Preparation, Huaiyin Institute of Technology, 1 Meicheng Road, Huaian, 223003, Jiangsu Province, China
| | - Yuxiang Yang
- Jiangsu Provincial Key Construction Laboratory of Probiotics Preparation, Huaiyin Institute of Technology, 1 Meicheng Road, Huaian, 223003, Jiangsu Province, China
| | - Wenyi Hou
- Jiangsu Provincial Key Construction Laboratory of Probiotics Preparation, Huaiyin Institute of Technology, 1 Meicheng Road, Huaian, 223003, Jiangsu Province, China
| | - Xiangqian Li
- Jiangsu Provincial Key Construction Laboratory of Probiotics Preparation, Huaiyin Institute of Technology, 1 Meicheng Road, Huaian, 223003, Jiangsu Province, China.
| | - Jianlong He
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiang West Road, Huaian, 223300, Jiangsu Province, China.
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Oliveira-Filho ER, de Macedo MA, Lemos ACC, Adams F, Merkel OM, Taciro MK, Gomez JGC, Silva LF. Engineering Burkholderia sacchari to enhance poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] production from xylose and hexanoate. Int J Biol Macromol 2022; 213:902-914. [PMID: 35690163 DOI: 10.1016/j.ijbiomac.2022.06.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/21/2022] [Accepted: 06/05/2022] [Indexed: 12/26/2022]
Abstract
Burkholderia sacchari LFM101 LMG19450T is a Brazilian bacterium isolated from sugarcane crops soil and a promising biotechnological platform for bioprocesses. It is an efficient producer of poly(3-hydroxybutyrate) from carbohydrates including xylose. In the present work, the expression of B. sacchari xylose consumption genes (xylA, xylB and tktA) was combined with the expression of Aeromonas sp. phaC (PHA synthase), aiming to increase both the growth rates in xylose and the 3-hydroxyhexanoate (3HHx) molar fractions in the produced PHA. Genes were cloned into pBBR1MCS-2 vectors and then expressed in the B. sacchari PHA- mutant LFM344. Maximum specific growth rates on xylose and PHA accumulation capacity of all recombinants were evaluated. In bioreactor experiments, up to 55.5 % CDW was accumulated as copolymer, hexanoate conversion to 3HHx raised from 2 % to 54 % of the maximum theoretical value, compared to wild type. 3HHx mol% ranged from 8 to 35, and molecular weights were between 111 and 220 kg/mol. Thermal analysis measurement showed a decrease in Tg and Tm values with higher 3HHx fraction, indicating improved thermomechanical characteristics. Recombinants construction and bioreactor strategies allowed the production of P(3HB-co-3HHx) with controlled monomeric composition from xylose and hexanoate, allowing its application in diverse fields, including the medical area.
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Affiliation(s)
- Edmar R Oliveira-Filho
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil; Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians University Munich, 81337 Munich, Germany
| | - Matheus A de Macedo
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Aline C C Lemos
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Friederike Adams
- Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians University Munich, 81337 Munich, Germany
| | - Olivia M Merkel
- Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians University Munich, 81337 Munich, Germany
| | - Marilda K Taciro
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - José Gregório C Gomez
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Luiziana F Silva
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Yong MI, Mohamad MS, Choon YW, Chan WH, Adli HK, Syazwan WSW KN, Yusoff N, Remli MA. A hybrid of Bees algorithm and regulatory on/off minimization for optimizing lactate and succinate production. J Integr Bioinform 2022; 19:jib-2022-0003. [PMID: 35852123 PMCID: PMC9521821 DOI: 10.1515/jib-2022-0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/26/2022] [Indexed: 12/03/2022] Open
Abstract
Metabolic engineering has expanded in importance and employment in recent years and is now extensively applied particularly in the production of biomass from microbes. Metabolic network models have been employed extravagantly in computational processes developed to enhance metabolic production and suggest changes in organisms. The crucial issue has been the unrealistic flux distribution presented in prior work on rational modelling framework adopting Optknock and OptGene. In order to address the problem, a hybrid of Bees Algorithm and Regulatory On/Off Minimization (BAROOM) is used. By employing Escherichia coli as the model organism, the most excellent set of genes in E. coli that can be removed and advance the production of succinate can be decided. Evidences shows that BAROOM outperforms alternative strategies used to escalate in succinate production in model organisms like E. coli by selecting the best set of genes to be removed.
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Affiliation(s)
- Mohd Izzat Yong
- Artificial Intelligence and Bioinformatics Research Group, Faculty of Computing, Universiti Teknologi Malaysia, 81310Johor, Malaysia
| | - Mohd Saberi Mohamad
- Health Data Science Lab Department of Genetics and Genomics,College of Medical and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, Abu Dhabi, United Arab Emirates
- Big Data Analytics Center, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Yee Wen Choon
- Institute for Artificial Intelligence and Big Data, Universiti Malaysia Kelantan, Kota Bharu, 16100, Kelantan, Malaysia
- Department of Data Science, Universiti Malaysia Kelantan, City Campus, Pengkalan Chepa, 16100Kota Bharu, Kelantan, Malaysia
| | - Weng Howe Chan
- Artificial Intelligence and Bioinformatics Research Group, Faculty of Computing, Universiti Teknologi Malaysia, 81310Johor, Malaysia
| | - Hasyiya Karimah Adli
- Institute for Artificial Intelligence and Big Data, Universiti Malaysia Kelantan, Kota Bharu, 16100, Kelantan, Malaysia
- Department of Data Science, Universiti Malaysia Kelantan, City Campus, Pengkalan Chepa, 16100Kota Bharu, Kelantan, Malaysia
| | - Khairul Nizar Syazwan WSW
- Institute for Artificial Intelligence and Big Data, Universiti Malaysia Kelantan, Kota Bharu, 16100, Kelantan, Malaysia
- Department of Data Science, Universiti Malaysia Kelantan, City Campus, Pengkalan Chepa, 16100Kota Bharu, Kelantan, Malaysia
| | - Nooraini Yusoff
- Institute for Artificial Intelligence and Big Data, Universiti Malaysia Kelantan, Kota Bharu, 16100, Kelantan, Malaysia
- Department of Data Science, Universiti Malaysia Kelantan, City Campus, Pengkalan Chepa, 16100Kota Bharu, Kelantan, Malaysia
| | - Muhammad Akmal Remli
- Institute for Artificial Intelligence and Big Data, Universiti Malaysia Kelantan, Kota Bharu, 16100, Kelantan, Malaysia
- Department of Data Science, Universiti Malaysia Kelantan, City Campus, Pengkalan Chepa, 16100Kota Bharu, Kelantan, Malaysia
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Song H, Yang Y, Li H, Du J, Hu Z, Chen Y, Yang N, Mei M, Xiong Z, Tang K, Yi L, Zhang Y, Yang S. Determination of Nucleotide Sequences within Promoter Regions Affecting Promoter Compatibility between Zymomonas mobilis and Escherichia coli. ACS Synth Biol 2022; 11:2811-2819. [PMID: 35771099 DOI: 10.1021/acssynbio.2c00187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A promoter plays a crucial role in controlling the expression of the target gene in cells, thus being one of the key biological parts for synthetic biology practices. Although significant efforts have been made to identify and characterize promoters with different strengths in various microorganisms, the compatibility of promoters within different hosts still lacks investigation. In this study, we chose the native Pgap promoter of Zymomonas mobilis to investigate nucleotide sequences within promoter regions affecting promoter compatibility between Escherichia coli and Z. mobilis. Pgap is one of the strongest promotors in Z. mobilis that has many excellent characteristics to be developed as microbial cell factories. Using EGFP as a reporter, a Z. mobilis-derived Pgap mutant library was constructed and sorted in E. coli, with candidate promoters exhibiting high fluorescence intensity collected. A total of 53 variants were finally selected and sequenced by Sanger sequencing. The sequencing results grouped these variants into 12 different Pgap variant types, among which seven types presented higher promoter strength than native Pgap in E. coli. The next-generation sequencing technique was then employed to identify key mutations within the Pgap promoter region that affect the promoter compatibility. Finally, six important sites were identified and confirmed to help increase Pgap strength in E. coli while keeping similar strength of native Pgap in Z. mobilis. Compared to native Pgap, synthetic promoters combining these sites had enhanced strength; especially, Pgap-6M combining all six sites exhibited 20-fold greater strength than native Pgap in E. coli. This study thus not only determined six important sites affecting promoter compatibility but also confirmed a series of Pgap promoter variants with strong promoter activity in both E. coli and Z. mobilis. In addition, a strategy was established in this study to investigate and determine nucleotide sequences in promoter regions affecting promoter compatibility, which can be applied in other microorganisms to help reveal universal factors affecting promoter compatibility and design promoters with desired strengths among different microbial cell factories.
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Affiliation(s)
- Haoyue Song
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Yongfu Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Han Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Jun Du
- Beijing Tsingke Biotechnology Co., Ltd., Beijing 101111, China
| | - Zhousheng Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Yunhao Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Ning Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Meng Mei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Zhiqiang Xiong
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Ke Tang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Li Yi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
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Chettri D, Verma AK, Verma AK. Innovations in CAZyme gene diversity and its modification for biorefinery applications. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 28:e00525. [PMID: 32963975 PMCID: PMC7490808 DOI: 10.1016/j.btre.2020.e00525] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/04/2020] [Accepted: 08/30/2020] [Indexed: 02/07/2023]
Abstract
For sustainable growth, concept of biorefineries as recourse to the "fossil derived" energy source is important. Here, the Carbohydrate Active enZymes (CAZymes) play decisive role in generation of biofuels and related sugar-based products utilizing lignocellulose as a carbon source. Given their industrial significance, extensive studies on the evolution of CAZymes have been carried out. Various bacterial and fungal organisms have been scrutinized for the development of CAZymes, where advance techniques for strain enhancement such as CRISPR and analysis of specific expression systems have been deployed. Specific Omic-based techniques along with protein engineering have been adopted to unearth novel CAZymes and improve applicability of existing enzymes. In-Silico computational research and functional annotation of new CAZymes to synergy experiments are being carried out to devise cocktails of enzymes for use in biorefineries. Thus, with the establishment of these technologies, increased diversity of CAZymes with broad span of functions and applications is seen.
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Wen Z, Lu M, Ledesma-Amaro R, Li Q, Jin M, Yang S. TargeTron Technology Applicable in Solventogenic Clostridia: Revisiting 12 Years' Advances. Biotechnol J 2019; 15:e1900284. [PMID: 31475782 DOI: 10.1002/biot.201900284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 08/20/2019] [Indexed: 12/11/2022]
Abstract
Clostridium has great potential in industrial application and medical research. But low DNA repair capacity and plasmids transformation efficiency severely delay development and application of genetic tools based on homologous recombination (HR). TargeTron is a gene editing technique dependent on the mobility of group II introns, rather than homologous recombination, which makes it very suitable for gene disruption of Clostridium. The application of TargeTron technology in solventogenic Clostridium is academically reported in 2007 and this tool has been introduced in various clostridia as it is easy to operate, time saving, and reliable. TargeTron has made great progress in solventogenic Clostridium in the aspects of acetone-butanol-ethanol (ABE) fermentation pathway modification, important functional genes identification, and xylose metabolic pathway analysis and reconstruction. In the review, 12 years' advances of TargeTron technology applicable in solventogenic Clostridium, including its principle, technical characteristics, application, and efforts to expand its capabilities, or to avoid potential drawbacks, are revisisted. Some other technologies as putative competitors or collaborators are also discussed. It is believed that TargeTron combined with CRISPR/Cas-assisted gene/base editing and gene-expression regulation system will make a better future for clostridial genetic modification.
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Affiliation(s)
- Zhiqiang Wen
- School of Environmental and Biological Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
| | - Minrui Lu
- School of Environmental and Biological Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
| | | | - Qi Li
- College of Life Sciences, Sichuan Normal University, Longquan, Chengdu, 610101, China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.,Huzhou Center of Industrial Biotechnology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Zhejiang, 313000, China
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Chemical Pretreatment-Independent Saccharifications of Xylan and Cellulose of Rice Straw by Bacterial Weak Lignin-Binding Xylanolytic and Cellulolytic Enzymes. Appl Environ Microbiol 2017; 83:AEM.01522-17. [PMID: 28864653 DOI: 10.1128/aem.01522-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 08/27/2017] [Indexed: 12/14/2022] Open
Abstract
Complete utilization of carbohydrate fractions is one of the prerequisites for obtaining economically favorable lignocellulosic biomass conversion. This study shows that xylan in untreated rice straw was saccharified to xylose in one step without chemical pretreatment, yielding 58.2% of the theoretically maximum value by Paenibacillus curdlanolyticus B-6 PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase. Moreover, xylose yield from untreated rice straw was enhanced to 78.9% by adding endoxylanases PcXyn10C and PcXyn11A from the same bacterium, resulting in improvement of cellulose accessibility to cellulolytic enzyme. After autoclaving the xylanolytic enzyme-treated rice straw, it was subjected to subsequent saccharification by a combination of the Clostridium thermocellum endoglucanase CtCel9R and Thermoanaerobacter brockii β-glucosidase TbCglT, yielding 88.5% of the maximum glucose yield, which was higher than the glucose yield obtained from ammonia-treated rice straw saccharification (59.6%). Moreover, this work presents a new environment-friendly xylanolytic enzyme pretreatment for beneficial hydrolysis of xylan in various agricultural residues, such as rice straw and corn hull. It not only could improve cellulose saccharification but also produced xylose, leading to an improvement of the overall fermentable sugar yields without chemical pretreatment.IMPORTANCE Ongoing research is focused on improving "green" pretreatment technologies in order to reduce energy demands and environmental impact and to develop an economically feasible biorefinery. The present study showed that PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase from P. curdlanolyticus B-6, was capable of conversion of xylan in lignocellulosic biomass such as untreated rice straw to xylose in one step without chemical pretreatment. It demonstrates efficient synergism with endoxylanases PcXyn10C and PcXyn11A to depolymerize xylan in untreated rice straw and enhanced the xylose production and improved cellulose hydrolysis. Therefore, it can be considered an enzymatic pretreatment. Furthermore, the studies here show that glucose yield released from steam- and xylanolytic enzyme-treated rice straw by the combination of CtCel9R and TbCglT was higher than the glucose yield obtained from ammonia-treated rice straw saccharification. This work presents a novel environment-friendly xylanolytic enzyme pretreatment not only as a green pretreatment but also as an economically feasible biorefinery method.
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Liu YF, Hsieh CW, Chang YS, Wung BS. Effect of acetic acid on ethanol production by Zymomonas mobilis mutant strains through continuous adaptation. BMC Biotechnol 2017; 17:63. [PMID: 28764759 PMCID: PMC5540488 DOI: 10.1186/s12896-017-0385-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/25/2017] [Indexed: 02/03/2023] Open
Abstract
Background Acetic acid is a predominant by-product of lignocellulosic biofuel process, which inhibits microbial biocatalysts. Development of bacterial strains that are tolerant to acetic acid is challenging due to poor understanding of the underlying molecular mechanisms. Results In this study, we generated and characterized two acetic acid-tolerant strains of Zymomonas mobilis using N-methyl-N′-nitro-N-nitrosoguanidine (NTG)-acetate adaptive breeding. Two mutants, ZMA-142 and ZMA-167, were obtained, showing a significant growth rate at a concentration of 244 mM sodium acetate, while the growth of Z. mobilis ATCC 31823 were completely inhibited in presence of 195 mM sodium acetate. Our data showed that acetate-tolerance of ZMA-167 was attributed to a co-transcription of nhaA from ZMO0117, whereas the co-transcription was absent in ATCC 31823 and ZMA-142. Moreover, ZMA-142 and ZMA-167 exhibited a converstion rate (practical ethanol yield to theorical ethanol yield) of 90.16% and 86% at 195 mM acetate-pH 5 stress condition, respectively. We showed that acid adaptation of ZMA-142 and ZMA-167 to 146 mM acetate increased ZMA-142 and ZMA-167 resulted in an increase in ethanol yield by 32.21% and 21.16% under 195 mM acetate-pH 5 stress condition, respectively. Conclusion The results indicate the acetate-adaptive seed culture of acetate-tolerant strains, ZMA-142 and ZMA-167, could enhance the ethanol production during fermentation.
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Affiliation(s)
- Yu-Fan Liu
- Division of Allergy, Department of Pediatrics, Chung-Shan Medical University Hospital, Taichung, Taiwan.,Department of Biomedical Sciences, College of Medicine Sciences and Technology, Chung Shan Medical University, Taichung, Taiwan
| | - Chia-Wen Hsieh
- Department of Microbiology, Immunology and Biopharmaceuticals, National Chiayi University, Chiayi, Taiwan.
| | - Yao-Sheng Chang
- Department of Microbiology, Immunology and Biopharmaceuticals, National Chiayi University, Chiayi, Taiwan
| | - Being-Sun Wung
- Department of Microbiology, Immunology and Biopharmaceuticals, National Chiayi University, Chiayi, Taiwan
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Going beyond E. coli: autotransporter based surface display on alternative host organisms. N Biotechnol 2015; 32:644-50. [PMID: 25579193 DOI: 10.1016/j.nbt.2014.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/19/2014] [Accepted: 12/31/2014] [Indexed: 11/21/2022]
Abstract
Autotransporters represent one of the most popular anchoring motifs used to display peptides, proteins or enzymes on the cell surface of a Gram-negative bacterium. Applications range from vaccine delivery to library screenings to biocatalysis and bioremediation. Although the underlying secretion mechanism is supposed to be available in most, if not all, Gram-negative bacteria, autotransporters have to date almost exclusively been used for surface display on Escherichia coli. However, for their utilisation beyond a laboratory scale, in particular for biocatalysis, host bacteria with specific features and industrial applicability are required. A few groups have addressed this issue and demonstrated that bacteria other than E. coli can also be used for autotransporter based surface display. We summarise these studies and discuss opportunities and challenges that arise from surface display of recombinant proteins using the autotransporter pathway in alternative hosts.
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Tozakidis IE, Sichwart S, Teese MG, Jose J. Autotransporter mediated esterase display on Zymomonas mobilis and Zymobacter palmae. J Biotechnol 2014; 191:228-35. [DOI: 10.1016/j.jbiotec.2014.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/01/2014] [Accepted: 07/08/2014] [Indexed: 01/02/2023]
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12
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Yin J, Chen JC, Wu Q, Chen GQ. Halophiles, coming stars for industrial biotechnology. Biotechnol Adv 2014; 33:1433-42. [PMID: 25447783 DOI: 10.1016/j.biotechadv.2014.10.008] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/10/2014] [Accepted: 10/19/2014] [Indexed: 10/24/2022]
Abstract
Industrial biotechnology aims to produce chemicals, materials and biofuels to ease the challenges of shortage on petroleum. However, due to the disadvantages of bioprocesses including energy consuming sterilization, high fresh water consumption, discontinuous fermentation to avoid microbial contamination, highly expensive stainless steel fermentation facilities and competing substrates for human consumption, industrial biotechnology is less competitive compared with chemical processes. Recently, halophiles have shown promises to overcome these shortcomings. Due to their unique halophilic properties, some halophiles are able to grow in high pH and high NaCl containing medium under higher temperature, allowing fermentation processes to run contamination free under unsterile conditions and continuous way. At the same time, genetic manipulation methods have been developed for halophiles. So far, halophiles have been used to produce bioplastics polyhydroxyalkanoates (PHA), ectoines, enzymes, and bio-surfactants. Increasing effects have been made to develop halophiles into a low cost platform for bioprocessing with advantages of low energy, less fresh water consumption, low fixed capital investment, and continuous production.
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Affiliation(s)
- Jin Yin
- MOE Key Lab of Bioinformatics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jin-Chun Chen
- MOE Key Lab of Bioinformatics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiong Wu
- MOE Key Lab of Bioinformatics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guo-Qiang Chen
- MOE Key Lab of Bioinformatics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.
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Jia X, Wei N, Wang T, Wang H. Use of an EZ-Tn5-based random mutagenesis system to create a Zymomonas mobilis with significant tolerance to heat stress and malnutrition. J Ind Microbiol Biotechnol 2013; 40:811-22. [PMID: 23702574 DOI: 10.1007/s10295-013-1287-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 05/07/2013] [Indexed: 11/30/2022]
Abstract
During ethanol production, the fermentation cells are always exposed to stresses like high temperature and low nutritional conditions, which affect their growth and productivity. Stress-tolerant strains with high ethanol yield are highly desirable. Therefore, a recombinant Zymomonas mobilis (Z. mobilis) designated as HYM was constructed by integrating three genes (yfdZ, metB, and Pfu-sHSP) into the genome of Z. mobilis CP4 (CP4) via Tn5 transposon in the present study. The yfdZ and metB genes from E. coli were used to decrease the nutritional requirement. The small heat shock protein gene (Pfu-sHSP) from Pyrococcus furiosus (P. furiosus) was used to increase the heat tolerance. The genomic integration of three genes confers on Z. mobilis the ability to grow in simple chemical defined medium without the addition of amino acid. The HYM not only demonstrated the high tolerance to unfavorable lower nutrition stresses but also the capability of converting glucose to ethanol with high yield at higher temperature. What is more, these genetic characteristics were stable up to 100 generations on nonselective medium. The effects of glucose concentration, fermentation temperature, and initial pH on ethanol production of the mutant strain HYM were optimized using a Box-Behnken design (BBD) experiment. The integration of three genes led to a significant increase in ethanol production by 9 % compared with its original Z. mobilis counterpart. The maximum ethanol production of HYM was as high as 105 g/l.
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Affiliation(s)
- Xianghui Jia
- Key Laboratory of Fermentation Engineering, Ministry of Education, Hubei University of Technology, Wuhan, 430068, China
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14
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Direct ethanol production from cellulosic materials by Zymobacter palmae carrying Cellulomonas endoglucanase and Ruminococcus β-glucosidase genes. Appl Microbiol Biotechnol 2013; 97:5137-47. [DOI: 10.1007/s00253-013-4874-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 10/26/2022]
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15
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Zheng J, Tashiro Y, Yoshida T, Gao M, Wang Q, Sonomoto K. Continuous butanol fermentation from xylose with high cell density by cell recycling system. BIORESOURCE TECHNOLOGY 2013; 129:360-365. [PMID: 23262012 DOI: 10.1016/j.biortech.2012.11.066] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 11/12/2012] [Accepted: 11/17/2012] [Indexed: 06/01/2023]
Abstract
A continuous butanol production system with high-density Clostridium saccharoperbutylacetonicum N1-4 generated by cell recycling was established to examine the characteristics of butanol fermentation from xylose. In continuous culture without cell recycling, cell washout was avoided by maintaining pH>5.6 at a dilution rate of 0.26 h(-1), indicating pH control was critical to this experiment. Subsequently, continuous culture with cell recycling increased cell concentration to 17.4 g L(-1), which increased butanol productivity to 1.20 g L(-1) h(-1) at a dilution rate of 0.26 h(-1) from 0.529 g L(-1) h(-1) without cell recycling. The effect of dilution rates on butanol production was also investigated in continuous culture with cell recycling. Maximum butanol productivity (3.32 g L(-1) h(-1)) was observed at a dilution rate of 0.78 h(-1), approximately 6-fold higher than observed in continuous culture without cell recycling (0.529 g L(-1) h(-1)).
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Affiliation(s)
- Jin Zheng
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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16
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Kojima M, Akahoshi T, Okamoto K, Yanase H. Expression and surface display of Cellulomonas endoglucanase in the ethanologenic bacterium Zymobacter palmae. Appl Microbiol Biotechnol 2012; 96:1093-104. [DOI: 10.1007/s00253-012-4424-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/06/2012] [Accepted: 09/07/2012] [Indexed: 11/29/2022]
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17
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Abstract
The two metabolically versatile actinobacteria Rhodococcus opacus PD630 and R. jostii RHA1 can efficiently convert diverse organic substrates into neutral lipids mainly consisting of triacylglycerol (TAG), the precursor of energy-rich hydrocarbon. Neither, however, is able to utilize xylose, the important component present in lignocellulosic biomass, as the carbon source for growth and lipid accumulation. In order to broaden their substrate utilization range, the metabolic pathway of d-xylose utilization was introduced into these two strains. This was accomplished by heterogenous expression of two well-selected genes, xylA, encoding xylose isomerase, and xylB, encoding xylulokinase from Streptomyces lividans TK23, under the control of the tac promoter with an Escherichia coli-Rhodococcus shuttle vector. The recombinant R. jostii RHA1 bearing xylA could grow on xylose as the sole carbon source, and additional expression of xylB further improved the biomass yield. The recombinant could consume both glucose and xylose in the sugar mixture, although xylose metabolism was still affected by the presence of glucose. The xylose metabolic pathway was also introduced into the high-lipid-producing strain R. opacus PD630 by expression of xylA and xylB. Under nitrogen-limited conditions, the fatty acid composition was determined, and lipid produced from xylose by recombinants of R. jostii RHA1 and R. opacus PD630 carrying xylA and xylB represented up to 52.5% and 68.3% of the cell dry weight (CDW), respectively. This work demonstrates that it is feasible to produce lipid from the sugars, including xylose, derived from renewable feedstock by genetic modification of rhodococcus strains.
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Yanase H, Miyawaki H, Sakurai M, Kawakami A, Matsumoto M, Haga K, Kojima M, Okamoto K. Ethanol production from wood hydrolysate using genetically engineered Zymomonas mobilis. Appl Microbiol Biotechnol 2012; 94:1667-78. [DOI: 10.1007/s00253-012-4094-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Revised: 04/01/2012] [Accepted: 04/10/2012] [Indexed: 10/28/2022]
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19
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Designer Xylanosomes: Protein Nanostructures for Enhanced Xylan Hydrolysis. Appl Biochem Biotechnol 2012; 167:395-411. [DOI: 10.1007/s12010-012-9680-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/10/2012] [Indexed: 10/28/2022]
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20
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Ma Y, Dong H, Zou S, Hong J, Zhang M. Comparison of glucose/xylose co-fermentation by recombinant Zymomonas mobilis under different genetic and environmental conditions. Biotechnol Lett 2012; 34:1297-304. [DOI: 10.1007/s10529-012-0897-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
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Meijnen JP, de Winde JH, Ruijssenaars HJ. Metabolic and regulatory rearrangements underlying efficient D-xylose utilization in engineered Pseudomonas putida S12. J Biol Chem 2012; 287:14606-14. [PMID: 22416130 DOI: 10.1074/jbc.m111.337501] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Previously, an efficient D-xylose utilizing Pseudomonas putida S12 strain was obtained by introducing the D-xylose isomerase pathway from Escherichia coli, followed by evolutionary selection. In the present study, systemic changes associated with the evolved phenotype were identified by transcriptomics, enzyme activity analysis, and inverse engineering. A key element in improving the initially poor D-xylose utilization was the redistribution of 6-phospho-D-gluconate (6-PG) between the Entner-Doudoroff pathway and the oxidative pentose phosphate (PP) pathway. This redistribution increased the availability of 6-PG for oxidative decarboxylation to D-ribose-5-phosphate, which is essential for the utilization of D-xylose via the nonoxidative PP pathway. The metabolic redistribution of 6-PG was procured by modified HexR regulation, which in addition appeared to control periplasmic sugar oxidation. Because the absence of periplasmic D-xylonate formation was previously demonstrated to be essential for achieving a high biomass yield on D-xylose, the aberrant HexR control appeared to underlie both the improved growth rate and biomass yield of the evolved D-xylose utilizing P. putida strain. The increased oxidative PP pathway activity furthermore resulted in an elevated NADH/NAD(+) ratio that caused the metabolic flux to be redirected from the TCA cycle to the glyoxylate shunt, which was also activated transcriptionally. Clearly, these findings may serve as an important case in point to engineer and improve the utilization of non-natural carbon sources in a wide range of industrial microorganisms.
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Affiliation(s)
- Jean-Paul Meijnen
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
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22
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Argandoña M, Vargas C, Reina-Bueno M, Rodríguez-Moya J, Salvador M, Nieto JJ. An extended suite of genetic tools for use in bacteria of the Halomonadaceae: an overview. Methods Mol Biol 2012; 824:167-201. [PMID: 22160899 DOI: 10.1007/978-1-61779-433-9_9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Halophilic gammaproteobacteria of the family Halomonadaceae (including the genera Aidingimonas, Carnimonas, Chromohalobacter, Cobetia, Halomonas, Halotalea, Kushneria, Modicisalibacter, Salinicola, and Zymobacter) have current and promising applications in biotechnology mainly as a source of compatible solutes (powerful stabilizers of biomolecules and cells, with exciting potentialities in biomedicine), salt-tolerant enzymes, biosurfactants, and extracellular polysaccharides, among other products. In addition, they display a number of advantages to be used as cell factories, alternative to conventional prokaryotic hosts like Escherichia coli or Bacillus, for the production of recombinant proteins: (1) their high salt tolerance decreases to a minimum the necessity for aseptic conditions, resulting in cost-reducing conditions, (2) they are very easy to grow and maintain in the laboratory, and their nutritional requirements are simple, and (3) the majority can use a large range of compounds as a sole carbon and energy source. In the last 15 years, the efforts of our group and others have made possible the genetic manipulation of this bacterial group. In this review, the most relevant and recent tools for their genetic manipulation are described, with emphasis on nucleic acid isolation procedures, cloning and expression vectors, genetic exchange mechanisms, mutagenesis approaches, reporter genes, and genetic expression analyses. Complementary sections describing the influence of salinity on the susceptibility of these bacteria to antimicrobials, as well as the growth media most routinely used and culture conditions, for these microorganisms, are also included.
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Affiliation(s)
- Montserrat Argandoña
- Department of Microbiology and Parasitology, University of Seville, Seville, Spain
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Comparative shotgun proteomic analysis of Clostridium acetobutylicum from butanol fermentation using glucose and xylose. Proteome Sci 2011; 9:66. [PMID: 22008648 PMCID: PMC3212805 DOI: 10.1186/1477-5956-9-66] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 10/18/2011] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Butanol is a second generation biofuel produced by Clostridium acetobutylicum through acetone-butanol-ethanol (ABE) fermentation process. Shotgun proteomics provides a direct approach to study the whole proteome of an organism in depth. This paper focuses on shotgun proteomic profiling of C. acetobutylicum from ABE fermentation using glucose and xylose to understand the functional mechanisms of C. acetobutylicum proteins involved in butanol production. RESULTS We identified 894 different proteins in C. acetobutylicum from ABE fermentation process by two dimensional - liquid chromatography - tandem mass spectrometry (2D-LC-MS/MS) method. This includes 717 proteins from glucose and 826 proteins from the xylose substrate. A total of 649 proteins were found to be common and 22 significantly differentially expressed proteins were identified between glucose and xylose substrates. CONCLUSION Our results demonstrate that flagellar proteins are highly up-regulated with glucose compared to xylose substrate during ABE fermentation. Chemotactic activity was also found to be lost with the xylose substrate due to the absence of CheW and CheV proteins. This is the first report on the shotgun proteomic analysis of C. acetobutylicum ATCC 824 in ABE fermentation between glucose and xylose substrate from a single time data point and the number of proteins identified here is more than any other study performed on this organism up to this report.
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Fan JX, Yang Q, Liu ZH, Huang XM, Song JZ, Chen ZX, Sun Y, Liang Q, Wang S. The characterization of transaldolase gene tal from Pichia stipitis and its heterologous expression in Fusarium oxysporum. Mol Biol Rep 2010; 38:1831-40. [DOI: 10.1007/s11033-010-0299-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 09/03/2010] [Indexed: 11/28/2022]
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25
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la Grange DC, den Haan R, van Zyl WH. Engineering cellulolytic ability into bioprocessing organisms. Appl Microbiol Biotechnol 2010; 87:1195-208. [DOI: 10.1007/s00253-010-2660-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 05/02/2010] [Accepted: 05/02/2010] [Indexed: 10/19/2022]
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26
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Zhao H, Baker GA, Cowins JV. Fast enzymatic saccharification of switchgrass after pretreatment with ionic liquids. Biotechnol Prog 2010; 26:127-33. [PMID: 19918908 DOI: 10.1002/btpr.331] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The pretreatment of cellulose using ionic liquids (ILs) has been shown to be an effective method for improving the enzymatic hydrolysis of cellulose; this technique affords a fast and complete saccharification of cellulose into reducing sugars (Dadi et al., Biotechnol Bioeng. 2006; 95:904-910; Liu and Chen, Chinese Sci Bull. 2006; 51:2432-2436; Zhao et al., J Biotechnol. 2009; 139:47-54). Motivated by these advances, this study examines the effect of IL-pretreatment on the enzymatic hydrolysis of purified xylan (as a model system of hemicellulose) and switchgrass (as a real lignocellulose). The IL-pretreatment resulted in no improvement in the hydrolysis of xylan. The likely reason is that pure xylan has a low degree of polymerization (DP), and is readily biodegraded even without any pretreatment. However, in real cellulosic materials (such as switchgrass), xylan is entrapped within the cellulosic matrix, and cannot be conveniently accessed by enzymes. Our data demonstrate that the IL-pretreatment of switchgrass significantly improved the enzymatic saccharification of both cellulose (96% D-glucose yield in 24 h) and xylan (63% D-xylose yield in 24 h). The compositional analysis of switchgrass suggests a lower lignin content after IL-pretreatment. In addition, the infrared spectrum of regenerated switchgrass indicates a lower substrate crystallinity, whereas the enzyme adsorption isotherm further implies that the regenerated substrate is more accessible to enzymes. This study has further confirmed that IL-pretreatment is an effective tool in enhancing the enzymatic hydrolysis of cellulosic biomass, and allowing a more complete saccharification.
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Affiliation(s)
- Hua Zhao
- Chemistry Program, Savannah State University, Savannah, GA 31404, USA.
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27
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Okamoto K, Imashiro K, Akizawa Y, Onimura A, Yoneda M, Nitta Y, Maekawa N, Yanase H. Production of ethanol by the white-rot basidiomycetes Peniophora cinerea and Trametes suaveolens. Biotechnol Lett 2010; 32:909-13. [DOI: 10.1007/s10529-010-0243-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 02/23/2010] [Accepted: 02/24/2010] [Indexed: 11/28/2022]
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28
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Gu Y, Li J, Zhang L, Chen J, Niu L, Yang Y, Yang S, Jiang W. Improvement of xylose utilization in Clostridium acetobutylicum via expression of the talA gene encoding transaldolase from Escherichia coli. J Biotechnol 2009; 143:284-7. [PMID: 19695296 DOI: 10.1016/j.jbiotec.2009.08.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 07/30/2009] [Accepted: 08/07/2009] [Indexed: 10/20/2022]
Abstract
Clostridium acetobutylicum ATCC 824 was metabolically engineered for improved xylose utilization. The gene talA, which encodes transaldolase from Escherichia coli K-12, was cloned and overexpressed in C. acetobutylicum ATCC 824. Compared with C. acetobutylicum ATCC 824 (824-WT), the transformant bearing the E. coli talA gene (824-TAL) showed improved ability on xylose utilization and solvents production using xylose as the sole carbon source. During the fermentation of xylose and glucose mixtures with three xylose/glucose ratios (approximately 1:2, 1:1 and 2:1), the rate of xylose consumption and final solvents titers of 824-TAL were all higher than those of 824-WT, despite glucose repression on xylose uptake still existing. These results suggest that the insufficiency of transaldolase in the pentose phosphate pathway (PPP) of C. acetobutylicum is one of the bottlenecks for xylose metabolism and therefore, overexpressing the gene encoding transaldolase is able to improve xylose utilization and solvent production.
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Affiliation(s)
- Yang Gu
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
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Sasaki M, Jojima T, Kawaguchi H, Inui M, Yukawa H. Engineering of pentose transport in Corynebacterium glutamicum to improve simultaneous utilization of mixed sugars. Appl Microbiol Biotechnol 2009; 85:105-15. [DOI: 10.1007/s00253-009-2065-x] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2009] [Revised: 05/29/2009] [Accepted: 05/29/2009] [Indexed: 11/28/2022]
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30
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Margeot A, Hahn-Hagerdal B, Edlund M, Slade R, Monot F. New improvements for lignocellulosic ethanol. Curr Opin Biotechnol 2009; 20:372-80. [DOI: 10.1016/j.copbio.2009.05.009] [Citation(s) in RCA: 280] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 05/12/2009] [Accepted: 05/14/2009] [Indexed: 11/29/2022]
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31
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Yomano LP, York SW, Shanmugam KT, Ingram LO. Deletion of methylglyoxal synthase gene (mgsA) increased sugar co-metabolism in ethanol-producing Escherichia coli. Biotechnol Lett 2009; 31:1389-98. [PMID: 19458924 PMCID: PMC2721133 DOI: 10.1007/s10529-009-0011-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 04/27/2009] [Accepted: 04/30/2009] [Indexed: 11/28/2022]
Abstract
The use of lignocellulose as a source of sugars for bioproducts requires the development of biocatalysts that maximize product yields by fermenting mixtures of hexose and pentose sugars to completion. In this study, we implicate mgsA encoding methylglyoxal synthase (and methylglyoxal) in the modulation of sugar metabolism. Deletion of this gene (strain LY168) resulted in the co-metabolism of glucose and xylose, and accelerated the metabolism of a 5-sugar mixture (mannose, glucose, arabinose, xylose and galactose) to ethanol.
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Affiliation(s)
- L P Yomano
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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32
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Wu CH, Mulchandani A, Chen W. Versatile microbial surface-display for environmental remediation and biofuels production. Trends Microbiol 2008; 16:181-8. [DOI: 10.1016/j.tim.2008.01.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 01/18/2008] [Indexed: 11/15/2022]
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