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Grewal J, Khare SK, Drewniak L, Pranaw K. Recent perspectives on microbial and ionic liquid interactions with implications for biorefineries. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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2
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He Y, Zhang Y, Huang X, Xu J, Zhang H, Dai X, Xie L. Deciphering the internal driving mechanism of microbial community for carbon conversion and nitrogen fixation during food waste composting with multifunctional microbial inoculation. BIORESOURCE TECHNOLOGY 2022; 360:127623. [PMID: 35850391 DOI: 10.1016/j.biortech.2022.127623] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
In this study, the effects of multifunctional microbial inoculation on food waste composting based on the synergistic property between organic matter degradation and nitrogen fixation were investigated. The results showed that inoculation simultaneously strengthened organic matter degradation by 9.9% and improved the nitrogen content by 20.6% compared with that of the control group. Additionally, spectral analysis demonstrated that inoculation was conducive to the enhanced humification, which was supported by the improvement in polyphenol oxidase activity. Microbial analysis showed that most of the introduced microorganisms (Bacillus, Streptomyces, Saccharomonospora) successfully colonized, and stimulated the growth of other indigenous microorganisms (Enterobacter, Paenibacillus). Meanwhile, the change in microbial community structure was accompanied by the enhanced tricarboxylic acid cycle and amino acid metabolism. Furthermore, network analysis and structural equation model revealed that the enhanced cooperation of microorganisms, in which more carbon sources could be provided by cellulose decomposition for nitrogen fixation.
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Affiliation(s)
- Yingying He
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Yidie Zhang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Xia Huang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Jun Xu
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Hongning Zhang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Xiaohu Dai
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China
| | - Li Xie
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai 200092, PR China.
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3
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Yadav N, Nain L, Khare SK. One-pot production of lactic acid from rice straw pretreated with ionic liquid. BIORESOURCE TECHNOLOGY 2021; 323:124563. [PMID: 33360946 DOI: 10.1016/j.biortech.2020.124563] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/12/2020] [Accepted: 12/14/2020] [Indexed: 05/27/2023]
Abstract
Production of platform chemicals has been advocated as a sustainable option to tackle the problems associated with agro-waste management. In this report, for the first time, efforts were made to effectively produce second-generation lactic acid from rice straw pretreated with imidazolium ionic liquid [EMIM][OAc] and subsequently fermented with a promising Lactobacillus plantarum SKL-22 strain saccharified with a commercial cellulase enzyme. Medium optimization was carried out to enhance the lactic acid (LA) yield by response surface methodology. In a 5 L bioreactor, the process was further upscale, and a yield increment of 1.11% was observed. The process using rice straw as substrate led to a LA yield of 36.75 g/L from L. plantarum SKL-22 in a single pot bioprocess. Overall, the above finding has shown the ability of L. plantarum SKL-22 to produce LA from the hydrolysate of rice straw. This study presented a novel environmental-friendly method for LA production.
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Affiliation(s)
- Neerja Yadav
- Department of Chemistry, Indian Institute of Technology Delhi, India
| | - Lata Nain
- Division of Microbiology, ICAR - Indian Agricultural Research Institute, Delhi, India
| | - Sunil K Khare
- Department of Chemistry, Indian Institute of Technology Delhi, India.
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Sitepu I, Enriquez L, Nguyen V, Fry R, Simmons B, Singer S, Simmons C, Boundy-Mills KL. Ionic Liquid Tolerance of Yeasts in Family Dipodascaceae and Genus Wickerhamomyces. Appl Biochem Biotechnol 2020; 191:1580-1593. [PMID: 32185613 DOI: 10.1007/s12010-020-03293-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/13/2020] [Indexed: 11/26/2022]
Abstract
In previous studies of ionic liquid (IL) tolerance of numerous species of ascomycetous yeasts, two strains of Wickerhamomyces ciferrii and Galactomyces candidus had unusually high tolerance in media containing up to 5% (w/v) of the 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]). The study aimed at investigating whether additional strains of these species, and additional species in the Dipodascaceae family, also possess IL tolerance, and to compare sensitivity to the acetate and chloride versions of the ionic liquid. Fifty five yeast strains in the family Dipodascaceae, which encompasses genera Galactomyces, Geotrichum, and Dipodascus, and seven yeast strains of species Wickerhamomyces ciferrii were tested for ability to grow in laboratory medium containing no IL, 242 mM [C2C1Im][OAc], or 242 mM [C2C1Im]Cl, and in IL-pretreated switchgrass hydrolysate. Many yeasts exhibited tolerance of one or both ILs, with higher tolerance of the chloride anion than of the acetate anion. Different strains of the same species exhibited varying degrees of IL tolerance. Galactomyces candidus, UCDFSTs 52-260, and 50-64, had exceptionally robust growth in [C2C1Im][OAc], and also grew well in the switchgrass hydrolysate. Identification of IL tolerant and IL resistant yeast strains will facilitate studies of the mechanism of IL tolerance, which could include superior efflux, metabolism or exclusion.
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Affiliation(s)
- Irnayuli Sitepu
- Department of Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Lauren Enriquez
- Department of Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Valerie Nguyen
- Department of Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Russell Fry
- Department of Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Blake Simmons
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Steve Singer
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Department of Biomass Science and Conversion Technology, Sandia National Laboratories, Livermore, CA, 94550, USA
| | - Christopher Simmons
- Department of Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Kyria L Boundy-Mills
- Department of Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA.
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Sivapragasam M, Moniruzzaman M, Goto M. An Overview on the Toxicological Properties of Ionic Liquids toward Microorganisms. Biotechnol J 2020; 15:e1900073. [PMID: 31864234 DOI: 10.1002/biot.201900073] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 11/21/2019] [Indexed: 12/27/2022]
Abstract
Ionic liquids (ILs), a class of materials with unique physicochemical properties, have been used extensively in the fields of chemical engineering, biotechnology, material sciences, pharmaceutics, and many others. Because ILs are very polar by nature, they can migrate into the environment with the possibility of inclusion in the food chain and bioaccumulation in living organisms. However, the chemical natures of ILs are not quintessentially biocompatible. Therefore, the practical uses of ILs must be preceded by suitable toxicological assessments. Among different methods, the use of microorganisms to evaluate IL toxicity provides many advantages including short generation time, rapid growth, and environmental and industrial relevance. This article reviews the recent research progress on the toxicological properties of ILs toward microorganisms and highlights the computational prediction of various toxicity models.
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Affiliation(s)
- Magaret Sivapragasam
- Biotechnology Department, QUEST International University Perak, 30250, Ipoh, Perak, Malaysia
| | - Muhammad Moniruzzaman
- Chemical Engineering Department, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak, Malaysia.,Center of Researches in Ionic Liquids (CORIL), Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak, Malaysia
| | - Masahiro Goto
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Fukuoka, 819-0395, Japan.,Center for Future Chemistry, Kyushu University, Fukuoka, 819-0395, Japan
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Pal S, Sar A, Dam B. Moderate halophilic bacteria, but not extreme halophilic archaea can alleviate the toxicity of short-alkyl side chain imidazolium-based ionic liquids. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 184:109634. [PMID: 31520950 DOI: 10.1016/j.ecoenv.2019.109634] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/26/2019] [Accepted: 09/01/2019] [Indexed: 06/10/2023]
Abstract
Imidazolium-based ionic liquids (IL) with short-alkyl side chain such as 1-ethyl-3-methyl-imidazolium chloride ([Emim]Cl) and 1-butyl-3-methyl-imidazolium chloride ([Bmim]Cl) has immense application potential including in lignocellulosic bioenergy production. But they are toxic to most microorganisms, and those isolated from different environments as IL-tolerant have salt tolerance capabilities. This study evaluates the relationship between salt and [Emim]Cl tolerance of microorganisms using different salinity sediments (2-19%) and brines (35%) of India's largest inland hypersaline lake, Sambhar in Rajasthan as the model system. While samples with 2% and 35% salinities do not yield any [Emim]Cl (100 mM) tolerant colonies, others have 6-50% colonies tolerant to the IL. Similar trend was observed with 50 mM [Bmim]Cl. Moderate halophilic isolates of genera Halomonas and Bacillus (growth in 0.7-3.0 M NaCl) isolated from the sediments could grow in as high as 375 mM [Emim]Cl, or 125 mM [Bmim]Cl facilitated by higher synthesis, and uptake of organic osmolytes; and up to 1.7-fold increased activity of active efflux pumps. [Bmim]Cl was more toxic than [Emim]Cl in all performed experiments. [Emim]Cl-adapted cells could trounce IL-induced stress. Interestingly, enrichment with 100 mM [Emim]Cl resulted in increase of IL-tolerant colonies in all sediments including the one with 2% salinity. However, the salt saturated brines (35%) do not yield any such colony even after repeated incubations. Extreme halophilic archaea, Natronomonas (growth in 3.0-4.0 M NaCl) isolated from such brines, were exceedingly sensitive to even 5 mM [Emim]Cl, or 1 mM [Bmim]Cl. Two additional extremophilic archaea, namely Haloferax and Haladaptatus were also sensitive to the tested ILs. Archaeal sensitivity is possibly due to the competitive interaction of [Emim]+ with their acidic proteome (15.4-17.5% aspartic and glutamic acids, against 10.7-12.9% in bacteria) that they maintain to stabilize the high amount of K+ ion accumulated by salt-in strategy. Thus, general salt adaptation strategies of moderate halophilic bacteria help them to restrain toxicity of these ILs, but extremophilic archaea are highly sensitive and demands meticulous use of these solvents to prevent environmental contamination.
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Affiliation(s)
- Srikanta Pal
- Microbiology Laboratory, Department of Botany (DST-FIST & UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Abhijit Sar
- Microbiology Laboratory, Department of Botany (DST-FIST & UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India
| | - Bomba Dam
- Microbiology Laboratory, Department of Botany (DST-FIST & UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India.
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Guanidine Riboswitch-Regulated Efflux Transporters Protect Bacteria against Ionic Liquid Toxicity. J Bacteriol 2019; 201:JB.00069-19. [PMID: 30988034 DOI: 10.1128/jb.00069-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/09/2019] [Indexed: 11/20/2022] Open
Abstract
Plant cell walls contain a renewable, nearly limitless supply of sugar that could be used to support microbial production of commodity chemicals and biofuels. Imidazolium ionic liquid (IIL) solvents are among the best reagents for gaining access to the sugars in this otherwise recalcitrant biomass. However, the sugars from IIL-treated biomass are inevitably contaminated with residual IILs that inhibit growth in bacteria and yeast, blocking biochemical production by these organisms. IIL toxicity is, therefore, a critical roadblock in many industrial biosynthetic pathways. Although several IIL-tolerant (IILT) bacterial and yeast isolates have been identified in nature, few genetic mechanisms have been identified. In this study, we identified two IILT Bacillus isolates as well as a spontaneous IILT Escherichia coli lab strain that are tolerant to high levels of two widely used IILs. We demonstrate that all three IILT strains contain one or more pumps of the small multidrug resistance (SMR) family, and two of these strains contain mutations that affect an adjacent regulatory guanidine riboswitch. Furthermore, we show that the regulation of E. coli sugE by the guanidine II riboswitch can be exploited to promote IIL tolerance by the simple addition of guanidine to the medium. Our results demonstrate the critical role that transporter genes play in IIL tolerance in their native bacterial hosts. The study presented here is another step in engineering IIL tolerance into industrial strains toward overcoming this key gap in biofuels and industrial biochemical production processes.IMPORTANCE This study identifies bacteria that are tolerant to ionic liquid solvents used in the production of biofuels and industrial biochemicals. For industrial microbiology, it is essential to find less-harmful reagents and microbes that are resistant to their cytotoxic effects. We identified a family of small multidrug resistance efflux transporters, which are responsible for the tolerance of these strains. We also found that this resistance can be caused by mutations in the sequences of guanidine-specific riboswitches that regulate these efflux pumps. Extending this knowledge, we demonstrated that guanidine itself can promote ionic liquid tolerance. Our findings will inform genetic engineering strategies that improve conversion of cellulosic sugars into biofuels and biochemicals in processes where low concentrations of ionic liquids surpass bacterial tolerance.
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Barbosa MS, Freire CCC, Souza RL, Cabrera‐Padilla RY, Pereira MM, Freire MG, Lima ÁS, Soares CMF. Effects of phosphonium‐based ionic liquids on the lipase activity evaluated by experimental results and molecular docking. Biotechnol Prog 2019; 35:e2816. [DOI: 10.1002/btpr.2816] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/19/2019] [Accepted: 03/27/2019] [Indexed: 12/11/2022]
Affiliation(s)
| | | | - Ranyere L. Souza
- Universidade Tiradentes Aracaju Sergipe Brazil
- Instituto de Tecnologia e Pesquisa Aracaju Sergipe Brazil
| | - Rebeca Y. Cabrera‐Padilla
- Universidade Tiradentes Aracaju Sergipe Brazil
- Instituto de Tecnologia e Pesquisa Aracaju Sergipe Brazil
| | - Matheus M. Pereira
- Universidade Tiradentes Aracaju Sergipe Brazil
- Instituto de Tecnologia e Pesquisa Aracaju Sergipe Brazil
| | - Mara G. Freire
- Departamento de QuímicaUniversidade de Aveiro, CICECO – Instituto de Materiais de Aveiro Aveiro Portugal
| | - Álvaro S. Lima
- Universidade Tiradentes Aracaju Sergipe Brazil
- Instituto de Tecnologia e Pesquisa Aracaju Sergipe Brazil
| | - Cleide M. F. Soares
- Universidade Tiradentes Aracaju Sergipe Brazil
- Instituto de Tecnologia e Pesquisa Aracaju Sergipe Brazil
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Egorova KS, Ananikov VP. Ionic liquids in whole-cell biocatalysis: a compromise between toxicity and efficiency. Biophys Rev 2018; 10:881-900. [PMID: 29313188 PMCID: PMC5988618 DOI: 10.1007/s12551-017-0389-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/13/2017] [Indexed: 12/11/2022] Open
Abstract
Comparison of chemical catalysis by metal complexes, enzymatic catalysis and whole-cell biocatalysis shows well-addressed advantages of the latter approach. However, a critical limitation in the practical applications originates from the high sensitivity of microorganisms to the toxic effects of organic solvents. In the present review, we consider toxic solvent properties of ionic liquid/water systems towards the development of efficient applications in practical organic transformations.
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Affiliation(s)
- Ksenia S Egorova
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, Moscow, 119991, Russia
| | - Valentine P Ananikov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, Moscow, 119991, Russia.
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10
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Optimization of Ionic Liquid Pretreatment of Mixed Softwood by Response Surface Methodology and Reutilization of Ionic Liquid from Hydrolysate. BIOTECHNOL BIOPROC E 2018. [DOI: 10.1007/s12257-017-0209-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Egorova KS, Gordeev EG, Ananikov VP. Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine. Chem Rev 2017; 117:7132-7189. [PMID: 28125212 DOI: 10.1021/acs.chemrev.6b00562] [Citation(s) in RCA: 906] [Impact Index Per Article: 129.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ionic liquids are remarkable chemical compounds, which find applications in many areas of modern science. Because of their highly tunable nature and exceptional properties, ionic liquids have become essential players in the fields of synthesis and catalysis, extraction, electrochemistry, analytics, biotechnology, etc. Apart from physical and chemical features of ionic liquids, their high biological activity has been attracting significant attention from biochemists, ecologists, and medical scientists. This Review is dedicated to biological activities of ionic liquids, with a special emphasis on their potential employment in pharmaceutics and medicine. The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems. Dedicated attention is given to a novel active pharmaceutical ingredient-ionic liquid (API-IL) concept, which suggests using traditional drugs in the form of ionic liquid species. The main aim of this Review is to attract a broad audience of chemical, biological, and medical scientists to study advantages of ionic liquid pharmaceutics. Overall, the discussed data highlight the importance of the research direction defined as "Ioliomics", studies of ions in liquids in modern chemistry, biology, and medicine.
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Affiliation(s)
- Ksenia S Egorova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47, Moscow 119991, Russia
| | - Evgeniy G Gordeev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47, Moscow 119991, Russia
| | - Valentine P Ananikov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47, Moscow 119991, Russia.,Department of Chemistry, Saint Petersburg State University , Stary Petergof 198504, Russia
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Ionic Liquids Impact the Bioenergy Feedstock-Degrading Microbiome and Transcription of Enzymes Relevant to Polysaccharide Hydrolysis. mSystems 2016; 1:mSystems00120-16. [PMID: 27981239 PMCID: PMC5155067 DOI: 10.1128/msystems.00120-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/15/2016] [Indexed: 01/12/2023] Open
Abstract
Pretreatment using ionic liquids (IL) is a promising approach for the conversion of lignocellulose to biofuels. Because IL can be inhibitory to enzymes and microorganisms involved in downstream hydrolysis and fermentation steps, discovery of IL-tolerant organisms and enzymes is critical for advancing this technology. Employing metatranscriptomics in the analysis of IL-enriched cultures facilitated tracking of dynamic changes in a complex microbial community at the level of gene transcription and doing so with genome resolution. Specific organisms were discovered that could simultaneously tolerate a moderate IL concentration and transcribe a diverse array of cellulolytic enzymes. Gene sequences of cellulolytic enzymes and efflux pumps from those same organisms were also identified, providing important resources for future research on engineering IL-tolerant organisms and enzymes. Ionic liquid (IL) pretreatment is a promising approach for the conversion of lignocellulose to biofuels. The toxicity of residual IL, however, negatively impacts the performance of industrial enzymes and microorganisms in hydrolysis and fermentation. In this study, a thermophilic microbial community was cultured on switchgrass amended with various levels of the ionic liquid 1-ethyl-3-methylimidazolium acetate. Changes in the microbial community composition and transcription of genes relevant to IL tolerance and lignocellulose hydrolysis were quantified. Increasing the level of IL to 0.1% (wt) led to increased levels of relative abundance and transcription in organisms of the phylum Firmicutes. Interestingly, IL concentrations of up to 1% (wt) also resulted in greater xylanase transcription and enzyme activity as well as increased transcription of endoglucanase, beta-glucosidase, and IL tolerance genes compared to communities without IL. IL levels above 1% (wt) resulted in decreased enzyme activity and transcription of genes involved in lignocellulose hydrolysis. The results indicate that moderate levels of IL select for thermophilic microorganisms that not only tolerate IL but also effectively hydrolyze lignocellulose from switchgrass. Discovery of IL-tolerant organisms and enzymes is critical for the development of biological processes that convert IL-pretreated biomass to biofuels and chemicals. Employing metatranscriptomic analysis of enrichment cultures can facilitate the discovery of microorganisms and enzymes that may be active in the presence of toxic compounds such as ionic liquids. IMPORTANCE Pretreatment using ionic liquids (IL) is a promising approach for the conversion of lignocellulose to biofuels. Because IL can be inhibitory to enzymes and microorganisms involved in downstream hydrolysis and fermentation steps, discovery of IL-tolerant organisms and enzymes is critical for advancing this technology. Employing metatranscriptomics in the analysis of IL-enriched cultures facilitated tracking of dynamic changes in a complex microbial community at the level of gene transcription and doing so with genome resolution. Specific organisms were discovered that could simultaneously tolerate a moderate IL concentration and transcribe a diverse array of cellulolytic enzymes. Gene sequences of cellulolytic enzymes and efflux pumps from those same organisms were also identified, providing important resources for future research on engineering IL-tolerant organisms and enzymes.
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Yu C, Simmons BA, Singer SW, Thelen MP, VanderGheynst JS. Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts. Appl Microbiol Biotechnol 2016; 100:10237-10249. [PMID: 27838839 DOI: 10.1007/s00253-016-7955-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/19/2016] [Accepted: 10/21/2016] [Indexed: 11/26/2022]
Abstract
Chemical and physical pretreatment of biomass is a critical step in the conversion of lignocellulose to biofuels and bioproducts. Ionic liquid (IL) pretreatment has attracted significant attention due to the unique ability of certain ILs to solubilize some or all components of the plant cell wall. However, these ILs inhibit not only the enzyme activities but also the growth and productivity of microorganisms used in downstream hydrolysis and fermentation processes. While pretreated biomass can be washed to remove residual IL and reduce inhibition, extensive washing is costly and not feasible in large-scale processes. IL-tolerant microorganisms and microbial communities have been discovered from environmental samples and studies begun to elucidate mechanisms of IL tolerance. The discovery of IL tolerance in environmental microbial communities and individual microbes has lead to the proposal of molecular mechanisms of resistance. In this article, we review recent progress on discovering IL-tolerant microorganisms, identifying metabolic pathways and mechanisms of tolerance, and engineering microorganisms for IL tolerance. Research in these areas will yield new approaches to overcome inhibition in lignocellulosic biomass bioconversion processes and increase opportunities for the use of ILs in biomass pretreatment.
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Affiliation(s)
- Chaowei Yu
- Department of Biological and Agricultural Engineering, University of California, One Shields Ave., Davis, CA, 95616, USA
| | - Blake A Simmons
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Steven W Singer
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Michael P Thelen
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Biosciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94551, USA
| | - Jean S VanderGheynst
- Department of Biological and Agricultural Engineering, University of California, One Shields Ave., Davis, CA, 95616, USA.
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.
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Xu J, Wang X, Hu L, Xia J, Wu Z, Xu N, Dai B, Wu B. A novel ionic liquid-tolerant Fusarium oxysporum BN secreting ionic liquid-stable cellulase: consolidated bioprocessing of pretreated lignocellulose containing residual ionic liquid. BIORESOURCE TECHNOLOGY 2015; 181:18-25. [PMID: 25625459 DOI: 10.1016/j.biortech.2014.12.080] [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: 11/13/2014] [Revised: 12/22/2014] [Accepted: 12/23/2014] [Indexed: 06/04/2023]
Abstract
In this study, microbial communities from chemicals polluted microhabitats were cultured with the addition of imidazolium-based ionic liquid (IL) to enrich for IL-tolerant microbes. A strain of Fusarium oxysporum BN producing cellulase from these enrichments was capable of growing in 10% (w/v) 1-ethyl-3-methylimidazolium phosphinate, much higher than the normal IL concentrations in the lignocellulose regenerated from ILs. Cellulase secreted by the strain showed high resistance to ILs based on phosphate and sulfate radicals, evidencing of a high conformational stability in relevant media. Gratifyingly, F. oxysporum BN can directly convert IL-pretreated rice straw to bioethanol via consolidated bioprocessing (I-CBP). At optimum fermentation condition, a maximum ethanol yield of 0.125 g ethanol g(-1) of rice straw was finally obtained, corresponding to 64.2% of the theoretical yield.
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Affiliation(s)
- Jiaxing Xu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China
| | - Xinfeng Wang
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China; Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian 223300, China
| | - Lei Hu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China
| | - Jun Xia
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China
| | - Zhen Wu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China
| | - Ning Xu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China
| | - Benlin Dai
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, 111 Changjiangxi Road, Huaian 223300, China
| | - Bin Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, 30 Puzhunan Road, Nanjing 210000, China.
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15
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Sitepu IR, Shi S, Simmons BA, Singer SW, Boundy-Mills K, Simmons CW. Yeast tolerance to the ionic liquid 1-ethyl-3-methylimidazolium acetate. FEMS Yeast Res 2014; 14:1286-94. [DOI: 10.1111/1567-1364.12224] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 10/17/2014] [Indexed: 11/30/2022] Open
Affiliation(s)
- Irnayuli R. Sitepu
- Department of Food Science and Technology; University of California; Davis CA USA
- Forestry Research and Development Agency (FORDA); The Ministry of Forestry; Bogor Indonesia
| | - Shuang Shi
- Department of Food Science and Technology; University of California; Davis CA USA
| | - Blake A. Simmons
- Deconstruction Division; Joint BioEnergy Institute; Emeryville CA USA
- Biological and Materials Sciences Center; Sandia National Laboratories; Livermore CA USA
| | - Steven W. Singer
- Deconstruction Division; Joint BioEnergy Institute; Emeryville CA USA
- Earth Sciences Division; Lawrence Berkeley National Laboratory; Berkeley CA USA
| | - Kyria Boundy-Mills
- Department of Food Science and Technology; University of California; Davis CA USA
| | - Christopher W. Simmons
- Department of Food Science and Technology; University of California; Davis CA USA
- Deconstruction Division; Joint BioEnergy Institute; Emeryville CA USA
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