1
|
Wang Z, Dien BS, Rausch KD, Tumbleson ME, Singh V. Fermentation of undetoxified sugarcane bagasse hydrolyzates using a two stage hydrothermal and mechanical refining pretreatment. BIORESOURCE TECHNOLOGY 2018; 261:313-321. [PMID: 29677659 DOI: 10.1016/j.biortech.2018.04.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
In this study, liquid hot water pretreatment was combined with disk milling for pretreatment of sugarcane bagasse. Sugarcane bagasse was pretreated using liquid hot water (LHW) at 140-180 °C for 10 min (20% w/w solids content) and then disk milled. Disk milling improved glucose release 41-177% and ethanol production from glucose/xylose cofermentation by 80% compared to only using LHW pretreatment. The highest ethanol conversion efficiency achieved was 94%, which was observed when bagasse was treated at 180 °C with LHW and disk milled. However, a small amount of residual xylose (3 g/L) was indicative that further improvement could be achieved to increase ethanol production.
Collapse
Affiliation(s)
- Zhaoqin Wang
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bruce S Dien
- National Center for Agricultural Utilization Research, US Department of Agriculture, Peoria, IL, USA
| | - Kent D Rausch
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - M E Tumbleson
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Vijay Singh
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| |
Collapse
|
2
|
Affiliation(s)
- Tao Jin
- Iowa State University; Department of Chemical and Biological Engineering; 2114 Sweeney Hall, 618 Bissell Rd. Ames, IA 50011 USA
| | - Jieni Lian
- Iowa State University; Department of Chemical and Biological Engineering; 2114 Sweeney Hall, 618 Bissell Rd. Ames, IA 50011 USA
| | - Laura R. Jarboe
- Iowa State University; Department of Chemical and Biological Engineering; 2114 Sweeney Hall, 618 Bissell Rd. Ames, IA 50011 USA
| |
Collapse
|
3
|
Shi A, Zheng H, Yomano LP, York SW, Shanmugam KT, Ingram LO. Plasmidic Expression of nemA and yafC* Increased Resistance of Ethanologenic Escherichia coli LY180 to Nonvolatile Side Products from Dilute Acid Treatment of Sugarcane Bagasse and Artificial Hydrolysate. Appl Environ Microbiol 2016; 82:2137-2145. [PMID: 26826228 PMCID: PMC4807516 DOI: 10.1128/aem.03488-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/24/2016] [Indexed: 11/20/2022] Open
Abstract
Hydrolysate-resistant Escherichia coli SL100 was previously isolated from ethanologenic LY180 after sequential transfers in AM1 medium containing a dilute acid hydrolysate of sugarcane bagasse and was used as a source of resistance genes. Many genes that affect tolerance to furfural, the most abundant inhibitor, have been described previously. To identify genes associated with inhibitors other than furfural, plasmid clones were selected in an artificial hydrolysate that had been treated with a vacuum to remove furfural. Two new resistance genes were discovered from Sau3A1 libraries of SL100 genomic DNA: nemA (N-ethylmaleimide reductase) and a putative regulatory gene containing a mutation in the coding region, yafC*. The presence of these mutations in SL100 was confirmed by sequencing. A single mutation was found in the upstream regulatory region of nemR (nemRA operon) in SL100. This mutation increased nemA activity 20-fold over that of the parent organism (LY180) in AM1 medium without hydrolysate and increased nemA mRNA levels >200-fold. Addition of hydrolysates induced nemA expression (mRNA and activity), in agreement with transcriptional control. NemA activity was stable in cell extracts (9 h, 37°C), eliminating a role for proteinase in regulation. LY180 with a plasmid expressing nemA or yafC* was more resistant to a vacuum-treated sugarcane bagasse hydrolysate and to a vacuum-treated artificial hydrolysate than LY180 with an empty-vector control. Neither gene affected furfural tolerance. The vacuum-treated hydrolysates inhibited the reduction of N-ethylmaleimide by NemA while also serving as substrates. Expression of the nemA or yafC* plasmid in LY180 doubled the rate of ethanol production from the vacuum-treated sugarcane bagasse hydrolysate.
Collapse
Affiliation(s)
- Aiqin Shi
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Huabao Zheng
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Lorraine P Yomano
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Sean W York
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Keelnatham T Shanmugam
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Lonnie O Ingram
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
4
|
Peterson JD, Ingram LO. Anaerobic respiration in engineered Escherichia coli with an internal electron acceptor to produce fuel ethanol. Ann N Y Acad Sci 2008; 1125:363-72. [PMID: 18378606 DOI: 10.1196/annals.1419.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Environmental concerns and unease with U.S. dependence on foreign oil have renewed interest in converting biomass into fuel ethanol. The volume of plant matter available makes lignocellulose conversion to ethanol desirable, although no one isolated organism has been shown to break bonds in lignocellulose and efficiently metabolize resulting sugars into one product. This work reviews directed engineering coupled with metabolic evolution resulting in microbial biocatalysts that produce up to 45 g L(-1) ethanol in 48 hours in a simple mineral salts medium and that convert various compounds of lignocellulosic materials to ethanol. Mutations contributing to ethanologenesis are discussed along with adding enzymatic capabilities to existing biocatalysts in order to decrease the commercial enzymes required to reduce plant matter into fermentable sugars.
Collapse
|
5
|
Doran-Peterson J, Cook DM, Brandon SK. Microbial conversion of sugars from plant biomass to lactic acid or ethanol. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 54:582-592. [PMID: 18476865 DOI: 10.1111/j.1365-313x.2008.03480.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Concerns for our environment and unease with our dependence on foreign oil have renewed interest in converting plant biomass into fuels and 'green' chemicals. The volume of plant matter available makes lignocellulose conversion desirable, although no single isolated organism has been shown to depolymerize lignocellulose and efficiently metabolize the resulting sugars into a specific product. This work reviews selected chemicals and fuels that can be produced from microbial fermentation of plant-derived cell-wall sugars and directed engineering for improvement of microbial biocatalysts. Lactic acid and ethanol production are highlighted, with a focus on engineered Escherichia coli.
Collapse
Affiliation(s)
- Joy Doran-Peterson
- Microbiology Department, 1000 Cedar Street, 527 Biological Sciences Building, University of Georgia, Athens, GA 30602, USA.
| | | | | |
Collapse
|
6
|
Affiliation(s)
- D. Y. Corredor
- Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, KS 66506
| | - S. Bean
- USDA-ARS Grain Marketing and Production Research Center, Manhattan, KS 66502. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable
| | - D. Wang
- Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, KS 66506
- Corresponding author. Phone: 785-532-2919. Fax: 785-532-5825. E-mail:
| |
Collapse
|
7
|
Jarboe LR, Grabar TB, Yomano LP, Shanmugan KT, Ingram LO. Development of ethanologenic bacteria. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2007; 108:237-61. [PMID: 17665158 DOI: 10.1007/10_2007_068] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The utilization of lignocellulosic biomass as a petroleum alternative faces many challenges. This work reviews recent progress in the engineering of Escherichia coli and Klebsiella oxytoca to produce ethanol from biomass with minimal nutritional supplementation. A combination of directed engineering and metabolic evolution has resulted in microbial biocatalysts that produce up to 45 g L(-1) ethanol in 48 h in a simple mineral salts medium, and convert various lignocellulosic materials to ethanol. Mutations contributing to ethanologenesis are discussed. The ethanologenic biocatalyst design approach was applied to other commodity chemicals, including optically pure D: (-)- and L: (+)-lactic acid, succinate and L: -alanine with similar success. This review also describes recent progress in growth medium development, the reduction of hemicellulose hydrolysate toxicity and reduction of the demand for fungal cellulases.
Collapse
Affiliation(s)
- L R Jarboe
- Department of Microbiology and Cell Science, University of Florida, 32611, Gainesville, FL 32611, USA.
| | | | | | | | | |
Collapse
|
8
|
The effect of overliming on the toxicity of dilute acid pretreated lignocellulosics: the role of inorganics, uronic acids and ether-soluble organics. Enzyme Microb Technol 2000; 27:240-247. [PMID: 10899549 DOI: 10.1016/s0141-0229(00)00216-7] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Although the treatment of dilute acid pretreated lignocellulosics with calcium hydroxide or carbonate (overliming) is known to improve the fermentability of carbohydrate-rich hydrolyzate streams, a firm understanding of the chemistry behind the process is lacking. Quantitative evaluation of inorganics, uronic acids, and non-polar organics indicates that only a portion of the improvement can be ascribed to these materials. Upon overliming the concentrations of inorganics either increase (Ca, Mg), decrease (Fe, P, Zn, K) or remain relatively the same (Al, Na). Furthermore, organic compounds that are not extractable with tert-butyl methyl ether (MTBE) are toxic to Zymomonas mobilis CP4(pZB5). Overliming and direct neutralization are somewhat effective in removing sulfate anions, although sulfate toxicity is considerably less than that of acetic acid. Uronic acids were found to be non-toxic under pH controlled conditions.
Collapse
|
9
|
Stenberg K, Galbe M, Zacchi G. The influence of lactic acid formation on the simultaneous saccharification and fermentation (SSF) of softwood to ethanol. Enzyme Microb Technol 2000. [DOI: 10.1016/s0141-0229(99)00127-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
10
|
Zaldivar J, Ingram LO. Effect of organic acids on the growth and fermentation of ethanologenic Escherichia coli LY01. Biotechnol Bioeng 1999; 66:203-10. [PMID: 10578090 DOI: 10.1002/(sici)1097-0290(1999)66:4<203::aid-bit1>3.0.co;2-#] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hemicellulose residues can be hydrolyzed into a sugar syrup using dilute mineral acids. Although this syrup represents a potential feedstock for biofuel production, toxic compounds generated during hydrolysis limit microbial metabolism. Escherichia coli LY01, an ethanologenic biocatalyst engineered to ferment the mixed sugars in hemicellulose syrups, has been tested for resistance to selected organic acids that are present in hemicellulose hydrolysates. Compounds tested include aromatic acids derived from lignin (ferulic, gallic, 4-hydroxybenzoic, syringic, and vanillic acids), acetic acid from the hydrolysis of acetylxylan, and others derived from sugar destruction (furoic, formic, levulinic, and caproic acids). Toxicity was related to hydrophobicity. Combinations of acids were roughly additive as inhibitors of cell growth. When tested at concentrations that inhibited growth by 80%, none appeared to strongly inhibit glycolysis and energy generation, or to disrupt membrane integrity. Toxicity was not markedly affected by inoculum size or incubation temperature. The toxicity of all acids except gallic acid was reduced by an increase in initial pH (from pH 6.0 to pH 7.0 to pH 8.0). Together, these results are consistent with the hypothesis that both aliphatic and mononuclear organic acids inhibit growth and ethanol production in LY01 by collapsing ion gradients and increasing internal anion concentrations.
Collapse
Affiliation(s)
- J Zaldivar
- Institute of Food and Agricultural Sciences, Department of Microbiology and Cell Science, IFAS, PO Box 110700, University of Florida, Gainesville, Florida 32611, USA
| | | |
Collapse
|
11
|
Zaldivar J, Martinez A, Ingram LO. Effect of selected aldehydes on the growth and fermentation of ethanologenicEscherichia coli. Biotechnol Bioeng 1999. [DOI: 10.1002/(sici)1097-0290(19991005)65:1%3c24::aid-bit4%3e3.0.co;2-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
12
|
Abstract
Bioethanol production from lignocellulosic raw-materials requires the hydrolysis of carbohydrate polymers into a fermentable syrup. During the hydrolysis of hemicellulose with dilute acid, a variety of toxic compounds are produced such as soluble aromatic aldehydes from lignin and furfural from pentose destruction. In this study, we have investigated the toxicity of representative aldehydes (furfural, 5-hydroxymethlyfurfural, 4-hydroxybenzaldehyde, syringaldehyde, and vanillin) as inhibitors of growth and ethanol production by ethanologenic derivatives of Escherichia coli B (strains KO11 and LY01). Aromatic aldehydes were at least twice as toxic as furfural or 5-hydroxymethylfurfural on a weight basis. The toxicities of all aldehydes (and ethanol) except furfural were additive when tested in binary combinations. In all cases, combinations with furfural were unexpectedly toxic. Although the potency of these aldehydes was directly related to hydrophobicity indicating a hydrophobic site of action, none caused sufficient membrane damage to allow the leakage of intracellular magnesium even when present at sixfold the concentrations required for growth inhibition. Of the aldehydes tested, only furfural strongly inhibited ethanol production in vitro. A comparison with published results for other microorganisms indicates that LY01 is equivalent or more resistant than other biocatalysts to the aldehydes examined in this study.
Collapse
Affiliation(s)
- J Zaldivar
- Institute of Food and Agricultural Sciences, Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, Florida 32611, USA
| | | | | |
Collapse
|
13
|
Ingram LO, Gomez PF, Lai X, Moniruzzaman M, Wood BE, Yomano LP, York SW. Metabolic engineering of bacteria for ethanol production. Biotechnol Bioeng 1998. [DOI: 10.1002/(sici)1097-0290(19980420)58:2/3%3c204::aid-bit13%3e3.0.co;2-c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
14
|
Ingram LO, Gomez PF, Lai X, Moniruzzaman M, Wood BE, Yomano LP, York SW. Metabolic engineering of bacteria for ethanol production. Biotechnol Bioeng 1998; 58:204-14. [PMID: 10191391 DOI: 10.1002/(sici)1097-0290(19980420)58:2/3<204::aid-bit13>3.0.co;2-c] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Technologies are available which will allow the conversion of lignocellulose into fuel ethanol using genetically engineered bacteria. Assembling these into a cost-effective process remains a challenge. Our work has focused primarily on the genetic engineering of enteric bacteria using a portable ethanol production pathway. Genes encoding Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase have been integrated into the chromosome of Escherichia coli B to produce strain KO11 for the fermentation of hemicellulose-derived syrups. This organism can efficiently ferment all hexose and pentose sugars present in the polymers of hemicellulose. Klebsiella oxytoca M5A1 has been genetically engineered in a similar manner to produce strain P2 for ethanol production from cellulose. This organism has the native ability to ferment cellobiose and cellotriose, eliminating the need for one class of cellulase enzymes. The optimal pH for cellulose fermentation with this organism (pH 5.0-5.5) is near that of fungal cellulases. The general approach for the genetic engineering of new biocatalysts has been most successful with enteric bacteria thus far. However, this approach may also prove useful with Gram-positive bacteria which have other important traits for lignocellulose conversion. Many opportunities remain for further improvements in the biomass to ethanol processes. These include the development of enzyme-based systems which eliminate the need for dilute acid hydrolysis or other pretreatments, improvements in existing pretreatments for enzymatic hydrolysis, process improvements to increase the effective use of cellulase and hemicellulase enzymes, improvements in rates of ethanol production, decreased nutrient costs, increases in ethanol concentrations achieved in biomass beers, increased resistance of the biocatalysts to lignocellulosic-derived toxins, etc. To be useful, each of these improvements must result in a decrease in the cost for ethanol production. Copyright 1998 John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- LO Ingram
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| | | | | | | | | | | | | |
Collapse
|