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Louie TM, Louie K, DenHartog S, Gopishetty S, Subramanian M, Arnold M, Das S. Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor. Microb Cell Fact 2021; 20:50. [PMID: 33618706 PMCID: PMC7898734 DOI: 10.1186/s12934-021-01534-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 01/29/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Xylitol is a five-carbon sugar alcohol that has numerous beneficial health properties. It has almost the same sweetness as sucrose but has lower energy value compared to the sucrose. Metabolism of xylitol is insulin independent and thus it is an ideal sweetener for diabetics. It is widely used in food products, oral and personal care, and animal nutrition as well. Here we present a two-stage strategy to produce bio-xylitol from D-xylose using a recombinant Pichia pastoris expressing a heterologous xylose reductase gene. The recombinant P. pastoris cells were first generated by a low-cost, standard procedure. The cells were then used as a catalyst to make the bio-xylitol from D-xylose. RESULTS Pichia pastoris expressing XYL1 from P. stipitis and gdh from B. subtilis demonstrated that the biotransformation was very efficient with as high as 80% (w/w) conversion within two hours. The whole cells could be re-used for multiple rounds of catalysis without loss of activity. Also, the cells could directly transform D-xylose in a non-detoxified hemicelluloses hydrolysate to xylitol at 70% (w/w) yield. CONCLUSIONS We demonstrated here that the recombinant P. pastoris expressing xylose reductase could transform D-xylose, either in pure form or in crude hemicelluloses hydrolysate, to bio-xylitol very efficiently. This biocatalytic reaction happened without the external addition of any NAD(P)H, NAD(P)+, and auxiliary substrate as an electron donor. Our experimental design & findings reported here are not limited to the conversion of D-xylose to xylitol only but can be used with other many oxidoreductase reactions also, such as ketone reductases/alcohol dehydrogenases and amino acid dehydrogenases, which are widely used for the synthesis of high-value chemicals and pharmaceutical intermediates.
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Affiliation(s)
- Tai Man Louie
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA
| | - Kailin Louie
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA
| | - Samuel DenHartog
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA
| | - Sridhar Gopishetty
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA
| | - Mani Subramanian
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA
| | - Mark Arnold
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA
- Department of Chemistry, University of Iowa, Iowa City, IA, 52241, USA
| | - Shuvendu Das
- Center for Biocatalysis & Bioprocessing, University of Iowa, Iowa City, IA, 52241, USA.
- Department of Chemistry, University of Iowa, Iowa City, IA, 52241, USA.
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Ruchala J, Sibirny AA. Pentose metabolism and conversion to biofuels and high-value chemicals in yeasts. FEMS Microbiol Rev 2020; 45:6034013. [PMID: 33316044 DOI: 10.1093/femsre/fuaa069] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Pentose sugars are widespread in nature and two of them, D-xylose and L-arabinose belong to the most abundant sugars being the second and third by abundance sugars in dry plant biomass (lignocellulose) and in general on planet. Therefore, it is not surprising that metabolism and bioconversion of these pentoses attract much attention. Several different pathways of D-xylose and L-arabinose catabolism in bacteria and yeasts are known. There are even more common and really ubiquitous though not so abundant pentoses, D-ribose and 2-deoxy-D-ribose, the constituents of all living cells. Thus, ribose metabolism is example of endogenous metabolism whereas metabolism of other pentoses, including xylose and L-arabinose, represents examples of the metabolism of foreign exogenous compounds which normally are not constituents of yeast cells. As a rule, pentose degradation by the wild-type strains of microorganisms does not lead to accumulation of high amounts of valuable substances; however, productive strains have been obtained by random selection and metabolic engineering. There are numerous reviews on xylose and (less) L-arabinose metabolism and conversion to high value substances; however, they mostly are devoted to bacteria or the yeast Saccharomyces cerevisiae. This review is devoted to reviewing pentose metabolism and bioconversion mostly in non-conventional yeasts, which naturally metabolize xylose. Pentose metabolism in the recombinant strains of S. cerevisiae is also considered for comparison. The available data on ribose, xylose, L-arabinose transport, metabolism, regulation of these processes, interaction with glucose catabolism and construction of the productive strains of high-value chemicals or pentose (ribose) itself are described. In addition, genome studies of the natural xylose metabolizing yeasts and available tools for their molecular research are reviewed. Metabolism of other pentoses (2-deoxyribose, D-arabinose, lyxose) is briefly reviewed.
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Affiliation(s)
- Justyna Ruchala
- Department of Microbiology and Molecular Genetics, University of Rzeszow, Zelwerowicza 4, Rzeszow 35-601, Poland.,Department of Molecular Genetics and Biotechnology, Institute of Cell Biology NAS of Ukraine, Drahomanov Street, 14/16, Lviv 79005, Ukraine
| | - Andriy A Sibirny
- Department of Microbiology and Molecular Genetics, University of Rzeszow, Zelwerowicza 4, Rzeszow 35-601, Poland.,Department of Molecular Genetics and Biotechnology, Institute of Cell Biology NAS of Ukraine, Drahomanov Street, 14/16, Lviv 79005, Ukraine
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Process Optimization of Ethanol Production from Cotton Stalk Hydrolysate using Co Culture of Saccharomyces cerevisiae and Pachysolen tannophilus. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2016. [DOI: 10.22207/jpam.10.4.26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ur-Rehman S, Mushtaq Z, Zahoor T, Jamil A, Murtaza MA. Xylitol: a review on bioproduction, application, health benefits, and related safety issues. Crit Rev Food Sci Nutr 2016; 55:1514-28. [PMID: 24915309 DOI: 10.1080/10408398.2012.702288] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues.
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Affiliation(s)
- Salim Ur-Rehman
- a National Institute of Food Science & Technology, University of Agriculture , Faisalabad , 38040 , Pakistan
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Ali SS, Nugent B, Mullins E, Doohan FM. Fungal-mediated consolidated bioprocessing: the potential of Fusarium oxysporum for the lignocellulosic ethanol industry. AMB Express 2016; 6:13. [PMID: 26888202 PMCID: PMC4757592 DOI: 10.1186/s13568-016-0185-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 02/09/2016] [Indexed: 12/21/2022] Open
Abstract
Microbial bioprocessing of lignocellulose to bioethanol still poses challenges in terms of substrate catabolism. The most important challenge is to overcome substrate recalcitrance and to thus reduce the number of steps needed to biorefine lignocellulose. Conventionally, conversion involves chemical pretreatment of lignocellulose, followed by hydrolysis of biomass to monomer sugars that are subsequently fermented into bioethanol. Consolidated bioprocessing (CBP) has been suggested as an efficient and economical method of manufacturing bioethanol from lignocellulose. CBP integrates the hydrolysis and fermentation steps into a single process, thereby significantly reducing the amount of steps in the biorefining process. Filamentous fungi are remarkable organisms that are naturally specialised in deconstructing plant biomass and thus they have tremendous potential as components of CBP. The fungus Fusarium oxysporum has potential for CBP of lignocellulose to bioethanol. Here we discuss the complexity and potential of CBP, the bottlenecks in the process, and the potential influence of fungal genetic diversity, substrate complexity and new technologies on the efficacy of CPB of lignocellulose, with a focus on F. oxysporum.
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Mohamad NL, Mustapa Kamal SM, Mokhtar MN. Xylitol Biological Production: A Review of Recent Studies. FOOD REVIEWS INTERNATIONAL 2014. [DOI: 10.1080/87559129.2014.961077] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Saleh M, Cuevas M, García JF, Sánchez S. Valorization of olive stones for xylitol and ethanol production from dilute acid pretreatment via enzymatic hydrolysis and fermentation by Pachysolen tannophilus. Biochem Eng J 2014. [DOI: 10.1016/j.bej.2014.06.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mushtaq Z, Imran M, Zahoor T, Ahmad RS, Arshad MU. Biochemical perspectives of xylitol extracted from indigenous agricultural by-product mung bean (Vigna radiata) hulls in a rat model. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2014; 94:969-974. [PMID: 24757723 DOI: 10.1002/jsfa.6346] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND The production of xylitol from lignocellulosic material is of great interest around the world. It can be used as bulk sweetener and its possible lower energy value has increased acceptance for discerning consumers. Xylitol was produced from indigenous agricultural by-product (mung bean hulls) through Candida tropicalis fermentation. Further, xylitol incorporation at different concentrations (0, 100 and 200 g kg⁻¹) was carried out with the purpose of appraising the suitability and claimed health benefits of this dietetic ingredient in food products. Asserted biochemical perspectives of the xylitol intake were evaluated through biological studies for normal and streptozotocin-induced diabetic rats. RESULTS The addition of xylitol significantly affected feed intake, weight gain, liver and cecum weight in both normal and diabetic rats. The biochemical profile of serum was improved with xylitol incorporation in the diet. Serum glucose, cholesterol and triglycerides levels were decreased depending on xylitol intake level. CONCLUSION The results of the present study demonstrated that mung bean hulls have high potential as a new feedstock for xylitol production. In addressing the current concerns of obesity and diabetes, xylitol extracted from such agricultural waste should be considered in diet-based therapies for weight loss programmes.
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Effects of environmental conditions on production of xylitol byCandida boidinii. World J Microbiol Biotechnol 2014; 11:213-8. [PMID: 24414506 DOI: 10.1007/bf00704652] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 11/08/1994] [Accepted: 11/11/1994] [Indexed: 10/26/2022]
Abstract
Candida boidinii NRRL Y-17213 produced more xylitol thanC. magnolia (NRRL Y-4226 and NRRL Y-7621),Debaryomyces hansenii (C-98 M-21, C-56 M-9 and NRRL Y-7425), orPichia (Hansenula) anomala (NRRL Y-366). WithC. boidinii, highest xylitol productivity was at pH 7 but highest yield was at pH 8, using 5 g urea and 5 g Casamino acids/I. Decreasing the aeration rate decreased xylose consumption and cell growth but increased the xylitol yield. When an initial cell density of 5.1 g/l was used instead of 1.3 g/l, xylitol yield and the specific xylitol production rate doubled. Substrate concentration had the greatest effect on xylitol production; increasing xylose concentration 7.5-fold (to 150 g/l) gave a 71-fold increase in xylitol production (53 g/l) and a 10-fold increase in xylitol/ethanol ratio. The highest xylitol yield (0.47 g/g), corresponding to 52% of the theoretical yield, was obtained with 150 g xylose/l after 14 days. Xylose at 200 g/l inhibited xylitol production.
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Abu Tayeh H, Najami N, Dosoretz C, Tafesh A, Azaizeh H. Potential of bioethanol production from olive mill solid wastes. BIORESOURCE TECHNOLOGY 2013; 152:24-30. [PMID: 24275022 DOI: 10.1016/j.biortech.2013.10.102] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 10/24/2013] [Accepted: 10/28/2013] [Indexed: 06/02/2023]
Abstract
The main objective of this study was to screen endogenous microorganisms grown on olive mill solid wastes (OMSW) with the potential to ferment pentoses and produce ethanol. Two yeasts were isolated and identified as Issatchenkia orientalis, and Pichia galeiformis/manshurica. The adaptation of the strains displayed a positive impact on the fermentation process. In terms of xylose utilization and ethanol production, all strains were able to utilize xylose and produce xylitol but no ethanol was detected. Separate hydrolysis and fermentation process on hydrolysate undergo detoxification, strain I. orientalis showed the best efficiency in producing of ethanol when supplemented with glucose. Using simultaneous saccharification and fermentation process following pretreatment of OMSW, the average ethanol yield was 3 g/100 g dry OMSW. Bioethanol production from OMSW is not economic despite the raw material is cheap.
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Affiliation(s)
- Hiba Abu Tayeh
- Institute of Applied Research, Affiliated with University of Haifa, The Galilee Society, P.O. Box 437, Shefa-Amr 20200, Israel.
| | - Naim Najami
- Institute of Applied Research, Affiliated with University of Haifa, The Galilee Society, P.O. Box 437, Shefa-Amr 20200, Israel; The Academic Arab College of Education, Haifa, Israel.
| | - Carlos Dosoretz
- Department of Environments, Water & Agriculture Engineering, Technion Institute, Haifa 32000, Israel.
| | - Ahmed Tafesh
- Institute of Applied Research, Affiliated with University of Haifa, The Galilee Society, P.O. Box 437, Shefa-Amr 20200, Israel.
| | - Hassan Azaizeh
- Institute of Applied Research, Affiliated with University of Haifa, The Galilee Society, P.O. Box 437, Shefa-Amr 20200, Israel; Tel Hai College, Upper Galilee 12208, Israel.
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11
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Draft genome sequence of the yeast Pachysolen tannophilus CBS 4044/NRRL Y-2460. EUKARYOTIC CELL 2012; 11:827. [PMID: 22645232 DOI: 10.1128/ec.00114-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A draft genome sequence of the yeast Pachysolen tannophilus CBS 4044/NRRL Y-2460 is presented. The organism has the potential to be developed as a cell factory for biorefineries due to its ability to utilize waste feedstocks. The sequenced genome size was 12,238,196 bp, consisting of 34 scaffolds. A total of 4,463 genes from 5,346 predicted open reading frames were annotated with function.
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12
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dos Santos VC, Bragança CRS, Passos FJV, Passos FML. Kinetics of growth and ethanol formation from a mix of glucose/xylose substrate by Kluyveromyces marxianus UFV-3. Antonie van Leeuwenhoek 2012; 103:153-61. [PMID: 22965752 DOI: 10.1007/s10482-012-9794-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 08/09/2012] [Indexed: 11/27/2022]
Abstract
The fermentation of both glucose and xylose is important to maximize ethanol yield from renewable biomass feedstocks. In this article, we analyze growth, sugar consumption, and ethanol formation by the yeast Kluyveromyces marxianus UFV-3 using various glucose and xylose concentrations and also under conditions of reduced respiratory activity. In almost all the conditions analyzed, glucose repressed xylose assimilation and xylose consumption began after glucose had been exhausted. A remarkable difference was observed when mixtures of 5 g L(-1) glucose/20 g L(-1) xylose and 20 g L(-1) glucose/20 g L(-1) xylose were used. In the former, the xylose consumption began immediately after the glucose depletion. Indeed, there was no striking diauxic phase, as observed in the latter condition, in which there was an interval of 30 h between glucose depletion and the beginning of xylose consumption. Ethanol production was always higher in a mixture of glucose and xylose than in glucose alone. The highest ethanol concentration (8.65 g L(-1)) and cell mass concentration (4.42 g L(-1)) were achieved after 8 and 74 h, respectively, in a mixture of 20 g L(-1) glucose/20 g L(-1) xylose. When inhibitors of respiration were added to the medium, glucose repression of xylose consumption was alleviated completely and K. marxianus was able to consume xylose and glucose simultaneously.
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Affiliation(s)
- Valdilene Canazart dos Santos
- Department of Microbiology, Institute for Biotechnology Applied to Agriculture and Animal Science, Federal University of Viçosa, Viçosa, MG, Brazil
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Laluce C, Schenberg ACG, Gallardo JCM, Coradello LFC, Pombeiro-Sponchiado SR. Advances and Developments in Strategies to Improve Strains of Saccharomyces cerevisiae and Processes to Obtain the Lignocellulosic Ethanol−A Review. Appl Biochem Biotechnol 2012; 166:1908-26. [DOI: 10.1007/s12010-012-9619-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 02/16/2012] [Indexed: 10/28/2022]
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14
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Liu X, Jensen PR, Workman M. Bioconversion of crude glycerol feedstocks into ethanol by Pachysolen tannophilus. BIORESOURCE TECHNOLOGY 2012; 104:579-86. [PMID: 22093973 DOI: 10.1016/j.biortech.2011.10.065] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 05/21/2023]
Abstract
Glycerol, the by-product of biodiesel production, is considered as a waste by biodiesel producers. This study demonstrated the potential of utilising the glycerol surplus through conversion to ethanol by the yeast Pachysolen tannophilus (CBS4044). This study demonstrates a robust bioprocess which was not sensitive to the batch variability in crude glycerol dependent on raw materials used for biodiesel production. The oxygen transfer rate (OTR) was a key factor for ethanol production, with lower OTR having a positive effect on ethanol production. The highest ethanol production was 17.5 g/L on 5% (v/v) crude glycerol, corresponding to 56% of the theoretical yield. A staged batch process achieved 28.1g/L ethanol, the maximum achieved so far for conversion of glycerol to ethanol in a microbial bioprocess. The fermentation physiology has been investigated as a means to designing a competitive bioethanol production process, potentially improving economics and reducing waste from industrial biodiesel production.
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Affiliation(s)
- Xiaoying Liu
- Center for Systems Microbiology, Department of Systems Biology, Building 301, Matematiktorvet, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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15
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Improving Biomass Sugar Utilization by Engineered Saccharomyces cerevisiae. MICROBIOLOGY MONOGRAPHS 2012. [DOI: 10.1007/978-3-642-21467-7_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Slininger PJ, Thompson SR, Weber S, Liu ZL, Moon J. Repression of xylose-specific enzymes by ethanol in Scheffersomyces (Pichia) stipitis and utility of repitching xylose-grown populations to eliminate diauxic lag. Biotechnol Bioeng 2011; 108:1801-15. [DOI: 10.1002/bit.23119] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 02/21/2011] [Accepted: 02/22/2011] [Indexed: 11/07/2022]
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Delgenes JP, Moletta R, Navarro JM. Fermentation of D-xylose, D-glucose, L-arabinose mixture by Pichia stipitis: Effect of the oxygen transfer rate on fermentation performance. Biotechnol Bioeng 2010; 34:398-402. [PMID: 18588117 DOI: 10.1002/bit.260340314] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- J P Delgenes
- Institut National de la Recherche Agronomique, Station d'Oenologie et de Technologie des Produits Végétaux, Boulevard du Général de Gaulle 11104 Narbonne Cedex France
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Ferrari MD, Neirotti E, Albornoz C, Saucedo E. Ethanol production from eucalyptus wood hemicellulose hydrolysate by Pichia stipitis. Biotechnol Bioeng 2010; 40:753-9. [PMID: 18601178 DOI: 10.1002/bit.260400702] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ethanol production was evaluated from eucalyptus wood hemicellulose acid hydrolysate using Pichia stipitis NRRL Y-7124. An initial lag phase characterized by flocculation and viability loss of the yeast inoculated was observed. Subsequently, cell regrowth occurred with sequential consumption of sugars and production of ethanol. Polyol formation was detected. Acetic acid present in the hydrolysate was an important inhibitor of the fermentation, reducing the rate and the yield. Its toxic effect was due essentially to its undissociated form. The fermentation was more effective at an oxygen transfer rate between 1.2 and 2.4 mmol/L h and an initial pH of 6.5. The hydrolysate used in the experiences had the following composition (expressed in grams per liter): xylose 30, arabinose 2.8, glucose 1.5, galactose 3.7, mannose 1.0, cellobiose 0.5, acetic acid 10, glucuronic acid 1.5, and galacturonic acid 1.0. The best values obtained were maximum ethanol concentration 12.6 g/L, fermentation time 75 h, fermentable sugar consumption 99% ethanol yield 0.35 g/g sugars consumed, and volumetric ethanol productivity 4 g/L day. (
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Affiliation(s)
- M D Ferrari
- Centro de Investigaciones Tecnológicas, Administración Nacional de Combustibles, Alcohol y Portland, (ANCAP), Pando, Canelones, C.P. 91000, Uruguay
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Slininger PJ, Branstrator LE, Bothast RJ, Okos MR, Ladisch MR. Growth, death, and oxygen uptake kinetics of Pichia stipitis on xylose. Biotechnol Bioeng 2009; 37:973-80. [PMID: 18597323 DOI: 10.1002/bit.260371012] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pichia stipitis NRRL Y-7124 has potential application in the fermentation of xylose-rich waste streams, produced by wood hydrolysis. Kinetic models of cell growth, death, and oxygen uptake were investigated in batch and oxygen-limited continuous cultures fed a rich synthetic medium. Variables included rates of dilution (D) and oxygen transfer (K(1)a) and concentrations of xylose (X), ethanol (E), and dissolved oxygen (C(ox)). Sustained cell growth required the presence of oxygen. Given excess xylose, specific growth rate (micro) was a Monod function of C(ox). Specific oxygen uptake rate was proportional to mu by a yield coefficient relating biomass production to oxygen consumption; but oxygen uptake for maintenance was negligible. Thus steady-state C(OX) depended only on D, while steady-state biomass concentration was controlled by both D and K(1)a. Given excess oxygen, cells grew subject to Monod limitation by xylose, which became inhibitory above 40 g/L. Ethanol inhibition was consistent with Luong's model, and 64. 3 g/L was the maximum ethanol concentration allowing growth. Actively growing cells died at a rate that was 20% of micro. The dying portion increased with E and X.
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Affiliation(s)
- P J Slininger
- Fermentation Biochemistry Research Unit, Northern Regional Research Center, USDA, Agricultural Research Service, 1815 N University Street, Peoria, Illinois 61604
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Dellweg H, Klein C, Prahl S, Rizzi M, Weigert B. Kinetics of ethanol production from D‐xylose by the yeastpichia stipitis. FOOD BIOTECHNOL 2009. [DOI: 10.1080/08905439009549729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- H. Dellweg
- a Institute of Biotechnology , Technical University of Berlin, Institut für Gärungsgewerbe und Biotechnologie , Berlin 65, Seestraße 13 , D 1000
| | - C. Klein
- a Institute of Biotechnology , Technical University of Berlin, Institut für Gärungsgewerbe und Biotechnologie , Berlin 65, Seestraße 13 , D 1000
| | - S. Prahl
- a Institute of Biotechnology , Technical University of Berlin, Institut für Gärungsgewerbe und Biotechnologie , Berlin 65, Seestraße 13 , D 1000
| | - M. Rizzi
- a Institute of Biotechnology , Technical University of Berlin, Institut für Gärungsgewerbe und Biotechnologie , Berlin 65, Seestraße 13 , D 1000
| | - B. Weigert
- a Institute of Biotechnology , Technical University of Berlin, Institut für Gärungsgewerbe und Biotechnologie , Berlin 65, Seestraße 13 , D 1000
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Xu Q, Singh A, Himmel ME. Perspectives and new directions for the production of bioethanol using consolidated bioprocessing of lignocellulose. Curr Opin Biotechnol 2009; 20:364-71. [PMID: 19520566 DOI: 10.1016/j.copbio.2009.05.006] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/24/2022]
Abstract
The U.S. DOE Energy Independence and Security Act (EISA) mandated attainment of a national production level of 36 billion gallons of biofuels (to be added to gasoline) by 2022, of which 21 billion gallons must be derived from renewable/sustainable feedstocks (e.g. lignocellulose). In order to attain these goals, the development of cost effective process technologies that can convert plant biomass to fermentable sugars must occur. An alternative route to production of bioethanol is the utilization of microorganisms that can both convert biomass to fermentable sugars and ferment the resultant sugars to ethanol in a process known as consolidated bioprocessing (CBP). Although various economic benefits and technology hurdles must be weighed in the course of choosing the CBP strategy to be pursued, we present arguments for developing the powerfully cellulolytic fungus, Trichoderma reesei, as an effective CBP microorganism.
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Affiliation(s)
- Qi Xu
- Chemical and Biosciences Center, National Renewable Energy Laboratory, Golden CO 80401, USA
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22
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Zhao L, Yu J, Zhang X, Tan T. The ethanol tolerance of Pachysolen tannophilus in fermentation on xylose. Appl Biochem Biotechnol 2008; 160:378-85. [PMID: 18651246 DOI: 10.1007/s12010-008-8308-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Accepted: 06/26/2008] [Indexed: 11/27/2022]
Abstract
The influence of ethanol on fermentation by Pachysolen tannophilus was studied. When xylose utilization rate was 80%, ethanol concentration began to decline. Fermentation of P. tannophilus was affected by ethanol addition in the beginning of fermentation; average xylose consumption rate was 0.065 g.l(-1).h(-1), and maximum specific growth rate was 0.07 h(-1) at 28 g.l(-1) ethanol, comparing with the average xylose consumption rate of 0.38 g.l(-1).h(-1) and maximum specific growth rate of 0.14 h(-1) in fermentation with no ethanol addition; P. tannophilus stopped growth at 40 g.l(-1) ethanol. When the initial ethanol concentration was 30 g.l(-1), the addition of glucose in xylose media made the growth of P. tannophilus better, and the most favorable glucose concentration was 15 g.l(-1) with the highest biomass of 1.51 g.l(-1) as compared with that of 0.95 g.l(-1) in pure xylose media.
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Affiliation(s)
- Lei Zhao
- Beijing University of Chemical Technology, China
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23
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Fermentation of d-glucose and d-xylose mixtures by Candida tropicalis NBRC 0618 for xylitol production. World J Microbiol Biotechnol 2007. [DOI: 10.1007/s11274-007-9527-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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24
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van Zyl WH, Lynd LR, den Haan R, McBride JE. Consolidated bioprocessing for bioethanol production using Saccharomyces cerevisiae. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2007; 108:205-35. [PMID: 17846725 DOI: 10.1007/10_2007_061] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Consolidated bioprocessing (CBP) of lignocellulose to bioethanol refers to the combining of the four biological events required for this conversion process (production of saccharolytic enzymes, hydrolysis of the polysaccharides present in pretreated biomass, fermentation of hexose sugars, and fermentation of pentose sugars) in one reactor. CBP is gaining increasing recognition as a potential breakthrough for low-cost biomass processing. Although no natural microorganism exhibits all the features desired for CBP, a number of microorganisms, both bacteria and fungi, possess some of the desirable properties. This review focuses on progress made toward the development of baker's yeast (Saccharomyces cerevisiae) for CBP. The current status of saccharolytic enzyme (cellulases and hemicellulases) expression in S. cerevisiae to complement its natural fermentative ability is highlighted. Attention is also devoted to the challenges ahead to integrate all required enzymatic activities in an industrial S. cerevisiae strain(s) and the need for molecular and selection strategies pursuant to developing a yeast capable of CBP.
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Affiliation(s)
- Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, 7602, Matieland, South Africa.
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25
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Slininger PJ, Dien BS, Gorsich SW, Liu ZL. Nitrogen source and mineral optimization enhance d-xylose conversion to ethanol by the yeast Pichia stipitis NRRL Y-7124. Appl Microbiol Biotechnol 2006; 72:1285-96. [PMID: 16676180 DOI: 10.1007/s00253-006-0435-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2005] [Revised: 03/20/2006] [Accepted: 03/24/2006] [Indexed: 10/24/2022]
Abstract
Nutrition-based strategies to optimize xylose to ethanol conversion by Pichia stipitis were identified in growing and stationary-phase cultures provided with a defined medium varied in nitrogen, vitamin, purine/pyrimidine, and mineral content via full or partial factorial designs. It is surprising to note that stationary-phase cultures were unable to ferment xylose (or glucose) to ethanol without the addition of a nitrogen source, such as amino acids. Ethanol accumulation increased with arginine, alanine, aspartic acid, glutamic acid, glycine, histidine, leucine, and tyrosine, but declined with isoleucine. Ethanol production from 150 g/l xylose was maximized (61+/-9 g/l) by providing C:N in the vicinity of approximately 57-126:1 and optimizing the combination of urea and amino acids to supply 40-80 % nitrogen from urea and 60-20 % from amino acids (casamino acids supplemented with tryptophan and cysteine). When either urea or amino acids were used as sole nitrogen source, ethanol accumulation dropped to 11 or 24 g/l, respectively, from the maximum of 46 g/l for the optimal nitrogen combination. The interaction of minerals with amino acids and/or urea was key to optimizing ethanol production by cells in both growing and stationary-phase cultures. In nongrowing cultures supplied with nitrogen as amino acids, ethanol concentration increased from 24 to 54 g/l with the addition of an optimized mineral supplement of Fe, Mn, Mg, Ca, Zn, and others.
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Affiliation(s)
- Patricia J Slininger
- U. S. Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N. University Street, Peoria, IL 61604, USA.
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26
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Olsson L, Hahn-Hägerdal B, Zacchi G. Kinetics of ethanol production by recombinantEscherichia coliKO11. Biotechnol Bioeng 2004; 45:356-65. [DOI: 10.1002/bit.260450410] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Influence of temperature on the fermentation of d-xylose by Pachysolen tannophilus to produce ethanol and xylitol. Process Biochem 2004. [DOI: 10.1016/s0032-9592(03)00139-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Sharma SK, Kalra KL, Grewal HS. Fermentation of enzymatically saccharified sunflower stalks for ethanol production and its scale up. BIORESOURCE TECHNOLOGY 2002; 85:31-33. [PMID: 12146639 DOI: 10.1016/s0960-8524(02)00076-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Pretreated sunflower stalks saccharified with a Trichoderma reesei Rut-C 30 cellulase showed 57.8% saccharification. Enzyme hydrolysate concentrated to 40 g/l reducing sugars was fermented under optimum conditions of fermentation time (24 h), pH (5.0), temperature (30 degrees C) and inoculum size (3% v/v) and, showed a maximum ethanol yield of 0.444 g/g ethanol. Ethanol production scaled up in a 1 l and a 15 l fermenter under optimum conditions revealed maximum ethanol yields of 0.439 and 0.437 g/g respectively.
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Affiliation(s)
- Sanjeev K Sharma
- Department of Microbiology, College of Basic Sciences and Humanities, Punjab Agricultural University, India
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29
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Hahn-Hägerdal B, Wahlbom CF, Gárdonyi M, van Zyl WH, Cordero Otero RR, Jönsson LJ. Metabolic engineering of Saccharomyces cerevisiae for xylose utilization. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2002; 73:53-84. [PMID: 11816812 DOI: 10.1007/3-540-45300-8_4] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metabolic engineering of Saccharomyces cerevisiae for ethanolic fermentation of xylose is summarized with emphasis on progress made during the last decade. Advances in xylose transport, initial xylose metabolism, selection of host strains, transformation and classical breeding techniques applied to industrial polyploid strains as well as modeling of xylose metabolism are discussed. The production and composition of the substrates--lignocellulosic hydrolysates--is briefly summarized. In a future outlook iterative strategies involving the techniques of classical breeding, quantitative physiology, proteomics, DNA micro arrays, and genetic engineering are proposed for the development of efficient xylose-fermenting recombinant strains of S. cerevisiae.
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Affiliation(s)
- B Hahn-Hägerdal
- Department of Applied Microbiology, Lund University, PO Box 124, 221 00 Lund, Sweden.
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Hasegawa Y, Adachi S, Matsuno R. Effect of the molar ratio of an energy source to the substrate on yeast-mediated production of 2-chloro-α-methylbenzyl alcohol. J Biosci Bioeng 2000; 89:329-33. [PMID: 16232754 DOI: 10.1016/s1389-1723(00)88954-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/1999] [Accepted: 12/27/1999] [Indexed: 11/17/2022]
Abstract
Pachysolen tannophilus cells immobilized in Ca-alginate gels were shown to catalyze the asymmetric reduction of acetophenone (AP) and chloroacetophenones (Cl-APs) to their corresponding alcohols. The position of the Cl-group on the aromatic ring of AP greatly affected the reaction rate, and o-Cl-AP was the most readily reduced. For the reduction of o-Cl-AP to 2-chloro-alpha-methylbenzyl alcohol, the effect of the molar ratio of the energy source, glucose, to the substrate was examined in both batch and continuous operations, and a molar ratio much lower than that conventionally used was found to be sufficient for the reduction.
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Affiliation(s)
- Y Hasegawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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31
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Chandrakant P, Bisaria VS. Simultaneous bioconversion of cellulose and hemicellulose to ethanol. Crit Rev Biotechnol 1999; 18:295-331. [PMID: 9887507 DOI: 10.1080/0738-859891224185] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Lignocellulosic materials containing cellulose, hemicellulose, and lignin as their main constituents are the most abundant renewable organic resource present on Earth. The conversion of both cellulose and hemicellulose for production of fuel ethanol is being studied intensively with a view to develop a technically and economically viable bioprocess. The fermentation of glucose, the main constituent of cellulose hydrolyzate, to ethanol can be carried out efficiently. On the other hand, although bioconversion of xylose, the main pentose sugar obtained on hydrolysis of hemicellulose, to ethanol presents a biochemical challenge, especially if it is present along with glucose, it needs to be fermented to make the biomass-to-ethanol process economical. A lot of attention therefore has been focussed on the utilization of both glucose and xylose to ethanol. Accordingly, while describing the advancements that have taken place to get xylose converted efficiently to ethanol by xylose-fermenting organisms, the review deals mainly with the strategies that have been put forward for bioconversion of both the sugars to achieve high ethanol concentration, yield, and productivity. The approaches, which include the use of (1) xylose-fermenting yeasts alone, (2) xylose isomerase enzyme as well as yeast, (3) immobilized enzymes and cells, and (4) sequential fermentation and co-culture process are described with respect to their underlying concepts and major limitations. Genetic improvements in the cultures have been made either to enlarge the range of substrate utilization or to channel metabolic intermediates specifically toward ethanol. These contributions represent real significant advancements in the field and have also been adequately dealt with from the point of view of their impact on utilization of both cellulose and hemicellulose sugars to ethanol.
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Affiliation(s)
- P Chandrakant
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Hauz Khas, New Delhi, India
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32
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Bolen PL, Hayman GT, Shepherd HS. Sequence and analysis of an aldose (xylose) reductase gene from the xylose‐fermenting yeast
Pachysolen tannophilus. Yeast 1998. [DOI: 10.1002/(sici)1097-0061(199610)12:13<1367::aid-yea33>3.0.co;2-#] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Paul L. Bolen
- Microbial Properties Research, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 N. University St, Peoria, IL 61604, U.S.A
| | - G. Thomas Hayman
- Microbial Properties Research, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 N. University St, Peoria, IL 61604, U.S.A
| | - Hurley S. Shepherd
- Microbial Properties Research, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 N. University St, Peoria, IL 61604, U.S.A
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Belkacemi K, Turcotte G, de Halleux D, Savoie P. Ethanol production from AFEX-treated forages and agricultural residues. Appl Biochem Biotechnol 1998; 70-72:441-62. [PMID: 9627392 DOI: 10.1007/bf02920159] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lignocellulosic materials derived from forages, namely timothy grass, alfalfa, reed canary grass, and agricultural residues, such as corn stalks and barley straw, were pretreated using ammonia fiber explosion (AFEX) process. The pretreated materials were directly saccharified by cellulolytic enzymes. Sixty to 80% of theoretical yield of sugars were obtained from the pretreated biomasses. Subsequent ethanolic fermentation of the hydrolysates by Pachysolen tannophilus ATCC 32691 resulted in 40-60% of theoretical yield after 24 h, based on the sugars present in the hydrolysates. The uptake of sugars was not complete, indicating a possible inhibitory effect on P. tannophilus during the fermentation of these substrates.
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Affiliation(s)
- K Belkacemi
- Department of Food Science and Nutrition, Agri-Food Engineering University Laval, Québec, Canada
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34
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Saha BC, Dien BS, Bothast RJ. Fuel ethanol production from corn fiber current status and technical prospects. Appl Biochem Biotechnol 1998. [DOI: 10.1007/bf02920129] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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35
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36
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Belkacemi K, Turcotte G, Savoie P, Chornet E. Ethanol Production from Enzymatic Hydrolyzates of Cellulosic Fines and Hemicellulose-Rich Liquors Derived from Aqueous/Steam Fractionation of Forages. Ind Eng Chem Res 1997. [DOI: 10.1021/ie970105j] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Khaled Belkacemi
- Department of Food Science and Nutrition, Université Laval, Pavillon Comtois, Sainte-Foy, Quebec, Canada G1K 7P4, Agriculture and Agri-Food Canada, 2650 boul. Hochelaga, Sainte-Foy, Quebec, Canada G1V 2J3, and Department of Chemical Engineering, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Quebec, Canada J1K 2R1
| | - Ginette Turcotte
- Department of Food Science and Nutrition, Université Laval, Pavillon Comtois, Sainte-Foy, Quebec, Canada G1K 7P4, Agriculture and Agri-Food Canada, 2650 boul. Hochelaga, Sainte-Foy, Quebec, Canada G1V 2J3, and Department of Chemical Engineering, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Quebec, Canada J1K 2R1
| | - Philippe Savoie
- Department of Food Science and Nutrition, Université Laval, Pavillon Comtois, Sainte-Foy, Quebec, Canada G1K 7P4, Agriculture and Agri-Food Canada, 2650 boul. Hochelaga, Sainte-Foy, Quebec, Canada G1V 2J3, and Department of Chemical Engineering, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Quebec, Canada J1K 2R1
| | - Esteban Chornet
- Department of Food Science and Nutrition, Université Laval, Pavillon Comtois, Sainte-Foy, Quebec, Canada G1K 7P4, Agriculture and Agri-Food Canada, 2650 boul. Hochelaga, Sainte-Foy, Quebec, Canada G1V 2J3, and Department of Chemical Engineering, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Quebec, Canada J1K 2R1
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Saucedo VM, Karim MN. Experimental optimization of a real time fed-batch fermentation process using Markov decision process. Biotechnol Bioeng 1997; 55:317-27. [DOI: 10.1002/(sici)1097-0290(19970720)55:2<317::aid-bit9>3.0.co;2-l] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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38
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Diminished Respirative Growth and Enhanced Assimilative Sugar Uptake Result in Higher Specific Fermentation Rates by the MutantPichia stipitis FPL-061. Appl Biochem Biotechnol 1997; 63-65:109-16. [DOI: 10.1007/bf02920417] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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39
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Bothast RJ, Saha BC. Ethanol Production from Agricultural Biomass Substrates. ADVANCES IN APPLIED MICROBIOLOGY 1997. [DOI: 10.1016/s0065-2164(08)70464-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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40
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Hahn-Hägerdal B, Hallborn J, Jeppsson H, Meinander N, Walfridsson M, Ojamo H, Penttilä M, Zimmermann FK. Redox balances in recombinant Saccharomyces cerevisiae. Ann N Y Acad Sci 1996; 782:286-96. [PMID: 8659905 DOI: 10.1111/j.1749-6632.1996.tb40569.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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41
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Kruse B, Schügerl K. Investigation of ethanol formation by Pachysolen tannophilus from xylose and glucose/xylose co-substrates. Process Biochem 1996. [DOI: 10.1016/0032-9592(95)00070-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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42
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Olsson L, Hahn-Hägerdal B. Fermentation of lignocellulosic hydrolysates for ethanol production. Enzyme Microb Technol 1996. [DOI: 10.1016/0141-0229(95)00157-3] [Citation(s) in RCA: 498] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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43
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Effect of corn steep liquor on fermentation of mixed sugars byCandida shehatae FPL-702. Appl Biochem Biotechnol 1996. [DOI: 10.1007/bf02941735] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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44
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Dien BS, Kurtzman CP, Saha BC, Bothast RJ. Screening forl-arabinose fermenting yeasts. Appl Biochem Biotechnol 1996. [DOI: 10.1007/bf02941704] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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45
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Alcohol fermentation of enzymatic hydrolysate of exploded rice straw by Pichia stipitis. World J Microbiol Biotechnol 1995; 11:646-8. [DOI: 10.1007/bf00361008] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/1995] [Accepted: 06/21/1995] [Indexed: 11/27/2022]
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46
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Response surface optimization of temperature and pH for the growth of Pachysolen tannophilus. Enzyme Microb Technol 1995. [DOI: 10.1016/0141-0229(94)00046-t] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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47
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Bravo V, Camacho F, Sánchez S, Castro E. Influence of the concentrations of d-xylose and yeast extract on ethanol production by Pachysolen tannophilus. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0922-338x(95)94749-h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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48
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Vandeska E, Kuzmanova S, Jeffries TW. Xylitol formation and key enzyme activities in Candida boidinii under different oxygen transfer rates. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0922-338x(96)80929-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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49
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Hahn-Hägerdal B, Jeppsson H, Skoog K, Prior B. Biochemistry and physiology of xylose fermentation by yeasts. Enzyme Microb Technol 1994. [DOI: 10.1016/0141-0229(94)90002-7] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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du Preez J. Process parameters and environmental factors affecting d-xylose fermentation by yeasts. Enzyme Microb Technol 1994. [DOI: 10.1016/0141-0229(94)90003-5] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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