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Cadete RM, de las Heras AM, Sandström AG, Ferreira C, Gírio F, Gorwa-Grauslund MF, Rosa CA, Fonseca C. Exploring xylose metabolism in Spathaspora species: XYL1.2 from Spathaspora passalidarum as the key for efficient anaerobic xylose fermentation in metabolic engineered Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:167. [PMID: 27499810 PMCID: PMC4974763 DOI: 10.1186/s13068-016-0570-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 07/12/2016] [Indexed: 05/21/2023]
Abstract
BACKGROUND The production of ethanol and other fuels and chemicals from lignocellulosic materials is dependent of efficient xylose conversion. Xylose fermentation capacity in yeasts is usually linked to xylose reductase (XR) accepting NADH as cofactor. The XR from Scheffersomyces stipitis, which is able to use NADH as cofactor but still prefers NADPH, has been used to generate recombinant xylose-fermenting Saccharomyces cerevisiae. Novel xylose-fermenting yeasts species, as those from the Spathaspora clade, have been described and are potential sources of novel genes to improve xylose fermentation in S. cerevisiae. RESULTS Xylose fermentation by six strains from different Spathaspora species isolated in Brazil, plus the Sp. passalidarum type strain (CBS 10155(T)), was characterized under two oxygen-limited conditions. The best xylose-fermenting strains belong to the Sp. passalidarum species, and their highest ethanol titers, yields, and productivities were correlated to higher XR activity with NADH than with NADPH. Among the different Spathaspora species, Sp. passalidarum appears to be the sole harboring two XYL1 genes: XYL1.1, similar to the XYL1 found in other Spathaspora and yeast species and XYL1.2, with relatively higher expression level. XYL1.1p and XYL1.2p from Sp. passalidarum were expressed in S. cerevisiae TMB 3044 and XYL1.1p was confirmed to be strictly NADPH-dependent, while XYL1.2p to use both NADPH and NADH, with higher activity with the later. Recombinant S. cerevisiae strains expressing XYL1.1p did not show anaerobic growth in xylose medium. Under anaerobic xylose fermentation, S. cerevisiae TMB 3504, which expresses XYL1.2p from Sp. passalidarum, revealed significant higher ethanol yield and productivity than S. cerevisiae TMB 3422, which harbors XYL1p N272D from Sc. stipitis in the same isogenic background (0.40 vs 0.34 g gCDW (-1) and 0.33 vs 0.18 g gCDW (-1) h(-1), respectively). CONCLUSION This work explored a new clade of xylose-fermenting yeasts (Spathaspora species) towards the engineering of S. cerevisiae for improved xylose fermentation. The new S. cerevisiae TMB 3504 displays higher XR activity with NADH than with NADPH, with consequent improved ethanol yield and productivity and low xylitol production. This meaningful advance in anaerobic xylose fermentation by recombinant S. cerevisiae (using the XR/XDH pathway) paves the way for the development of novel industrial pentose-fermenting strains.
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Affiliation(s)
- Raquel M. Cadete
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901 Brazil
- Laboratório Nacional de Energia e Geologia, I.P., Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038 Lisbon, Portugal
- Department of Applied Microbiology, Lund University, PO Box 124, 22100 Lund, Sweden
| | | | - Anders G. Sandström
- Department of Applied Microbiology, Lund University, PO Box 124, 22100 Lund, Sweden
- Novozymes A/S, Krogshøjvej 36, 2880 Bagsværd, Denmark
| | - Carla Ferreira
- Laboratório Nacional de Energia e Geologia, I.P., Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038 Lisbon, Portugal
| | - Francisco Gírio
- Laboratório Nacional de Energia e Geologia, I.P., Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038 Lisbon, Portugal
| | | | - Carlos A. Rosa
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901 Brazil
| | - César Fonseca
- Laboratório Nacional de Energia e Geologia, I.P., Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038 Lisbon, Portugal
- Section for Sustainable Biotechnology, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450 Copenhagen SV, Denmark
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Celińska E, Borkowska M, Białas W. Evaluation of a recombinant insect-derived amylase performance in simultaneous saccharification and fermentation process with industrial yeasts. Appl Microbiol Biotechnol 2015; 100:2693-707. [PMID: 26545757 PMCID: PMC4761610 DOI: 10.1007/s00253-015-7098-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/11/2015] [Accepted: 10/13/2015] [Indexed: 12/18/2022]
Abstract
Starch is the dominant feedstock consumed for the bioethanol production, accounting for 60 % of its global production. Considering the significant contribution of bioethanol to the global fuel market, any improvement in its major operating technologies is economically very attractive. It was estimated that up to 40 % of the final ethanol unit price is derived from the energy input required for the substrate pre-treatment. Application of raw starch hydrolyzing enzymes (RSHE), combined with operation of the process according to a simultaneous saccharification and fermentation (SSF) strategy, constitutes the most promising solutions to the current technologies limitations. In this study, we expressed the novel RSHE derived from an insect in Saccharomyces cerevisiae strain dedicated for the protein overexpression. Afterwards, the enzyme performance was assessed in SSF process conducted by industrial ethanologenic or thermotolerant yeast species. Comparison of the insect-derived RSHE preparation with commercially available amylolytic RSH preparation was conducted. Our results demonstrate that the recombinant alpha-amylase from rice weevil can be efficiently expressed and secreted with its native signal peptide in S. cerevisiae INVSc-pYES2-Amy1 expression system (accounting for nearly 72 % of the strain’s secretome). Application of the recombinant enzyme-based preparation in SSF process secured sufficient amylolytic activity for the yeast cell propagation and ethanol formation from raw starch. (Oligo)saccharide profiles generated by the compared preparations differed with respect to homogeneity of the sugar mixtures. Concomitantly, as demonstrated by a kinetic model developed in this study, the kinetic parameters describing activity of the compared preparations were different.
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Affiliation(s)
- Ewelina Celińska
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, ul. Wojska Polskiego 48, 60-627, Poznań, Poland.
| | - Monika Borkowska
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, ul. Wojska Polskiego 48, 60-627, Poznań, Poland
| | - Wojciech Białas
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, ul. Wojska Polskiego 48, 60-627, Poznań, Poland
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103
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Miklenić M, Žunar B, Štafa A, Svetec IK. Improved electroporation procedure for genetic transformation ofDekkera/Brettanomyces bruxellensis. FEMS Yeast Res 2015; 15:fov096. [DOI: 10.1093/femsyr/fov096] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2015] [Indexed: 11/14/2022] Open
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