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Radecka D, Mukherjee V, Mateo RQ, Stojiljkovic M, Foulquié-Moreno MR, Thevelein JM. Looking beyond Saccharomyces: the potential of non-conventional yeast species for desirable traits in bioethanol fermentation. FEMS Yeast Res 2015; 15:fov053. [PMID: 26126524 DOI: 10.1093/femsyr/fov053] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2015] [Indexed: 01/18/2023] Open
Abstract
Saccharomyces cerevisiae has been used for millennia in the production of food and beverages and is by far the most studied yeast species. Currently, it is also the most used microorganism in the production of first-generation bioethanol from sugar or starch crops. Second-generation bioethanol, on the other hand, is produced from lignocellulosic feedstocks that are pretreated and hydrolyzed to obtain monomeric sugars, mainly D-glucose, D-xylose and L-arabinose. Recently, S. cerevisiae recombinant strains capable of fermenting pentose sugars have been generated. However, the pretreatment of the biomass results in hydrolysates with high osmolarity and high concentrations of inhibitors. These compounds negatively influence the fermentation process. Therefore, robust strains with high stress tolerance are required. Up to now, more than 2000 yeast species have been described and some of these could provide a solution to these limitations because of their high tolerance to the most predominant stress conditions present in a second-generation bioethanol reactor. In this review, we will summarize what is known about the non-conventional yeast species showing unusual tolerance to these stresses, namely Zygosaccharomyces rouxii (osmotolerance), Kluyveromyces marxianus and Ogataea (Hansenula) polymorpha (thermotolerance), Dekkera bruxellensis (ethanol tolerance), Pichia kudriavzevii (furan derivatives tolerance) and Z. bailii (acetic acid tolerance).
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Affiliation(s)
- Dorota Radecka
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Vaskar Mukherjee
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Laboratory for Process Microbial Ecology and Bioinspirational Management, Cluster for Bioengineering Technology (CBeT), Department of Microbial and Molecular Systems (M2S), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Flanders, Belgium
| | - Raquel Quintilla Mateo
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Marija Stojiljkovic
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - María R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
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Pelz K, Hopfener K, Wiedmann-Al-Ahmad M, Jahnke H, Wittmer A, Otten JE. Differences in the fatty acid composition of KB-cells and gingival keratinocytes is culture medium additive dependent. Biomed Chromatogr 2006; 20:870-80. [PMID: 16389636 DOI: 10.1002/bmc.610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The influence of culture medium additives foetal bovine serum (FBS), serum effective substitutes (SES) and human autologous serum on the fatty acid profile of KB-cells and human gingival keratinocytes was examined. The KB-cells were cultivated in RPMI medium added with FBS or SES and the gingival keratinocytes in D-MEM added with FBS or human autologous serum. Two days before the cells were prepared for gas chromatography (GC), the media were changed to serum- and antibiotic-free media. Whole fatty acids of the cells were analysed using GC and the fatty acid profiles were compared. KB-cells as well as gingival keratinocytes changed their fatty acid composition, according to the medium additive used. Significant differences were observed. In the case of KB-cells cultivated with SES the fatty acid changes suggest an increase of the membrane fluidity. Corresponding and significant differences were observed with gingival keratinocytes cultivated in medium added with human autologous serum: the membrane fluidity of the gingival keratinocytes was increased. It is supposed that an increased membrane fluidity caused by a different fatty acid spectrum of the host cell may relate to mechanisms of bacterial adhesion. Consequently, in vitro studies on invasion and adhesion of bacteria or virus are dependent on the medium used. Further analyses are necessary of the functional effects caused by differences in the content of specific FAs, especially with regard to the application of cultivated cells in the field of tissue engineering.
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Affiliation(s)
- K Pelz
- Institut für Medizinische Mikrobiologie und Hygiene, Albert-Ludwigs-Universität Freiburg, D-79106 Freiburg, Germany.
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Shen B, Hohmann S, Jensen RG, Bohnert AH. Roles of sugar alcohols in osmotic stress adaptation. Replacement of glycerol by mannitol and sorbitol in yeast. PLANT PHYSIOLOGY 1999; 121:45-52. [PMID: 10482659 PMCID: PMC59388 DOI: 10.1104/pp.121.1.45] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/1999] [Accepted: 05/14/1999] [Indexed: 05/18/2023]
Abstract
For many organisms there is a correlation between increases of metabolites and osmotic stress tolerance, but the mechanisms that cause this protection are not clear. To understand the role of polyols, genes for bacterial mannitol-1-P dehydrogenase and apple sorbitol-6-P dehydrogenase were introduced into a Saccharomyces cerevisiae mutant deficient in glycerol synthesis. Sorbitol and mannitol provided some protection, but less than that generated by a similar concentration of glycerol generated by glycerol-3-P dehydrogenase (GPD1). Reduced protection by polyols suggested that glycerol had specific functions for which mannitol and sorbitol could not substitute, and that the absolute amount of the accumulating osmoticum might not be crucial. The retention of glycerol and mannitol/sorbitol, respectively, was a major difference. During salt stress, cells retained more of the six-carbon polyols than glycerol. We suggest that the loss of >98% of the glycerol synthesized could provide a safety valve that dissipates reducing power, while a similar high intracellular concentration of retained polyols would be less protective. To understand the role of glycerol in salt tolerance, salt-tolerant suppressor mutants were isolated from the glycerol-deficient strain. One mutant, sr13, partially suppressed the salt-sensitive phenotype of the glycerol-deficient line, probably due to a doubling of [K(+)] accumulating during stress. We compare these results to the "osmotic adjustment" concept typically applied to accumulating metabolites in plants. The accumulation of polyols may have dual functions: facilitating osmotic adjustment and supporting redox control.
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Affiliation(s)
- B Shen
- Department of Plant Sciences, The University of Arizona, Tucson 85721, USA
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Sajbidor J. Effect of some environmental factors on the content and composition of microbial membrane lipids. Crit Rev Biotechnol 1997; 17:87-103. [PMID: 9192472 DOI: 10.3109/07388559709146608] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lipids are known as a part of an effective adaptation mechanism reflecting the changes in the extracellular environment. The fluidity of biological membranes is influenced by the lipid structure and the portion of saturated, unsaturated, branched, or cyclic fatty acids in individual phospholipids. For all living organisms undergoing environmental adaptation, the fluidity can be changed only to a relatively small extent. This range is genetically determined and it is specific for every microorganism. This article presents recent knowledge about the influence of some environmental parameters (temperature, osmotic pressure, pH, the presence of salt or ethanol in medium) on a microbial membrane with the emphasis on regulation aspect in fatty acid biosynthesis. The main tools for regulation of membrane fluidity, for example, fatty acid desaturation or incorporation of branched and cyclic fatty acids into phospholipids, are discussed in more detail.
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Affiliation(s)
- J Sajbidor
- Department of Biochemical Technology, Faculty of Chemical Technology, Slovak Technical University, Bratislava
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