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Effect of Working Atmospheres on the Detection of Diacetyl by Resistive SnO2 Sensor. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app12010367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nanostructured metal oxide semiconductors (MOS) are considered proper candidates to develop low cost and real-time resistive sensors able to detect volatile organic compounds (VOCs), e.g., diacetyl. Small quantities of diacetyl are generally produced during the fermentation and storage of many foods and beverages, conferring a typically butter-like aroma. Since high diacetyl concentrations are undesired, its monitoring is fundamental to identify and characterize the quality of products. In this work, a tin oxide sensor (SnO2) is used to detect gaseous diacetyl. The effect of different working atmospheres (air, N2 and CO2), as well as the contemporary presence of ethanol vapors, used to reproduce the typical alcoholic fermentation environment, are evaluated. SnO2 sensor is able to detect diacetyl in all the analyzed conditions, even when an anaerobic environment is considered, showing a detection limit lower than 0.01 mg/L and response/recovery times constantly less than 50 s.
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Cui DY, Wei YN, Lin LC, Chen SJ, Feng PP, Xiao DG, Lin X, Zhang CY. Increasing Yield of 2,3,5,6-Tetramethylpyrazine in Baijiu Through Saccharomyces cerevisiae Metabolic Engineering. Front Microbiol 2020; 11:596306. [PMID: 33324376 PMCID: PMC7726194 DOI: 10.3389/fmicb.2020.596306] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/28/2020] [Indexed: 12/15/2022] Open
Abstract
Baijiu is a traditional distilled beverage in China with a rich variety of aroma substances. 2,3,5,6-tetramethylpyrazine (TTMP) is an important component in Baijiu and has the function of promoting cardiovascular and cerebrovascular health. During the brewing of Baijiu, the microorganisms in jiuqu produce acetoin and then synthesize TTMP, but the yield of TTMP is very low. In this work, 2,3-butanediol dehydrogenase (BDH) coding gene BDH1 and another BDH2 gene were deleted or overexpressed to evaluate the effect on the content of acetoin and TTMP in Saccharomyces cerevisiae. The results showed that the acetoin synthesis of strain α5-D1B2 was significantly enhanced by disrupting BDH1 and overexpressing BDH2, leading to a 2.6-fold increase of TTMP production up to 10.55 mg/L. To further improve the production level of TTMP, the α-acetolactate synthase (ALS) of the pyruvate decomposition pathway was overexpressed to enhance the synthesis of diacetyl. However, replacing the promoter of the ILV2 gene with a strong promoter (PGK1p) to increase the expression level of the ILV2 gene did not result in further increased diacetyl, acetoin and TTMP production. Based on these evidences, we constructed the diploid strains AY-SB1 (ΔBDH1:loxP/ΔBDH1:loxP) and AY-SD1B2 (ΔBDH1:loxP-PGK1p-BDH2-PGK1t/ΔBDH1:loxP-PGK1p-BDH2-PGK1t) to ensure the fermentation performance of the strain is more stable in Baijiu brewing. The concentration of TTMP in AY-SB1 and AY-SD1B2 was 7.58 and 9.47 mg/L, respectively, which represented a 2.3- and 2.87-fold increase compared to the parental strain. This work provides an example for increasing TTMP production in S. cerevisiae by genetic engineering, and highlight a novel method to improve the quality and beneficial health attributes of Baijiu.
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Affiliation(s)
- Dan-Yao Cui
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, China
| | - Ya-Nan Wei
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, China
| | - Liang-Cai Lin
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, China
| | - Shi-Jia Chen
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, China
| | - Peng-Peng Feng
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, China
| | - Dong-Guang Xiao
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, China
| | - Xue Lin
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Cui-Ying Zhang
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Key Laboratory of Wuliangye-flavor Liquor Solid-state Fermentation, China National Light Industry, Yibin, China
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Eldarov MA, Mardanov AV. Metabolic Engineering of Wine Strains of Saccharomyces cerevisiae. Genes (Basel) 2020; 11:E964. [PMID: 32825346 PMCID: PMC7565949 DOI: 10.3390/genes11090964] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 01/26/2023] Open
Abstract
Modern industrial winemaking is based on the use of starter cultures of specialized wine strains of Saccharomyces cerevisiae yeast. Commercial wine strains have a number of advantages over natural isolates, and it is their use that guarantees the stability and reproducibility of industrial winemaking technologies. For the highly competitive wine market with new demands for improved wine quality, it has become increasingly critical to develop new wine strains and winemaking technologies. Novel opportunities for precise wine strain engineering based on detailed knowledge of the molecular nature of a particular trait or phenotype have recently emerged due to the rapid progress in genomic and "postgenomic" studies with wine yeast strains. The review summarizes the current achievements of the metabolic engineering of wine yeast, the results of recent studies and the prospects for the application of genomic editing technologies for improving wine S. cerevisiae strains.
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Affiliation(s)
| | - Andrey V. Mardanov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia;
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Li P, Li T, Zhang CY, Xiao DG. Effect of ILV2 deletion and ILV3 or/and ILV5 overexpression in Saccharomyces uvarum on diacetyl and higher alcohols metabolism during wine fermentation. Eur Food Res Technol 2020. [DOI: 10.1007/s00217-019-03422-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Salazar AN, Gorter de Vries AR, van den Broek M, Brouwers N, de la Torre Cortès P, Kuijpers NGA, Daran JMG, Abeel T. Chromosome level assembly and comparative genome analysis confirm lager-brewing yeasts originated from a single hybridization. BMC Genomics 2019; 20:916. [PMID: 31791228 PMCID: PMC6889557 DOI: 10.1186/s12864-019-6263-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/05/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The lager brewing yeast, S. pastorianus, is a hybrid between S. cerevisiae and S. eubayanus with extensive chromosome aneuploidy. S. pastorianus is subdivided into Group 1 and Group 2 strains, where Group 2 strains have higher copy number and a larger degree of heterozygosity for S. cerevisiae chromosomes. As a result, Group 2 strains were hypothesized to have emerged from a hybridization event distinct from Group 1 strains. Current genome assemblies of S. pastorianus strains are incomplete and highly fragmented, limiting our ability to investigate their evolutionary history. RESULTS To fill this gap, we generated a chromosome-level genome assembly of the S. pastorianus strain CBS 1483 from Oxford Nanopore MinION DNA sequencing data and analysed the newly assembled subtelomeric regions and chromosome heterozygosity. To analyse the evolutionary history of S. pastorianus strains, we developed Alpaca: a method to compute sequence similarity between genomes without assuming linear evolution. Alpaca revealed high similarities between the S. cerevisiae subgenomes of Group 1 and 2 strains, and marked differences from sequenced S. cerevisiae strains. CONCLUSIONS Our findings suggest that Group 1 and Group 2 strains originated from a single hybridization involving a heterozygous S. cerevisiae strain, followed by different evolutionary trajectories. The clear differences between both groups may originate from a severe population bottleneck caused by the isolation of the first pure cultures. Alpaca provides a computationally inexpensive method to analyse evolutionary relationships while considering non-linear evolution such as horizontal gene transfer and sexual reproduction, providing a complementary viewpoint beyond traditional phylogenetic approaches.
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Affiliation(s)
- Alex N Salazar
- Delft Bioinformatics Lab, Delft University of Technology, 2628, CD, Delft, The Netherlands
| | - Arthur R Gorter de Vries
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Marcel van den Broek
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Nick Brouwers
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Pilar de la Torre Cortès
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Niels G A Kuijpers
- HEINEKEN Supply Chain B.V., Global Innovation and Research, Zoeterwoude, Netherlands
| | - Jean-Marc G Daran
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands
| | - Thomas Abeel
- Delft Bioinformatics Lab, Delft University of Technology, 2628, CD, Delft, The Netherlands.
- Broad Institute of MIT and Harvard, Boston, MA, 02142, USA.
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Wess J, Brinek M, Boles E. Improving isobutanol production with the yeast Saccharomyces cerevisiae by successively blocking competing metabolic pathways as well as ethanol and glycerol formation. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:173. [PMID: 31303893 PMCID: PMC6604370 DOI: 10.1186/s13068-019-1486-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 06/07/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND Isobutanol is a promising candidate as second-generation biofuel and has several advantages compared to bioethanol. Another benefit of isobutanol is that it is already formed as a by-product in fermentations with the yeast Saccharomyces cerevisiae, although only in very small amounts. Isobutanol formation results from valine degradation in the cytosol via the Ehrlich pathway. In contrast, valine is synthesized from pyruvate in mitochondria. This spatial separation into two different cell compartments is one of the limiting factors for higher isobutanol production in yeast. Furthermore, some intermediate metabolites are also substrates for various isobutanol competing pathways, reducing the metabolic flux toward isobutanol production. We hypothesized that a relocation of all enzymes involved in anabolic and catabolic reactions of valine metabolism in only one cell compartment, the cytosol, in combination with blocking non-essential isobutanol competing pathways will increase isobutanol production in yeast. RESULTS Here, we overexpressed the three endogenous enzymes acetolactate synthase (Ilv2), acetohydroxyacid reductoisomerase (Ilv5) and dihydroxy-acid dehydratase (Ilv3) of the valine synthesis pathway in the cytosol and blocked the first step of mitochondrial valine synthesis by disrupting endogenous ILV2, leading to a 22-fold increase of isobutanol production up to 0.22 g/L (5.28 mg/g glucose) with aerobic shake flask cultures. Then, we successively deleted essential genes of competing pathways for synthesis of 2,3-butanediol (BDH1 and BDH2), leucine (LEU4 and LEU9), pantothenate (ECM31) and isoleucine (ILV1) resulting in an optimized metabolic flux toward isobutanol and titers of up to 0.56 g/L (13.54 mg/g glucose). Reducing ethanol formation by deletion of the ADH1 gene encoding the major alcohol dehydrogenase did not result in further increased isobutanol production, but in strongly enhanced glycerol formation. Nevertheless, deletion of glycerol-3-phosphate dehydrogenase genes GPD1 and GPD2 prevented formation of glycerol and increased isobutanol production up to 1.32 g/L. Finally, additional deletion of aldehyde dehydrogenase gene ALD6 reduced the synthesis of the by-product isobutyrate, thereby further increasing isobutanol production up to 2.09 g/L with a yield of 59.55 mg/g glucose, corresponding to a more than 200-fold increase compared to the wild type. CONCLUSIONS By overexpressing a cytosolic isobutanol synthesis pathway and by blocking non-essential isobutanol competing pathways, we could achieve isobutanol production with a yield of 59.55 mg/g glucose, which is the highest yield ever obtained with S. cerevisiae in shake flask cultures. Nevertheless, our results indicate a still limiting capacity of the isobutanol synthesis pathway itself.
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Affiliation(s)
- Johannes Wess
- Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Martin Brinek
- Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Eckhard Boles
- Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
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Li P, Gao Y, Wang C, Zhang CY, Guo X, Xiao D. Effect of ILV6 Deletion and Expression of aldB from Lactobacillus plantarum in Saccharomyces uvarum on Diacetyl Production and Wine Flavor. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:8556-8565. [PMID: 30027745 DOI: 10.1021/acs.jafc.8b02356] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Diacetyl generates an aromatic off-flavor in wine at a high level. The present study expressed α-acetolactate decarboxylase (ALDB) from Lactobacillus plantarum and/or inactivated acetohydroxyacid synthase (Ilv6) in Saccharomyces uvarum, and the effects on diacetyl production and wine flavor in mutants were investigated through sequential fermentation and cofermentation in mixed cultures of S. uvarum and L. plantarum. The diacetyl content of WYDΔ6 (disrupted one ILV6 allele), WYSΔ6 ( ILV6 complete deletion), WYADΔ6 (disrupted one ILV6 allele with aldB expression), and WYASΔ6 ( ILV6 complete deletion with aldB expression) decreased by 25.71%, 41.30%, 47.77%, and 50.00%, respectively, after sequential fermentation and decreased by 15.15%, 26.72%, 35.26%, and 43.80%, respectively, after cofermentation, compared with that of the parental strain. In addition, Ilv6 inactivation not only decreased the acetic acid content but also balanced the flavor profile in wine effectively. This work provided a valuable insight into the metabolic pathway of diacetyl and wine flavor in S. uvarum.
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Affiliation(s)
- Ping Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , People's Republic of China
| | - Yingying Gao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , People's Republic of China
| | - Cailing Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , People's Republic of China
| | - Cui-Ying Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , People's Republic of China
| | - Xuewu Guo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , People's Republic of China
| | - Dongguang Xiao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , People's Republic of China
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