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Sornlek W, Sonthirod C, Tangphatsornruang S, Ingsriswang S, Runguphan W, Eurwilaichtr L, Champreda V, Tanapongpipat S, Schaap PJ, Martins Dos Santos VAP. Genes controlling hydrolysate toxin tolerance identified by QTL analysis of the natural Saccharomyces cerevisiae BCC39850. Appl Microbiol Biotechnol 2024; 108:21. [PMID: 38159116 DOI: 10.1007/s00253-023-12843-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 09/21/2023] [Accepted: 09/30/2023] [Indexed: 01/03/2024]
Abstract
Lignocellulosic material can be converted to valorized products such as fuels. Pretreatment is an essential step in conversion, which is needed to increase the digestibility of the raw material for microbial fermentation. However, pretreatment generates by-products (hydrolysate toxins) that are detrimental to microbial growth. In this study, natural Saccharomyces strains isolated from habitats in Thailand were screened for their tolerance to synthetic hydrolysate toxins (synHTs). The Saccharomyces cerevisiae natural strain BCC39850 (toxin-tolerant) was crossed with the laboratory strain CEN.PK2-1C (toxin-sensitive), and quantitative trait locus (QTL) analysis was performed on the segregants using phenotypic scores of growth (OD600) and glucose consumption. VMS1, DET1, KCS1, MRH1, YOS9, SYO1, and YDR042C were identified from QTLs as candidate genes associated with the tolerance trait. CEN.PK2-1C knockouts of the VMS1, YOS9, KCS1, and MRH1 genes exhibited significantly greater hydrolysate toxin sensitivity to growth, whereas CEN.PK2-1C knock-ins with replacement of VMS1 and MRH1 genes from the BCC39850 alleles showed significant increased ethanol production titers compared with the CEN.PK2-1C parental strain in the presence of synHTs. The discovery of VMS1, YOS9, MRH1, and KCS1 genes associated with hydrolysate toxin tolerance in S. cerevisiae indicates the roles of the endoplasmic-reticulum-associated protein degradation pathway, plasma membrane protein association, and the phosphatidylinositol signaling system in this trait. KEY POINTS: • QTL analysis was conducted using a hydrolysate toxin-tolerant S. cerevisiae natural strain • Deletion of VMS1, YOS9, MRH1, and KCS1 genes associated with hydrolysate toxin-sensitivity • Replacement of VMS1 and MRH1 with natural strain alleles increased ethanol production titers in the presence of hydrolysate toxins.
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Affiliation(s)
- Warasirin Sornlek
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
- The Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Chutima Sonthirod
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Sithichoke Tangphatsornruang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Supawadee Ingsriswang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Weerawat Runguphan
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Lily Eurwilaichtr
- National Energy Technology Center, 114 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Verawat Champreda
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Sutipa Tanapongpipat
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, 12120, Pathum Thani, Thailand.
| | - Peter J Schaap
- The Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Vitor A P Martins Dos Santos
- The Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
- Bioprocess Engineering Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
- LifeGlimmer GmbH, Markelstrasse 38, 12163, Berlin, Germany.
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Mota MN, Matos M, Bahri N, Sá-Correia I. Shared and more specific genetic determinants and pathways underlying yeast tolerance to acetic, butyric, and octanoic acids. Microb Cell Fact 2024; 23:71. [PMID: 38419072 PMCID: PMC10903034 DOI: 10.1186/s12934-024-02309-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/17/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND The improvement of yeast tolerance to acetic, butyric, and octanoic acids is an important step for the implementation of economically and technologically sustainable bioprocesses for the bioconversion of renewable biomass resources and wastes. To guide genome engineering of promising yeast cell factories toward highly robust superior strains, it is instrumental to identify molecular targets and understand the mechanisms underlying tolerance to those monocarboxylic fatty acids. A chemogenomic analysis was performed, complemented with physiological studies, to unveil genetic tolerance determinants in the model yeast and cell factory Saccharomyces cerevisiae exposed to equivalent moderate inhibitory concentrations of acetic, butyric, or octanoic acids. RESULTS Results indicate the existence of multiple shared genetic determinants and pathways underlying tolerance to these short- and medium-chain fatty acids, such as vacuolar acidification, intracellular trafficking, autophagy, and protein synthesis. The number of tolerance genes identified increased with the linear chain length and the datasets for butyric and octanoic acids include the highest number of genes in common suggesting the existence of more similar toxicity and tolerance mechanisms. Results of this analysis, at the systems level, point to a more marked deleterious effect of an equivalent inhibitory concentration of the more lipophilic octanoic acid, followed by butyric acid, on the cell envelope and on cellular membranes function and lipid remodeling. The importance of mitochondrial genome maintenance and functional mitochondria to obtain ATP for energy-dependent detoxification processes also emerged from this chemogenomic analysis, especially for octanoic acid. CONCLUSIONS This study provides new biological knowledge of interest to gain further mechanistic insights into toxicity and tolerance to linear-chain monocarboxylic acids of increasing liposolubility and reports the first lists of tolerance genes, at the genome scale, for butyric and octanoic acids. These genes and biological functions are potential targets for synthetic biology approaches applied to promising yeast cell factories, toward more robust superior strains, a highly desirable phenotype to increase the economic viability of bioprocesses based on mixtures of volatiles/medium-chain fatty acids derived from low-cost biodegradable substrates or lignocellulose hydrolysates.
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Affiliation(s)
- Marta N Mota
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
- i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
| | - Madalena Matos
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
- i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
| | - Nada Bahri
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
- i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal
| | - Isabel Sá-Correia
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal.
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal.
- i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001, Lisbon, Portugal.
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Wang C, Kuzyakov Y. Mechanisms and implications of bacterial-fungal competition for soil resources. THE ISME JOURNAL 2024; 18:wrae073. [PMID: 38691428 PMCID: PMC11104273 DOI: 10.1093/ismejo/wrae073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 03/24/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024]
Abstract
Elucidating complex interactions between bacteria and fungi that determine microbial community structure, composition, and functions in soil, as well as regulate carbon (C) and nutrient fluxes, is crucial to understand biogeochemical cycles. Among the various interactions, competition for resources is the main factor determining the adaptation and niche differentiation between these two big microbial groups in soil. This is because C and energy limitations for microbial growth are a rule rather than an exception. Here, we review the C and energy demands of bacteria and fungi-the two major kingdoms in soil-the mechanisms of their competition for these and other resources, leading to niche differentiation, and the global change impacts on this competition. The normalized microbial utilization preference showed that bacteria are 1.4-5 times more efficient in the uptake of simple organic compounds as substrates, whereas fungi are 1.1-4.1 times more effective in utilizing complex compounds. Accordingly, bacteria strongly outcompete fungi for simple substrates, while fungi take advantage of complex compounds. Bacteria also compete with fungi for the products released during the degradation of complex substrates. Based on these specifics, we differentiated spatial, temporal, and chemical niches for these two groups in soil. The competition will increase under the main five global changes including elevated CO2, N deposition, soil acidification, global warming, and drought. Elevated CO2, N deposition, and warming increase bacterial dominance, whereas soil acidification and drought increase fungal competitiveness.
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Affiliation(s)
- Chaoqun Wang
- National Key Laboratory of Wheat Improvement, College of Agronomy, Shandong Agricultural University, Tai'an 271018, Shandong, China
- Biogeochemistry of Agroecosystems, University of Göttingen, Göttingen 37077, Germany
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver V6T1Z4, Canada
| | - Yakov Kuzyakov
- National Key Laboratory of Wheat Improvement, College of Agronomy, Shandong Agricultural University, Tai'an 271018, Shandong, China
- Department of Soil Science of Temperate Ecosystems, University of Göttingen, Göttingen 37077, Germany
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Guo Z, Li M, Guo Z, Zhu R, Xin Y, Gu Z, Zhang L. Trehalose metabolism targeting as a novel strategy to modulate acid tolerance of yeasts and its application in food industry. Food Microbiol 2023; 114:104300. [PMID: 37290876 DOI: 10.1016/j.fm.2023.104300] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 06/10/2023]
Abstract
Some spoilage yeasts are able to develop resistance to commonly used weak-acid preservatives. We studied the trehalose metabolism and its regulation in Saccharomyces cerevisiae in response to propionic acid stress. We show interruption of trehalose synthetic pathway caused the mutant hypersensitive to the acid stress, while its overexpression conferred acid-tolerance to yeast. Interestingly, this acid-tolerance phenotype was largely independent of trehalose but relied on the trehalose synthetic pathway. We demonstrate trehalose metabolism played a vital role in regulation of glycolysis flux and Pi/ATP homeostasis in yeast during acid-adaptation, and the PKA and TOR signaling pathways were involved in regulating trehalose synthesis at transcriptional level. This work confirmed the regulatory function of trehalose metabolism and improved our understanding of molecular mechanism of acid-adaptation of yeast. By exemplifying trehalose metabolism interruption limited the growth of S. cerevisiae exposed to weak acids, and trehalose pathway overexpression conferring acid-resistance to Yarrowia lipolytica enhanced citric acid production, this work provides new insights into the development of efficient preservation strategies and robust organic acid producers.
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Affiliation(s)
- Zhongpeng Guo
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, China.
| | - Moying Li
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Zitao Guo
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Rui Zhu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Yu Xin
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Zhenghua Gu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Liang Zhang
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, China.
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Xi Y, Xu H, Zhan T, Qin Y, Fan F, Zhang X. Metabolic engineering of the acid-tolerant yeast Pichia kudriavzevii for efficient L-malic acid production at low pH. Metab Eng 2023; 75:170-180. [PMID: 36566973 DOI: 10.1016/j.ymben.2022.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/27/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Currently, the biological production of L-malic acid (L-MA) is mainly based on the fermentation of filamentous fungi at near-neutral pH, but this process requires large amounts of neutralizing agents, resulting in the generation of waste salts when free acid is obtained in the downstream process, and the environmental hazards associated with the waste salts limit the practical application of this process. To produce L-MA in a more environmentally friendly way, we metabolically engineered the acid-tolerant yeast Pichia kudriavzevii and achieved efficient production of L-MA through low pH fermentation. First, an initial L-MA-producing strain that relies on the reductive tricarboxylic acid (rTCA) pathway was constructed. Subsequently, the L-MA titer and yield were further increased by fine-tuning the flux between the pyruvate and oxaloacetate nodes. In addition, we found that the insufficient supply of NADH for cytoplasmic malate dehydrogenase (MDH) hindered the L-MA production at low pH, which was resolved by overexpressing the soluble pyridine nucleotide transhydrogenase SthA from E. coli. Transcriptomic and metabolomic data showed that overexpression of EcSthA contributed to the activation of the pentose phosphate pathway and provided additional reducing power for MDH by converting NADPH to NADH. Furthermore, overexpression of EcSthA was found to help reduce the accumulation of the by-product pyruvate but had no effect on the accumulation of succinate. In microaerobic batch fermentation in a 5-L fermenter, the best strain, MA009-10-URA3 produced 199.4 g/L L-MA with a yield of 0.94 g/g glucose (1.27 mol/mol), with a productivity of 1.86 g/L/h. The final pH of the fermentation broth was approximately 3.10, meaning that the amount of neutralizer used was reduced by more than 50% compared to the common fermentation processes using filamentous fungi. To our knowledge, this is the first report of the efficient bioproduction of L-MA at low pH and represents the highest yield of L-MA in yeasts reported to date.
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Affiliation(s)
- Yongyan Xi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China; Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China; National Innovation Center for Synthetic Biotechnology, Tianjin, 300308, PR China
| | - Hongtao Xu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China; Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China; National Innovation Center for Synthetic Biotechnology, Tianjin, 300308, PR China
| | - Tao Zhan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China; Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China; National Innovation Center for Synthetic Biotechnology, Tianjin, 300308, PR China
| | - Ying Qin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China; Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China; National Innovation Center for Synthetic Biotechnology, Tianjin, 300308, PR China
| | - Feiyu Fan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China; Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China; National Innovation Center for Synthetic Biotechnology, Tianjin, 300308, PR China.
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China; Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China; National Innovation Center for Synthetic Biotechnology, Tianjin, 300308, PR China.
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Functional Analysis of the Plasma Membrane H +-ATPases of Ustilago maydis. J Fungi (Basel) 2022; 8:jof8060550. [PMID: 35736033 PMCID: PMC9225265 DOI: 10.3390/jof8060550] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 02/05/2023] Open
Abstract
Plasma membrane H+-ATPases of fungi, yeasts, and plants act as proton pumps to generate an electrochemical gradient, which is essential for secondary transport and intracellular pH maintenance. Saccharomyces cerevisiae has two genes (PMA1 and PMA2) encoding H+-ATPases. In contrast, plants have a larger number of genes for H+-ATPases. In Ustilago maydis, a biotrophic basidiomycete that infects corn and teosinte, the presence of two H+-ATPase-encoding genes has been described, one with high identity to the fungal enzymes (pma1, UMAG_02851), and the other similar to the plant H+-ATPases (pma2, UMAG_01205). Unlike S. cerevisiae, these two genes are expressed jointly in U. maydis sporidia. In the present work, mutants lacking one of these genes (Δpma1 and Δpma2) were used to characterize the role of each one of these enzymes in U. maydis physiology and to obtain some of their kinetic parameters. To approach this goal, classical biochemical assays were performed. The absence of any of these H+-ATPases did not affect the growth or fungal basal metabolism. Membrane potential tests showed that the activity of a single H+-ATPase was enough to maintain the proton-motive force. Our results indicated that in U. maydis, both H+-ATPases work jointly in the generation of the electrochemical proton gradient, which is important for secondary transport of metabolites and regulation of intracellular pH.
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7
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Wu M, Tian L, Fu J, Liao S, Li H, Gai Z, Gong G. Antibacterial mechanism of Protocatechuic acid against Yersinia enterocolitica and its application in pork. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108573] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Fu J, Liu C, Li L, Liu J, Tie Y, Wen X, Zhao Q, Qiao Z, An Z, Zheng J. Adaptive response and tolerance to weak acids in
Saccharomyces cerevisiae boulardii
: a metabolomics approach. Int J Food Sci Technol 2022. [DOI: 10.1111/ijfs.15598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Junjie Fu
- College of Biotechnology Engineering Sichuan University of Science and Engineering Yibin 644000 China
| | - Chaolan Liu
- Antibiotics Research and Re‐evalution Key Laboratory of Sichuan Province Sichuan Industrial Institute of Antibiotics Chengdu University Chengdu 610052 China
| | - Li Li
- College of Biotechnology Engineering Sichuan University of Science and Engineering Yibin 644000 China
| | - Jun Liu
- College of Biotechnology Engineering Sichuan University of Science and Engineering Yibin 644000 China
| | - Yu Tie
- College of Biotechnology Engineering Sichuan University of Science and Engineering Yibin 644000 China
- Solid‐State Fermentation Resource Utilisation Key Laboratory of Sichuan Province Yibin 644000 China
| | - Xueping Wen
- College of Biotechnology Engineering Sichuan University of Science and Engineering Yibin 644000 China
| | - Qikai Zhao
- College of Biotechnology Engineering Sichuan University of Science and Engineering Yibin 644000 China
- HengfengHuaBang Biological Science and Technology Co., Ltd. Leshan 614000 China
| | | | - Zheming An
- Wuliangye Yibin Co, Ltd Yibin 644000 China
| | - Jia Zheng
- Wuliangye Yibin Co, Ltd Yibin 644000 China
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9
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Abstract
The industrial relevance of organic acids is high; because of their chemical properties, they can be used as building blocks as well as single-molecule agents with a huge annual market. Organic acid chemical platforms can derive from fossil sources by petrochemical refining processes, but most of them also represent natural metabolites produced by many cells. They are the products, by-products or co-products of many primary metabolic processes of microbial cells. Thanks to the potential of microbial cell factories and to the development of industrial biotechnology, from the last decades of the previous century, the microbial-based production of these molecules has started to approach the market. This was possible because of a joint effort of microbial biotechnologists and biochemical and process engineers that boosted natural production up to the titer, yield and productivity needed to be industrially competitive. More recently, the possibility to utilize renewable residual biomasses as feedstock not only for biofuels, but also for organic acids production is further augmenting the sustainability of their production, in a logic of circular bioeconomy. In this review, we briefly present the latest updates regarding the production of some industrially relevant organic acids (citric fumaric, itaconic, lactic and succinic acid), discussing the challenges and possible future developments of successful production.
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10
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The Role of Sch9 and the V-ATPase in the Adaptation Response to Acetic Acid and the Consequences for Growth and Chronological Lifespan. Microorganisms 2021; 9:microorganisms9091871. [PMID: 34576766 PMCID: PMC8472237 DOI: 10.3390/microorganisms9091871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/20/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
Studies with Saccharomyces cerevisiae indicated that non-physiologically high levels of acetic acid promote cellular acidification, chronological aging, and programmed cell death. In the current study, we compared the cellular lipid composition, acetic acid uptake, intracellular pH, growth, and chronological lifespan of wild-type cells and mutants lacking the protein kinase Sch9 and/or a functional V-ATPase when grown in medium supplemented with different acetic acid concentrations. Our data show that strains lacking the V-ATPase are especially more susceptible to growth arrest in the presence of high acetic acid concentrations, which is due to a slower adaptation to the acid stress. These V-ATPase mutants also displayed changes in lipid homeostasis, including alterations in their membrane lipid composition that influences the acetic acid diffusion rate and changes in sphingolipid metabolism and the sphingolipid rheostat, which is known to regulate stress tolerance and longevity of yeast cells. However, we provide evidence that the supplementation of 20 mM acetic acid has a cytoprotective and presumable hormesis effect that extends the longevity of all strains tested, including the V-ATPase compromised mutants. We also demonstrate that the long-lived sch9Δ strain itself secretes significant amounts of acetic acid during stationary phase, which in addition to its enhanced accumulation of storage lipids may underlie its increased lifespan.
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11
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Peh E, Kittler S, Seinige D, Valero A, Kehrenberg C. Adaptation of Campylobacter field isolates to propionic acid and sorbic acid is associated with fitness costs. J Appl Microbiol 2021; 131:1749-1761. [PMID: 33683781 DOI: 10.1111/jam.15057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/10/2021] [Accepted: 02/25/2021] [Indexed: 12/22/2022]
Abstract
AIMS To reduce the burden of Campylobacter at different stages of the food chain, recent studies have shown the effectiveness of organic acids as a risk mitigation strategy. However, very little is known about possible adaptation responses of Campylobacter that lead to reduced susceptibility to organic acids. Here we investigated the adaptive responses of Campylobacter field isolates to organic acids and estimated the fitness costs. METHODS AND RESULTS Exposure of two Campylobacter jejuni and one Campylobacter coli isolate to subinhibitory concentrations of propionic acid or sorbic acid resulted in twofold to fourfold increased minimal inhibitory concentration values for the adapted variants. With one exception, the decreased susceptibility was stable in at least 10 successive subcultures without selection pressure. Growth competition experiments revealed a reduced fitness of adapted variants compared to the wild-type isolates. A linear regression model allowed an estimation of the fitness cost. Growth kinetics experiments showed significantly prolonged lag phases in five of six adapted isolates while there was not a direct correlation in the maximum growth rates compared to the wild-type isolates. CONCLUSIONS The results of the study showed that a stepwise adaptation of Campylobacter to organic acids is possible, but at the detriment of changes in growth behaviour and reduced fitness. SIGNIFICANCE AND IMPACT OF THE STUDY The study contributes to the understanding of adaptive responses of Campylobacter to organic acids treatments, for example, as part of risk mitigation strategies.
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Affiliation(s)
- E Peh
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - S Kittler
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - D Seinige
- Lower Saxony State Office for Consumer Protection and Food Safety, Wardenburg, Germany
| | - A Valero
- Department of Food Science and Technology, University of Cordoba, Agrifood Campus of International, Córdoba, Spain
| | - C Kehrenberg
- Institute for Veterinary Food Science, Justus-Liebig-University Giessen, Giessen, Germany
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12
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Rose Jørgensen M, Thestrup Rikvold P, Lichtenberg M, Østrup Jensen P, Kragelund C, Twetman S. Lactobacillus rhamnosus strains of oral and vaginal origin show strong antifungal activity in vitro. J Oral Microbiol 2020; 12:1832832. [PMID: 33178403 PMCID: PMC7594750 DOI: 10.1080/20002297.2020.1832832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 12/21/2022] Open
Abstract
Background: Intake of probiotic bacteria may prevent oral Candida infection. Objective: To screen the antifungal activity of 14 Lactobacillus candidate strains of human origin, against six opportunistic C. albicans and non-albicans species. A second aim was to study the acid production of the four strains showing the strongest antifungal activity. Methods: We used an agar overlay growth inhibition assay to the assess the antifungal activity of the lactobacilli. The acid-producing capacity was measured with pH micro-sensors. Results: All 14 Lactobacillus candidates inhibited the growth of the Candida spp. The four best-performing strains were L. rhamnosus DSM 32992 (oral origin), L. rhamnosus DSM 32991 (oral), L. jensenii 22B42 (vaginal), and L. rhamnosus PB01 (vaginal). The difference between L. rhamnosus DSM 32992 and the other three strains was statistically significant (p < 0.001). The Candida spp. differed in susceptibility; C. parapsilosis was highly inhibited, while C. krusei was not or slightly inhibited. The oral L. rhamnosus DSM 32992 and DSM 32991 strains showed the lowest pH-values. Conclusion: Screening of probiotic lactobacilli showed significant strain-dependent variations in their antifungal capacity in a pH-dependent mode. Two strains of oral origin were most effective. A further characterization seems justified to elaborate on their probiotic properties.
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Affiliation(s)
- Mette Rose Jørgensen
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pernille Thestrup Rikvold
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Peter Østrup Jensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Camilla Kragelund
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Svante Twetman
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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13
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Munford ARG, Chaves RD, Sant'Ana AS. Inactivation kinetics of beer spoilage bacteria (Lactobacillus brevis, Lactobacillus casei, and Pediococcus damnosus) during acid washing of brewing yeast. Food Microbiol 2020; 91:103513. [PMID: 32539960 DOI: 10.1016/j.fm.2020.103513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/26/2020] [Accepted: 04/13/2020] [Indexed: 11/25/2022]
Abstract
This work aimed to estimate the inactivation kinetic parameters of four potential beer spoilage bacteria (Lactobacillus brevis DSM 6235, Lactobacillus casei ATCC 334, Pediococcus damnosus DSM 20289 and Pediococcus damnosus ATCC 29358) inoculated in brewing yeast submitted to acid washing with purposes of yeast recycle. The experiments were conducted at 4 °C in solutions with pH 1.5, pH 2, and pH 3 adjusted employing 85% phosphoric acid. The acid washing treatment of brewing yeasts in the most common pH used (pH 2.0) demanded almost 50 min for the first decimal reduction (δ) of L. brevis DSM 6235. Sensible strains to acid washing such as P. damnosus DSM 20289 demanded almost 70 min for 4 log reductions to be achieved. On the other hand, pH reduction of the acid washing from 2.0 to 1.5 allowed 4 log reduction of L. brevis DSM 6235) to be obtained in less than 50 min, without ruining brewer's yeast viability. Acid washing in pH 1.5 is a viable method for the inactivation of bacterial contaminants of brewing yeasts. Recycling of brewing yeasts through this approach may contribute to a more sustainable and environmental-friendly industry.
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Affiliation(s)
- Allan R G Munford
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Rafael D Chaves
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Anderson S Sant'Ana
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil.
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Tugnoli B, Giovagnoni G, Piva A, Grilli E. From Acidifiers to Intestinal Health Enhancers: How Organic Acids Can Improve Growth Efficiency of Pigs. Animals (Basel) 2020; 10:ani10010134. [PMID: 31947627 PMCID: PMC7022919 DOI: 10.3390/ani10010134] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/23/2019] [Accepted: 01/09/2020] [Indexed: 12/22/2022] Open
Abstract
Organic acids have been used successfully in pig production as a cost-effective performance-enhancing option and they continue to be the number one alternative to antibiotic growth promoters. The aim of this review is to provide the biological rationale behind organic acids use in pig production, focusing on their different effects along the gastrointestinal tract of pigs. Organic acids are reviewed for their antimicrobial properties and for their classic use as acidifiers, with particular attention to pH modulation and microflora control. Additional beneficial effects on intestinal health and general metabolism are presented and we explain the advantage of microencapsulation as a tool to deliver organic acids along the intestine.
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Affiliation(s)
| | - Giulia Giovagnoni
- Dipartimento di Scienze Mediche Veterinarie, DIMEVET-Università di Bologna-Via Tolara di sopra, 50-40064 Ozzano Emilia, Bologna, Italy; (G.G.); (E.G.)
| | - Andrea Piva
- Vetagro S.p.A.-Via Porro 2, 42124 Reggio Emilia, Italy;
- Dipartimento di Scienze Mediche Veterinarie, DIMEVET-Università di Bologna-Via Tolara di sopra, 50-40064 Ozzano Emilia, Bologna, Italy; (G.G.); (E.G.)
- Correspondence: ; Tel.: +39-051-209-7387
| | - Ester Grilli
- Dipartimento di Scienze Mediche Veterinarie, DIMEVET-Università di Bologna-Via Tolara di sopra, 50-40064 Ozzano Emilia, Bologna, Italy; (G.G.); (E.G.)
- Vetagro Inc., 116 W. Jackson Blvd., Suite #320, Chicago, IL 60604, USA
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15
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Gao R, Li Z, Zhou X, Bao W, Cheng S, Zheng L. Enhanced lipid production by Yarrowia lipolytica cultured with synthetic and waste-derived high-content volatile fatty acids under alkaline conditions. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:3. [PMID: 31911818 PMCID: PMC6945533 DOI: 10.1186/s13068-019-1645-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 12/27/2019] [Indexed: 05/02/2023]
Abstract
BACKGROUND Volatile fatty acids (VFAs) can be effective and promising alternate carbon sources for microbial lipid production by a few oleaginous yeasts. However, the severe inhibitory effect of high-content (> 10 g/L) VFAs on these yeasts has impeded the production of high lipid yields and their large-scale application. Slightly acidic conditions have been commonly adopted because they have been considered favorable to oleaginous yeast cultivation. However, the acidic pH environment further aggravates this inhibition because VFAs appear largely in an undissociated form under this condition. Alkaline conditions likely alleviate the severe inhibition of high-content VFAs by significantly increasing the dissociation degree of VFAs. This hypothesis should be verified through a systematic research. RESULTS The combined effects of high acetic acid concentrations and alkaline conditions on VFA utilization, cell growth, and lipid accumulation of Yarrowia lipolytica were systematically investigated through batch cultures of Y. lipolytica by using high concentrations (30-110 g/L) of acetic acid as a carbon source at an initial pH ranging from 6 to 10. An initial pH of 8 was determined as optimal. The highest biomass and lipid production (37.14 and 10.11 g/L) were obtained with 70 g/L acetic acid, whereas cultures with > 70 g/L acetic acid had decreased biomass and lipid yield due to excessive anion accumulation. Feasibilities on high-content propionic acid, butyric acid, and mixed VFAs were compared and evaluated. Results indicated that Y X/S and Y L/S of cultures on butyric acid (0.570, 0.144) were comparable with those on acetic acid (0.578, 0.160) under alkaline conditions. The performance on propionic acid was much inferior to that on other acids. Mixed VFAs were more beneficial to fast adaptation and lipid production than single types of VFA. Furthermore, cultures on food waste (FW) and fruit and vegetable waste (FVW) fermentate were carried out and lipid production was effectively improved under this alkaline condition. The highest biomass and lipid production on FW fermentate reached 14.65 g/L (Y X/S: 0.414) and 3.20 g/L (Y L/S: 0.091) with a lipid content of 21.86%, respectively. By comparison, the highest biomass and lipid production on FVW fermentate were 11.84 g/L (Y X/S: 0.534) and 3.08 g/L (Y L/S: 0.139), respectively, with a lipid content of 26.02%. CONCLUSIONS This study assumed and verified that alkaline conditions (optimal pH 8) could effectively alleviate the lethal effect of high-content VFA on Y. lipolytica and significantly improve biomass and lipid production. These results could provide a new cultivation strategy to achieve simple utilizations of high-content VFAs and increase lipid production. Feasibilities on FW and FVW-derived VFAs were evaluated, and meaningful information was provided for practical applications.
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Affiliation(s)
- Ruiling Gao
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083 People’s Republic of China
| | - Zifu Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083 People’s Republic of China
| | - Xiaoqin Zhou
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083 People’s Republic of China
| | - Wenjun Bao
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083 People’s Republic of China
| | - Shikun Cheng
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083 People’s Republic of China
| | - Lei Zheng
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083 People’s Republic of China
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16
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Giovagnoni G, Tugnoli B, Piva A, Grilli E. Organic Acids and Nature Identical Compounds Can Increase the Activity of Conventional Antibiotics Against Clostridium Perfringens and Enterococcus Cecorum In Vitro. J APPL POULTRY RES 2019. [DOI: 10.3382/japr/pfz101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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17
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Kim MS, Cho KH, Park KH, Jang J, Hahn JS. Activation of Haa1 and War1 transcription factors by differential binding of weak acid anions in Saccharomyces cerevisiae. Nucleic Acids Res 2019; 47:1211-1224. [PMID: 30476185 PMCID: PMC6379682 DOI: 10.1093/nar/gky1188] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 10/31/2018] [Accepted: 11/07/2018] [Indexed: 01/03/2023] Open
Abstract
In Saccharomyces cerevisiae, Haa1 and War1 transcription factors are involved in cellular adaptation against hydrophilic weak acids and lipophilic weak acids, respectively. However, it is unclear how these transcription factors are differentially activated depending on the identity of the weak acid. Using a field-effect transistor (FET)-type biosensor based on carbon nanofibers, in the present study we demonstrate that Haa1 and War1 directly bind to various weak acid anions with different affinities. Haa1 is most sensitive to acetate, followed by lactate, whereas War1 is most sensitive to benzoate, followed by sorbate, reflecting their differential activation during weak acid stresses. We show that DNA binding by Haa1 is induced in the presence of acetic acid and that the N-terminal Zn-binding domain is essential for this activity. Acetate binds to the N-terminal 150-residue region, and the transcriptional activation domain is located between amino acid residues 230 and 483. Our data suggest that acetate binding converts an inactive Haa1 to the active form, which is capable of DNA binding and transcriptional activation.
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Affiliation(s)
- Myung Sup Kim
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Kyung Hee Cho
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Kwang Hyun Park
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jyongsik Jang
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ji-Sook Hahn
- School of Chemical and Biological Engineering, Seoul National University, Institute of Chemical Processes, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
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18
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de Witt RN, Kroukamp H, Volschenk H. Proteome response of two natural strains of Saccharomyces cerevisiae with divergent lignocellulosic inhibitor stress tolerance. FEMS Yeast Res 2019; 19:5145847. [PMID: 30371771 DOI: 10.1093/femsyr/foy116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/25/2018] [Indexed: 12/30/2022] Open
Abstract
Strains of Saccharomyces cerevisiae with improved tolerance to plant hydrolysates are of utmost importance for the cost-competitive production of value-added chemicals and fuels. However, engineering strategies are constrained by a lack of understanding of the yeast response to complex inhibitor mixtures. Natural S. cerevisiae isolates display niche-specific phenotypic and metabolic diversity, encoded in their DNA, which has evolved to overcome external stresses, utilise available resources and ultimately thrive in their challenging environments. Industrial and laboratory strains, however, lack these adaptations due to domestication. Natural strains can serve as a valuable resource to mitigate engineering constraints by studying the molecular mechanisms involved in phenotypic variance and instruct future industrial strain improvement to lignocellulosic hydrolysates. We, therefore, investigated the proteomic changes between two natural S. cerevisiae isolates when exposed to a lignocellulosic inhibitor mixture. Comparative shotgun proteomics revealed that isolates respond by regulating a similar core set of proteins in response to inhibitor stress. Furthermore, superior tolerance was linked to NAD(P)/H and energy homeostasis, concurrent with inhibitor and reactive oxygen species detoxification processes. We present several candidate proteins within the redox homeostasis and energy management cellular processes as possible targets for future modification and study. Data are available via ProteomeXchange with identifier PXD010868.
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Affiliation(s)
- R N de Witt
- Department of Microbiology, Stellenbosch University, De Beer Street, Stellenbosch, 7600, Western Cape, South Africa
| | - H Kroukamp
- Department of Molecular Sciences, Macquarie University, Balaclava Rd, North Ryde NSW 2109, Australia
| | - H Volschenk
- Department of Microbiology, Stellenbosch University, De Beer Street, Stellenbosch, 7600, Western Cape, South Africa
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de Souza de Azevedo PO, de Azevedo HF, Figueroa E, Converti A, Domínguez JM, de Souza Oliveira RP. Effects of pH and sugar supplements on bacteriocin-like inhibitory substance production by Pediococcus pentosaceus. Mol Biol Rep 2019; 46:4883-4891. [PMID: 31243723 DOI: 10.1007/s11033-019-04938-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 06/20/2019] [Indexed: 11/28/2022]
Abstract
To improve bacteriocin-like inhibitory substance (BLIS) production by Pediococcus pentosaceus ATCC 43200, the influence of pH as well as the addition of sugars-either prebiotic (inulin) or not (sucrose)-on its metabolism were investigated. This strain was grown at pH 5.0 or 6.0 either in glucose-based MRS medium (control) or after addition of 0.5, 1.0 or 1.5% (w/w) sucrose and inulin (GSI-MRS) in the same percentages. In the control medium at pH 5.0, cell mass concentration after 48 h of fermentation (Xmax = 2.26 g/L), maximum specific growth rate (µmax = 0.180 h-1) and generation time (Tg = 3.84 h) were statistically coincident with those obtained in supplemented media. At pH 6.0 some variations occurred in these parameters between the control medium (Xmax = 2.68 g/L; µmax = 0.32 h-1; Tg = 2.17 h) and the above supplemented media (Xmax = 1.90, 2.52 and 1.86 g/L; µmax = 0.26, 0.33 and 0.32 h-1; Tg = 2.62, 2.06 and 2.11 h, respectively). Lactate production was remarkable at both pH values (13 and 16 g/L) and improved in all supplemented media, being 34 and 54% higher than in their respective control media, regardless of the concentration of these ingredients. Cell-free supernatant of the fermented control medium at pH 5.0 displayed an antimicrobial activity against Enterococcus 101 5.3% higher than that at pH 6.0 and even 20% higher than those of all supplemented media, regardless of the concentration of supplements. BLIS production was favored either at pH 5.0 or in the absence of any additional supplements, which were able, instead, to stimulate growth and lactate production by P. pentosaceus.
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Affiliation(s)
- Pamela Oliveira de Souza de Azevedo
- Department of Biochemical and Pharmaceutical Technology Department, School of Pharmaceutical Sciences, University of São Paulo, Av. Lineu Prestes 580, São Paulo, 05508-900, Brazil
| | - Hernando Fernandes de Azevedo
- Department of Biochemical and Pharmaceutical Technology Department, School of Pharmaceutical Sciences, University of São Paulo, Av. Lineu Prestes 580, São Paulo, 05508-900, Brazil
| | - Elías Figueroa
- Núcleo de Investigación en Producción Alimentaria. Departamento de Ciencias Biológicas y Químicas. Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile
| | - Attilio Converti
- Department of Civil, Chemical and Environmental Engineering, Pole of Chemical Engineering, Via Opera Pia 15, 16145, Genoa, Italy
| | - José Manuel Domínguez
- Department of Chemical Engineering, Faculty of Science, University of Vigo (Campus Ourense), As Lagoas s/n, 32004, Ourense, Spain
| | - Ricardo Pinheiro de Souza Oliveira
- Department of Biochemical and Pharmaceutical Technology Department, School of Pharmaceutical Sciences, University of São Paulo, Av. Lineu Prestes 580, São Paulo, 05508-900, Brazil.
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Favaro L, Jansen T, van Zyl WH. Exploring industrial and naturalSaccharomyces cerevisiaestrains for the bio-based economy from biomass: the case of bioethanol. Crit Rev Biotechnol 2019; 39:800-816. [DOI: 10.1080/07388551.2019.1619157] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Trudy Jansen
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
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21
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Xu X, Williams TC, Divne C, Pretorius IS, Paulsen IT. Evolutionary engineering in Saccharomyces cerevisiae reveals a TRK1-dependent potassium influx mechanism for propionic acid tolerance. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:97. [PMID: 31044010 PMCID: PMC6477708 DOI: 10.1186/s13068-019-1427-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Propionic acid (PA), a key platform chemical produced as a by-product during petroleum refining, has been widely used as a food preservative and an important chemical intermediate in many industries. Microbial PA production through engineering yeast as a cell factory is a potentially sustainable alternative to replace petroleum refining. However, PA inhibits yeast growth at concentrations well below the titers typically required for a commercial bioprocess. RESULTS Adaptive laboratory evolution (ALE) with PA concentrations ranging from 15 to 45 mM enabled the isolation of yeast strains with more than threefold improved tolerance to PA. Through whole genome sequencing and CRISPR-Cas9-mediated reverse engineering, unique mutations in TRK1, which encodes a high-affinity potassium transporter, were revealed as the cause of increased propionic acid tolerance. Potassium supplementation growth assays showed that mutated TRK1 alleles and extracellular potassium supplementation not only conferred tolerance to PA stress but also to multiple organic acids. CONCLUSION Our study has demonstrated the use of ALE as a powerful tool to improve yeast tolerance to PA. Potassium transport and maintenance is not only critical in yeast tolerance to PA but also boosts tolerance to multiple organic acids. These results demonstrate high-affinity potassium transport as a new principle for improving organic acid tolerance in strain engineering.
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Affiliation(s)
- Xin Xu
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109 Australia
| | - Thomas C. Williams
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109 Australia
- CSIRO Synthetic Biology Future Science Platform, Canberra, ACT 2601 Australia
| | - Christina Divne
- KTH School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - Isak S. Pretorius
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109 Australia
| | - Ian T. Paulsen
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109 Australia
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22
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Gu H, Zhu Y, Peng Y, Liang X, Liu X, Shao L, Xu Y, Xu Z, Liu R, Li J. Physiological mechanism of improved tolerance of Saccharomyces cerevisiae to lignin-derived phenolic acids in lignocellulosic ethanol fermentation by short-term adaptation. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:268. [PMID: 31755875 PMCID: PMC6854637 DOI: 10.1186/s13068-019-1610-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/04/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Phenolic acids are lignin-derived fermentation inhibitors formed during many pretreatment processes of lignocellulosic biomass. In this study, vanillic, p-hydroxybenzoic, and syringic acids were selected as the model compounds of phenolic acids, and the effect of short-term adaptation strategies on the tolerance of S. cerevisiae to phenolic acids was investigated. The mechanism of phenolic acids tolerance in the adapted yeast strains was studied at the morphological and physiological levels. RESULTS The multiple phenolic acids exerted the synergistic inhibitory effect on the yeast cell growth. In particular, a significant interaction between vanillic and hydroxybenzoic acids was found. The optimal short-term adaptation strategies could efficiently improve the growth and fermentation performance of the yeast strain not only in the synthetic media with phenolic acids, but also in the simultaneous saccharification and ethanol fermentation of corncob residue. Morphological analysis showed that phenolic acids caused the parental strain to generate many cytoplasmic membrane invaginations with crack at the top of these sites and some mitochondria gathered around. The adapted strain presented the thicker cell wall and membrane and smaller cell size than those of the parental strain. In particular, the cytoplasmic membrane generated many little protrusions with regular shape. The cytoplasmic membrane integrity was analyzed by testing the relative electrical conductivity, leakage of intracellular substance, and permeation of fluorescent probe. The results indicated that the short-term adaptation improved the membrane integrity of yeast cell. CONCLUSION The inhibition mechanism of phenolic acid might be attributed to the combined effect of the cytoplasmic membrane damage and the intracellular acidification. The short-term adaptation strategy with varied stressors levels and adaptive processes accelerated the stress response of yeast cell structure to tolerate phenolic acids. This strategy will contribute to the development of robust microbials for biofuel production from lignocellulosic biomass.
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Affiliation(s)
- Hanqi Gu
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237 China
| | - Yuyong Zhu
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Yanfang Peng
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Xiujun Liang
- Basic Medical Institute, Chengde Medical University, Chengde, 067000 Hebei China
| | - Xiaoguang Liu
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Lingzhi Shao
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Yanyan Xu
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Zhaohe Xu
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Ran Liu
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
| | - Jie Li
- Department of Biology and Food Science, Hebei Normal University for Nationalities, Chengde, 067000 Hebei China
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Palma M, Sá-Correia I. Physiological Genomics of the Highly Weak-Acid-Tolerant Food Spoilage Yeasts of Zygosaccharomyces bailii sensu lato. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 58:85-109. [PMID: 30911890 DOI: 10.1007/978-3-030-13035-0_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Zygosaccharomyces bailii and two closely related species, Z. parabailii and Z. pseudobailii ("Z. bailii species complex", "Z. bailii sensu lato" or simply "Z. bailii (s.l.)"), are frequently implicated in the spoilage of acidified preserved foods and beverages due to their tolerance to very high concentrations of weak acids used as food preservatives. The recent sequencing and annotation of these species' genomes have clarified their genomic organization and phylogenetic relationship, which includes events of interspecies hybridization. Mechanistic insights into their adaptation and tolerance to weak acids (e.g., acetic and lactic acids) are also being revealed. Moreover, the potential of Z. bailii (s.l.) to be used in industrial biotechnological processes as interesting cell factories for the production of organic acids, reduction of the ethanol content, increase of alcoholic beverages aroma complexity, as well as of genetic source for increasing weak acid resistance in yeast, is currently being considered. This chapter includes taxonomical, ecological, physiological, and biochemical aspects of Z. bailii (s.l.). The focus is on the exploitation of physiological genomics approaches that are providing the indispensable holistic knowledge to guide the effective design of strategies to overcome food spoilage or the rational exploitation of these yeasts as promising cell factories.
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Affiliation(s)
- Margarida Palma
- Institute for Bioengineering and Biosciences (iBB) and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisbon, Portugal
| | - Isabel Sá-Correia
- Institute for Bioengineering and Biosciences (iBB) and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisbon, Portugal.
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Guo ZP, Khoomrung S, Nielsen J, Olsson L. Changes in lipid metabolism convey acid tolerance in Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:297. [PMID: 30450126 PMCID: PMC6206931 DOI: 10.1186/s13068-018-1295-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/15/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND The yeast Saccharomyces cerevisiae plays an essential role in the fermentation of lignocellulosic hydrolysates. Weak organic acids in lignocellulosic hydrolysate can hamper the use of this renewable resource for fuel and chemical production. Plasma-membrane remodeling has recently been found to be involved in acquiring tolerance to organic acids, but the mechanisms responsible remain largely unknown. Therefore, it is essential to understand the underlying mechanisms of acid tolerance of S. cerevisiae for developing robust industrial strains. RESULTS We have performed a comparative analysis of lipids and fatty acids in S. cerevisiae grown in the presence of four different weak acids. The general response of the yeast to acid stress was found to be the accumulation of triacylglycerols and the degradation of steryl esters. In addition, a decrease in phosphatidic acid, phosphatidylcholine, phosphatidylserine and phosphatidylethanolamine, and an increase in phosphatidylinositol were observed. Loss of cardiolipin in the mitochondria membrane may be responsible for the dysfunction of mitochondria and the dramatic decrease in the rate of respiration of S. cerevisiae under acid stress. Interestingly, the accumulation of ergosterol was found to be a protective mechanism of yeast exposed to organic acids, and the ERG1 gene in ergosterol biosynthesis played a key in ergosterol-mediated acid tolerance, as perturbing the expression of this gene caused rapid loss of viability. Interestingly, overexpressing OLE1 resulted in the increased levels of oleic acid (18:1n-9) and an increase in the unsaturation index of fatty acids in the plasma membrane, resulting in higher tolerance to acetic, formic and levulinic acid, while this change was found to be detrimental to cells exposed to lipophilic cinnamic acid. CONCLUSIONS Comparison of lipid profiles revealed different remodeling of lipids, FAs and the unsaturation index of the FAs in the cell membrane in response of S. cerevisiae to acetic, formic, levulinic and cinnamic acid, depending on the properties of the acid. In future work, it will be necessary to combine lipidome and transcriptome analysis to gain a better understanding of the underlying regulation network and interactions between central carbon metabolism (e.g., glycolysis, TCA cycle) and lipid biosynthesis.
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Affiliation(s)
- Zhong-peng Guo
- Department of Biology and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- Present Address: LISBP, INSA, INRA, CNRS, Université de Toulouse, Toulouse, France
| | - Sakda Khoomrung
- Department of Biochemistry and Siriraj Metabolomics and Phenomics Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Department of Biology and Biological Engineering, Systems and Synthetic Biology, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Systems and Synthetic Biology, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, 2800 Kongens Lyngby, Denmark
| | - Lisbeth Olsson
- Department of Biology and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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Inactivation of the transcription factor mig1 (YGL035C) in Saccharomyces cerevisiae improves tolerance towards monocarboxylic weak acids: acetic, formic and levulinic acid. ACTA ACUST UNITED AC 2018; 45:735-751. [DOI: 10.1007/s10295-018-2053-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 05/29/2018] [Indexed: 10/14/2022]
Abstract
Abstract
Toxic concentrations of monocarboxylic weak acids present in lignocellulosic hydrolyzates affect cell integrity and fermentative performance of Saccharomyces cerevisiae. In this work, we report the deletion of the general catabolite repressor Mig1p as a strategy to improve the tolerance of S. cerevisiae towards inhibitory concentrations of acetic, formic or levulinic acid. In contrast with the wt yeast, where the growth and ethanol production were ceased in presence of acetic acid 5 g/L or formic acid 1.75 g/L (initial pH not adjusted), the m9 strain (Δmig1::kan) produced 4.06 ± 0.14 and 3.87 ± 0.06 g/L of ethanol, respectively. Also, m9 strain tolerated a higher concentration of 12.5 g/L acetic acid (initial pH adjusted to 4.5) without affecting its fermentative performance. Moreover, m9 strain produced 33% less acetic acid and 50–70% less glycerol in presence of weak acids, and consumed acetate and formate as carbon sources under aerobic conditions. Our results show that the deletion of Mig1p provides a single gene deletion target for improving the acid tolerance of yeast strains significantly.
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de Souza de Azevedo PO, Converti A, Domínguez JM, de Souza Oliveira RP. Stimulating Effects of Sucrose and Inulin on Growth, Lactate, and Bacteriocin Productions by Pediococcus pentosaceus. Probiotics Antimicrob Proteins 2018; 9:466-472. [PMID: 28560515 DOI: 10.1007/s12602-017-9292-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sucrose and inulin, when combined with glucose, behaved as stimulating agents of bacteriocin production by Pediococcus pentosaceus ATCC 43200. When such microbial strain was grown in glucose-based Man, Rogosa, and Sharpe (MRS) medium, without any additional supplement, it showed higher maximum cell concentration (2.68 ± 1.10 g/L) and longer generation time (2.17 ± 0.02 h), but lower specific growth rate (0.32 ± 0.01 h-1) than in the same medium supplemented with 1.0% of both ingredients (2.53 ± 1.10 g/L, 1.60 ± 0.05 h and 0.43 ± 0.02 h-1, respectively). Glucose replacement by sucrose or inulin almost completely suppressed growth, hence confirming that it is the preferred carbon source for this strain. Qualitatively, similar results were observed for lactate production, which was 59.8% higher in glucose-based medium. Enterococcus and Listeria strains were sensitive to bacteriocin, whose antimicrobial effect after 8 h increased from 120.25 ± 0.35 to 144.00 ± 1.41 or 171.00 ± 1.41 AU/mL when sucrose or inulin was added to the glucose-based MRS medium. Sucrose and inulin were also able to speed up P. pentosaceus growth in the exponential phase.
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Affiliation(s)
- Pamela Oliveira de Souza de Azevedo
- Biochemical and Pharmaceutical Technology Department, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Lineu Prestes 580, São Paulo, 05508-900, Brazil
| | - Attilio Converti
- Department of Civil, Chemical and Environmental Engineering, Genoa University, 16145, Genoa, Italy
| | - José Manuel Domínguez
- Department of Chemical Engineering, Faculty of Science, University of Vigo (Campus Ourense), As Lagoas s/n, 32004, Ourense, Spain
| | - Ricardo Pinheiro de Souza Oliveira
- Biochemical and Pharmaceutical Technology Department, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Lineu Prestes 580, São Paulo, 05508-900, Brazil.
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27
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Synthesis and antimicrobial activities of novel sorbic and benzoic acid amide derivatives. Food Chem 2018; 268:220-232. [PMID: 30064751 DOI: 10.1016/j.foodchem.2018.06.071] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/30/2018] [Accepted: 06/14/2018] [Indexed: 01/17/2023]
Abstract
A series of sorbic and benzoic acid amide derivatives were synthesized by conjugating sorbic acid (SAAD, a1-a7) or benzoic acid (BAAD b1-b6) with amino acid esters and their antimicrobial activities were investigated against Escherichia coli, Bacillus subtilis and Staphylococcus aureus, mixed bacteria from rancid milk, Saccharomyces cerevisiae, and Aspergillus niger. The antimicrobial activity of sorbic acid amides was better than that of benzoic acid amides. The minimum inhibitory concentrations (MIC) of compound isopropyl N-[1-oxo-2, 4-hexadien-1-yl]-L-phenylalaninate (a7) were 0.17 mM against B. subtilis, and 0.50 mM against S. aureus, while the MIC values of sorbic acid were more than 2 mM respectively. Also, compound a7 displayed pH-independent antimicrobial activity in the range of pH 5.0-9.0 and was effective at pH 9.0. These results demonstrated that the conjugation of sorbic acid with amino acid esters led to significant improvement of in vitro antimicrobial attributes, but little effect was observed for benzoic acid amide derivatives.
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28
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Recek N, Zhou R, Zhou R, Te'o VSJ, Speight RE, Mozetič M, Vesel A, Cvelbar U, Bazaka K, Ostrikov KK. Improved fermentation efficiency of S. cerevisiae by changing glycolytic metabolic pathways with plasma agitation. Sci Rep 2018; 8:8252. [PMID: 29844402 PMCID: PMC5974074 DOI: 10.1038/s41598-018-26227-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 04/18/2018] [Indexed: 12/14/2022] Open
Abstract
Production of ethanol by the yeast Saccharomyces cerevisiae is a process of global importance. In these processes, productivities and yields are pushed to their maximum possible values leading to cellular stress. Transient and lasting enhancements in tolerance and performance have been obtained by genetic engineering, forced evolution, and exposure to moderate levels of chemical and/or physical stimuli, yet the drawbacks of these methods include cost, and multi-step, complex and lengthy treatment protocols. Here, plasma agitation is shown to rapidly induce desirable phenotypic changes in S. cerevisiae after a single treatment, resulting in improved conversion of glucose to ethanol. With a complex environment rich in energetic electrons, highly-reactive chemical species, photons, and gas flow effects, plasma treatment simultaneously mimics exposure to multiple environmental stressors. A single treatment of up to 10 minutes performed using an atmospheric pressure plasma jet was sufficient to induce changes in cell membrane structure, and increased hexokinase 2 activity and secondary metabolite production. These results suggest that plasma treatment is a promising strategy that can contribute to improving metabolic activity in industrial microbial strains, and thus the practicality and economics of industrial fermentations.
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Affiliation(s)
- Nina Recek
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia.,Department of Surface Engineering and Optoelectronics, Jožef Stefan Institute, Ljubljana, SI-1000, Slovenia
| | - Renwu Zhou
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Rusen Zhou
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | | | - Robert E Speight
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Miran Mozetič
- Department of Surface Engineering and Optoelectronics, Jožef Stefan Institute, Ljubljana, SI-1000, Slovenia
| | - Alenka Vesel
- Department of Surface Engineering and Optoelectronics, Jožef Stefan Institute, Ljubljana, SI-1000, Slovenia
| | - Uros Cvelbar
- Department of Surface Engineering and Optoelectronics, Jožef Stefan Institute, Ljubljana, SI-1000, Slovenia
| | - Kateryna Bazaka
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia. .,CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organisation, P. O. Box 218, Lindfield, NSW 2070, Australia.
| | - Kostya Ken Ostrikov
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia. .,CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organisation, P. O. Box 218, Lindfield, NSW 2070, Australia.
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29
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Free lactic acid production under acidic conditions by lactic acid bacteria strains: challenges and future prospects. Appl Microbiol Biotechnol 2018; 102:5911-5924. [DOI: 10.1007/s00253-018-9092-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/10/2018] [Accepted: 05/10/2018] [Indexed: 11/27/2022]
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30
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Narendranath NV, Thomas KC, Ingledew WM. Acetic Acid and Lactic Acid Inhibition of Growth ofSaccharomyces Cerevisiaeby Different Mechanisms. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-59-0187] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Neelakantam V. Narendranath
- Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
| | - Kolothumannil C. Thomas
- Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
| | - W. Michael Ingledew
- Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
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31
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Engineering of global regulators and cell surface properties toward enhancing stress tolerance in Saccharomyces cerevisiae. J Biosci Bioeng 2017; 124:599-605. [DOI: 10.1016/j.jbiosc.2017.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 01/22/2023]
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32
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Bagam P, Singh DP, Inda ME, Batra S. Unraveling the role of membrane microdomains during microbial infections. Cell Biol Toxicol 2017; 33:429-455. [PMID: 28275881 PMCID: PMC7088210 DOI: 10.1007/s10565-017-9386-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/06/2017] [Indexed: 01/06/2023]
Abstract
Infectious diseases pose major socioeconomic and health-related threats to millions of people across the globe. Strategies to combat infectious diseases derive from our understanding of the complex interactions between the host and specific bacterial, viral, and fungal pathogens. Lipid rafts are membrane microdomains that play important role in life cycle of microbes. Interaction of microbial pathogens with host membrane rafts influences not only their initial colonization but also their spread and the induction of inflammation. Therefore, intervention strategies aimed at modulating the assembly of membrane rafts and/or regulating raft-directed signaling pathways are attractive approaches for the. management of infectious diseases. The current review discusses the latest advances in terms of techniques used to study the role of membrane microdomains in various pathological conditions and provides updated information regarding the role of membrane rafts during bacterial, viral and fungal infections.
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Affiliation(s)
- Prathyusha Bagam
- Laboratory of Pulmonary Immuno-Toxicology, Department of Environmental Toxicology, Health Research Center, Southern University and A&M College, Baton Rouge, LA, 70813, USA
| | - Dhirendra P Singh
- Laboratory of Pulmonary Immuno-Toxicology, Department of Environmental Toxicology, Health Research Center, Southern University and A&M College, Baton Rouge, LA, 70813, USA
| | - Maria Eugenia Inda
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Suipacha, Rosario, Argentina
| | - Sanjay Batra
- Laboratory of Pulmonary Immuno-Toxicology, Department of Environmental Toxicology, Health Research Center, Southern University and A&M College, Baton Rouge, LA, 70813, USA.
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33
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Valík Ľ, Ačai P, Liptáková D. Modelling the effects of lactic acid, sodium benzoate and temperature on the growth of Candida maltosa. Lett Appl Microbiol 2017; 65:453-460. [PMID: 28915310 DOI: 10.1111/lam.12803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 12/01/2022]
Abstract
The growth of the oxidatively imperfect yeast Candida maltosa Komagata, Nakase et Katsuya was studied experimentally and modelled mathematically in relation to sodium benzoate and lactic acid concentrations at different temperatures. Application of gamma models for the growth rate resulted in determination of cardinal temperature parameters for the growth environment containing lactic acid or sodium benzoate (Tmin = 0·7/1·3°C, Tmax = 45·3/45·0°C, Topt = 36·1/37·0°C, μopt = 0·88/0·96 h-1 ) as well as the maximal lactic acid concentration for growth (1·9%) or sodium benzoate (1397 mg kg-1 ). Based on the model, the times to reach the density of C. maltosa at the level of 105 CFU per ml can be determined at each combination of storage temperature and preservative concentration. The approach used in this study can broaden knowledge of the microbiological quality of fermented milk products during storage as well as the preservation efficacy of mayonnaise dressing for storage and consumption. SIGNIFICANCE AND IMPACT OF THE STUDY The strain of Candida maltosaYP1 was originally isolated from air filters that ensured clean air overpressure in yoghurt fermentation tanks. Its growth in contaminated yoghurts manifested outwardly through surface growth, assimilation lactic acid and slight production of carbon dioxide. This was the opportunity to model the effects of lactic acid and sodium benzoate on growth and predict its behaviour in foods. The approach used in this study provides knowledge about microbiological quality development during storage of the fermented milk products as well as some preserved foods for storage and consumption.
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Affiliation(s)
- Ľ Valík
- Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Bratislava, Slovakia
| | - P Ačai
- Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Bratislava, Slovakia
| | - D Liptáková
- Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Bratislava, Slovakia
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Wagle BR, Arsi K, Upadhyay A, Shrestha S, Venkitanarayanan K, Donoghue AM, Donoghue DJ. β-Resorcylic Acid, a Phytophenolic Compound, Reduces Campylobacter jejuni in Postharvest Poultry. J Food Prot 2017; 80:1243-1251. [PMID: 28686495 DOI: 10.4315/0362-028x.jfp-16-475] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Human Campylobacter infections, a leading foodborne illness globally, has been linked with the high prevalence of this bacterium on raw retail chicken products. Reduction of Campylobacter counts on poultry products would greatly reduce the risk of subsequent infections in humans. To this end, this study investigated the potential of the phytophenolic compound β-resorcylic acid (BR) to reduce Campylobacter counts on postharvest poultry (chicken skin or meat). Four trials in total, two each on thigh skin or breast meat, were conducted in which chicken skin or meat samples (2 ± 0.1 g; 10 samples per treatment) were inoculated with 50 μL (∼106 CFU per sample) of a cocktail of four wild strains of C. jejuni. After 30 min of attachment, inoculated samples were dipped in a 0, 0.5, 1, or 2% BR solution for 30 s immediately followed by vigorously vortexing the samples in Butterfield's phosphate diluent and plating the supernatant for Campylobacter enumeration. In addition, the effect of BR on the color of skin and meat samples was studied. Moreover, the change in the expression of survival and virulence genes of C. jejuni exposed to BR was evaluated. Data were analyzed by the PROC MIXED procedure of SAS (P < 0.05; SAS Institute Inc., Cary, NC). All BR treatments significantly reduced Campylobacter populations on both chicken or meat samples by 1 to 3 log CFU/g compared with non-BR-treated washed controls. No significant difference in the lightness, redness, and yellowness of skin and meat samples was observed on exposure to BR wash (P > 0.05). Real-time PCR results revealed that BR treatment down-regulated expression of select genes coding for motility (motA, motB) and attachment (cadF, ciaB) in the majority of C. jejuni strains. Stress response genes (sodB, katA) were upregulated in C. jejuni S-8 (P < 0.05). Overall, our results suggest that BR could be effectively used as antimicrobial dip treatment during poultry processing for reducing Campylobacter on chicken carcasses.
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Affiliation(s)
- B R Wagle
- 1 Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701
| | - K Arsi
- 1 Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701
| | - A Upadhyay
- 1 Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701
| | - S Shrestha
- 1 Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701
| | - K Venkitanarayanan
- 2 Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269; and
| | - A M Donoghue
- 3 U.S. Department of Agriculture, Agricultural Research Service, Poultry Production and Product Safety Research Unit, Fayetteville, Arkansas 72701, USA
| | - D J Donoghue
- 1 Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701
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35
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Brown AJP, Cowen LE, di Pietro A, Quinn J. Stress Adaptation. Microbiol Spectr 2017; 5:10.1128/microbiolspec.FUNK-0048-2016. [PMID: 28721857 PMCID: PMC5701650 DOI: 10.1128/microbiolspec.funk-0048-2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Indexed: 01/21/2023] Open
Abstract
Fungal species display an extraordinarily diverse range of lifestyles. Nevertheless, the survival of each species depends on its ability to sense and respond to changes in its natural environment. Environmental changes such as fluctuations in temperature, water balance or pH, or exposure to chemical insults such as reactive oxygen and nitrogen species exert stresses that perturb cellular homeostasis and cause molecular damage to the fungal cell. Consequently, fungi have evolved mechanisms to repair this damage, detoxify chemical insults, and restore cellular homeostasis. Most stresses are fundamental in nature, and consequently, there has been significant evolutionary conservation in the nature of the resultant responses across the fungal kingdom and beyond. For example, heat shock generally induces the synthesis of chaperones that promote protein refolding, antioxidants are generally synthesized in response to an oxidative stress, and osmolyte levels are generally increased following a hyperosmotic shock. In this article we summarize the current understanding of these and other stress responses as well as the signaling pathways that regulate them in the fungi. Model yeasts such as Saccharomyces cerevisiae are compared with filamentous fungi, as well as with pathogens of plants and humans. We also discuss current challenges associated with defining the dynamics of stress responses and with the elaboration of fungal stress adaptation under conditions that reflect natural environments in which fungal cells may be exposed to different types of stresses, either sequentially or simultaneously.
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Affiliation(s)
- Alistair J P Brown
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Antonio di Pietro
- Departamento de Genética, Universidad de Córdoba, Campus de Rabanales, Edificio Gregor Mendel C5, 14071 Córdoba, Spain
| | - Janet Quinn
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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Cunha DV, Salazar SB, Lopes MM, Mira NP. Mechanistic Insights Underlying Tolerance to Acetic Acid Stress in Vaginal Candida glabrata Clinical Isolates. Front Microbiol 2017; 8:259. [PMID: 28293217 PMCID: PMC5329028 DOI: 10.3389/fmicb.2017.00259] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 02/07/2017] [Indexed: 11/13/2022] Open
Abstract
During colonization of the vaginal tract Candida glabrata cells are challenged with the presence of acetic acid at a low pH, specially when dysbiosis occurs. To avoid exclusion from this niche C. glabrata cells are expected to evolve efficient adaptive responses to cope with this stress; however, these responses remain largely uncharacterized, especially in vaginal strains. In this work a cohort of 18 vaginal strains and 2 laboratory strains (CBS138 and KUE100) were phenotyped for their tolerance against inhibitory concentrations of acetic acid at pH 4. Despite some heterogeneity has been observed among the vaginal strains tested, in general these strains were considerably more tolerant to acetic acid than the laboratory strains. To tackle the mechanistic insights behind this differential level of tolerance observed, a set of vaginal strains differently tolerant to acetic acid (VG281∼VG49 < VG99 < VG216) and the highly susceptible laboratory strain KUE100 were selected for further studies. When suddenly challenged with acetic acid the more tolerant vaginal strains exhibited a higher activity of the plasma membrane proton pump CgPma1 and a reduced internal accumulation of the acid, these being two essential features to maximize tolerance. Based on the higher level of resistance exhibited by the vaginal strains against the action of a β-1,3-glucanase, it is hypothesized that the reduced internal accumulation of acetic acid inside these strains may originate from them having a different cell wall structure resulting in a reduced porosity to undissociated acetic acid molecules. Both the vaginal and the two laboratory strains were found to consume acetic acid in the presence of glucose indicating that metabolization of the acid is used by C. glabrata species as a detoxification mechanism. The results gathered in this study advance the current knowledge on the mechanisms underlying the increased competitiveness of C. glabrata in the vaginal tract, a knowledge that can be used to guide more suitable strategies to treat infections caused by this pathogenic yeast.
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Affiliation(s)
- Diana V Cunha
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
| | - Sara B Salazar
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
| | - Maria M Lopes
- Faculdade de Farmácia da Universidade de Lisboa, Departamento de Microbiologia e Imunologia Lisboa, Portugal
| | - Nuno P Mira
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
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Elimination of indigenous linear plasmids in Streptomyces hygroscopicus var. jinggangensis and Streptomyces sp. FR008 to increase validamycin A and candicidin productivities. Appl Microbiol Biotechnol 2017; 101:4247-4257. [DOI: 10.1007/s00253-017-8165-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 01/14/2017] [Accepted: 01/27/2017] [Indexed: 12/22/2022]
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38
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Florentino AP, Stams AJM, Sánchez-Andrea I. Genome Sequence of Desulfurella amilsii Strain TR1 and Comparative Genomics of Desulfurellaceae Family. Front Microbiol 2017; 8:222. [PMID: 28265263 PMCID: PMC5317093 DOI: 10.3389/fmicb.2017.00222] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/31/2017] [Indexed: 11/13/2022] Open
Abstract
The acidotolerant sulfur reducer Desulfurella amilsii was isolated from sediments of Tinto River, an extremely acidic environment. Its ability to grow in a broad range of pH and to tolerate certain heavy metals offers potential for metal recovery processes. Here we report its high-quality draft genome sequence and compare it to the available genome sequences of other members of Desulfurellaceae family: D. acetivorans. D. multipotens, Hippea maritima. H. alviniae, H. medeae, and H. jasoniae. For most species, pairwise comparisons for average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) revealed ANI values from 67.5 to 80% and DDH values from 12.9 to 24.2%. D. acetivorans and D. multipotens, however, surpassed the estimated thresholds of species definition for both DDH (98.6%) and ANI (88.1%). Therefore, they should be merged to a single species. Comparative analysis of Desulfurellaceae genomes revealed different gene content for sulfur respiration between Desulfurella and Hippea species. Sulfur reductase is only encoded in D. amilsii, in which it is suggested to play a role in sulfur respiration, especially at low pH. Polysulfide reductase is only encoded in Hippea species; it is likely that this genus uses polysulfide as electron acceptor. Genes encoding thiosulfate reductase are present in all the genomes, but dissimilatory sulfite reductase is only present in Desulfurella species. Thus, thiosulfate respiration via sulfite is only likely in this genus. Although sulfur disproportionation occurs in Desulfurella species, the molecular mechanism behind this process is not yet understood, hampering a genome prediction. The metabolism of acetate in Desulfurella species can occur via the acetyl-CoA synthetase or via acetate kinase in combination with phosphate acetyltransferase, while in Hippea species, it might occur via the acetate kinase. Large differences in gene sets involved in resistance to acidic conditions were not detected among the genomes. Therefore, the regulation of those genes, or a mechanism not yet known, might be responsible for the unique ability of D. amilsii. This is the first report on comparative genomics of sulfur-reducing bacteria, which is valuable to give insight into this poorly understood metabolism, but of great potential for biotechnological purposes and of environmental significance.
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Affiliation(s)
- Anna P Florentino
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands; Sub-department of Environmental Technology, Wageningen UniversityWageningen, Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands; Centre of Biological Engineering, University of MinhoBraga, Portugal
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Jørgensen MR, Kragelund C, Jensen PØ, Keller MK, Twetman S. Probiotic Lactobacillus reuteri has antifungal effects on oral Candida species in vitro. J Oral Microbiol 2017; 9:1274582. [PMID: 28326154 PMCID: PMC5328390 DOI: 10.1080/20002297.2016.1274582] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/14/2016] [Accepted: 12/16/2016] [Indexed: 12/18/2022] Open
Abstract
Background: An alternative approach for managing Candida infections in the oral cavity by modulating the oral microbiota with probiotic bacteria has been proposed. Objective: The aim was to investigate the antifungal potential of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) against six oral Candida species (C. albicans, C. glabrata, C. krusei, C. tropicalis, C. dubliniensis, and C. parapsilosis).
Design: The lactobacilli were tested for their ability to co-aggregate with and inhibit the growth of the yeasts assessed by spectrophotometry and the agar overlay inhibition assay. Additionally, the pH was evaluated with microsensors, and the production of hydrogen peroxide (H2O2) by the lactobacilli was verified. Results: Both L. reuteri strains showed co-aggregation abilities with the yeasts. The lactobacilli almost completely inhibited the growth of C. albicans and C. parapsilosis, but did not affect C. krusei. Statistically significant differences in co-aggregation and growth inhibition capacities between the two L. reuteri strains were observed (p<0.001). The pH measurements suggested that C. krusei can resist the acids produced by the lactobacilli. Conclusions:L. reuteri exhibited antifungal properties against five of the six most common oral Candida species. Further, the results reconfirms that the probiotic capacity of L. reuteri is strain specific.
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Affiliation(s)
- Mette Rose Jørgensen
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Camilla Kragelund
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | | | - Mette Kirstine Keller
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Svante Twetman
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
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Nasution O, Lee YM, Kim E, Lee Y, Kim W, Choi W. Overexpression ofOLE1enhances stress tolerance and constitutively activates the MAPK HOG pathway inSaccharomyces cerevisiae. Biotechnol Bioeng 2016; 114:620-631. [DOI: 10.1002/bit.26093] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 07/26/2016] [Accepted: 08/28/2016] [Indexed: 01/10/2023]
Affiliation(s)
- Olviyani Nasution
- Interdisciplinary Program of EcoCreative; The Graduate School; Ewha Womans University; Seoul 03766 Korea
| | - Young Mi Lee
- Department of Pharmacology; School of Medicine; Ajou University; Suwon Korea
| | - Eunjung Kim
- Department of Pharmacology; School of Medicine; Ajou University; Suwon Korea
| | - Yeji Lee
- Department of Life Sciences; College of Natural Sciences, Ewha Womans University; Seoul Korea
| | - Wankee Kim
- Department of Pharmacology; School of Medicine; Ajou University; Suwon Korea
| | - Wonja Choi
- Interdisciplinary Program of EcoCreative; The Graduate School; Ewha Womans University; Seoul 03766 Korea
- Department of Life Sciences; College of Natural Sciences, Ewha Womans University; Seoul Korea
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Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells. Appl Environ Microbiol 2016; 82:6463-6471. [PMID: 27565617 DOI: 10.1128/aem.02063-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 08/21/2016] [Indexed: 11/20/2022] Open
Abstract
Intracellular pH (pHi) critically affects bacterial cell physiology. Hence, a variety of food preservation strategies are aimed at perturbing pHi homeostasis. Unfortunately, accurate pHi quantification with existing methods is suboptimal, since measurements are averages across populations of cells, not taking into account interindividual heterogeneity. Yet, physiological heterogeneity in isogenic populations is well known to be responsible for differences in growth and division kinetics of cells in response to external stressors. To assess in this context the behavior of intracellular acidity, we have developed a robust method to quantify pHi at single-cell levels in Bacillus subtilis Bacilli spoil food, cause disease, and are well known for their ability to form highly stress-resistant spores. Using an improved version of the genetically encoded ratiometric pHluorin (IpHluorin), we have quantified pHi in individual B. subtilis cells, cultured at an external pH of 6.4, in the absence or presence of weak acid stresses. In the presence of 3 mM potassium sorbate, a decrease in pHi and an increase in the generation time of growing cells were observed. Similar effects were observed when cells were stressed with 25 mM potassium acetate. Time-resolved analysis of individual bacteria in growing colonies shows that after a transient pH decrease, long-term pH evolution is highly cell dependent. The heterogeneity at the single-cell level shows the existence of subpopulations that might be more resistant and contribute to population survival. Our approach contributes to an understanding of pHi regulation in individual bacteria and may help scrutinizing effects of existing and novel food preservation strategies. IMPORTANCE This study shows how the physiological response to commonly used weak organic acid food preservatives, such as sorbic and acetic acids, can be measured at the single-cell level. These data are key to coupling often-observed single-cell heterogeneous growth behavior upon the addition of weak organic acid food preservatives. Generally, these data are gathered in the form of plate counting of samples incubated with the acids. Here, we visualize the underlying heterogeneity in cellular pH homeostasis, opening up avenues for mechanistic analyses of the heterogeneity in the weak acid stress response. Thus, microbial risk assessment can become more robust, widening the scope of use of these well-known weak organic acid food preservatives.
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Lee Y, Nasution O, Lee YM, Kim E, Choi W, Kim W. Overexpression of PMA1 enhances tolerance to various types of stress and constitutively activates the SAPK pathways in Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2016; 101:229-239. [PMID: 27730338 DOI: 10.1007/s00253-016-7898-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 09/10/2016] [Accepted: 09/25/2016] [Indexed: 11/26/2022]
Abstract
PMA1 encodes a transmembrane polypeptide that functions to pump protons out of the cell. Ectopic PMA1 overexpression in Saccharomyces cerevisiae enhances tolerance to weak acids, reactive oxygen species (ROS) and ethanol, and changes the following physiological properties: better proton efflux, lower membrane permeability, and lessened internal hydrogen peroxide production. The enhanced stress tolerance was dependent on the mitogen-activated protein kinase (MAPK) Hog1 of the high osmolarity glycerol (HOG) pathway, but not the MAPK Slt2 of the cell wall integrity (CWI) pathway; however, a PMA1 overexpression constitutively activated both Hog1 and Slt2. The constitutive Hog1 activation required the MAPK kinase kinase (MAP3K) Ssk2 of the HOG pathway, but not Ste11 and Ssk22, two other MAP3Ks of the same pathway. The constitutive Slt2 activation did not require Rom2 and the membrane sensors of the CWI pathway, whereas Bck1 was indispensable. The PMA1 overexpression activated the stress response element but not the cyclic AMP response element and the Rlm1 transcription factor. PMA1 overexpression may facilitate the construction of industrial strains with simultaneous tolerance to weak acids, ROS, and ethanol.
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Affiliation(s)
- Yeji Lee
- Interdisciplinary Program of EcoCreative, College of Natural Sciences, Ewha Womans University, Seoul, 03766, South Korea
| | - Olviyani Nasution
- Interdisciplinary Program of EcoCreative, College of Natural Sciences, Ewha Womans University, Seoul, 03766, South Korea
| | - Young Mi Lee
- Department of Life Sciences College of Natural Sciences, Ewha Womans University, Seoul, 03766, South Korea
| | - Eunjung Kim
- Department of Pharmacology, School of Medicine, Ajou University, Suwon, 16499, South Korea
| | - Wonja Choi
- Interdisciplinary Program of EcoCreative, College of Natural Sciences, Ewha Womans University, Seoul, 03766, South Korea.
- Department of Life Sciences College of Natural Sciences, Ewha Womans University, Seoul, 03766, South Korea.
| | - Wankee Kim
- Department of Pharmacology, School of Medicine, Ajou University, Suwon, 16499, South Korea.
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Sardi M, Rovinskiy N, Zhang Y, Gasch AP. Leveraging Genetic-Background Effects in Saccharomyces cerevisiae To Improve Lignocellulosic Hydrolysate Tolerance. Appl Environ Microbiol 2016; 82:5838-49. [PMID: 27451446 PMCID: PMC5038035 DOI: 10.1128/aem.01603-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/14/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED A major obstacle to sustainable lignocellulosic biofuel production is microbe inhibition by the combinatorial stresses in pretreated plant hydrolysate. Chemical biomass pretreatment releases a suite of toxins that interact with other stressors, including high osmolarity and temperature, which together can have poorly understood synergistic effects on cells. Improving tolerance in industrial strains has been hindered, in part because the mechanisms of tolerance reported in the literature often fail to recapitulate in other strain backgrounds. Here, we explored and then exploited variations in stress tolerance, toxin-induced transcriptomic responses, and fitness effects of gene overexpression in different Saccharomyces cerevisiae (yeast) strains to identify genes and processes linked to tolerance of hydrolysate stressors. Using six different S. cerevisiae strains that together maximized phenotypic and genetic diversity, first we explored transcriptomic differences between resistant and sensitive strains to identify common and strain-specific responses. This comparative analysis implicated primary cellular targets of hydrolysate toxins, secondary effects of defective defense strategies, and mechanisms of tolerance. Dissecting the responses to individual hydrolysate components across strains pointed to synergistic interactions between osmolarity, pH, hydrolysate toxins, and nutrient composition. By characterizing the effects of high-copy gene overexpression in three different strains, we revealed the breadth of the background-specific effects of gene fitness contributions in synthetic hydrolysate. Our approach identified new genes for engineering improved stress tolerance in diverse strains while illuminating the effects of genetic background on molecular mechanisms. IMPORTANCE Recent studies on natural variation within Saccharomyces cerevisiae have uncovered substantial phenotypic diversity. Here, we took advantage of this diversity, using it as a tool to infer the effects of combinatorial stress found in lignocellulosic hydrolysate. By comparing sensitive and tolerant strains, we implicated primary cellular targets of hydrolysate toxins and elucidated the physiological states of cells when exposed to this stress. We also explored the strain-specific effects of gene overexpression to further identify strain-specific responses to hydrolysate stresses and to identify genes that improve hydrolysate tolerance independent of strain background. This study underscores the importance of studying multiple strains to understand the effects of hydrolysate stress and provides a method to find genes that improve tolerance across strain backgrounds.
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Affiliation(s)
- Maria Sardi
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA Microbiology Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nikolay Rovinskiy
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Yaoping Zhang
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Audrey P Gasch
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Overexpression of ESBP6 improves lactic acid resistance and production in Saccharomyces cerevisiae. J Biosci Bioeng 2016; 122:415-20. [DOI: 10.1016/j.jbiosc.2016.03.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/12/2016] [Accepted: 03/16/2016] [Indexed: 12/28/2022]
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Comparative transcriptome assembly and genome-guided profiling for Brettanomyces bruxellensis LAMAP2480 during p-coumaric acid stress. Sci Rep 2016; 6:34304. [PMID: 27678167 PMCID: PMC5039629 DOI: 10.1038/srep34304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 09/07/2016] [Indexed: 11/08/2022] Open
Abstract
Brettanomyces bruxellensis has been described as the main contaminant yeast in wine production, due to its ability to convert the hydroxycinnamic acids naturally present in the grape phenolic derivatives, into volatile phenols. Currently, there are no studies in B. bruxellensis which explains the resistance mechanisms to hydroxycinnamic acids, and in particular to p-coumaric acid which is directly involved in alterations to wine. In this work, we performed a transcriptome analysis of B. bruxellensis LAMAP248rown in the presence and absence of p-coumaric acid during lag phase. Because of reported genetic variability among B. bruxellensis strains, to complement de novo assembly of the transcripts, we used the high-quality genome of B. bruxellensis AWRI1499, as well as the draft genomes of strains CBS2499 and0 g LAMAP2480. The results from the transcriptome analysis allowed us to propose a model in which the entrance of p-coumaric acid to the cell generates a generalized stress condition, in which the expression of proton pump and efflux of toxic compounds are induced. In addition, these mechanisms could be involved in the outflux of nitrogen compounds, such as amino acids, decreasing the overall concentration and triggering the expression of nitrogen metabolism genes.
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Guo ZP, Olsson L. Physiological responses to acid stress by Saccharomyces cerevisiae when applying high initial cell density. FEMS Yeast Res 2016; 16:fow072. [PMID: 27620460 PMCID: PMC5094285 DOI: 10.1093/femsyr/fow072] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2016] [Indexed: 12/20/2022] Open
Abstract
High initial cell density is used to increase volumetric productivity and shorten production time in lignocellulosic hydrolysate fermentation. Comparison of physiological parameters in high initial cell density cultivation of Saccharomyces cerevisiae in the presence of acetic, formic, levulinic and cinnamic acids demonstrated general and acid-specific responses of cells. All the acids studied impaired growth and inhibited glycolytic flux, and caused oxidative stress and accumulation of trehalose. However, trehalose may play a role other than protecting yeast cells from acid-induced oxidative stress. Unlike the other acids, cinnamic acid did not cause depletion of cellular ATP, but abolished the growth of yeast on ethanol. Compared with low initial cell density, increasing initial cell density reduced the lag phase and improved the bioconversion yield of cinnamic acid during acid adaptation. In addition, yeast cells were able to grow at elevated concentrations of acid, probable due to the increase in phenotypic cell-to-cell heterogeneity in large inoculum size. Furthermore, the specific growth rate and the specific rates of glucose consumption and metabolite production were significantly lower than at low initial cell density, which was a result of the accumulation of a large fraction of cells that persisted in a viable but non-proliferating state.
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Affiliation(s)
- Zhong-Peng Guo
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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Carmona L, Varela J, Godoy L, Ganga MA. Comparative proteome analysis of Brettanomyces bruxellensis under hydroxycinnamic acid growth. ELECTRON J BIOTECHN 2016. [DOI: 10.1016/j.ejbt.2016.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Shi C, Song K, Zhang X, Sun Y, Sui Y, Chen Y, Jia Z, Sun H, Sun Z, Xia X. Antimicrobial Activity and Possible Mechanism of Action of Citral against Cronobacter sakazakii. PLoS One 2016; 11:e0159006. [PMID: 27415761 PMCID: PMC4945043 DOI: 10.1371/journal.pone.0159006] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/24/2016] [Indexed: 11/19/2022] Open
Abstract
Citral is a flavor component that is commonly used in food, beverage and fragrance industries. Cronobacter sakazakii is a food-borne pathogen associated with severe illness and high mortality in neonates and infants. The objective of the present study was to evaluate antimicrobial effect of citral against C. sakazakii strains. The minimum inhibitory concentration (MIC) of citral against C. sakazakii was determined via agar dilution method, then Gompertz models were used to quantitate the effect of citral on microbial growth kinetics. Changes in intracellular pH (pHin), membrane potential, intracellular ATP concentration, and membrane integrity were measured to elucidate the possible antimicrobial mechanism. Cell morphology changes were also examined using a field emission scanning electron microscope. The MICs of citral against C. sakazakii strains ranged from 0.27 to 0.54 mg/mL, and citral resulted in a longer lag phase and lower growth rate of C. sakazakii compared to the control. Citral affected the cell membrane of C. sakazakii, as evidenced by decreased intracellular ATP concentration, reduced pHin, and cell membrane hyperpolarization. Scanning electron microscopy analysis further confirmed that C. sakazakii cell membranes were damaged by citral. These findings suggest that citral exhibits antimicrobial effect against C. sakazakii strains and could be potentially used to control C. sakazakii in foods. However, how it works in food systems where many other components may interfere with its efficacy should be tested in future research before its real application.
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Affiliation(s)
- Chao Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Kaikuo Song
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaorong Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Yi Sun
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Yue Sui
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Yifei Chen
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhenyu Jia
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Huihui Sun
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Zheng Sun
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaodong Xia
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
- Sino-US Joint Research Center for Food Safety, Yangling, Shaanxi, China
- * E-mail:
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Wu X, Zhang L, Jin X, Fang Y, Zhang K, Qi L, Zheng D. Deletion of JJJ1 improves acetic acid tolerance and bioethanol fermentation performance of Saccharomyces cerevisiae strains. Biotechnol Lett 2016; 38:1097-106. [PMID: 27067354 DOI: 10.1007/s10529-016-2085-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/17/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To improve tolerance to acetic acid that is present in lignocellulosic hydrolysates and affects bioethanol production by Saccharomyces cerevisiae. RESULTS Saccharomyces cerevisiae strains with improved tolerance to acetic acid were obtained through deletion of the JJJ1 gene. The lag phase of the JJJ1 deletion mutant BYΔJJJ1 was ~16 h shorter than that of the parent strain, BY4741, when the fermentation medium contained 4.5 g acetic acid/l. Additionally, the specific ethanol production rate of BYΔJJJ1 was increased (0.057 g/g h) compared to that of the parent strain (0.051 g/g h). Comparative transcription and physiological analyses revealed higher long chain fatty acid, trehalose, and catalase contents might be critical factors responsible for the acetic acid resistance of JJJ1 knockout strains. CONCLUSIONS JJJ1 deletion improves acetic acid tolerance and ethanol fermentation performance of S. cerevisiae.
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Affiliation(s)
- Xuechang Wu
- College of Life Science, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Lijie Zhang
- College of Life Science, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Xinna Jin
- College of Life Science, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Yahong Fang
- College of Life Science, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Ke Zhang
- College of Life Science, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Lei Qi
- Ocean College, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Daoqiong Zheng
- Ocean College, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China.
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Availability of Amino Acids Extends Chronological Lifespan by Suppressing Hyper-Acidification of the Environment in Saccharomyces cerevisiae. PLoS One 2016; 11:e0151894. [PMID: 26991662 PMCID: PMC4798762 DOI: 10.1371/journal.pone.0151894] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/04/2016] [Indexed: 11/24/2022] Open
Abstract
The chronological lifespan of Saccharomyces cerevisiae represents the duration of cell survival in the postdiauxic and stationary phases. Using a prototrophic strain derived from the standard auxotrophic laboratory strain BY4742, we showed that supplementation of non-essential amino acids to a synthetic defined (SD) medium increases maximal cell growth and extends the chronological lifespan. The positive effects of amino acids can be reproduced by modulating the medium pH, indicating that amino acids contribute to chronological longevity in a cell-extrinsic manner by alleviating medium acidification. In addition, we showed that the amino acid-mediated effects on extension of chronological longevity are independent of those achieved through a reduction in the TORC1 pathway, which is mediated in a cell-intrinsic manner. Since previous studies showed that extracellular acidification causes mitochondrial dysfunction and leads to cell death, our results provide a path to premature chronological aging caused by differences in available nitrogen sources. Moreover, acidification of culture medium is generally associated with culture duration and cell density; thus, further studies are required on cell physiology of auxotrophic yeast strains during the stationary phase because an insufficient supply of essential amino acids may cause alterations in environmental conditions.
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