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Attfield PV. Crucial aspects of metabolism and cell biology relating to industrial production and processing of Saccharomyces biomass. Crit Rev Biotechnol 2023; 43:920-937. [PMID: 35731243 DOI: 10.1080/07388551.2022.2072268] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/27/2022] [Accepted: 04/21/2022] [Indexed: 12/16/2022]
Abstract
The multitude of applications to which Saccharomyces spp. are put makes these yeasts the most prolific of industrial microorganisms. This review considers biological aspects pertaining to the manufacture of industrial yeast biomass. It is proposed that the production of yeast biomass can be considered in two distinct but interdependent phases. Firstly, there is a cell replication phase that involves reproduction of cells by their transitions through multiple budding and metabolic cycles. Secondly, there needs to be a cell conditioning phase that enables the accrued biomass to withstand the physicochemical challenges associated with downstream processing and storage. The production of yeast biomass is not simply a case of providing sugar, nutrients, and other growth conditions to enable multiple budding cycles to occur. In the latter stages of culturing, it is important that all cells are induced to complete their current budding cycle and subsequently enter into a quiescent state engendering robustness. Both the cell replication and conditioning phases need to be optimized and considered in concert to ensure good biomass production economics, and optimum performance of industrial yeasts in food and fermentation applications. Key features of metabolism and cell biology affecting replication and conditioning of industrial Saccharomyces are presented. Alternatives for growth substrates are discussed, along with the challenges and prospects associated with defining the genetic bases of industrially important phenotypes, and the generation of new yeast strains."I must be cruel only to be kind: Thus bad begins, and worse remains behind." William Shakespeare: Hamlet, Act 3, Scene 4.
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Zhu H, Li T, Li C, Liu Y, Miao Y, Liu D, Shen Q. Intracellular kynurenine promotes acetaldehyde accumulation, further inducing the apoptosis in soil beneficial fungi Trichoderma guizhouense NJAU4742 under acid stress. Environ Microbiol 2023; 25:331-351. [PMID: 36367399 DOI: 10.1111/1462-2920.16286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/10/2022] [Indexed: 11/13/2022]
Abstract
In this study, the growth of fungi Trichoderma guizhouense NJAU4742 was significantly inhibited under acid stress, and the genes related to acid stress were identified based on transcriptome analysis. Four genes including tna1, adh2/4, and bna3 were significantly up-regulated. Meanwhile, intracellular hydrogen ions accumulated under acid stress, and ATP synthesis was induced to transport hydrogen ions to maintain hydrogen ion balance. The enhancement of glycolysis pathway was also detected, and a large amount of pyruvic acid from glycolysis was accumulated due to the activity limitation of PDH enzymes. Finally, acetaldehyde accumulated, resulting in the induction of adh2/4. In order to cope with stress caused by acetaldehyde, cells enhanced the synthesis of NAD+ by increasing the expression of tna1 and bna3 genes. NAD+ effectively improved the antioxidant capacity of cells, but the NAD+ supplement pathway mediated by bna3 could also cause the accumulation of kynurenine (KYN), which was an inducer of apoptosis. In addition, KYN had a specific promoting effect on acetaldehyde synthesis by improving the expression of eno2 gene, which led to the extremely high intracellular acetaldehyde in the cell under acidic stress. Our findings provided a route to better understand the response of filamentous fungi under acid stress.
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Affiliation(s)
- Han Zhu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Tuo Li
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Chi Li
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Yang Liu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Youzhi Miao
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Dongyang Liu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Qirong Shen
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving fertilizers, Jiangsu, People's Republic of China
- Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
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Liu L, Zhao PT, Hu CY, Tian D, Deng H, Meng YH. Screening low-methanol and high-aroma produced yeasts for cider fermentation by transcriptive characterization. Front Microbiol 2022; 13:1042613. [PMID: 36439849 PMCID: PMC9691974 DOI: 10.3389/fmicb.2022.1042613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/27/2022] [Indexed: 11/12/2022] Open
Abstract
The commercial active dry yeast strains used for cider production in China are far behind the requirements of the cider industry development in recent decades. In this study, eight yeasts, including Saccharomyces cerevisiae, Schizosaccharomyces pombe, Pichia bruneiensis, and Pichia kudriavzevii, were screened and assessed by growth performance, methanol production, aroma analysis, and their transcriptive characterization. Saccharomyces cerevisiae strains WFC-SC-071 and WFC-SC-072 were identified as promising alternatives for cider production. Strains WFC-SC-071 and WFC-SC-072 showed an excellent growth capacity characterized by 91.6 and 88.8% sugar utilization, respectively. Methanol production by both strains was below 200 mg/L. Key aroma compounds imparting cider appreciably characteristic aroma increased in cider fermented by strains WFC-SC-071 and WFC-SC-072. RT-qPCR analysis suggested that most genes associated with growth capacity, carbohydrate uptake, and aroma production were upregulated in WFC-SC-071 and WFC-SC-072. Overall, two Saccharomyces cerevisiae strains are the optimal starters for cider production to enable the diversification of cider, satisfy the differences in consumer demand, and promote cider industry development.
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Affiliation(s)
- Liang Liu
- The Engineering Research Center for High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, National Research and Development Center of Apple Processing Technology, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xian, China
| | - Peng Tao Zhao
- The Engineering Research Center for High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, National Research and Development Center of Apple Processing Technology, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xian, China
| | - Ching Yuan Hu
- The Engineering Research Center for High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, National Research and Development Center of Apple Processing Technology, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xian, China
- Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, Honolulu, HI, United States
| | - Dan Tian
- The Engineering Research Center for High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, National Research and Development Center of Apple Processing Technology, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xian, China
| | - Hong Deng
- The Engineering Research Center for High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, National Research and Development Center of Apple Processing Technology, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xian, China
- *Correspondence: Hong Deng,
| | - Yong Hong Meng
- The Engineering Research Center for High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, National Research and Development Center of Apple Processing Technology, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xian, China
- Yong Hong Meng,
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An engineered non-oxidative glycolytic bypass based on Calvin-cycle enzymes enables anaerobic co-fermentation of glucose and sorbitol by Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:112. [PMID: 36253796 PMCID: PMC9578259 DOI: 10.1186/s13068-022-02200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/17/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Saccharomyces cerevisiae is intensively used for industrial ethanol production. Its native fermentation pathway enables a maximum product yield of 2 mol of ethanol per mole of glucose. Based on conservation laws, supply of additional electrons could support even higher ethanol yields. However, this option is disallowed by the configuration of the native yeast metabolic network. To explore metabolic engineering strategies for eliminating this constraint, we studied alcoholic fermentation of sorbitol. Sorbitol cannot be fermented anaerobically by S. cerevisiae because its oxidation to pyruvate via glycolysis yields one more NADH than conversion of glucose. To enable re-oxidation of this additional NADH by alcoholic fermentation, sorbitol metabolism was studied in S. cerevisiae strains that functionally express heterologous genes for ribulose-1,5-bisphosphate carboxylase (RuBisCO) and phosphoribulokinase (PRK). Together with the yeast non-oxidative pentose-phosphate pathway, these Calvin-cycle enzymes enable a bypass of the oxidative reaction in yeast glycolysis. RESULTS Consistent with earlier reports, overproduction of the native sorbitol transporter Hxt15 and the NAD+-dependent sorbitol dehydrogenase Sor2 enabled aerobic, but not anaerobic growth of S. cerevisiae on sorbitol. In anaerobic, slow-growing chemostat cultures on glucose-sorbitol mixtures, functional expression of PRK-RuBisCO pathway genes enabled a 12-fold higher rate of sorbitol co-consumption than observed in a sorbitol-consuming reference strain. Consistent with the high Km for CO2 of the bacterial RuBisCO that was introduced in the engineered yeast strains, sorbitol consumption and increased ethanol formation depended on enrichment of the inlet gas with CO2. Prolonged chemostat cultivation on glucose-sorbitol mixtures led to loss of sorbitol co-fermentation. Whole-genome resequencing after prolonged cultivation suggested a trade-off between glucose-utilization and efficient fermentation of sorbitol via the PRK-RuBisCO pathway. CONCLUSIONS Combination of the native sorbitol assimilation pathway of S. cerevisiae and an engineered PRK-RuBisCO pathway enabled RuBisCO-dependent, anaerobic co-fermentation of sorbitol and glucose. This study demonstrates the potential for increasing the flexibility of redox-cofactor metabolism in anaerobic S. cerevisiae cultures and, thereby, to extend substrate range and improve product yields in anaerobic yeast-based processes by enabling entry of additional electrons.
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Wang R, Wu J, Jiang N, Lin H, An F, Wu C, Yue X, Shi H, Wu R. Recent developments in horizontal gene transfer with the adaptive innovation of fermented foods. Crit Rev Food Sci Nutr 2022; 63:569-584. [PMID: 35647734 DOI: 10.1080/10408398.2022.2081127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Horizontal gene transfer (HGT) has contributed significantly to the adaptability of bacteria, yeast and mold in fermented foods, whose evidence has been found in several fermented foods. Although not every HGT has biological significance, it plays an important role in improving the quality of fermented foods. In this review, how HGT facilitated microbial domestication and adaptive evolution in fermented foods was discussed. HGT can assist in the industrial innovation of fermented foods, and this adaptive evolution strategy can improve the quality of fermented foods. Additionally, the mechanism underlying HGT in fermented foods were analyzed. Furthermore, the critical bottlenecks involved in optimizing HGT during the production of fermented foods and strategies for optimizing HGT were proposed. Finally, the prospect of HGT for promoting the industrial innovation of fermented foods was highlighted. The comprehensive report on HGT in fermented foods provides a new trend for domesticating preferable starters for food fermentation, thus optimizing the quality and improving the industrial production of fermented foods.
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Affiliation(s)
- Ruhong Wang
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China
| | - Junrui Wu
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China.,Liaoning Engineering Research Center of Food Fermentation Technology, Shenyang Agricultural University, Shenyang, P.R. China.,Shenyang Key Laboratory of Microbial Fermentation Technology Innovation, Shenyang Agricultural University, Shenyang, P.R. China
| | - Nan Jiang
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China
| | - Hao Lin
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China
| | - Feiyu An
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China
| | - Chen Wu
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China
| | - Xiqing Yue
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China.,Liaoning Engineering Research Center of Food Fermentation Technology, Shenyang Agricultural University, Shenyang, P.R. China.,Shenyang Key Laboratory of Microbial Fermentation Technology Innovation, Shenyang Agricultural University, Shenyang, P.R. China
| | - Haisu Shi
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China.,Liaoning Engineering Research Center of Food Fermentation Technology, Shenyang Agricultural University, Shenyang, P.R. China.,Shenyang Key Laboratory of Microbial Fermentation Technology Innovation, Shenyang Agricultural University, Shenyang, P.R. China
| | - Rina Wu
- College of Food Science, Shenyang Agricultural University, Shenyang, P.R. China.,Liaoning Engineering Research Center of Food Fermentation Technology, Shenyang Agricultural University, Shenyang, P.R. China.,Shenyang Key Laboratory of Microbial Fermentation Technology Innovation, Shenyang Agricultural University, Shenyang, P.R. China
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Walker ME, Watson TL, Large CRL, Berkovich Y, Lang TA, Dunham MJ, Formby S, Jiranek V. Directed evolution as an approach to increase fructose utilization in synthetic grape juice by wine yeast AWRI 796. FEMS Yeast Res 2022; 22:foac022. [PMID: 35472090 PMCID: PMC9329090 DOI: 10.1093/femsyr/foac022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 03/25/2022] [Accepted: 04/22/2022] [Indexed: 11/13/2022] Open
Abstract
In winemaking, slow or stuck alcoholic fermentation can impact processing efficiency and wine quality. Residual fructose in the later stages of fermentation can leave the wine 'out of specification' unless removed, which requires reinoculation or use of a more fructophilic yeast. As such, robust, fermentation efficient strains are still highly desirable to reduce this risk. We report on a combined EMS mutagenesis and Directed Evolution (DE) approach as a 'proof of concept' to improve fructose utilization and decrease fermentation duration. One evolved isolate, Tee 9, was evaluated against the parent, AWRI 796 in defined medium (CDGJM) and Semillon juice. Interestingly, Tee 9 exhibited improved fermentation in CDGJM at several nitrogen contents, but not in juice. Genomic comparison between AWRI 796 and Tee 9 identified 371 mutations, but no chromosomal copy number variation. A total of 95 noncoding and 276 coding mutations were identified in 297 genes (180 of which encode proteins with one or more substitutions). Whilst introduction of two of these, Gid7 (E726K) or Fba1 (G135S), into AWRI 796 did not lead to the fermentation improvement seen in Tee 9, similar allelic swaps with the other mutations are needed to understand Tee 9's adaption to CDGJM. Furthermore, the 378 isolates, potentially mutagenized but with the same genetic background, are likely a useful resource for future phenotyping and genome-wide association studies.
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Affiliation(s)
- Michelle E Walker
- Department of Wine Science, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Tommaso L Watson
- Department of Wine Science, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Christopher R L Large
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, United States
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, United States
| | - Yan Berkovich
- Department of Wine Science, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Tom A Lang
- Department of Wine Science, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Maitreya J Dunham
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, United States
| | - Sean Formby
- Bioinformatics Graduate Program, University of British Columbia, Genome Sciences Centre, BCCA, 100-570 West 7th Avenue, Vancouver, BC, V5Z 4S6, Canada
| | - Vladimir Jiranek
- Department of Wine Science, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
- Australian Research Council Training Centre for Innovative Wine Production, PMB 1, Glen Osmond, SA 5064, Australia
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