Dataset Information

Engineering Saccharomyces cerevisiae for improved biofilm formation and ethanol production in continuous fermentation.

ABSTRACT:

Background

Biofilm-immobilized continuous fermentation has the potential to enhance cellular environmental tolerance, maintain cell activity and improve production efficiency.

Results

In this study, different biofilm-forming genes (FLO5, FLO8 and FLO10) were integrated into the genome of S. cerevisiae for overexpression, while FLO5 and FLO10 gave the best results. The biofilm formation of the engineered strains 1308-FLO5 and 1308-FLO10 was improved by 31.3% and 58.7% compared to that of the WT strain, respectively. The counts of cells adhering onto the biofilm carrier were increased. Compared to free-cell fermentation, the average ethanol production of 1308, 1308-FLO5 and 1308-FLO10 was increased by 17.4%, 20.8% and 19.1% in the biofilm-immobilized continuous fermentation, respectively. Due to good adhering ability, the fermentation broth turbidity of 1308-FLO5 and 1308-FLO10 was decreased by 22.3% and 59.1% in the biofilm-immobilized fermentation, respectively. Subsequently, for biofilm-immobilized fermentation coupled with membrane separation, the engineered strain significantly reduced the pollution of cells onto the membrane and the membrane separation flux was increased by 36.3%.

Conclusions

In conclusion, enhanced biofilm-forming capability of S. cerevisiae could offer multiple benefits in ethanol fermentation.

SUBMITTER: Wang Z

PROVIDER: S-EPMC10391976 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Engineering Saccharomyces cerevisiae for improved biofilm formation and ethanol production in continuous fermentation.

Wang Zhenyu Z Xu Weikai W Gao Yixuan Y Zha Mingwei M Zhang Di D Peng Xiwei X Zhang Huifang H Wang Cheng C Xu Chenchen C Zhou Tingqiu T Liu Dong D Niu Huanqing H Liu Qingguo Q Chen Yong Y Zhu Chenjie C Guo Ting T Ying Hanjie H

Biotechnology for biofuels and bioproducts 20230731 1

<h4>Background</h4>Biofilm-immobilized continuous fermentation has the potential to enhance cellular environmental tolerance, maintain cell activity and improve production efficiency.<h4>Results</h4>In this study, different biofilm-forming genes (FLO5, FLO8 and FLO10) were integrated into the genome of S. cerevisiae for overexpression, while FLO5 and FLO10 gave the best results. The biofilm formation of the engineered strains 1308-FLO5 and 1308-FLO10 was improved by 31.3% and 58.7% compared to t ...[more]

PMID: 37525255

Similar Datasets

Project description:Saccharomyces cerevisiae is known for its outstanding ability to produce ethanol in industry. Underlying the dynamics of gene expression in S. cerevisiae in response to fermentation could provide informative results, required for the establishment of any ethanol production improvement program. Thus, representing a new approach, this study was conducted to identify the discriminative genes between improved and repressed ethanol production as well as clarifying the molecular responses to this process through mining the transcriptomic data. The significant differential expression probe sets were extracted from available microarray datasets related to yeast fermentation performance. To identify the most effective probe sets contributing to discriminate ethanol content, 11 machine learning algorithms from RapidMiner were employed. Further analysis including pathway enrichment and regulatory analysis were performed on discriminative probe sets. Besides, the decision tree models were constructed, the performance of each model was evaluated and the roots were identified. Based on the results, 171 probe sets were identified by at least 5 attribute weighting algorithms (AWAs) and 17 roots were recognized with 100% performance Some of the top ranked presets were found to be involved in carbohydrate metabolism, oxidative phosphorylation, and ethanol fermentation. Principal component analysis (PCA) and heatmap clustering validated the top-ranked selective probe sets. In addition, the top-ranked genes were validated based on GSE78759 and GSE5185 dataset. From all discriminative probe sets, OLI1 and CYC3 were identified as the roots with the best performance, demonstrated by the most weighting algorithms and linked to top two significant enriched pathways including porphyrin biosynthesis and oxidative phosphorylation. ADH5 and PDA1 were also recognized as differential top-ranked genes that contribute to ethanol production. According to the regulatory clustering analysis, Tup1 has a significant effect on the top-ranked target genes CYC3 and ADH5 genes. This study provides a basic understanding of the S. cerevisiae cell molecular mechanism and responses to two different medium conditions (Mg2+ and Cu2+) during the fermentation process.

Project description:BackgroundContinuous fermentation offers advantages in improving production efficiency and reducing costs, making it highly competitive for industrial ethanol production. A key requirement for Saccharomyces cerevisiae strains used in this process is their tolerance to high ethanol concentrations, which enables them to adapt to continuous fermentation conditions. To explore how yeast cells respond to varying levels of ethanol stress during fermentation, a two-month continuous fermentation was conducted. Cells were collected at different ethanol concentrations (from 60 g/L to 100 g/L) for comparative transcriptomic analysis.ResultsDuring continuous fermentation, as ethanol concentration increased, the expression of genes associated with cytoplasmic ribosomes, translation, and fatty acid biosynthesis progressively declined, while the expression of genes related to heat shock proteins (HSPs) and ubiquitin-mediated protein degradation gradually increased. Besides, cells exhibited distinct responses to varying ethanol concentrations. At lower ethanol concentrations (nearly 70 g/L), genes involved in mitochondrial ribosomes, oxidative phosphorylation, the tricarboxylic acid (TCA) cycle, antioxidant enzymes, ergosterol synthesis, and glycerol biosynthesis were specifically upregulated compared to those at 60 g/L. This suggests that cells enhanced respiratory energy production, ROS scavenging capacity, and the synthesis of ergosterol and glycerol to counteract stress. At relatively higher ethanol concentrations (nearly 80 g/L), genes involved in respiration and ergosterol synthesis were inhibited, while those associated with glycolysis and glycerol biosynthesis were notably upregulated. This suggests a metabolic shift from respiration towards enhanced glycerol synthesis. Interestingly, the longevity-regulating pathway seemed to play a pivotal role in mediating the cellular adaptations to different ethanol concentrations. Upon reaching an ethanol concentration of 100 g/L, the aforementioned metabolic activities were largely inhibited. Cells primarily focused on enhancing the clearance of denatured proteins to preserve cellular viability.ConclusionsThis study elucidated the mechanisms by which an ethanol-tolerant S. cerevisiae strain adapts to increasing ethanol concentrations during continuous fermentation. The findings suggest that the longevity-regulating pathway may play a critical role in adapting to varying ethanol stress by regulating mitochondrial respiration, glycerol synthesis, ergosterol synthesis, antioxidant enzyme, and HSPs. This work provides a novel and valuable understanding of the mechanisms that govern ethanol tolerance during continuous fermentation.

Project description:BackgroundIn the yeast Saccharomyces cerevisiae, which is widely applied for industrial bioethanol production, uptake of hexoses is mediated by transporters with a facilitated diffusion mechanism. In anaerobic cultures, a higher ethanol yield can be achieved when transport of hexoses is proton-coupled, because of the lower net ATP yield of sugar dissimilation. In this study, the facilitated diffusion transport system for hexose sugars of S. cerevisiae was replaced by hexose-proton symport.ResultsIntroduction of heterologous glucose- or fructose-proton symporters in an hxt0 yeast background strain (derived from CEN.PK2-1C) restored growth on the corresponding sugar under aerobic conditions. After applying an evolutionary engineering strategy to enable anaerobic growth, the hexose-proton symporter-expressing strains were grown in anaerobic, hexose-limited chemostats on synthetic defined medium, which showed that the biomass yield of the resulting strains was decreased by 44.0-47.6%, whereas the ethanol yield had increased by up to 17.2% (from 1.51 to 1.77 mol mol hexose-1) compared to an isogenic strain expressing the hexose uniporter HXT5. To apply this strategy to increase the ethanol yield on sucrose, we constructed a platform strain in which all genes encoding hexose transporters, disaccharide transporters and disaccharide hydrolases were deleted, after which a combination of a glucose-proton symporter, fructose-proton symporter and extracellular invertase (SUC2) were introduced. After evolution, the resulting strain exhibited a 16.6% increased anaerobic ethanol yield (from 1.51 to 1.76 mol mol hexose equivalent-1) and 46.6% decreased biomass yield on sucrose.ConclusionsThis study provides a proof-of-concept for the replacement of the endogenous hexose transporters of S. cerevisiae by hexose-proton symport, and the concomitant decrease in ATP yield, to greatly improve the anaerobic yield of ethanol on sugar. Moreover, the sugar-negative platform strain constructed in this study acts as a valuable starting point for future studies on sugar transport or development of cell factories requiring specific sugar transport mechanisms.

Dataset Information

Engineering Saccharomyces cerevisiae for improved biofilm formation and ethanol production in continuous fermentation.

Background

Results

Conclusions

Publications

Engineering Saccharomyces cerevisiae for improved biofilm formation and ethanol production in continuous fermentation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets