Dataset Information

Promiscuous activities of heterologous enzymes lead to unintended metabolic rerouting in Saccharomyces cerevisiae engineered to assimilate various sugars from renewable biomass.

ABSTRACT:

Background

Understanding the global metabolic network, significantly perturbed upon promiscuous activities of foreign enzymes and different carbon sources, is crucial for systematic optimization of metabolic engineering of yeast Saccharomyces cerevisiae. Here, we studied the effects of promiscuous activities of overexpressed enzymes encoded by foreign genes on rerouting of metabolic fluxes of an engineered yeast capable of assimilating sugars from renewable biomass by profiling intracellular and extracellular metabolites.

Results

Unbiased metabolite profiling of the engineered S. cerevisiae strain EJ4 revealed promiscuous enzymatic activities of xylose reductase and xylitol dehydrogenase on galactose and galactitol, respectively, resulting in accumulation of galactitol and tagatose during galactose fermentation. Moreover, during glucose fermentation, a trisaccharide consisting of glucose accumulated outside of the cells probably owing to the promiscuous and transglycosylation activity of ?-glucosidase expressed for hydrolyzing cellobiose. Meanwhile, higher accumulation of fatty acids and secondary metabolites was observed during xylose and cellobiose fermentations, respectively.

Conclusions

The heterologous enzymes functionally expressed in S. cerevisiae showed promiscuous activities that led to unintended metabolic rerouting in strain EJ4. Such metabolic rerouting could result in a low yield and productivity of a final product due to the formation of unexpected metabolites. Furthermore, the global metabolic network can be significantly regulated by carbon sources, thus yielding different patterns of metabolite production. This metabolomic study can provide useful information for yeast strain improvement and systematic optimization of yeast metabolism to manufacture bio-based products.

SUBMITTER: Yun EJ

PROVIDER: S-EPMC5950193 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Promiscuous activities of heterologous enzymes lead to unintended metabolic rerouting in <i>Saccharomyces cerevisiae</i> engineered to assimilate various sugars from renewable biomass.

Yun Eun Ju EJ Oh Eun Joong EJ Liu Jing-Jing JJ Yu Sora S Kim Dong Hyun DH Kwak Suryang S Kim Kyoung Heon KH Jin Yong-Su YS

Biotechnology for biofuels 20180514

<h4>Background</h4>Understanding the global metabolic network, significantly perturbed upon promiscuous activities of foreign enzymes and different carbon sources, is crucial for systematic optimization of metabolic engineering of yeast <i>Saccharomyces cerevisiae</i>. Here, we studied the effects of promiscuous activities of overexpressed enzymes encoded by foreign genes on rerouting of metabolic fluxes of an engineered yeast capable of assimilating sugars from renewable biomass by profiling in ...[more]

PMID: 29785207

Similar Datasets

Project description:Recent national strategic plans in China have set renewable energy targets for rural household energy programs, including those that advance the production of densified biomass fuels (e.g. pellets, briquettes) for use in household cooking and heating stoves. There is presently very little information on potential barriers to the successful development of densified biomass for household cooking and heating in China, but such knowledge may be informative in settings that aim to replace unprocessed coal and other polluting fuels with renewable, cleaner-burning energy sources. We designed a case study to coordinate data-gathering efforts at rural field sites in southwestern Sichuan province and northeastern Jilin and Heilongjiang provinces, where production of densified biomass fuels is under development for household end-users. We conducted interviews with factory personnel, local administrative leaders, and sector experts involved in the production and distribution of densified fuel, including pellets and briquettes, for household use. Results from our qualitative textual data analysis yielded several recommendations for improving development of densified biomass fuels for household end-use. These included reducing heterogeneity of feedstocks, increasing financial support for operational costs (e.g. collection, transport, and storage of raw materials; storage and distribution of final products), improving household perceptions of and subsequent demand for densified biomass fuels, and increasing enforcement of national and provincial policies banning the use of coal and open-field biomass burning. Collection and storage of raw materials and the final densified fuel product were consistently noted as critical challenges to scaling up production at all three sites. Finally, the perspectives of factory managers and local village administrators that we present also indicated that production of densified biomass fuels would most likely be more successful and reproducible in places where national-level policies are viewed as obligatory.