5 research outputs found
Global Metabolomic and Network analysis of <i>Escherichia coli</i> Responses to Exogenous Biofuels
Although synthetic biology progress
has made it possible to produce
various biofuels in more user-friendly hosts, such as <i>Escherichia
coli</i>, the large-scale biofuel production in these non-native
systems is still challenging, mostly due to the very low tolerance
of these non-native hosts to the biofuel toxicity. To address the
issues, in this study we determined the metabolic responses of <i>E. coli</i> induced by three major biofuel products, ethanol,
butanol, and isobutanol, using a gas chromatography–mass spectrometry
(GC–MS) approach. A metabolomic data set of 65 metabolites
identified in all samples was then subjected to principal component
analysis (PCA) to compare their effects and a weighted correlation
network analysis (WGCNA) to identify the metabolic modules specifically
responsive to each of the biofuel stresses, respectively. The PCA
analysis showed that cellular responses caused by the biofuel stress
were in general similar to aging cells at stationary phase, inconsistent
with early studies showing a high degree of dissimilarity between
metabolite responses during growth cessation as induced through stationary
phases or through various environmental stress applications. The WGCNA
analysis allowed identification of 2, 4, and 2 metabolic modules specifically
associated with ethanol, butanol, and isobutanol treatments, respectively.
The biofuel-associated modules included amino acids and osmoprotectants,
such as isoleucine, valine, glycine, glutamate, and trehalose, suggesting
amino acid metabolism and osmoregulation are among the key protection
mechanisms against biofuel stresses in <i>E. coli</i>. Interestingly,
no module was found associated with all three biofuel products, suggesting
differential effects of each biofuel on <i>E. coli</i>.
The findings enhanced our understanding of <i>E. coli</i> responses to exogenous biofuels and also demonstrated the effectiveness
of the metabolomic and network analysis in identifying key targets
for biofuel tolerance
Global Metabolomic and Network analysis of <i>Escherichia coli</i> Responses to Exogenous Biofuels
Although synthetic biology progress
has made it possible to produce
various biofuels in more user-friendly hosts, such as <i>Escherichia
coli</i>, the large-scale biofuel production in these non-native
systems is still challenging, mostly due to the very low tolerance
of these non-native hosts to the biofuel toxicity. To address the
issues, in this study we determined the metabolic responses of <i>E. coli</i> induced by three major biofuel products, ethanol,
butanol, and isobutanol, using a gas chromatography–mass spectrometry
(GC–MS) approach. A metabolomic data set of 65 metabolites
identified in all samples was then subjected to principal component
analysis (PCA) to compare their effects and a weighted correlation
network analysis (WGCNA) to identify the metabolic modules specifically
responsive to each of the biofuel stresses, respectively. The PCA
analysis showed that cellular responses caused by the biofuel stress
were in general similar to aging cells at stationary phase, inconsistent
with early studies showing a high degree of dissimilarity between
metabolite responses during growth cessation as induced through stationary
phases or through various environmental stress applications. The WGCNA
analysis allowed identification of 2, 4, and 2 metabolic modules specifically
associated with ethanol, butanol, and isobutanol treatments, respectively.
The biofuel-associated modules included amino acids and osmoprotectants,
such as isoleucine, valine, glycine, glutamate, and trehalose, suggesting
amino acid metabolism and osmoregulation are among the key protection
mechanisms against biofuel stresses in <i>E. coli</i>. Interestingly,
no module was found associated with all three biofuel products, suggesting
differential effects of each biofuel on <i>E. coli</i>.
The findings enhanced our understanding of <i>E. coli</i> responses to exogenous biofuels and also demonstrated the effectiveness
of the metabolomic and network analysis in identifying key targets
for biofuel tolerance