5 research outputs found
Coproduction of Bioelectricity and Acetoin by Unbalanced Fermentation of Glycerol in Shewanella oneidensis Based on a Genome-Scale Metabolic Network
Unbalanced fermentation is a promising innovative strategy
for
biotechnological production processes. Guided by the genome-scale
metabolic network iLJ1162, the central carbon metabolism
was rewired to enhance the synthesis of (3R)-acetoin and link it to
establish efficient extracellular electron transfer through unbalanced
fermentation in Shewanella oneidensis. We first successfully constructed an engineered strain using glycerol
as the sole carbon source to coproduce (3R)-acetoin and bioelectricity.
Key engineering targets for (3R)-acetoin synthesis and bioelectricity
were predicted by iLJ1162, including the glycolysis
module (gapA and pgk), the serine
bypass module (glyA, serA, serB, and serC), and the pyruvate fermentation
module (fdh). As a result, we discovered that the serB gene was conducive to the production of bioelectricity
(35.91 ± 1.04 mW m–2), and serC promoted the synthesis of (3R)-acetoin (213.5 ± 6.07 mg L–1) in the serine bypass module. However, the low power
output capacity became the bottleneck, limiting the acetoin yield.
To further balance the reducing force, we developed functional electrodes
composed of carbon nanotubes and graphene oxide, as well as electron
shuttles for improving electricity generation. The power density and
the titer of (3R)-acetoin, respectively, reached up to 149.72 ±
2.72 mW m–2 and 313.61 ± 5.48 mg L–1, which were 5.08 and 1.00 times higher than in the control. The
optical purity of the resulting (3R)-acetoin surpassed 90%. This study
provides a new paradigm for achieving the “balance”
between high value-added products with low reducibility and electricity
production in unbalanced fermentation while boosting the titer of
products based on model guidance
MOESM3 of Enhancement of scutellarin oral delivery efficacy by vitamin B12-modified amphiphilic chitosan derivatives to treat type II diabetes induced-retinopathy
Additional file 3. FTIR spectra and photo of Chit-DC-FITC. (A) FTIR spectra of Chit-DC and Chit-DC-FITC. (B) Fluorescence spectra and a photo of FITC-labeled amphiphilic chitosan derivatives
MOESM2 of Enhancement of scutellarin oral delivery efficacy by vitamin B12-modified amphiphilic chitosan derivatives to treat type II diabetes induced-retinopathy
Additional file 2. Synthesis of FITC-labelled amphiphilic chitosan derivatives: (A) the Chit-DC-FITC derivative and (B) the Chit-DC-B12-FITC derivative
MOESM4 of Enhancement of scutellarin oral delivery efficacy by vitamin B12-modified amphiphilic chitosan derivatives to treat type II diabetes induced-retinopathy
Additional file 4. Effects of chronic treatment of Scu or Scu-loaded nanoparticles on body weight and blood-glucose in STZ-induced diabetic rats. (A) The changes of body weight of rats. (B) The changes of blood-glucose in rats. STZ was administrated to the DM group, DM +Chit-DC group, DM + Scu group, DM + Chit-DC-Scu group, and DM + Chit-DC-VB12-Scu group at week 8(n = 8)
MOESM1 of Enhancement of scutellarin oral delivery efficacy by vitamin B12-modified amphiphilic chitosan derivatives to treat type II diabetes induced-retinopathy
Additional file 1. 1H NMR spectra of (a) deoxycholic acid (DMSO-d6), (b) Chit-DC (D2O), (c) Chit-DC-VB12 (D2O) and (d) vitamin B12 (D2O)