9 research outputs found
A CHOP-regulated microRNA controls rhodopsin expression
ER stress induces expression of miR-708, which suppresses the production of rhodopsin to prevent ER overloading in retinal epithelial cells
Evaluation of the Potential of Chlorella vulgaris for Bioethanol Production
For
bioethanol to be a sustainable transportation fuel, appropriate
feedstock needs to be established. The focus of the current work is
to evaluate if the microalga Chlorella vulgaris could be the feedstock of choice. Exclusive formation of glucose
was observed upon the acid (HCl) hydrolysis of C. vulgaris. Microwave irradiation as well as hydrothermal reaction were employed
as heating methods. Under optimal hydrolysis conditions using microwave
irradiation (100 °C, 1 M HCl, and 10 min), the glucose yield
was 20 ± 3.5 wt % compared to 23 ± 4 wt % under the optimal
hydrothermal reaction conditions (120 °C, 1 M HCl, and 60 min).
The hydrothermal-based hydrolysis process was further scaled up from
a 0.2 g batch to a 2.0 g batch, and the glucose obtained was converted
to bioethanol in a fermentation process at 30 °C for 28 h using Saccharomyces cerevisiae. An ethanol yield as high
as 13.2 ± 0.5 wt % was obtained from C. vulgaris
<i>In-Situ</i> Transesterification of <i>Chlorella vulgaris</i> Using Carbon-Dot Functionalized Strontium Oxide as a Heterogeneous Catalyst under Microwave Irradiation
The main goal of
this study is to functionalize SrO with carbon
dots (C-dots) and to explore the composite as a catalyst for fatty
acid methyl esters (FAME) production using <i>Chlorella vulgaris</i> as feedstock. C-dots are synthesized by sonicating polyethylene
glycol followed by sonochemical modification of SrÂ(NO<sub>3</sub>)<sub>2</sub> (precursor for SrO) with C-dots. Sonication facilitates the
adhesion of C-dots to the surface of SrÂ(NO<sub>3</sub>)<sub>2</sub>. The resulting material is calcined in an inert environment to form
a SrO–C-dot composite. The effect of functionalizing SrO with
C-dots on the transesterification of the lipids in the alga with methanol
is studied. The optimization of a one-stage process of conversion
of the lipid fraction of microalga <i>Chlorella vulgaris</i> into FAME using direct transesterification under microwave irradiation
is illustrated. A lipid conversion value of 45.5 wt % is achieved
using the SrO–C-dot catalyst after 2.5 min of microwave (MW)
irradiation. The catalyst displayed better activity than commercial
SrO. Microwave irradiation accelerates the disruption of the microalgal
cells and facilitates the release of lipid content into the reaction
medium. The catalyst is characterized by a variety of physicochemical
techniques. The FAME product obtained from the alga is quantified
using <sup>1</sup>H NMR spectroscopy. The new catalyst, namely, SrO–C-dot
nanoparticles (NPs), yielded 97 wt % FAME from <i>Chlorella vulgaris</i> in 2.5 min of MW irradiation