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| ARPN Journal of Agricultural and Biological
Science
October 2017 | Vol. 12 No. 10 |
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Title: |
Aphidicidal potential of
green synthesized magnesium hydroxide nanoparticles using
olea europaea leaves extract |
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Author (s): |
Alaa Y. Ghidan, Tawfiq M. Al-Antary,
Akl M. Awwad and Muhand W. Akash |
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Abstract: |
Magnesium hydroxide (MgHNPs)
nanoparticles were synthesized using Olea europaeaaqueous
extract at ambient temperature and in one-single step. X-ray
diffraction (XRD) analysis showed that synthesized MgHNPs
have spherical shape with an average size diameter 40nm.
Fourier transform infrared (FT-IR), scanning electron
microscopy (SEM) and UV-vis spectrophotometry were used to
characterize the synthesized magnesium hydroxide
nanoparticles. This study determined the mortality
efficacyof different concentrations of the synthesized
MgHNPs against early and late nymphal instars of the green
peach aphid. There were significant differences in the aphid
mortalities between the different concentrations of the
MgHNPs nanoparticles. In addition, the differences between
the different concentrations and the control were
significantly obvious. |
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Title: |
Preliminary investigation
of reuse of ricotta-cheese whey (Scotta) as substrate for
the growth of rhodotorula glutinisintended for the
production of carotenoids |
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Author (s): |
Josè Evangelista Ribeiro, Mina
Martini, Andrea Andreucci, Iolanda Altomonte, Carlo
D’ascenzi, Margherita Marzoni, Simona Nardoni, Roberto
Amerigo Papini, Stefania Perrucci, Federica Salari, Amanda
Marilia Da Silva Sant’ana, Carlo Sorce and Francesca
Mancianti |
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Abstract: |
The ricotta-cheese whey, also
called scotta, is the main by-product of ricotta-cheese
manufacture process. This by-product is rich in nutrients
that could make it a good substrate in biotechnological
processes for the production of commercial high-value
compounds. Nowadays, the demand for natural pigments and
health-promoting food ingredients has increased. Carotenoids
present a high commercial value as it is widely used in
food, feed, pharmaceutical and cosmetic industries. A wide
range of microorganisms and Rhodotorula genera yeast are
able to produce carotenoids. The aim of this study was to
evaluate the potential re -use of ricotta cheese whey (scotta)
as substrate for the growth of Rhodotorula glutinis intended
for the production of carotenoids. Under the cultivation
conditions used, R. glutinis strain showed similar ability
to grow and to produce carotenoids when cultivated in scotta
compared to a semi-synthetic substrate. Under the
cultivation conditions used, R. glutinis strain showed
similar ability to grow and to produce carotenoids when
cultivated in scotta compared to the semi-synthetic
substrate. Thus, the results showed that scotta has
potential to be used in a biotechnological process to obtain
a high-value molecule. Further investigations are needed to
test if changes in the cultivation parameters and the
hydrolysis of lactose could improve the growth and the
amount of cellular ß-carotene. |
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Title: |
Identification of
phytophthora sp. (Oomycota, Peronospora) as a causal agent
of stem rot and dieback in fig trees (Ficus Carica Var.
“Brown Turkey”) of Costa Rica |
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Author (s): |
L. Alvarado-Marchena, A.
Schmidt-Durán, R. Chacón-Cerdas, C. Alvarado-Ulloa and D.
Flores-Mora |
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Abstract: |
This research describes the
morphological and molecular identification of Phytophthorasp.
from fig (Ficus carica var. “Brown Turkey”) stem and shoot
samples, infected in experimental fields located in the
Pacific coastal region, in the county of Turrubares, at the
province of San José, Costa Rica. The study was performed in
the Centro de Investigación en Biotecnologíaand the
Laboratorio Institucional de Microscopíaof the Instituto
Tecnológico de Costa Rica, by using symptomatic tree
samples, from where the microorganisms of interest were
isolated with V8 + Benomil (2g/l) culture medium. Growth of
a cottonlike, starred and radiated micelia was observed.
Through optical microscopy (OM) and scanning electron
microscopy (SEM) techniques, it was posible to determine the
presence of spongarium and chlamydospores which are common
traits of the Phytophthora genus. Additionally, a high
quality DNA sample was obtained for the analysis through ITS
markers reported for the Phytophthora genus. With the
amplification of the IT’S region of the rDNA with the A2 and
I2 primers, the presence of Phytophthora sp. was confirmed.
The digestion of the ITS amplicon obtained with the MSp I,
Rsa I and Taq I enzymes, complemented with the bioinformatic
analysis of the amplified sequences allowed to confirm the
presence of P. cinnamomi in the stem and P. palmivora in the
shoots; being the causal agent of the fig rot. |
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Title: |
Microbial desalination
cell technology for simultaneous water desalination and
reduction of chromium ion Cr+6 |
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Author (s): |
Alshehri A. N. Z. |
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Abstract: |
Technology of microbial
desalination cell (MDC) is a novel approach to produce
renewable power, desalinate saline water and treat
wastewater simultaneously. In this study, an reactor of MDC
using wastewater involving Cr+6 as the catholyte was used
simultaneously to desalinate brine and reduce Cr+6, in the
desalination compartment and cathode compartment ,
respectively. The desalination rate was 2.1 mg/h, and the
efficiency of chromium ion removal attained 83%, with values
of voltage and current density, 384 mV and 823 mA/m2,
respectively, when the pH was below 2.0 and the initial Cr+6
concentration was 50 mg/L. By increasing the initial Cr+6
concentration to 100 and 1000 mg/L, as results the current
density also increased to 963 and 1453 mA/m2, respectively,
as well as the salt removal rate increased to 2.16 and 3.04
mg/h, where the salt removal efficiency were 81.8 and 93.4%,
respectively. Scanning electron microscope-energy dispersive
spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy
(XPS) indicated that the Cr+6 was reduced to Cr2O3 and
precipitated on the cathode surface. From the present
findings, it would be suggested that further enlarge the
application of MDC using Cr+6 as an electron acceptor. |
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