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Journal of Ecosystem & Ecography | ISSN: 2157-7625 | Volume: 8
June 28-29, 2018 | Alexandria, Egypt
International Pre Conference Workshop on
Microbial Ecology & Eco Systems
Extracellular generation of silver nanoparticles using
Fusarium solani
MH005062
1
Marwa R Obiedallah,
2
Mohamed B Aboul-Nasr,
2
Sabah S Mohamed
and
3
Simon C Andrews
1
Botany and Microbiology department, Faculty of Science, University of Sohag, Egypt
2
Faculty of Science, University of Sohag, Egypt
3
School of Biological Sciences, University of Reading, UK
T
he mechanism of biological generation of silver nanoparticles (SNP) is still not fully understood with most studies merely
providing detailed information describing the mechanism by which fungi reduce AgNO
3
into SNP. In our work, we
demonstrate that proteins are mainly involved in the myco-generation of SNP. Fifty-three and 27 fungal isolates were obtained
from
Padina
(brown algae) and
Avicennia marina
(leaves) marine samples and were assessed for SNP generation using fungal
supernatants. Fifty out of 80 isolates were found to be positive for SNP generation. Due to the lack of researches discussing
the exact mechanism by which
Fusarium solani
(an important plant pathogen) can generate SNP intra/extracellularly, it was
selected in this study.
Fusarium solani
isolate was purified using single-spore isolation technique then molecularly identified
by amplifying internal transcribed spacer (ITS), ITS1 and ITS2 sequences surrounding the 5.8S rRNA. The ITS sequence
was deposited in the GenBank with an accession number: MH005062. Mycelia of F. solani MH005062 were challenged with
different concentrations of AgNO
3
, extracellular proteins were estimated by Bradford essay and results confirmed that the
observed silver reduction reaction is dependent upon proteins secreted by the fungus. Fungal filtrate of four-day cultures was
treated with 1 mM AgNO
3
which resulted in SNP production as detected using UV-Vis spectroscopy, and characterized by
TEM, HR-TEM and X-ray diffraction. Two particles forms were noted with an average size of 7.58 ±0.27 and 30.5 ±1.10 nm.
SNP generation was optimized using different parameters. Here, we show that heat treatment eliminated SNP generation. Our
findings support the hypothesis that extracellular proteins have a key role in SNP formation, although those proteins are yet
to be identified.
Keywords:
Extracellular proteins, fungal filtrate,
Fusarium solani,
marine samples, Silver nanoparticles.
Biography
Marwa R. Obiedallah is currently an assistant lecturer of Microbiology at Faculty of Science, University of Sohag, Egypt. She has MSc in mycotoxins (2011), and
gained wide experience in fungal natural products and mycotoxins during her study. She was offered a scholarship from the Egyptian cultural affairs and missions
sector for her PhD project at the at School of Biological Sciences, University of Reading, UK, where she had the opportunity to improve her skills and experience.
She is a postgraduate member at the British Mycological Society (2017-2019). Her research interests now is focusing on nanotechnology, where she is paying
attention for the mechanism by which fungal species can generate nanoparticles of their metal salts. She believes that he findings will direct future researches for
proteome studies of promising fungal isolates.
m.r.a.obiedallah@gmail.comMarwa R Obiedallah et al., J Ecosys Ecograph 2018, Volume: 8
DOI: 10.4172/2157-7625-C2-035