Biotechnology
Karrar K. Hameed; Iman H. Gatea; Amal A. Hussein
Abstract
Polyhydroxyalkanoate (PHA) is an eco-friendly polymer that has various important biomedical uses, as well as biodegradability, drug delivery, and medical implants. It is a kind of polyester synthesized by various microorganisms as energy reserve material under inappropriate conditions. This study focused ...
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Polyhydroxyalkanoate (PHA) is an eco-friendly polymer that has various important biomedical uses, as well as biodegradability, drug delivery, and medical implants. It is a kind of polyester synthesized by various microorganisms as energy reserve material under inappropriate conditions. This study focused on testing waste cooking oil as the source of carbon to optimize PHA production. The tests included the most important environmental components within the culture medium affecting the growth of the bacterial isolate under the experiment and its ability to produce a polymer. Results revealed that the cultivation of Acinetobacter lwoffii, pre-isolated from hydrocarbon contaminated soil, under optimum conditions showed the highest productivity after 72 hours. Corn oil waste as the carbon and urea as the source of nitrogen were discovered to be the best nutritive sources for concentrated PHA production, with, 2% and 0.5 g/L as the best carbon and nitrogen sources concentrations, respectively. Through the results, it was found that there is an important role for the change, both qualitatively and quantitatively, in the components of the nutrient medium and the surrounding condition in increasing the efficiency of isolation, as it had a significant role in increasing the efficiency of the isolate. There was a significant increase in the PHA content ranging from 10 to 75% and the production of biomass to 3.6 g/L. respectively. Finally, this study concluded that the use of bacterial isolate in the production of PHA can contribute to solving the critical problem of environmental pollution caused by the use of industrial plastic and replacing it with environmentally friendly and low-cost materials.
Nanotechnology
Zahraa S. Ghazi; Mohammad R. Mohammad; Manal A. Abbood; Amal A. Hussein
Abstract
Silver nanoparticles were prepared by the chemical reduction method. Silver nitrate was taken as a metal precursor and sodium borohydride as a reducing agent with polyvinyl alcohol (PVA) stabilizers of different concentrations, polyvinylpyrrolidone (PVP). X-ray diffraction (XRD), transmission electron ...
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Silver nanoparticles were prepared by the chemical reduction method. Silver nitrate was taken as a metal precursor and sodium borohydride as a reducing agent with polyvinyl alcohol (PVA) stabilizers of different concentrations, polyvinylpyrrolidone (PVP). X-ray diffraction (XRD), transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques have been used, these measurement results showed that the prepared material is silver nanoparticles. The average size of silver nanoparticles using the Scherrer equation with values ranging from 8.49-12.15nm. TEM images showed that the silver nanoparticles are spherical in size between 5-47nm. Nanoscale distribution of silver nanoparticles (AgNPs) prepared at different concentrations was studied by AFM. Silver nanoparticles showed high antimicrobial and antibacterial activity against Gram-positive bacteria such as Escherichia Coli and Gram-negative Staphylococcus aureus, whose bacterial activity was dependent on the concentration of PVA and PVP and the degree of intramolecular accumulation. Low concentrations of PVP lead to increase the activity, while high concentrations of PVA give better activity.
