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The aim of the work is to compare the biogenic silica nanoparticles, which have been isolated from rice husks with synthetically produced silica brand Cab-O-Sil LM-150. The comparison is based on an evaluation of the two systems from the point of view of chemical composition, particle size and structure, ability to form clusters of particles and interactions with selected bacterial systems. Methods used for comparison were: SEM, EDX, TEM, FTIR, ICPOES and bacteriological tests. Husks are standardly contaminated by accompanying ions that are important for plant growth, but undesirable for obtaining a quality product. Rice husk used for the silica isolation were purified by boiling in 10% HCl for 2 hours. Rice husks were then washed with distilled water until pH 7. The dried and purified husks were burned in an oven at 650oC of ramping temperature 10oC/min during 2 hours. The obtained product has a chemical composition analogous to the synthetic product. Biogenic particles reach a size of about 20 nm, about 10 nm synthetic. Both materials have an amorphous structure. Interaction with bacterial systems was performed with Gram-negative bacteria Escherichia coli W3110 strain and Gram-positive bacteria Bacillus cereus. In both cases analogous behaviour was observed depending on the concentration of nanoparticles and reducing the growth rate of cultures of 8% for E. coli and 5% for B. cereus resulted nanoparticles at the concentration of 150 mg/ litter of medium.
Keywords: biogenic silica, synthetic silica, chemical composition, particle size, bacterial systems© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.