Abstract :
Abstract: Living organisms are giving a major support in nanomaterial synthesis for various applications like drug delivery, biological imaging and sensors. Diatom is a well diverse marine microorganism. In this study aim to synthesis silicon (Si) and germanium (Ge) based diatom nanomaterial for antibacterial activity. Coscinodiscus sp. is unicellular microalgae that make microscale silica frustules with nanoscale two dimensional pore arrays. Diatoms are made the
unique silica structure in well organized by micro to nanoscale. The Ge is metabolically slot in marine diatom Coscinodiscus sp. frustule by two steps culturing process in laboratory condition. First the diatom cultured in culture medium with silicon starvation state, then the silicon starved diatom was transferred into Si: Ge (2:1) mixed culture medium. Electron microscopic observation has been shows that the nanomaterial synthesis does not causes any structural changes in cell structure. But in diatom frustules carries some changes in its pore size. In XRD result patterns also shows that some peaks have been appeared in 2θ at 10.81, 27.33, 31.69, 45.42, 56.41, 66.27 and 75.21 are conformed the cubic phase of both Si and Ge present in diatom frustules. Moreover, Si and Ge was measured and found that it is a Si-Ge nanocomposite in diatom frustules. The biogenic Si-Ge nanocomposite was analyzed for its anti-bacterial activity and the result has also showed significant inhibition against both gram negative and positive bacteria. This is the first study to demonstrate the applications of biogenic Si-Ge nanocomposite in antibacterial activity study. This study might fulfill the biomedical applications in near future.
Keyword :
Diatom, Biosynthesis, Nanocomposite, Silica and Germanium