Biotechnology

Objective(s): For the development of reliable, ecofriendly, less expensive process for the synthesis of silver nanoparticles
and to evaluate the bactericidal, and cytotoxicity properties of silver nanoparticles synthesized from root extract of
Croton bonplandianum, Baill.
Materials and Methods: The synthesis of silver nanoparticles by plant part of Croton bonplandianum was carried out.
The formation of nanoparticles was confirmed by Transmission Electron Microscopy (TEM), Scanning Electron
Microscopy (SEM), XRD and UV-Vis spectrophotometric analysis. The biochemical properties were assayed by
antibacterial study, cytotoxicity assay using cancer cell line.
Results: The formation of silver nanoparticles was confirmed by UV-VIS spectroscopic analysis which showed absorbance
peak at 425 nm. X-ray diffraction photograph indicated the face centered cubic structure of the synthesized AgNPs.
TEM has displayed the different dimensional images of biogenic silver nanoparticles with particle size distribution
ranging from 15-40 nm with an average size of 32 nm. Silver particles are spherical in shape, clustered. The EDX
analysis was used to identify the elemental composition of synthesized AgNPs. Antibacterial activity of the synthesized
AgNPs against three Gram positive and Gram negative bacteria strains like Staphylococcus aureus, Escherichia coli and
Pseudomonas aeruginosa carried out showed significant zones of inhibition. The cytotoxicity study by AgNPS also
showed cytotoxicity on ovarian cancer cell line PA-1 and lung epithelial cancer cell line A549.
Conclusion: The present study confirms that the AgNPs have great promise as antibacterial, and anticancer agent.

Gelatinase Bacteria a b s t r a c t A new bacterial strain was isolated from polycyclic aromatic hydrocarbon (PAH) contaminated soil, near an oil refinery, West Bengal, India. The strain was identified by 16S rDNA sequences. It was found to be capable of mineralizing some toxic PAHs like benzo[a]pyrene, anthracene, fluoranthene and pyrene. It was able to produce some commercially important biochemicals including biosurfactant. High gelatinase activity was associated with this PAH degrading Bacillus species. /locate /J OPR j o u r n a l o f p h a r m a c y r e s e a r c h 6 ( 2 0 1 3 ) 1 9 9 e2 0 4

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic in nature; they are less soluble in water; so bacteria cannot access or degrade them easily. They are very much toxic to us. A new bacterial strain Bacillus thuringiensis strain NA2 has been isolated from a major petroleum oil contaminated site of India and found to degrade some more toxic members of PAHs like fluoranthene and pyrene. Optimization of this biodegradation has been done by changing different bio-stimulating factors like temperature, pH and addition of glucose as co substrate, Tween 80, H 2 O 2 or organic solvent. The results show an optimum condition at which the bioremediation is very significant. So the bacteria may be employed directly with the contaminated soil or sludge to see its effectiveness.