IJSR - INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH 63 Volume : 3 | Issue : 2 | February 2014 • ISSN No 2277 - 8179 Research Paper Engineering Arul Jothi Nagarajan Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA Sivaraj Irusappan Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA Gautami Amarnath Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA Swathine Chandrasekaran Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA Sruthi Abirhami B K Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA Janitri V Babu Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA Harishankar M K Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA * Dr. Devi A Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Chennai - INDIA. * is correspondent author. Expeditious Synthesis of Silver Nanoparticles By A Novel Strain Sporosarcina pasteurii SRMNP1 and Patrocladogram Analysis For Exploration of its Closely Related Species KEYWORDS : Sporosarcina pasteurii SRMNP1, Silver Nanoparticles, SEM- EDAX, Patrocladogram Analysis, Expedi- tious synthesis ABSTRACT Sporosarcina pasteurii is known for its calcite precipitation property and is being explored in biological cementing industries. The present study involves biological expeditious synthesis of silver nanoparticles by the bacteria in cost effective manner in less than 18 hours. The property of silver tolerance and reduction of Sporosarcina pasteurii SRMNP1 (Accession number KF214757) strain is explored for the first time. The bacteria were subjected to different concentrations of silver nitrate and maximum tolerance was observed at 20 mM. The reduction of silver nitrate was indicated by the colour change of solution from whitish to brown. The resultant biomass after 18 hours of incubation was dried and lyophilized and characterized using SEM and EDAX. The analysis shows that the bacteria posses crystalline silver nanoparticles on their surface which shows the ex- tracellular synthesis of silver by the bacteria. The study concludes that the Sporosarcina pasteurii SRMNP1 can be used as a potential source for biological synthesis of silver nanoparticles and further studies can also be made to explore the metal tolerance property of the organism. The evolutionarily close related species can also be explored for the bio-synthesis of silver nanoparticle in near future.a Introduction: The bio-synthesis of nanoparticles has received increasing at- tention due to a growing need to develop environmentally be- nign technology in material synthesis. The availability of silver nanoparticles has ensured a manifold application in molecular diagnostics, anti microbial activity and therapeutic uses etc [1]. Therefore attempts have been made to synthesize silver nanoparticles using both chemical and biological methods. Mi- croorganisms are recently found as possible Eco friendly nano factories [2]. The biosynthesis of silver nanoparticles employs use of biological agents like bacteria, yeast, and fungi [3]. The ability of microorganisms to grow in the presence of high metal concentration might result from specific mechanism of resist- ance, such as efflux system, alteration of solubility and toxicity by changes in the redox state of the metal ions and extracellular complexation [4]. This study presents data on the synthesis of silver nanoparticles by Sporosarcina pasteurii (Accession num- ber KF214757) formerly known as Bacillus pasteurii, a gram positive, aerobic endospore forming soil bacteria. It is known for its property of precipitating calcite and solidifying sand through the process of biological cementation. This work led to the exploration of silver reducing property of Sporosarcina pas- teurii and its active role in extracellular synthesis of silver nano- particle. The extracellular bio-synthesis of silver nanoparticles can be an attractive method for large scale synthesis because it offers the advantage of easy downstream processing [5]. The bacteria can synthesize Ag particles in less time compared to other microorganisms. Thus it can be used as a potential source in silver nanoparticles biosynthesis in future applications. Partrocladogram construction is an insilico approach to find the evolutionarily close related species, which may exhibit maxi- mum similar characteristic features. This study was also aimed in finding the closely related species of S.pasteurii and to iden- tify the applications of the related species in various fields as that of S.pasteurii. 2. Materials and methods: 2.1 Culturing of Sporosarcina pasteurii SRMNP1 Sporosarcina pasteurii SRMNP1 was inoculated into 100 ml of LB broth (pH 7.0) in Erlenmeyer flask and the culture was grown with continuous shaking on shaker at 150 rpm, 37 0 c overnight. The grown culture was harvested by centrifugation at 8000rpm, 4 0 c for 10 min and washed thrice with double dis- tilled water under aseptic conditions to remove the remaining media content. 2.2 Extracellular synthesis of Ag nanoparticles 1gm of the biomass was taken and added with filter sterilized Sliver Nitrate solution with varying concentrations 0.17g and 0.34g (10mM and 20mM) to two different flasks containing 100 ml sterile double distilled water each respectively. These flasks were covered with aluminium foil and incubated at 37 0 c in shaker at 150 rpm. The colour of the culture turned from white to brown indicating the reduction of silver nitrate. Controls were kept to ensure that the change is mediated only by the extracellular en- zymes of the bacteria. The bacteria showed maximum tolerance at 20mM and reduced the silver nitrate solution to crystalline sil- ver nanoparticles. The biomass was harvested by centrifugation and lyophilized for further characterization studies.