NOPR Collection: Special Issue on Emerging Trends in Biotechnology (ICETB-2014) (Guest Editors: Professor Indu Shekhar Thakur, Professor Ashok Pandey & Professor Guillermo R Castro)

Green synthesis and cytotoxicity of silver nanoparticles from extracts of the marine macroalgae Gracilaria corticata

2015-04-01T00:00:00Z

Title: Green synthesis and cytotoxicity of silver nanoparticles from extracts of the marine macroalgae Gracilaria corticata Authors: Bhimba, B Valentin; Devi, J Saraniya; Nandhini, S Usha Abstract: The present study reports the synthesis of silver nanoparticles (AgNPs) using aqueous extract of a seaweed, Gracilaria corticata. Extremely stable AgNPs were characterized by UV-Vis spectrophotometer, FTIR, XRD, TEM and EDS analyses. The nanoparticles exhibited maximum absorbance at 424 nm in the UV spectrum. The presence of proteins was identified by FTIR. TEM micrograph revealed the formation of polydispersed and spherical shaped nanoparticles with the size range of 10-50 nm and the presence of elemental silver were confirmed by EDS analysis. These nanoparticles showed cytotoxic activity against MCF7 cells. Page(s): 276-281

Enzymatic transformation of the major ginsenoside Rb1 to compound K by Weissella hellenica DC06

2015-04-01T00:00:00Z

Title: Enzymatic transformation of the major ginsenoside Rb1 to compound K by Weissella hellenica DC06 Authors: Huq, Md Amdadul; Kim, Yeon-Ju; Min, Jin-Woo; Siraj, Fayeza Md; Siddiqi, Muhammad Zubair; Yang, Deok-Chun Abstract: In the present study, the major ginsenoside Rb1 was transformed into the more pharmacologically active minor ginsenoside compound K (C-K) via the enzymatic activity of food grade Weissella hellenica DC06 isolated from kimchi, a traditional Korean fermented food. The transformation products were analyzed by TLC, HPLC, and LC/MS. Within 4 d of incubation, 100% of Rb1 was decomposed and converted into F2 and C-K. The crude enzyme of W. hellenica DC06 hydrolyzed the two glucose moieties attached to the C-3 position and the outer glucose moiety attached to the C-20 position of the ginsenoside Rb1. Strain DC06 hydrolyzed ginsenoside Rb1 along the following pathway: Rb1→Rd→F2→CK. The optimum temperature and pH of the enzyme activity was 37°C and 7.0, respectively. DC06 was identified as a W. hellenica species based on its 16S rRNA gene sequences through the construction of a phylogenetic tree and homology analysis. This is the first report of the bioconversion of ginsenoside Rb1 to ginsenoside C-K using W. hellenica DC06. Page(s): 270-275

Optimization of inoculum density in hairy root culture of Plumbago rosea L. for enhanced growth and plumbagin production towards scaling-up in bioreactor

2015-04-01T00:00:00Z

Title: Optimization of inoculum density in hairy root culture of Plumbago rosea L. for enhanced growth and plumbagin production towards scaling-up in bioreactor Authors: Pillai, Dhanya B; Jose, Binoy; Satheeshkumar, K; Krishnan, P N Abstract: The present study evaluated the influence of initial inoculum density (ID) on growth and plumbagin production in hairy root culture of Plumbago rosea L. in shake-flask as well as air-sparged bioreactor. IDs ranging from that of single root tip (0.08 g/L) to 10 g/L were analyzed in 50 mL MS basal media of 250 mL Erlenmeyer flasks. For scaling-up in bioreactor of 2 L working-capacity, 0.5, 1, 5, 10 and 15 g/L IDs were analysed. Optimal ID was found to be 1 g/L in shake-flask culture, producing a growth index of 36.15 on 30^thd with plumbagin content of 1.325 g in 100 g DW of roots (1.325%). In the bioreactor, biomass increase was maximum for 5 g/L with a growth index of 11.428 and plumbagin content of 1.425%. Here we report the maximum plumbagin concentration (1.325%) in P. rosea hairy root culture, enhanced from 0.99% innate plumbagin content of the mother culture through sole optimization of ID. Further enhancement to 1.425% was attained by scaling-up in the bioreactor. The plumbagin concentration obtained in bioreactor culture of P. rosea hairy roots (1.425%) is also the highest reported so far in scaling-up. Thus results indicate that ID is a critical parameter influencing enhanced production of root biomass and plumbagin in hairy root cultures of P. rosea. Page(s): 264-269

COI based molecular identification of mango leaf hoppers (Hemiptera: Cicadellidae) in India

2015-04-01T00:00:00Z

Title: COI based molecular identification of mango leaf hoppers (Hemiptera: Cicadellidae) in India Authors: Asokan, R; Chaitanya, B N; Rebijith, K B; Kumar, N K Krishna; Viraktamath, C A; Ramamurthy, V V Abstract: Rapid, accurate and timely identification of invasive pest insects, such as, mango leafhoppers, is important and a challenge worldwide. In this regard, DNA barcoding employing a 658 bp fragment of 5 ' region of the mitochondrial cytochrome oxidase I (COI) gene is an effective tool in addressing the above. In the present study, we developed DNA barcodes for five species of mango leaf hoppers, viz., Amritodus atkinsoni, A. brevistylus, Idioscopus clypealis, I. nagpurensis and I. niveosparsus, which were collected from Karnataka, India. Our study will help in providing a rapid, convenient and precise tool for species discrimination in mango leaf hoppers, regardless of their life stages and polymorphism. Page(s): 260-263