Department of Biotechnology

About: Department of Biotechnology is a government organization based out in New Delhi, India. It is known for research contribution in the topics: Population & Silver nanoparticle. The organization has 4800 authors who have published 5033 publications receiving 82022 citations.

Purification and Characterization of Melanogenic Enzyme Tyrosinase from Button Mushroom

Abstract: Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis. Since the discovery of its melanogenic properties, tyrosinase has been in prime focus and microbial sources of the enzyme are sought. Agaricus bisporus widely known as the common edible mushroom, it’s taking place in high amounts of proteins, enzyme, carbohydrates, fibers, and low fat contents are frequently cited in the literature in relation to their nutritional value. In the present study tyrosinase from Agaricus bisporus was purified by ammonium sulphate precipitation, dialysis followed by gel filtration chromatography on Sephadex G-100, and ion exchange chromatography on DEAE-Cellulose; the enzyme was purified, 16.36-fold to give 26.6% yield on total activity in the crude extract and final specific activity of 52.19 U/mg. The SDS-PAGE electrophoresis showed a migrating protein band molecular weight of 95 kDa. The purified tyrosinase was optimized and the results revealed that the optimum values are pH 7.0 and temperature 35°C. The highest activity was reported towards its natural substrate, L-DOPA, with an apparent Km value of 0.933 mM. This indicated that tyrosinase purified from Agaricus bisporus is a potential source for medical applications.

Statistical Approach for Optimization of Physiochemical Requirements on Alkaline Protease Production from Bacillus licheniformis NCIM 2042

Abstract: The optimization of physiochemical parameters for alkaline protease production using Bacillus licheniformis NCIM 2042 were carried out by Plackett-Burman design and response surface methodology (RSM). The model was validated experimentally and the maximum protease production was found 315.28 U using optimum culture conditions. The protease was purified using ammonium sulphate (60%) precipitation technique. The HPLC analysis of dialyzed sample showed that the retention time is 1.84 min with 73.5% purity. This enzyme retained more than 92% of its initial activity after preincubation for 30 min at 37∘C in the presence of 25% v/v DMSO, methanol, ethanol, ACN, 2-propanol, benzene, toluene, and hexane. In addition, partially purified enzyme showed remarkable stability for 60 min at room temperature, in the presence of anionic detergent (Tween-80 and Triton X-100), surfactant (SDS), bleaching agent (sodium perborate and hydrogen peroxide), and anti-redeposition agents (Na2CMC, Na2CO3). Purified enzyme containing 10% w/v PEG 4000 showed better thermal, surfactant, and local detergent stability.

In vitro cytotoxicity of zinc oxide, iron oxide and copper nanopowders prepared by green synthesis.

Abstract: In vitro cytotoxic effects of ZnO, FeO and Cu metallic nanopowders (NPs) on Vero (African green monkey kidney cell line), PK 15 (Pig kidney cell line) and Madin Darby Bovine Kidney (MDBK) cell lines were investigated at different time intervals (24 and 48 h). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to determine the cytotoxic effects of green synthesized (plant based) nanopowders. The comparative effects of exposure period and concentration of nanopowders on cell viability were studied. Green synthesized nanopowders showed varying activity on different type of cells and the effect was generally based on the concentration and exposure time. In MDBK cells, only ZnO nanopowder (NP) showed significant effect on cell viability. The ZnO NP showed improved cell viability at lower concentration (10 μg/100 μl) in all type of cells (Vero, PK 15 and MDBK cells). In contrast, FeO NP showed better activity at the concentration of 10 μg/100 μl, 50 μg/100 μl and 40 μg/100 μl after 24 h exposure time in Vero, PK 15 and MDBK cells respectively. However better cell viability was observed in Cu NP treated Vero, PK 15 and MDBK cells at 40 μg/100 μl, 20 μg/100 μl and 10 μg/100 μl correspondingly. These studies suggested that the activity of green synthesized NPs were highly dependent on concentration, exposure time and type of cells.