Optimizing the fermentation conditions and enhanced production of keratinase from Bacillus cereus isolated from halophilic environment.

Keratinase degrading Bacillus cereus was isolated from the halophilic environment in Tamilnadu, India and keratinase production was optimized using wheat bran substrate. Of the screened bacterial isolates, four were found to have the ability to produce keratinolytic enzyme. The process parameters were optimized using one-variable-at-a-time approach and response surface methodology. Supplementation of 1% lactose supported more keratinase production (120 U/g). Among the selected nitrogen sources, addition of casein significantly enhanced maximum keratinase production (132.5 U/g). Among the ions, manganese chloride significantly enhanced keratinsase production (102.6 U/g), however addition of zinc sulphate and copper sulphate decreased keratinase production. The maximum keratinase production was obtained in the wheat bran medium containing 1% lactose, 0.5% manganese with 80% moisture (292 U/g). Statistics based contour plots were generated to explore the variations in the response surface and to find the relationship between the keratinase yield and the bioprocess conditions.

Rapid biosynthesis and characterization of silver nanoparticles from the leaf extract of Tropaeolum majus L. and its enhanced in-vitro antibacterial, antifungal, antioxidant and anticancer properties.

Eco-friendly biosynthesis of nanoparticles from medicinal plants as reducing agent has gained importance due to its potential therapeutic uses. In the present study Silver nanoparticles (AgNPs) were eco-friendly synthesized using the leaf extracts of the medicinal plant Tropaeolum majus. The obtained AgNPs were characterized by UV - visible spectrum, FTIR, SEM and XRD which clearly showed the reduction of Ag+ ions to Ag0. In addition, the aqueous and ethanolic extracts were analyzed for phytochemicals and its antioxidant activities. GC-MS spectrum showed the presence of 25 compounds with benzeneacetic acid as the dominant contents. The synthesized AgNPs revealed maximum absorption spectrum at 463 nm and FTIR vibrational peaks at 3357.46, 21,966.52, 2118.42, 1637.27, 658.571 and 411.728 cm-1 respectively. SEM and XRD studies evidenced the nature of nanocrystalline with face centered cubic (fcc) crystal structure. Both AgNPs and plant extracts showed more inhibition activity against Pseudomonas aeroginosa compared to other bacteria with MIC value of 6.25 µg/ml. Antifungal activities was higher for Penicilium notatum with MIC value 31.2 µg/ml. The IC50 values for MCF7 for aqueous extract were found to be 4.68 µg/ml, ethanol extract 7.5 µg/ml, AgNPs 2.49 µg/ml, and doxorubicin 1.4 µg/ml. The IC50 values for VERO cell line for aqueous extract was 8.1 µg/ml, ethanol extract with 6.8 µg/ml, silver nanoparticles 5.3 µg/ml and doxorubicin 2.6 µg/ml respectively. Conclusively, the antibacterial, antifungal, antioxidant and anticancer properties of the synthesized AgNPs from Tropaeolum majus act as major therapeutic drug for microbial infectious disease and other health associated disorders.

Green synthesis of silver nanoparticles from leaf extract of Mimusops elengi, Linn. for enhanced antibacterial activity against multi drug resistant clinical isolates.

Green synthesis of metallic silver nanoparticles has attracted nowadays and alternative to physical and chemical approaches. In the present study, silver nanoparticles (AgNPs) were synthesized from leaf extract of Mimusops elengi, L. at room temperature. Formation of stable AgNPs at 1mM concentrations of silver nitrate (AgNO3) typically gave spherical shape particles with diameter range from 55 to 83nm. The kinetic properties of particle formation were proportional to the effect of concentration of AgNO3 solution. In order to identify the compounds responsible for the bioreduction of Ag(+) ion and the stabilization of AgNPs produced, the functional group present in Mimusops elengi, L. leaf extract was investigated using FTIR. The formation of nanoparticle was confirmed using the surface plasmon resonance band shown in UV-vis spectrophotometer. The topography and morphology of the particles were determined using scanning electron microscopy. The crystalline nature of nanoparticles was confirmed from the XRD pattern. Furthermore these green synthesized AgNPs were found to show higher antimicrobial efficacy against multi drug resistant clinical isolates.

Antihyperglycemic effect of Hypericum perforatum ethyl acetate extract on streptozotocin-induced diabetic rats.

OBJECTIVE: To evaluate the antihyperglycemic activity of ethyl acetate extract of Hypericum perforatum (H. perforatum) in streptozotocin (STZ)-induced diabetic rats. METHODS: Acute toxicity and oral glucose tolerance test were performed in normal rats. Male albino rats were rendered diabetic by STZ (40 mg/kg, intraperitoneally). H. perforatum ethyl acetate extract was orally administered to diabetic rats at 50, 100 and 200 mg/kg doses for 15 days to determine the antihyperglycemic activity. Biochemical parameters were determined at the end of the treatment. RESULTS: H. perforatum ethyl acetate extract showed dose dependant fall in fasting blood glucose (FBG). After 30 min of extract administration, FBG was reduced significantly when compared with normal rats. H. perforatum ethyl acetate extract produced significant reduction in plasma glucose level, serum total cholesterol, triglycerides, glucose-6-phosphatase levels. Tissue glycogen content, HDL-cholesterol, glucose-6-phosphate dehydrogenase were significantly increased compared with diabetic control. No death or lethal effect was observed in the toxic study. CONCLUSIONS: The results demonstrate that H. perforatum ethyl acetate extract possesses potent antihyperglycemic activity in STZ induced diabetic rats.