Hexavalent Chromium Reduction from Pollutant Samples by Achromobacter xylosoxidans SHB 204 and its Kinetics Study.

Cr(VI) is most toxic heavy metal and second most widespread hazardous metal compound worldwide. Present work focused on Cr(VI) reduction from synthetic solutions and polluted samples by Achromobacter xylosoxidans SHB 204. It could tolerate Cr(VI) up to 1600 ppm and reduce 500 ppm with 4.5 chromium reductase enzyme units (U) having protein size 30 kDa. Changes in morphology of cells on interaction with Cr(VI) metal ion was also studied using SEM-EDX and FTIR. Microcosm studies in pollutant samples for Cr(VI) reduction and adsorption isotherm with biomass of bacterium was best fitted with Langmuir model along with kinetic studies. This study focuses on significance of Cr reduction from synthetic solutions and polluted samples by A. xylosoxidans SHB 204 and its potential for bioremediation.

Effective feather degradation and keratinase production by Bacillus pumilus GRK for its application as bio-detergent additive.

An effecient feather-degrading bacterium was isolated from poultry dumping yard and identified as Bacillus pumilus GRK based on 16S rRNA sequencing. Complete feather degradation (98.3±1.52%) with high keratinase production (373±4 U/ml) was observed in 24h under optimized conditions (substrate 1% (w/w); inoculum size 4% (v/v); pH 10; 200rpm at 37°C) with feathers as sole carbon and nitrogen source in tap water. The fermented broth was enriched with amino acids like tryptophan (221.44µg/ml), isoleucine (15.0µg/ml), lysine (10.81µg/ml) and methionine (7.24µg/ml) suggesting its potential use as feed supplement. The keratinase produced was a detergent stable serine protease and its activity was further enhanced by Ca+2 and Mg+2. Bacillus pumilus GRK keratinase was successfully utilised as bioadditive in detergent formulations for removing the blood stains from cloth without affecting its fiber and texture.

Influence of micronutrients on yeast growth and ß-d-fructofuranosidase production.

ß-d-fructofuranosidase is one of the most important enzymes of the food industry especially due to its application in preparation of soft centered candies, confectioneries and to produce fructose syrups. Although several bacteria and filamentous fungi are reported for its production, yeasts are the most preferred source for this enzyme. In the present study mineral nutrients were screened for their effect on yeast growth and the enzyme production using Plackett-Burman design. Of the 11 nutrients screened, three variables (KH(2)PO(4), FeCl(3) and CoCl(2)) were significantly effecting yeast growth while six variables, i.e. KH(2)PO(4), CaCl(2), MnSO(4), Na(2)MoO(4), ZnSO(4) and CoCl(2) had significant effect on enzyme production.