NOPR Collection:

Decolourization and Biodegradation of Reactive Azo Dyes by Mixed Culture

2011-03-22T16:30:46Z

Title: Decolourization and Biodegradation of Reactive Azo Dyes by Mixed Culture Authors: Vijaya, P P; Padmavathy, P; Sandhya, S Abstract: Synthetic dyes, azo dye in particular, are widely found in the effluents from textile industries. The persistence and toxicity of these compounds cause adverse impact in the receiving streams. A mixture of isolated cultures, from domestic sewage treatment plant was found to decolourize reactive azo dyes, Red RB, Blue M2B and Yellow, efficiently in the absence of added external nitrogen source. After shaking incubation for 48 hrs, mixture of cultures removed these dyes and decolourization was 95% for Red RB and Blue M2B and 50% for Yellow. The mixed culture could degrade 500 mgll Red RB efficiently with the release of 84.9 mgll of ammonia. There was also degradation of 100 mgll of Blue M2B and 50 mgll of Yellow dyes but the release of ammonia was not observed in Blue M2B and Yellow. Decolourization was remarkably enhanced when peptone was used in the medium. Azoreductase activity was high in the presence of reactive azo dyes and the enzyme could decolourize the reactive dyes much faster when decolourization was studied as cell free extract in the presence of individual dyes. Page(s): 259-263

Salt stress Induced Changes on Enzyme Activities during Different Developmental Stages of Rice (Oryza sativa Linn.)

2011-03-22T16:30:43Z

Title: Salt stress Induced Changes on Enzyme Activities during Different Developmental Stages of Rice (Oryza sativa Linn.) Authors: Swapna, T S Abstract: The effect of NaCI stress was studied in four rice varieties, 'Pokkali'- (salt tolerant variety), 'MI 48', 'Annapoorna' and 'Jyothi'- (salt sensitive varieties). The enzymes-esterase, isocitric dehydrogenase, superoxide dismutase, peroxidase and catalase were studied in different developmental stages such as embryo, 14-day-old seedling, tillering and flowering stage, and in undifferentiated embryo derived callus, before and after giving NaCI stress (100 mM). Esterase activity was found to be higher in embryo stage and isocitric dehydrogenase activity was higher in callus, but the stress caused a reduction in activity of these two enzymes during other developmental stages. An increase in activity of superoxide dismutase and peroxidase was also observed during the different developmental stages under stress. There was a fluctuation "incatalase activity under NaCI stress during the different developmental stages in all the varieties. Variety specific and developmental stage specific variation was found in activity of all the enzymes studied and can be reflected in metabolic processes which, when well-defined can serve as markers for salt tolerance. Page(s): 251-258

Detection of Azospirillum and PSB in Rice Rhizosphere Soil by Protein and Antibiotic Resistance Profile and Their Effect on Grain Yield of Rice

2011-03-22T16:30:41Z

Title: Detection of Azospirillum and PSB in Rice Rhizosphere Soil by Protein and Antibiotic Resistance Profile and Their Effect on Grain Yield of Rice Authors: Khan, M R; Talukdar, N C; Thakuria, D Abstract: Two biofertilizer agents, Azospirillum amazonense A10 and Bacillus megaterium P7, alone and in combination increased the grain yield of rice in autoclaved soil by 103-256% over control. Colonies of A, amazonense and B. megaterium were distinguished from the contaminant phosphate solubilizing bacteria (PSB) and Azospirilla colonies in the respective media based on colony morphology, colour and thickness of clearing zone, Population densities of A, amazonense and B. megaterium were found to be 2.6 x 108 and 2.9 x 108 CFUg .] soil, respectively at 48 day post transplanting. Protein and antibiotic resistance profiles of the inoculated and reisolated A. amazonense, B. megaterium and the contaminant colonies with the pure cultures indicated that the isolates were able to establish in the rice rhizosphere with the resultant enhancement of plant growth and yield. Page(s): 246-250

Nitrification by Some Diazotrophic Enterobacteria

2011-03-23T16:30:34Z

Title: Nitrification by Some Diazotrophic Enterobacteria Authors: Kannan, V; Raju, P N Abstract: Biological nitrogen fixers in addition to their involvement in nitrogen fixation also take part in nitrification and denitrification processes. Some members of enterobacteria used in the present study besides fixing nitrogen also oxidized ammonia to hydroxylamine and nitrite. The whole cells as well as cell free extract of nitrogen fixing populations of these organisms showed oxidation of ammonia and this activity of ammonia monooxygenase was higher at high oxygen.conditions which was also confirmed by the calorimetric estimation of hydroxylamine and nitrite in the enzyme assay mixture. Page(s): 240-245