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Process Optimization for Enhanced Production of Cell Biomass and Metabolites of Fluorescent Pseudomonad R81

Year: 2010 Volume: 4 Issue: 5 294 - 298 Pages

• Authors:
• M.V.R.K Sarma
• Krishna Saharan
• Lalit Kumar
• Ashwani Gautam
• Avhijeet Kapoor
• Nishant Srivastava
• Vikram Sahai
• V.S Bisaria

Abstract: The fluorescent pseudomonad strain R81 is a root colonizing rhizobacteria which promotes the growth of many plants by various mechanisms. Its broth containing siderophore (ironchelating compound) and 2,4- diacetyl phloroglucinol (DAPG) is used for preparing bioinoculant formulations for agronomical applications. Glycerol was found to be the best carbon source for improved biomass production. Splitting of nitrogen source to NH4Cl and urea had a stabilizing effect on pH during batch cultivation. Ltryptophan at 0.5 % in the medium increased the siderophore production to 850 mg/l. During batch cultivation of the strain in a bioreactor, a maximum of 4 g/l of dry cell mass, 1.8 g/l of siderophore and 20 mg/l of DAPG was achieved when glycerol was 15 g/l and C/N ratio was maintained at 12.5. In case of intermittent feeding of fresh medium during fed-batch cultivation, the dry cell mass was increased to 25 g/l with improved production of DAPG to 70 mg/l.

• Keywords:
• Batch cultivation
• Fed-batch cultivation
• fluorescent pseudomonad
• Metabolites

Application of Fluorescent Pseudomonads Inoculant Formulations on Vigna mungo through Field Trial

Year: 2009 Volume: 3 Issue: 3 149 - 153 Pages

• Authors:
• Sarma. M.V.R.K
• Saharan. K
• Prakash. A
• Bisaria. V. S
• Sahai.V

Abstract: Vermiculite was used to develop inorganic carrier-based formulations of fluorescent pseudomonad strains R62 and R81. The effect of bio-inoculation of fluorescent pseudomonad strains R62 and R81 (plant growth promoting and biocontrol agent) on growth responses of Vigna-mungo under field condition was enumerated. The combined bioinoculation of these two organisms in a formuation increased the pods yield by 300% in comparison to the control crop. There was also significant increment in the other plant growth responses such as dry root weight, dry shoot weight, shoot length and number of branches per plant.

• Keywords:
• Bio-inoculants formulation
• Fluorescent pseudomonad
• Plant growth promotion activity.

Cell Growth and Metabolites Produced by Fluorescent Pseudomonad R62 in Modified Chemically Defined Medium

Year: 2010 Volume: 4 Issue: 7 442 - 446 Pages

• Authors:
• K. Saharan
• M.V. R. K. Sarma
• A. S. Roesti
• A. Prakash
• B. N. Johri
• M. Aragno
• V. S. Bisaria
• V. Sahai

Abstract: Chemically defined Schlegel-s medium was modified to improve production of cell growth and other metabolites that are produced by fluorescent pseudomonad R62 strain. The modified medium does not require pH control as pH changes are kept within ± 0.2 units of the initial pH 7.1 during fermentation. The siderophore production was optimized for the fluorescent pseudomonad strain in the modified medium containing 1% glycerol as a major carbon source supplemented with 0.05% succinic acid and 0.5% Ltryptophan. Indole-3 acetic acid (IAA) production was higher when L-tryptophan was used at 0.5%. The 2,4- diacetylphloroglucinol (DAPG) was higher with amended three trace elements in medium. The optimized medium produced 2.28 g/l of dry cell mass and 900 mg/l of siderophore at the end of 36 h cultivation, while the production levels of IAA and DAPG were 65 mg/l and 81 mg/l respectively at the end of 48 h cultivation.

• Keywords:
• Fluorescent pseudomonad
• Fermentation
• Metabolites production
• PGPR.