• Journal of Life Science
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• v.13 no.5
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• pp.705-711
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• 2003

The gellan was produced by Pseudomonas elodea under aerobic condition. In this study, the effects of inoculum size, carbon sources and concentration, nitrogen source, and C/N ratio on the cell growth and the production of gellan were evaluated. The maximum growth of P. elodea and gellan production was obtained at 5% (v/v) of inoculum size and glucose showed best results among 9 carbon sources tested. The maximum specific yield of 2.22 and productivity of $0.03 g/\ell$h were obtained at 1.0% (w/v) of glucose. The maximum gellan production was obtained at medium without ammonium nitrate. This indicates that nitrogen limitation is essential for the production of gellan. The highest cell and gellan production were obtained at 20 of C/N ratio.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.414-419
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• 1987

Cultural conditions for the polysaccharide production by Pseudomonas elodea ATCC 31461, a thermogellable polysaccharide producer, were investigated. Optimum condition for polysaccharide production were: temperature; $30^{\circ}C$, pH; 6.5, glucose; 25 g/L. nitrogen source; peptone, C/N ratio; 5.0. Maximum production and yield at this condition were ca. 32 g/L and 128%, viscosity of 1% polysaccharide solution was 837 mPas at 35/sec.. Consistency index and flow behaviour index were 2570 mPas and 0.66

• KSBB Journal
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• v.5 no.3
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• pp.235-240
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• 1990

A quantitative physiological approach has been employed to estimate the metabolic parameters such as specific uptake rates of nutrients and specific production rate in continuous culture of Pseudomonas elodea for gellan gum production. The estimated values of metabolic parameters are used for process improvement. During the exponential growth phase, the specific growth rate was 0.16hr-1 in batch culture. The gellan gum concentration increased up to 0.7g dry weight/100g broth and the apparent viscosity of the culture broth was about 4,500 cp.(72hrs culture). The ratio of specific uptake rate of carbon to that of nitrogen were found to be optimum at about 3.0mg-carbon/mg-nitro-gen. With the improved medium, the maximum gellan production rate, 0.6g dry weight/1/hr, was obtained at D=0.14 hr-1. The shear stresses of culture broth were fairly well correlated with shear rates by using Casson equation and at highly viscous culture broth, oxygen transfer coefficient was greatly reduced.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1987.12a
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• pp.135-135
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• 1987

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.247-250
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• 2000

Extracellular polysaccharide was produced by Pseudomonas elodea ATCC 31461 under aerobic condition. Nitrogen sources in medium affected cell growth and production of exopolymer. Ammonium nitrate limitation was found to be essential for higher production of exopolymer. Conversion rate of exopolymer from glucose under ammonium nitrate limitation was about 5 times higher than with ammonium nitrate.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.334-337
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• 2000

Extracellular polysaccharide was produced by Pseudomonas elodea NK-2000 under nitrogen limitation and aerobic condition, The effect of agiatation speed on cell growth and production of exopolymer was investigated. The agitation speed of 7.5 L fermentor ranged from 200 to 500 rpm. Production of exopolymer increased with higher agitation speed. Maximal cell growth and production of exopolymer from 2% glucose were 3.35 g/l and 3.80 g/l, respectively when agitation speed was 400 rpm.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.17-26
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• 1988

The polysaccharide produced by pseudomonas elodea, Gellan gum, was rheologically characterized, compared with agar. Rheological properties were determined from the change in the value of intrinsic viscosity with the pH and salt concentration. At the range of pH 2∼ll and salt 0∼0.16M KC1, the intrinsic viscosity of Gellan gum ranged from 8.8 to 21.2dl/g and agar ranged from 1.97 to 11.46d1/g. In the absence of salt, the intrinsic viscosity of Gellan gum increased as the pH of solution increased up to neutral pH then decreased slightly at alkaline pH, whearas the intrinsic viscosity of agar increased as the pH of solution increased up to pH 9 then decreased slightly. Intrinsic viscosity of Gellan gum and agar decreased with an increase in salt concentration. The chain stiffness parameter for the Gellan gum was 0.033. The overlap parameter of Gellan gum and agar were 0.047g/dl and 0.087g/dl, respectively. Gellan gum and agar were shear rate dependent or pseudoplastic. The yield stress and proportionality constant of Gellan gum increased slightly as the concentration increase, on the other hand, the shear index of Gellan gum showed a maximum at 0.75g/dl and gradually decreased as the concentration increase. The apparent viscosity of Gellan gum and agar decreased as the temperature increase. A lower concentration of the divalent cations calcium and magnesium is required to obtain maximum gel strength than for the monovalent cations sodium and potassium.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.51-51
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• 2001

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.30-30
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• 2000

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.418-421
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• 2001

The gellan was produced by Pseudomonas elodea ATCC 31461 under aerobic condition. Gellan provides various functionalities such as gelling, suspending, stabilizing, emulsifying and binding properties in aqueous systems. In this study, the effect of glucose concentration and nitrogen sources concentration, bacto peptone and $NH_4NO_3$, on the cell growth and the production of gellan were evaluated. The maximum specific yield (g gellan/g cell) of 2.22 was obtained at 1.0% of glucose. Bacto peptone increased cell growth. And nitrogen limitation was essential for higher production of gellan. The highest cell and gellan production were abtained at 0.5 g/${\ell}$ of bacto peptone without $NH_4NO_3$.