• Korean Journal of Microbiology
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• v.37 no.3
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• pp.197-203
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• 2001

An ubiquitous bacterium, Pseudomonar cepacia KH410 was isolated from fresh water plant root and identified. Adsorption of heavy metals of lead, cadmium and copper by this strain was investigated. Optimal conditions foradsorption was 1.0 dry g-biomass, at pH 4.0 and temperature of $40^{\circ}C$. Adsorption equilibrium reached max-imum after 120 min in 1000 mg/l metal solutions. The adsorption capacity (K) of lead was 5.6 times higher thancadmium and 4.0 times higher than that of copper. Adsorption of lead was applicable for Langmuir modelwhereas Freundlich model for cadmium and copper, respectively. Adsorption strength (1/n) of heavy metal ionswere in the order of lead>copper>cadmium. Uptake capacity of lead, cadmium and copper by dried cell was83.2,42.0,65.2 mg/g-biomass, respectively. Effective desorption was induced 0.1 M HCI for lead and 0.1 $HNO_3$ for cadmium and copper. Pretreatment to increase ion strength was the most effective with 0.1 M KOH.Uptake by immobilized cell was 77.8,58.5,71.2 mg/g-biomass for lead, cadmium and copper, respectively. Theimmobilized cell was more effective than ion exchange resin on removal of heavy metals in solution containinglight metals.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.26-30
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• 2002

A ubiquitous bacterium,Effects of Lead, Copper and Cadmium on Pseudomonas cepacia KH410 Isolated from Freshwater Plant Root was isolated from freshwater plant root and interactions of lead, copper and cadmium with this strain was studied. Mass production of dry cell weight 2.72 g-DCW/ι-medium was obtained by cultivation in a nutrient medium containing 1% yeast extract, 1% soytone and 0.5% NaCl, pH 7.0, at temperature of 28℃ for 24 hrs under aeration. The mass of dry cell produced after exposure with 100 mg/ι of heavy metal was 1.98 g/ι for lead, 1.58 g/ι for copper and 0.20 g/ι for cadmium, respectively. The minimal inhibitory concentrations (MIC) for each heavy metal was 1.3 mM for lead,0.8 mM for copper and 0.4 mM fur cadmium, respectively. Cell aggregation occurred by each heavy metal exposure was observed from 1 day to 4 days by an optical microscope. Entrapment, precipitation effects on cell by heavy metals between 10 min and two hours were examined by an electron microscopy. Cadmium appeared to be the most toxic on cells and the order of toxicity was cadmium>copper>lead.