Earticle

초록

영어

A total of 35 phosphate solubilizing bacterial strains were isolated from waste mushroom bed of Agaricus bisporus in Buyeo-Gun, Chungnam and screened for the production of indole acetic acid (IAA). The best IAA producing strain was identified as Pantoea rodasii using 16S rRNA analysis. In addition to the IAA production, this strain could act as an efficient phosphate solubilizer (1100 μg ml-1 after 5 days of incubation) also. The selected strain was cultured under different conditions in order to assess the optimum conditions for maximum IAA production. The nutrient broth (NB) medium was recorded as the best medium, where the maximum IAA production (229 μg ml-1) was recorded at the start of stationary phase (12 hours after inoculation) of the bacteria growth. The performance of the strain was found to be maximum at the temperature of 30oC followed by 25oC. IAA production was found to be increased with increasing tryptophan concentration (from 0.1 to 0.6%), however beyond this limit, a slight reduction in IAA production was observed. The strains’ ability to produce IAA was further confirmed by extraction of crude IAA and subsequent TLC analysis. A specific spot from the extracted IAA preparation was found corresponding with the standard spot of IAA with same Rf value. The results of HPLC analysis conducted in identifying and quantifying the IAA production more precisely, are in agreement with the results of the assessment done with colorimetric method. As revealed by the results of the pot experiment, the isolated strain could significantly enhance the growth (as measured by shoot and root growth) of mung bean plants compared to that of non-inoculated plants. Therefore it can be concluded that the present strain, Pantoea rodasii has great potential to be used as bio-inoculants.

목차

ABSTRACT
 Introduction
 Materials and Methods
  Isolation of phosphate solubilizing bacterial strains
  Screening of bacterial isolates for IAA production
  Identification of the selected bacterial strain
  Assay of inorganic phosphate solubilization
 Optimization of IAA production
  Effect of incubation period on IAA production
  Effect of different media on IAA production
  Effect of different temperature on IAA production
  Effect of different tryptophan concentrations on IAA production
  Extraction of crude IAA and thin layer chromatography (TLC)
  Determination of IAA production by HPLC
  Plant growth promotion bioassay with mung bean (Vigna radiata)
  Statistical analysis
 Results
  Isolation of phosphate solubilizing bacterial strains and screening for IAA production
  Identification of the bacterial strain
  Assay of inorganic phosphate solubilization
 Optimization of IAA production
  Effect of different media on IAA production
  Effect of incubation period on IAA production
  Effect of different temperature on IAA production
  Effect of different tryptophan concentration on IAA production
  TLC and HPLC analysis
  Plant growth promotion bioassay with mung bean (Vigna radiata)
 Discussion
 Acknowledgment
 References

저자

• Buddhi Charana Walpola [ Department of Bio-Environmental Chemistry, College of Agriculture and Life Sciences, Chungnam National University ]
• Jae-Geun Noh [ Department of Bio-Environmental Chemistry, College of Agriculture and Life Sciences, Chungnam National University ]
• Chan Kyem Kim [ Department of Bio-Environmental Chemistry, College of Agriculture and Life Sciences, Chungnam National University ]
• Ki-Cheon Kyung [ Taean Lily Experiment Station, Chungcheongnam-do Agricultural Research and Extention Services. Taean 357-952, Korea ]
• Won-Sik Kong [ Mushroom Research Division, National Institute of Horticultural & Herbal Science, RDA, Eumseong 369-873, Korea ]
• Min-Ho Yoon [ Department of Bio-Environmental Chemistry, College of Agriculture and Life Sciences, Chungnam National University ] Corresponding author

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