earticle

영어

A Pseudomonas fluorescens was selected from mushrooms and studied in both batch and fed-batch cultures in order to get maximal biomass concentration. P. fluorescens is an aerobic bacterium and antagonistic to Pseudomonas tolaasii which causes blotch disease on the mushroom cap. P fluarescens and P. tolaasii were identified by Gram staining, gelatin liquefaction, oxidase test, etc. and were characterized by pigment production, temperature sensitivity, salt tolerance and rapid pitting test, etc., Celts of P. fluorescens well in medium containing 30g/L of glucose, whereas the growth was inhibited at the glucose levels at higher than 30g/L. The highest values of specific growth rate and productivity were obtained when using 10g/1 of yeast extract. Optimum concentrations of NH4Ci and (NH4CI)2SO4 for culture were found to be 1.0g/L and 0.1g/L respectively. Optimum concentration of MgSO4ㆍ7H2O used as a sulfursource was 1.0g/L. It was also found that the cell concentrations reached the maximum level when grown on the medium containing 1.0g/L of KH2PO4 and 0.1g/L of CaCl2. Also, the optimum culture conditions were and pH 6.0. Cultivation of P. fluarescens at high dissolved oxygen (DO) concentration led to a decrease of bacterial productivity in batch culture. Maximum productivity was achieved at 40% DO concentration.

한국어

버섯 갈변병 유발세균인 Pseudomonas tolaasii와 이에 대해 길항성을 나타내는 세균을 버섯으로부터 각각 분리 하여 Gram staining, gelatin liquefaction, oxidase test 등을 통해 P. fluorescens와 P. tolaasii 를 동정하였으며 , pigment production, tempera t ture sensitivity, salt tolerance, 그리고 rapid pit­ting test 등의 여러가지 실험을 통하여 특정을 알아 보았다. 또한 P. fluorescens를 대량으로 배양하기 위하여 최적 배지조성 및 배양의 최척조건을 확립하였고, 세포농도를 높이기 위하여 유가배양을 시행하였다. 세포성장에 있어서 carbon 및 energy source 인 glucose의 경우 30g/L일 때 세포농도가 가장 높았으며, yeast extract의 농도가 10g/L에서 세포농도가 최적으로 성장하였다. 질소원인 NH4Cl과 (NH4Cl)2SO4는 각각 1.0g/L와 O.lg/L일 때 세포성장이 가장 좋게 나타났고, sulfur source인 MgSO4ㆍ7H2O의 최적농도는 1.0g/L였다. 그리고 KH2PO4와 CaCl2는 각각 1.0g/L와 O.lg/L일 때 세포농도가 가장 높았으며, 온도30℃ , pH 6.0 그라고 DO는 40 %로 유지시켰을 때 세포성장이 가장 높았으며, 유가배양에 의해 세포농도를 증가시킬 수 있었다.