An auxin-producing bacteria (3YN11-02) was isolated from waste mushroom bed from Agaricus bisporus of Chungnam Buyeo-Gun area. The strain 3YN11-02 was identified as a novel species belongs to Rahnella aquatica by a chemotaxanomic and phylogenetic nalysis. The isolate was confirmed to produce indole-3-acetic acid (IAA) which is one of auxin hormone by TLC and HPLC analysis. When the concentration of IAA was assessed by performing HPLC quantity analysis, the maximal 290 mg L -1 of IAA detected in ether fraction extracted from the culture filtrate which was cultured in R2A broth containing 0.1% tryptophan for 24 h at 35℃. The molecular weight of the main peak obtained by LC-mass analysis was correspondent well to 175, that of IAA. To investigate the growth promoting effect of crop, when the culture broth of R. aquatica 3YN11-02 was infected onto water culture and seed pot of mung bean, the adventitious root induction and root growth of mung bean were 2.0 times higher than control.

Objectives : This study was carried out to investigate the acute toxicity and safety of Leejung-tang(Lizhong-tang) and fermented Leejung-tang(Lizhong-tang) extract.Methods : To evaluate their acute toxicity and safety, 0(control group), 1250, 2500 and 5000 ㎎/㎏ of Leejung-tang(Lizhong-tang) and fermented Leejung-tang (Lizhong-tang) extracts were orally administered to 35 male and 35 female ICR mice. After a single administration, we observed survival rates, general toxicity, changes of body weight, and autopsy. Results : Compared with the control group, we could not find any toxic alteration in any of treated groups (1250, 2500 and 5000 ㎎/㎏).Conclusions : LD50 of Leejung-tang(Lizhong-tang) and fermented Leejung-tang (Lizhong-tang) were over 5000 ㎎/㎏ and it is very safe to ICR mice.