Indole-3-acetic acid (IAA) 생성 Arthrobacter sp.의 분리 및 식물 생육촉진 효과

Isolation of Indole-3-acetic acid (IAA) producing Arthrobacter sp. and plant growth promotion effect

농업 재배지 토양으로부터 auxin 생성세균 KSD16, KSD33 그리고 KSD36를 분리하였다. 분리균주 KSD16, KSD33 그리고 KSD36 는 16S rRNA 유전자 계통분석을 통해 Arthrobacter 속으로 분류되었다. 이들 균주는 R2A배지에 0.1% L-tryptophan를 첨가한 배지에서 28℃, 48 시간 배양한 결과, auxin 의 일종인 indole-3-acetic acid (IAA)를 204.4 mg L -1 생성하는 것으로 확인되었다. IAA 생성세균의 녹두종자 발아에 미치는 영향을 확인한 결과, Arthrobacter 속 균주 KSD16, KSD33 그리고 KSD36 는 대조군에 비해 뿌리길이와 발근수가 증가하였다. Arthrobacter 속 균주의 녹두 성장촉진 효과를 확인한 결과, 녹두의 발아율이 대조군보다 73.4 % 증가하는 특징을 나타내었다.

An auxin-producing bacteria, KSD16, KSD33, and KSD36 were isolated from agricultural soil. The strain KSD16, KSD33, and KSD36 was classified as a strain of Arthrobacter sp. based on phylogenetic analysis of 16S rRNA gene. The isolated KDS16, KDS33, and KSD36 was confirmed to produce indole-3-acetic acid (IAA), which is one of the auxin hormones. When the concentration of IAA was assessed the maximum concentration of IAA, 206.62 mg L -1 , was detected from the culture broth incubated in R2A medium containing 0.1% L-tryptophan for 48 h at 28 ℃. To study the effect of IAA producing bacteria on germination rate, seeds of Mung bean were prepared for each treatment. KSD16, KSD33, and KSD36 showed significant increase in root length and number of adventitious roots than the controls. To investigate the growth-promoting effects on the crops, Arthrobacter species were placed in water cultures and seed pots of mung beans. In consequence, the seed germination of mung beans was 73.4% higher than the control.